Subject: [PATCH] [FEAT VS2038] libpv: New library for PV tools
From: Steffen Eiden <seiden@linux.ibm.com>

Summary:     pvattest: Create, perform, and verify attestation measurements
Description: pvattest is a tool to attest an IBM Secure Execution guest.
             
             In a trusted environment, one can create a request using
             `pvattest create`. To get a measurement of an untrusted
             IBM Secure Execution guest call 'pvattest perform'.
             Again in a trusted environment, call 'pvattest verify'
             to verify that the measurement is the expected one.
             
             The tool runs on s390 and x86.
             It has the same requirements like libpv and therefore
             requires openssl v1.1.1+, glib2.56+, and libcurl.
             Additionally, to measure, the linux kernel must provide
             the Ultravisor userspace interface `uvdevice` at /dev/uv
             and must be executed  on an IBM Secure Execution guest on
             hardware with Ultravisor attestation support,
             like IBM z16 or later.
Upstream-ID: 386392690d4940d336d83b3dc943d5c143c03e99
Problem-ID:  VS2038

Upstream-Description:

             libpv: New library for PV tools

             libpv is a collection of definitions and functions related to
             Protected Virtualization (PV).
             The functions cover mainly encryption (e.g. AES-GCM)
             and certificates (X509). There are also helping functions for glib2.

             Most of the code is extracted+refactored from `genprotimg`, which
             will use this library in future.

             Requires openssl v1.1.1+, glib2.56+, and libcurl.

             libpv is not designed or intended to be dynamically linked or used
             outside of this project. Its purpose is to avoid code duplication
             as PV tools do very similar things regarding cryptography.

             Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
             Acked-by: Marc Hartmayer <mhartmay@linux.ibm.com>
             Signed-off-by: Jan Hoeppner <hoeppner@linux.ibm.com>


Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 Makefile                       |    2 
 common.mak                     |    4 
 include/libpv/cert.h           |  438 ++++++++++
 include/libpv/common.h         |   35 
 include/libpv/crypto.h         |  200 ++++
 include/libpv/curl.h           |   53 +
 include/libpv/glib-helper.h    |  117 ++
 include/libpv/hash.h           |  119 ++
 include/libpv/macros.h         |   16 
 include/libpv/openssl-compat.h |   29 
 include/libpv/se-hdr.h         |   98 ++
 libpv/Makefile                 |  101 ++
 libpv/cert.c                   | 1645 +++++++++++++++++++++++++++++++++++++++++
 libpv/common.c                 |   45 +
 libpv/config.h                 |   15 
 libpv/crypto.c                 |  529 +++++++++++++
 libpv/curl.c                   |  116 ++
 libpv/glib-helper.c            |  179 ++++
 libpv/hash.c                   |  147 +++
 19 files changed, 3887 insertions(+), 1 deletion(-)

--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ include common.mak
 #
 BASELIB_DIRS = libutil libseckey
 LIB_DIRS = libvtoc libzds libdasd libvmdump libccw libvmcp libekmfweb \
-	   libkmipclient
+	   libkmipclient libpv
 TOOL_DIRS = zipl zdump fdasd dasdfmt dasdview tunedasd \
 	   tape390 osasnmpd qetharp ip_watcher qethconf scripts zconf \
 	   vmconvert vmcp man mon_tools dasdinfo vmur cpuplugd ipl_tools \
--- a/common.mak
+++ b/common.mak
@@ -383,6 +383,10 @@ $(rootdir)/libkmipclient/libkmipclient.s
 	$(MAKE) -C $(rootdir)/libkmipclient/ libkmipclient.so
 .PHONY: $(rootdir)/libkmipclient
 
+$(rootdir)/libpv/libpv.a: $(rootdir)/libpv
+	$(MAKE) -C $(rootdir)/libpv libpv.a
+.PHONY: $(rootdir)/libpv
+
 $(rootdir)/zipl/boot/data.o:
 	$(MAKE) -C $(rootdir)/zipl/boot/ data.o
 
--- /dev/null
+++ b/include/libpv/cert.h
@@ -0,0 +1,438 @@
+/*
+ * Certificate functions and definitions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_CERT_H
+#define LIBPV_CERT_H
+
+#include <openssl/x509v3.h>
+#include <openssl/err.h>
+
+#include "libpv/common.h"
+
+#define PV_IBM_Z_SUBJECT_COMMON_NAME "International Business Machines Corporation"
+#define PV_IBM_Z_SUBJECT_COUNTRY_NAME "US"
+#define PV_IBM_Z_SUBJECT_LOCALITY_NAME "Poughkeepsie"
+#define PV_IBM_Z_SUBJECT_ORGANIZATIONAL_UNIT_NAME_SUFFIX "Key Signing Service"
+#define PV_IBM_Z_SUBJECT_ORGANIZATION_NAME "International Business Machines Corporation"
+#define PV_IBM_Z_SUBJECT_STATE "New York"
+#define PV_IMB_Z_SUBJECT_ENTRY_COUNT 6
+
+/* Minimum security level for the keys/certificates used to establish a chain of
+ * trust (see https://www.openssl.org/docs/man1.1.1/man3/X509_VERIFY_PARAM_set_auth_level.html
+ * for details).
+ */
+#define PV_CERTS_SECURITY_LEVEL 2
+
+/** pv_cert_init:
+ *
+ * Should not be called by user.
+ * Use pv_init() instead which
+ * calls this function during creation.
+ *
+ * Sets up data structures for caching CRLs.
+ */
+void pv_cert_init(void);
+
+/** pv_cert_cleanup:
+ *
+ * Should not be called by user.
+ * Use pv_cleanup() instead which
+ * calls this function during creation.
+ *
+ * Cleans up data structures for caching CRLs.
+ */
+void pv_cert_cleanup(void);
+
+#define PV_CERT_ERROR g_quark_from_static_string("pv-cert-error-quark")
+typedef enum {
+	PV_CERT_ERROR_CERT_REVOKED,
+	PV_CERT_ERROR_CERT_SIGNATURE_INVALID,
+	PV_CERT_ERROR_CERT_SUBJECT_ISSUER_MISMATCH,
+	PV_CERT_ERROR_CRL_DOWNLOAD_FAILED,
+	PV_CERT_ERROR_CRL_SIGNATURE_INVALID,
+	PV_CERT_ERROR_CRL_SUBJECT_ISSUER_MISMATCH,
+	PV_CERT_ERROR_FAILED_DOWNLOAD_CRL,
+	PV_CERT_ERROR_INTERNAL,
+	PV_CERT_ERROR_INVALID_PARM,
+	PV_CERT_ERROR_INVALID_SIGNATURE_ALGORITHM,
+	PV_CERT_ERROR_INVALID_VALIDITY_PERIOD,
+	PV_CERT_ERROR_LOAD_CRL,
+	PV_CERT_ERROR_LOAD_DEFAULT_CA,
+	PV_CERT_ERROR_LOAD_ROOT_CA,
+	PV_CERT_ERROR_MALFORMED_CERTIFICATE,
+	PV_CERT_ERROR_MALFORMED_ROOT_CA,
+	PV_CERT_ERROR_NO_CRL,
+	PV_CERT_ERROR_NO_CRLDP,
+	PV_CERT_ERROR_NO_ISSUER_IBM_Z_FOUND,
+	PV_CERT_ERROR_NO_PUBLIC_KEY,
+	PV_CERT_ERROR_READ_CERTIFICATE,
+	PV_CERT_ERROR_READ_CRL,
+	PV_CERT_ERROR_SIGNATURE_ALGORITHM_MISMATCH,
+	PV_CERT_ERROR_SKID_AKID_MISMATCH,
+	PV_CERT_ERROR_VERIFICATION_FAILED,
+	PV_CERT_ERROR_WRONG_CA_USED,
+} PvCertErrors;
+
+/** PvX509WithPath - X509 certificate associated with a path
+ */
+typedef struct {
+	X509 *cert;
+	char *path;
+} PvX509WithPath;
+
+/** pv_x509_with_path_new:
+ *
+ *  @cert: X509 certificate
+ *  @path: Path of that X509 certificate
+ *
+ *  Returns: (nullable) (transfer full): new X509 with path
+ */
+PvX509WithPath *pv_x509_with_path_new(X509 *cert, const char *path);
+
+/** pv_x509_with_path_free:
+ *
+ * Frees the path and the PvX509WithPath; Decreases the refcount of the X509
+ */
+void pv_x509_with_path_free(PvX509WithPath *cert);
+
+typedef STACK_OF(DIST_POINT) STACK_OF_DIST_POINT;
+typedef STACK_OF(X509) STACK_OF_X509;
+typedef STACK_OF(X509_CRL) STACK_OF_X509_CRL;
+typedef GSList PvCertWithPathList;
+
+typedef struct {
+	X509 *cert;
+	STACK_OF_X509_CRL *crls;
+} PvX509Pair;
+
+/** pv_x509_pair_new_take:
+ * @cert: ptr to X509
+ * @crls: ptr to CRLs
+ *
+ * Takes a X509 and the associated CRLs and builds a pair.
+ * Both, *cert and *crls will be NULL afterwards, and owned by the pair.
+ *
+ * Returns: (nullable) (transfer full):	New PvX509Pair
+ */
+PvX509Pair *pv_x509_pair_new_take(X509 **cert, STACK_OF_X509_CRL **crls);
+
+/** pv_x509_pair_free:
+ *
+ * Decreases the refcount of the X509 and crls.
+ * Frees the PvX509Pair.
+ */
+void pv_x509_pair_free(PvX509Pair *pair);
+
+void STACK_OF_DIST_POINT_free(STACK_OF_DIST_POINT *stack);
+void STACK_OF_X509_free(STACK_OF_X509 *stack);
+void STACK_OF_X509_CRL_free(STACK_OF_X509_CRL *stack);
+
+/** pv_x509_from_pem_der_data:
+ *
+ * @data: GBytes containing the cert in PEM format
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full): X509 cert
+ */
+X509 *pv_x509_from_pem_der_data(GBytes *data, GError **error);
+
+/** pv_x509_get_ec_pubkey:
+ *
+ * @cert: X509 to extract elliptic curve pubkey from
+ * @nid: numerical identifier of the expected curve
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full):	corresponding pupkey for the given certificate
+ */
+EVP_PKEY *pv_x509_get_ec_pubkey(X509 *cert, int nid, GError **error);
+
+/** pv_get_ec_pubkeys:
+ *
+ * @certs_with_path: List of PvX509WithPath
+ * @nid: numerical identifier of the expected curve
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full):	List of corresponding public keys for the given certificate
+ */
+GSList *pv_get_ec_pubkeys(PvCertWithPathList *certs_with_path, int nid, GError **error);
+
+/* pv_load_certificates:
+ *
+ * @cert_paths: list of cert paths.
+ * @error: return location for a #GError
+ *
+ * @cert_paths must contain at least one element, otherwise an error is
+ * reported.
+ *
+ * Returns: (nullable) (transfer full):	List of PvX509WithPath corresponding to the given paths
+ */
+PvCertWithPathList *pv_load_certificates(char **cert_paths, GError **error);
+
+/* pv_load_first_cert_from_file:
+ *
+ * @path: location of the x509
+ * @error: return location for a #GError
+ *
+ * This function reads in only the first certificate and ignores all other. This
+ * is only relevant for the PEM file format. For the host-key document and the
+ * root CA this behavior is expected.
+ *
+ * Returns: (nullable) (transfer full):	PvX509WithPath corresponding to the given path
+ */
+X509 *pv_load_first_cert_from_file(const char *path, GError **error);
+
+/* pv_load_first_crl_from_file:
+ *
+ * @path: location of the x509 CRL
+ * @error: return location for a #GError
+ *
+ * This function reads in only the first CRL and ignores all other. This
+ * is only relevant for the PEM file format.
+ *
+ * Returns: (nullable) (transfer full):	X509_CRL corresponding to the given path
+ */
+X509_CRL *pv_load_first_crl_from_file(const char *path, GError **error);
+
+/** pv_store_setup_crl_download:
+ *
+ * @st: X509_STORE
+ */
+void pv_store_setup_crl_download(X509_STORE *st);
+
+/** pv_load_first_crl_by_cert:
+ * @cert: X509 to specify the download location.
+ * @error: return location for a #GError
+ *
+ * This function returns the first X509_CRL found from the CRL distribution
+ * points specified in @cert.
+ *
+ * Returns: (nullable) (transfer full):	x509 CRL corresponding to the given X509
+ */
+X509_CRL *pv_load_first_crl_by_cert(X509 *cert, GError **error);
+
+/** pv_try_load_crls_by_certs:
+ *
+ * @certs_with_path: List of PvX509WithPath
+ *
+ * Returns: (nullable) (transfer full):	Stack of CRLs corresponding to the given X509
+ */
+STACK_OF_X509_CRL *pv_try_load_crls_by_certs(PvCertWithPathList *certs_with_path);
+
+/** pv_store_setup:
+ *
+ * @root_ca_path: Location of the rootCA or NULL if SystemRoot CA shall be used
+ * @crl_paths: List of CRL paths or NULL
+ * @cert_with_crl_paths: List of (untrusted) X509 paths
+ * @error: return location for a #GError
+ *
+ * The untrusted certs need to be verified before actually verifying a Host Key Document.
+ *
+ * Returns: (nullable) (transfer full):	X509_store with given input data.
+ *
+ */
+X509_STORE *pv_store_setup(char *root_ca_path, char **crl_paths, char **cert_with_crl_paths,
+			   GError **error);
+
+/** pv_get_x509_stack:
+ *
+ * x509_with_path_list: list of PvX509WithPath
+ *
+ * Returns: (nullable) (transfer full):	Stack of X509 corresponding to the given x509 with path
+ */
+STACK_OF_X509 *pv_get_x509_stack(const GSList *x509_with_path_list);
+
+/** pv_init_store_ctx:
+ *
+ * @ctx: a uninitialized Store CTX
+ * @trusted: X509_STORE with a trusted rootCA
+ * @chain: untrusted X509s
+ * @error: return location for a #GError
+ *
+ * Can be called multiple times on the same context if X509_STORE_CTX_cleanup(ctx)
+ * was called before.
+ *
+ * Returns:
+ * 	0 on success
+ * 	-1 in failure
+ */
+int pv_init_store_ctx(X509_STORE_CTX *ctx, X509_STORE *trusted, STACK_OF_X509 *chain,
+		      GError **error) PV_NONNULL(1, 2, 3);
+
+/** pv_init_store_ctx:
+ *
+ * @trusted: X509_STORE with a trusted rootCA
+ * @chain: untrusted X509s
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full):	X509_STORE_CTX setup with the input data
+ */
+X509_STORE_CTX *pv_create_store_ctx(X509_STORE *trusted, STACK_OF_X509 *chain, GError **error)
+	PV_NONNULL(1, 2);
+/** pv_remove_ibm_signing_certs:
+ *
+ * @certs: Stack of X509s
+ *
+ * Returns: (transfer full):
+ * 	List of all IBM Z signing key certificates in @certs and remove them
+ * 		from the chain.
+ * 	Empty stack if no IBM Z signing key is found.
+ */
+STACK_OF_X509 *pv_remove_ibm_signing_certs(STACK_OF_X509 *certs);
+
+/** pv_c2b_name:
+ *
+ * Workaround to fix the mismatch between issuer name of the
+ * IBM Z signing CRLs and the IBM Z signing key subject name.
+ *
+ * In RFC 5280 the attributes of a (subject/issuer) name is not mandatory
+ * ordered. The problem is that our certificates are not consistent in the order
+ * (see https://tools.ietf.org/html/rfc5280#section-4.1.2.4 for details).
+ *
+ * This function tries to reorder the name attributes such that
+ * further OpenSSL calls can work with it.  The caller is
+ * responsible to free the returned value.
+ */
+X509_NAME *pv_c2b_name(const X509_NAME *name);
+
+/** pv_verify_host_key:
+ *
+ * @host_key: X509 to be verified
+ * @issuer_pairs: IBM signing key X509+CRLs Pairs used for verification
+ * @level: Security level. see PV_CERTS_SECURITY_LEVEL
+ * @error: return location for a #GError
+ *
+ * Returns:
+ * 	0 if Host key could be verified with one of the IBM signing keys
+ * 	-1 if no IBM signing key could verify the authenticity of the given host key
+ *
+ */
+int pv_verify_host_key(X509 *host_key, GSList *issuer_pairs, int verify_flags, int level,
+		       GError **error);
+
+/** pv_verify_cert:
+ *
+ * @ctx: trusted store ctx used for verification
+ * @cert: X509 to be verified
+ * @error: return location for a #GError
+ *
+ * Cannot be used to verify host keys with IBM signing keys, as IBM signing
+ * keys are no intermediate CAs. Use pv_verify_host_key() instead.
+ *
+ * Returns:
+ * 	0 if @cert could be verified
+ * 	-1 if @cert could not be verified
+ */
+int pv_verify_cert(X509_STORE_CTX *ctx, X509 *cert, GError **error) PV_NONNULL(1, 2);
+
+/** pv_check_crl_valid_for_cert:
+ *
+ * @crl: CRL to be verified
+ * @cert: Cert that probably issued the given CRL
+ * @verify_flags: X509 Verification flags (X509_V_FLAG_<TYPE>)
+ * @error: return location for a #GError
+ *
+ * Verify whether a revocation list @crl is valid and is issued by @cert. For
+ * this multiple steps must be done:
+ *
+ * 1. verify issuer of the CRL matches with the suject name of @cert
+ * 2. verify the validity period of the CRL
+ * 3. verify the signature of the CRL
+ *
+ * Important: This function does not verify whether @cert is allowed to issue a
+ * CRL.
+ *
+ * Returns:
+ * 	 0 if @crl is valid and issued by @cert
+ * 	 -1 otherwise
+ */
+int pv_verify_crl(X509_CRL *crl, X509 *cert, int verify_flags, GError **error);
+
+/** pv_check_chain_parameters:
+ *
+ * @chain: chain of trust to be validated
+ * @error: return location for a #GError
+ *
+ * Verifies that chain has at least a RootCA ans intermediate CA
+ * and logs the used ROD CA subject
+ *
+ * Returns:
+ * 	 0 @chain is valid
+ * 	 -1 otherwise
+ */
+int pv_check_chain_parameters(const STACK_OF_X509 *chain, GError **error);
+
+/** pv_store_set_verify_param:
+ *
+ * @store: X509_STORE to set parameters
+ * @error: return location for a #GError
+ *
+ * Returns:
+ * 	0 on success
+ * 	-1 on failure
+ */
+int pv_store_set_verify_param(X509_STORE *store, GError **error);
+
+/** pv_store_ctx_find_valid_crls:
+ *
+ * @ctx: STORE_CTX for searching CRLs
+ * @cert: X509 to match CRLs aggainst
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full):	STACK of CRLs related to given @crl fin @ctx
+ */
+STACK_OF_X509_CRL *pv_store_ctx_find_valid_crls(X509_STORE_CTX *ctx, X509 *cert, GError **error)
+	PV_NONNULL(1, 2);
+
+/** pv_verify_host_key_doc:
+ *
+ * @host_key_certs_with_path: X509s to be verified
+ * @trusted. X509_STORE with a rusted RootCA
+ * @untrusted_certs: STACK OF untrusted X509s
+ * @online: true if CRLs shall be downloaded
+ * @error: return location for a #GError
+ *
+ * Returns:
+ * 	0 if all given HKDs could be verified using the chain of trust.
+ * 	-1 otherwise
+ */
+int pv_verify_host_key_doc(PvCertWithPathList *host_key_certs_with_path, X509_STORE *trusted,
+			   STACK_OF_X509 *untrusted_certs, gboolean online, GError **error)
+	PV_NONNULL(1, 2, 3);
+
+/** pv_verify_host_key_docs_by_path:
+ *
+ * @host_key_paths: locations of X509 to be verified
+ * @optional_root_ca_path: rootCA location or NULL if Default shall be used
+ * @optional_crl_paths: locations of CRLs or NULL
+ * @untrusted_cert_paths: locations of IntermediateCAs including the IBM signing key
+ * @online: true if CRLs shall be downloaded
+ * @error: return location for a #GError
+ *
+ * Returns:
+ * 	0 if all given HKDs could be verfied using the chain of trust.
+ * 	-1 otherwise
+ */
+int pv_verify_host_key_docs_by_path(char **host_key_paths, char *optional_root_ca_path,
+				    char **optional_crl_paths, char **untrusted_cert_paths,
+				    gboolean online, GError **error) PV_NONNULL(1, 4);
+
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(AUTHORITY_KEYID, AUTHORITY_KEYID_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(PvX509WithPath, pv_x509_with_path_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(STACK_OF_DIST_POINT, STACK_OF_DIST_POINT_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(STACK_OF_X509, STACK_OF_X509_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(STACK_OF_X509_CRL, STACK_OF_X509_CRL_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509, X509_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_CRL, X509_CRL_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_LOOKUP, X509_LOOKUP_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_NAME, X509_NAME_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_VERIFY_PARAM, X509_VERIFY_PARAM_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(PvX509Pair, pv_x509_pair_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_STORE, X509_STORE_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_STORE_CTX, X509_STORE_CTX_free)
+
+#endif /*  LIBPV_CERT_H */
--- /dev/null
+++ b/include/libpv/common.h
@@ -0,0 +1,35 @@
+/*
+ * Libpv common definitions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ */
+#ifndef LIBPV_COMMON_H
+#define LIBPV_COMMON_H
+
+/* must be included before any (other) glib header to verify that
+ * the glib version is supported
+ */
+#include "libpv/glib-helper.h"
+
+#include <glib/gi18n-lib.h>
+
+#include "libpv/openssl-compat.h"
+#include "libpv/macros.h"
+
+/** pv_init:
+ *
+ * Must be called before any libpv call.
+ */
+int pv_init(void);
+
+/** pv_cleanup:
+ *
+ * Must be called when done with using libpv.
+ */
+void pv_cleanup(void);
+
+#endif /* LIBPV_COMMON_H */
--- /dev/null
+++ b/include/libpv/crypto.h
@@ -0,0 +1,200 @@
+/*
+ * General cryptography helper functions and definitions
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_CRYPTO_H
+#define LIBPV_CRYPTO_H
+
+#include <openssl/bio.h>
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/evp.h>
+
+#include "libpv/common.h"
+
+typedef struct pv_cipher_parms {
+	const EVP_CIPHER *cipher;
+	size_t tag_size;
+	GBytes *key;
+	union {
+		GBytes *iv;
+		GBytes *tweak;
+	};
+} PvCipherParms;
+
+typedef union {
+	struct {
+		uint8_t x[80];
+		uint8_t y[80];
+	};
+	uint8_t data[160];
+} PvEcdhPubKey;
+G_STATIC_ASSERT(sizeof(PvEcdhPubKey) == 160);
+
+typedef GSList PvEvpKeyList;
+
+enum PvCryptoMode {
+	PV_ENCRYPT,
+	PV_DECRYPT,
+};
+
+/** pv_get_openssl_error:
+ *
+ * Returns: (transfer full): String representing the error.
+ */
+const char *pv_get_openssl_error(void);
+
+/**
+ * pv_BIO_reset:
+ * @b: BIO to reset
+ *
+ * Resets a BIO to its initial state.
+ *
+ * Returns: 0 in case of success, -1 otherwise.
+ */
+int pv_BIO_reset(BIO *b);
+
+/**
+ * pv_generate_rand_data:
+ * @size: number of generated random bytes using a crypographically secure pseudo random generator
+ * @error: return location for a #GError
+ *
+ * Creates a new #GBytes with @size random bytes using a cryptographically
+ * secure pseudo random generator.
+ *
+ * Returns: (nullable) (transfer full): a new #GBytes, or %NULL in case of an error
+ */
+GBytes *pv_generate_rand_data(size_t size, GError **error);
+
+/**
+ * pv_generate_key:
+ * @cipher: specifies the OpenSSL cipher for which a cryptographically secure key should be generated
+ * @error: return location for a #GError
+ *
+ * Creates a random key for @cipher using a cryptographically secure pseudo
+ * random generator.
+ *
+ * Returns: (nullable) (transfer full): a new #GBytes, or %NULL in case of an error
+ */
+GBytes *pv_generate_key(const EVP_CIPHER *cipher, GError **error) PV_NONNULL(1);
+
+/**
+ * pv_generate_iv:
+ * @cipher: specifies the OpenSSL cipher for which a cryptographically secure IV should be generated
+ * @error: return location for a #GError
+ *
+ * Creates a random IV for @cipher using a cryptographically secure pseudo
+ * random generator.
+ *
+ * Returns: (nullable) (transfer full): a new #GBytes, or %NULL in case of an error
+ */
+GBytes *pv_generate_iv(const EVP_CIPHER *cipher, GError **error) PV_NONNULL(1);
+
+/* Symmetric en/decryption functions */
+
+/**
+ * pv_gcm_encrypt:
+ * @plain: data to encrypt
+ * @aad: (optional): additional data that should be authenticated with the key
+ * @parms:
+ * @cipher: (out): location to store the ciphertext
+ * @tag: (out): location to store the generated GCM tag
+ * @error: return location for a #GError
+ *
+ * Encrypts the @plain data and authenticates @aad data.
+ *
+ * Returns: number of bytes, or -1 in case of an error
+ */
+int64_t pv_gcm_encrypt(GBytes *plain, GBytes *aad, const PvCipherParms *parms, GBytes **cipher,
+		       GBytes **tag, GError **error) PV_NONNULL(1, 3, 4, 5);
+
+/**
+ * pv_gcm_decrypt:
+ * @cipher: ciphertext to decrypt
+ * @aad: (optional): additional date to authenticate
+ * @tag: the GCM tag
+ * @parms:
+ * @plain: (out): location to store the decrypted data
+ * @error: return location for a #GError
+ *
+ * Decrypts the @cipher data and authenticates the @aad data.
+ *
+ * Returns: number of bytes, or -1 in case of an error
+ */
+int64_t pv_gcm_decrypt(GBytes *cipher, GBytes *aad, GBytes *tag, const PvCipherParms *parms,
+		       GBytes **plain, GError **error) PV_NONNULL(1, 3, 4, 5);
+
+/** pv_hkdf_extract_and_expand:
+ * @derived_key_len: size of the output key
+ * @key: input key
+ * @salt: salt for the extraction
+ * @info: infor for the expansion
+ * @md: EVP mode of operation
+ * @error: return location for a #GError
+ *
+ * Performs a RFC 5869 HKDF.
+ *
+ * Returns: (nullable) (transfer full): Result of RFC 5869 HKDF
+ *
+ */
+GBytes *pv_hkdf_extract_and_expand(size_t derived_key_len, GBytes *key, GBytes *salt, GBytes *info,
+				   const EVP_MD *md, GError **error) PV_NONNULL(2, 3, 4, 5);
+
+/** pv_generate_ec_key:
+ *
+ * @nid: Numerical identifier of the curve
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full): new random key based on the given curve
+ */
+EVP_PKEY *pv_generate_ec_key(int nid, GError **error);
+
+/** pv_evp_pkey_to_ecdh_pub_key:
+ *
+ * @key: input key in EVP_PKEY format
+ * @error: return location for a #GError
+ *
+ * Returns: the public part of the input @key in ECDH format.
+ */
+PvEcdhPubKey *pv_evp_pkey_to_ecdh_pub_key(EVP_PKEY *key, GError **error) PV_NONNULL(1);
+
+/** pv_derive_exchange_key:
+ * @cust: Customer Key
+ * @host: Host key
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full): Shared Secret of @cust and @host
+ */
+GBytes *pv_derive_exchange_key(EVP_PKEY *cust, EVP_PKEY *host, GError **error) PV_NONNULL(1, 2);
+
+GQuark pv_crypto_error_quark(void);
+#define PV_CRYPTO_ERROR pv_crypto_error_quark()
+typedef enum {
+	PV_CRYPTO_ERROR_DERIVE,
+	PV_CRYPTO_ERROR_HKDF_FAIL,
+	PV_CRYPTO_ERROR_INTERNAL,
+	PV_CRYPTO_ERROR_INVALID_KEY_SIZE,
+	PV_CRYPTO_ERROR_KEYGENERATION,
+	PV_CRYPTO_ERROR_RANDOMIZATION,
+	PV_CRYPTO_ERROR_READ_FILE,
+	PV_CRYPTO_ERROR_NO_IBM_Z_SIGNING_KEY,
+	PV_CRYPTO_ERROR_NO_MATCH_TAG,
+} PvCryptoErrors;
+
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(ASN1_INTEGER, ASN1_INTEGER_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(ASN1_OCTET_STRING, ASN1_OCTET_STRING_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BIO, BIO_free_all)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BIGNUM, BN_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BN_CTX, BN_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_GROUP, EC_GROUP_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_KEY, EC_KEY_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_POINT, EC_POINT_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_CIPHER_CTX, EVP_CIPHER_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_PKEY, EVP_PKEY_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_PKEY_CTX, EVP_PKEY_CTX_free)
+
+#endif /* LIBPV_CRYPTO_H */
--- /dev/null
+++ b/include/libpv/curl.h
@@ -0,0 +1,53 @@
+/*
+ * Libcurl utils
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_CURL_H
+#define LIBPV_CURL_H
+
+#include <curl/curl.h>
+
+#include "libpv/common.h"
+
+#define CRL_DOWNLOAD_TIMEOUT_MS 3000
+#define CRL_DOWNLOAD_MAX_SIZE 0x100000
+
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(CURL, curl_easy_cleanup)
+
+/** curl_download:
+ * @url: URL to specify location of data
+ * @timeout_ms: time to wait until fail
+ * @max_size: Maximum size of the downloaded data
+ * @error: return location for a GError
+ *
+ * Returns: (nullable) (transfer full): Downloaded data as #GByteArray
+ */
+GByteArray *curl_download(const char *url, long timeout_ms, uint max_size, GError **err);
+
+/** pv_curl_init:
+ *
+ * Should not be called by user.
+ * Use pv_init() instead which
+ * calls this function during creation.
+ */
+int pv_curl_init(void);
+
+/** pv_curl_cleanup:
+ *
+ * Should not be called by user.
+ * Use pv_cleanup() instead which
+ * calls this function during creation.
+ */
+void pv_curl_cleanup(void);
+
+#define PV_CURL_ERROR g_quark_from_static_string("pv-curl-error-quark")
+typedef enum {
+	PV_CURL_ERROR_CURL_INIT_FAILED,
+	PV_CURL_ERROR_DOWNLOAD_FAILED,
+} PvCurlErrors;
+
+#endif /* LIBPV_CURL_H */
--- /dev/null
+++ b/include/libpv/glib-helper.h
@@ -0,0 +1,117 @@
+/*
+ * Glib convenience functions
+ * Shall be used instead of manually including glib.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_GLIB_HELPER_H
+#define LIBPV_GLIB_HELPER_H
+
+#if defined(GLIB_VERSION_MIN_REQUIRED)
+#if GLIB_VERSION_MIN_REQUIRED < GLIB_VERSION_2_56
+#error "GLIB_VERSION must be at least 2.56"
+#endif
+#else
+#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_56
+#endif
+
+#include <glib.h>
+#include <gmodule.h>
+#include <stdio.h>
+
+#include "libpv/macros.h"
+
+#ifdef __clang__
+#define WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(...)                                                 \
+	DO_PRAGMA(clang diagnostic push)                                                           \
+	DO_PRAGMA(clang diagnostic ignored "-Wunused-function")                                    \
+	G_DEFINE_AUTOPTR_CLEANUP_FUNC(__VA_ARGS__)                                                 \
+	DO_PRAGMA(clang diagnostic pop)
+#else
+#define WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(...) G_DEFINE_AUTOPTR_CLEANUP_FUNC(__VA_ARGS__)
+#endif
+
+#define pv_wrapped_g_assert(__expr) g_assert(__expr)
+
+/** pv_sec_gbytes_new_take:
+ *
+ * #g_bytes_new_take() with secure cleanup
+ */
+GBytes *pv_sec_gbytes_new_take(void *data, size_t size);
+
+/** pv_sec_gbytes_new:
+ *
+ * #g_bytes_new() with secure cleanup
+ */
+GBytes *pv_sec_gbytes_new(const void *data, size_t size);
+
+/** pv_file_get_content_as_secure_bytes:
+ *
+ * @filename: path to file for reading in
+ *
+ * read file and save as secure gbytes
+ *
+ * Return:
+ * 	Content of file as #GBytes with secure cleanup
+ */
+GBytes *pv_file_get_content_as_secure_bytes(const char *filename);
+
+/** pv_file_get_content_as_g_bytes:
+ *
+ * @filename: path to file for reading in
+ *
+ * read file and save as gbytes
+ *
+ * Return:
+ * 	Content of file as #GBytes
+ */
+GBytes *pv_file_get_content_as_g_bytes(const char *filename, GError **error);
+
+/** pv_file_seek:
+ *
+ * fseek with error reporting
+ */
+int pv_file_seek(FILE *file, long offset, int whence, GError **error);
+
+/** pv_file_write:
+ *
+ * fwrite with error reporting
+ */
+size_t pv_file_write(FILE *file, const void *ptr, size_t size, GError **error);
+
+/** pv_file_close:
+ *
+ * fclose with error reporting
+ */
+long pv_file_close(FILE *file, GError **error);
+
+/** pv_file_tell:
+ *
+ * ftell with error reporting
+ */
+long pv_file_tell(FILE *file, GError **error);
+
+/** pv_file_open:
+ *
+ * fopen with error reporting
+ */
+FILE *pv_file_open(const char *filename, const char *mode, GError **error);
+
+/** pv_gbytes_memcpy:
+ *
+ * memcpy with size check.
+ */
+void *pv_gbytes_memcpy(void *dst, size_t dst_size, GBytes *src);
+
+#define PV_GLIB_HELPER_ERROR g_quark_from_static_string("pv-glib-helper_error-quark")
+typedef enum {
+	PV_GLIB_HELPER_FILE_ERROR,
+} pv_glib_helper_error_e;
+
+void pv_auto_close_file(FILE *file);
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(FILE, pv_auto_close_file)
+
+#endif /* LIBPV_GLIB_HELPER_H */
--- /dev/null
+++ b/include/libpv/hash.h
@@ -0,0 +1,119 @@
+/*
+ * Hashing definitions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_HASH_H
+#define LIBPV_HASH_H
+
+#include <openssl/hmac.h>
+
+#include "libpv/common.h"
+
+/** pv_digest_ctx_new:
+ * @md: mode of digest, e.g. #EVP_sha256()
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full): a new #EVP_MD_CTX, or %NULL in case of an error
+ */
+EVP_MD_CTX *pv_digest_ctx_new(const EVP_MD *md, GError **error);
+
+/** pv_digest_ctx_update:
+ * @ctx: EVP_MD_CTX to add data
+ * @data: #GBytes to add to the context
+ * @error: return location for a #GError
+ *
+ * Adds @data to the digest context. Can be called multiple times.
+ *
+ * Returns: 0 in case of success, -1 otherwise.
+ */
+int pv_digest_ctx_update(EVP_MD_CTX *ctx, GBytes *data, GError **error);
+
+/** pv_digest_ctx_update_raw:
+ * @ctx: #EVP_MD_CTX to add data
+ * @buf: data to add to the context
+ * @size: size of @buf
+ * @error: return location for a #GError
+ *
+ * Adds @buf to the digest context. Can be called multiple times.
+ *
+ * Returns: 0 in case of success, -1 otherwise.
+ */
+int pv_digest_ctx_update_raw(EVP_MD_CTX *ctx, const uint8_t *buf, size_t size, GError **error);
+
+/** pv_digest_ctx_finalize:
+ * @ctx: #EVP_MD_CTX with data to digest
+ * @error: return location for a #GError
+ *
+ * Calculates the digest of all previously added data. Do not use @ctx afterwards.
+ *
+ * Returns: (nullable) (transfer full): Digest of all data added before as #GBytes, or NULL in case of error.
+ */
+GBytes *pv_digest_ctx_finalize(EVP_MD_CTX *ctx, GError **error);
+
+/** pv_sha256_hash:
+ * @buf: data for which a sha256 hash sould be calculated
+ * @size: size of @buf
+ * @error: return location for a #GError
+ *
+ * Shorthand for initializing a sha256-digest ctx, updating, and finalizing.
+ *
+ * Returns: (nullable) (transfer full): SHA256 of @buf as #GBytes, or NULL in case of error.
+ */
+GBytes *pv_sha256_hash(uint8_t *buf, size_t size, GError **error);
+
+/** pv_hmac_ctx_new:
+ * @key: key used for the HMAC
+ * @md: mode of digest, e.g. #EVP_sha512()
+ * @error: return location for a #GError
+ *
+ * Returns: (nullable) (transfer full): New #HMAC_CTX or NULL in case of error
+ */
+HMAC_CTX *pv_hmac_ctx_new(GBytes *key, const EVP_MD *md, GError **error);
+
+/** pv_hmac_ctx_update_raw:
+ * @ctx: #HMAC_CTX to add data
+ * @buf: data to add to the context
+ * @size: size of @buf
+ * @error: return location for a #GError
+ *
+ * Adds @buf to the HMAC context. Can be called multiple times.
+ *
+ * Returns: 0 in case of success, -1 otherwise.
+ */
+int pv_hmac_ctx_update_raw(HMAC_CTX *ctx, const void *data, size_t size, GError **error);
+
+/** pv_hmac_ctx_update:
+ * @ctx: #HMAC_CTX to add data
+ * @data: #GBytes to add to the context
+ * @error: return location for a #GError
+ *
+ * Adds @data to the HMAC context. Can be called multiple times.
+ *
+ * Returns: 0 in case of success, -1 otherwise.
+ */
+
+int pv_hmac_ctx_update(HMAC_CTX *ctx, GBytes *data, GError **error);
+
+/** pv_hmac_ctx_finalize:
+ * @ctx: #HMAC_CTX with data to digest
+ * @error: return location for a #GError
+ *
+ * Calculates the HMAC of all previously added data. Do not use @ctx afterwards.
+ *
+ * Returns: (nullable) (transfer full): HMAC of all data added before as #GBytes, or NULL in case of error.
+ */
+GBytes *pv_hamc_ctx_finalize(HMAC_CTX *ctx, GError **error);
+
+#define PV_HASH_ERROR g_quark_from_static_string("pv-crypro-error-quark")
+typedef enum {
+	PV_HASH_ERROR_INTERNAL,
+} PvHashErrors;
+
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_MD_CTX, EVP_MD_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(HMAC_CTX, HMAC_CTX_free)
+
+#endif /* LIBPV_HASH_H */
--- /dev/null
+++ b/include/libpv/macros.h
@@ -0,0 +1,16 @@
+/*
+ * Libpv common macro definitions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ */
+#ifndef LIBPV_MACROS_H
+#define LIBPV_MACROS_H
+
+#define PV_NONNULL(...)
+#define DO_PRAGMA(x) _Pragma(#x)
+
+#endif /* LIBPV_MACROS_H */
--- /dev/null
+++ b/include/libpv/openssl-compat.h
@@ -0,0 +1,29 @@
+/*
+ * OpenSSL compatibility utils
+ *
+ * Copyright IBM Corp. 2021
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_OPENSSL_COMPAT_H
+#define LIBPV_OPENSSL_COMPAT_H
+
+#include <openssl/opensslv.h>
+#include <openssl/x509.h>
+#include <openssl/x509_vfy.h>
+
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+#define pv_X509_STORE_CTX_get_current_cert(ctx) X509_STORE_CTX_get_current_cert(ctx)
+#define pv_X509_STORE_CTX_get1_crls(ctx, nm) X509_STORE_CTX_get1_crls((ctx), (nm))
+#define pv_X509_STORE_set_lookup_crls(st, cb) X509_STORE_set_lookup_crls(st, cb)
+#elif OPENSSL_VERSION_NUMBER >= 0x10100000L
+#define pv_X509_STORE_CTX_get_current_cert(ctx)                                                    \
+	X509_STORE_CTX_get_current_cert((X509_STORE_CTX *)(ctx))
+#define pv_X509_STORE_CTX_get1_crls(ctx, nm)                                                       \
+	X509_STORE_CTX_get1_crls((X509_STORE_CTX *)(ctx), (X509_NAME *)(nm))
+#define pv_X509_STORE_set_lookup_crls(st, cb)                                                      \
+	X509_STORE_set_lookup_crls(st, (X509_STORE_CTX_lookup_crls_fn)(cb))
+#endif
+
+#endif /* LIBPV_OPENSSL_COMPAT_H */
--- /dev/null
+++ b/include/libpv/se-hdr.h
@@ -0,0 +1,98 @@
+/*
+ * PV/SE header definitions
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+#ifndef LIBPV_SE_HDR_H
+#define LIBPV_SE_HDR_H
+
+#include "libpv/common.h"
+
+#include <openssl/sha.h>
+
+#include "boot/s390.h"
+#include "libpv/crypto.h"
+
+/* Magic number which is used to identify the file containing the PV
+ * header
+ */
+#define PV_MAGIC_NUMBER 0x49424d5365634578ULL
+#define PV_VERSION_1 0x00000100U
+
+/* Internal helper macro */
+#define __PV_BIT(nr) (1ULL << (63 - (nr)))
+
+/* Plaintext control flags */
+/* dumping of the configuration is allowed */
+#define PV_PCF_ALLOW_DUMPING __PV_BIT(34)
+/* prevent Ultravisor decryption during unpack operation */
+#define PV_PCF_NO_DECRYPTION __PV_BIT(35)
+/* PCKMO encrypt-DEA/TDEA-key functions allowed */
+#define PV_PCF_PCKMO_DEA_TDEA __PV_BIT(56)
+/* PCKMO encrypt-AES-key functions allowed */
+#define PV_PCF_PCKMO_AES __PV_BIT(57)
+/* PCKMO encrypt-ECC-key functions allowed */
+#define PV_PCF_PCKM_ECC __PV_BIT(58)
+
+/* maxima for the PV version 1 */
+#define PV_V1_IPIB_MAX_SIZE PAGE_SIZE
+#define PV_V1_PV_HDR_MIN_SIZE                                                                      \
+	(sizeof(struct pv_hdr_head) + sizeof(struct pv_hdr_encrypted) +                            \
+	 sizeof(((struct pv_hdr *)0)->tag) + 1 * sizeof(struct pv_hdr_key_slot))
+#define PV_V1_PV_HDR_MAX_SIZE (2 * PAGE_SIZE)
+
+#define PV_IMAGE_ENCR_KEY_SIZE 64
+
+typedef struct pv_hdr_key_slot {
+	uint8_t digest_key[SHA256_DIGEST_LENGTH];
+	uint8_t wrapped_key[32];
+	uint8_t tag[16];
+} __packed PvHdrKeySlot;
+
+typedef struct pv_hdr_opt_item {
+	uint32_t otype;
+	uint8_t ibk[32];
+	uint8_t data[];
+} __packed PvHdrOptItem;
+
+/* integrity protected data (by GCM tag), but non-encrypted */
+struct pv_hdr_head {
+	uint64_t magic;
+	uint32_t version;
+	uint32_t phs;
+	uint8_t iv[12];
+	uint32_t res1;
+	uint64_t nks;
+	uint64_t sea;
+	uint64_t nep;
+	uint64_t pcf;
+	PvEcdhPubKey cust_pub_key;
+	uint8_t pld[SHA512_DIGEST_LENGTH];
+	uint8_t ald[SHA512_DIGEST_LENGTH];
+	uint8_t tld[SHA512_DIGEST_LENGTH];
+} __packed;
+
+/* Must not have any padding */
+struct pv_hdr_encrypted {
+	uint8_t cust_comm_key[32];
+	uint8_t img_enc_key_1[PV_IMAGE_ENCR_KEY_SIZE / 2];
+	uint8_t img_enc_key_2[PV_IMAGE_ENCR_KEY_SIZE / 2];
+	struct psw_t psw;
+	uint64_t scf;
+	uint32_t noi;
+	uint32_t res2;
+};
+G_STATIC_ASSERT(sizeof(struct pv_hdr_encrypted) == 32 + 32 + 32 + sizeof(struct psw_t) + 8 + 4 + 4);
+
+typedef struct pv_hdr {
+	struct pv_hdr_head head;
+	struct pv_hdr_key_slot *slots;
+	struct pv_hdr_encrypted *encrypted;
+	struct pv_hdr_opt_item **optional_items;
+	uint8_t tag[16];
+} PvHdr;
+
+#endif /* LIBPV_SE_HDR_H */
--- /dev/null
+++ b/libpv/Makefile
@@ -0,0 +1,101 @@
+# Common definitions
+include ../common.mak
+
+.DEFAULT_GOAL := all
+
+LIB := libpv.a
+
+ifneq ($(shell sh -c 'command -v pkg-config'),)
+GLIB2_CFLAGS := $(shell pkg-config --silence-errors --cflags glib-2.0)
+GLIB2_LIBS := $(shell pkg-config --silence-errors --libs glib-2.0)
+LIBCRYPTO_CFLAGS := $(shell pkg-config --silence-errors --cflags libcrypto openssl)
+LIBCRYPTO_LIBS := $(shell pkg-config --silence-errors --libs libcrypto openssl)
+LIBCURL_CFLAGS := $(shell pkg-config --silence-errors --cflags libcurl)
+LIBCURL_LIBS := $(shell pkg-config --silence-errors --libs libcurl)
+else
+GLIB2_CFLAGS := -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include
+GLIB2_LIBS := -lglib-2.0
+LIBCRYPTO_CFLAGS :=
+LIBCRYPTO_LIBS := -lcrypto -lssl
+LIBCURL_CFLAGS := -I/usr/include/s390x-linux-gnu
+LIBCURL_LIBS := -lcurl
+endif
+LDLIBS += $(GLIB2_LIBS) $(LIBCRYPTO_LIBS) $(LIBCURL_LIBS)
+
+WARNINGS := -Wall -Wextra -Wshadow \
+	    -Wcast-align -Wwrite-strings -Wmissing-prototypes \
+	    -Wmissing-declarations -Wredundant-decls -Wnested-externs \
+	    -Wno-long-long -Wuninitialized -Wconversion -Wstrict-prototypes \
+	    -Wpointer-arith -Wno-error=inline \
+	    -Wno-unused-function -Wno-unused-parameter -Wno-unused-variable \
+	    -Werror \
+	    $(NULL)
+
+ALL_CFLAGS += -std=gnu11 \
+	      -DOPENSSL_API_COMPAT=0x10101000L \
+	      $(GLIB2_CFLAGS) \
+	      $(LIBCRYPTO_CFLAGS) \
+	      $(LIBCURL_CFLAGS) \
+	      $(WARNINGS) \
+	      $(NULL)
+
+BUILD_TARGETS := skip-$(LIB)
+ifneq (${HAVE_OPENSSL},0)
+ifneq (${HAVE_GLIB2},0)
+ifneq (${HAVE_LIBCURL},0)
+BUILD_TARGETS := $(LIB)
+endif
+endif
+endif
+
+sources := $(wildcard *.c)
+objects := $(patsubst %.c,%.o,$(sources))
+
+all: $(BUILD_TARGETS) .check_dep-$(LIB)
+
+$(LIB): $(objects)
+$(LIB): ALL_CFLAGS += -fPIC
+
+$(objects): .check-dep-$(LIB)
+
+install: all
+
+clean:
+	rm -f -- $(objects)
+	rm -f -- $(LIB)
+	rm -f -- .check-dep-$(LIB) .detect-openssl.dep.c
+
+skip-$(LIB):
+		echo "  SKIP    $(LIB) due to unresolved dependencies"
+
+.PHONY: all install clean skip-$(LIB) install-$(LIB)
+
+
+.detect-openssl.dep.c:
+	echo "#include <openssl/evp.h>" > $@
+	echo "#if OPENSSL_VERSION_NUMBER < 0x10101000L" >> $@
+	echo "  #error openssl version 1.1.0 is required" >> $@
+	echo "#endif" >> $@
+	echo "static void __attribute__((unused)) test(void) {" >> $@
+	echo "    EVP_MD_CTX *ctx = EVP_MD_CTX_new();" >> $@
+	echo "    EVP_MD_CTX_free(ctx);" >> $@
+	echo "}" >> $@
+
+.check-dep-$(LIB): .detect-openssl.dep.c
+	$(call check_dep, \
+		"$(LIB)", \
+		"glib.h", \
+		"glib2-devel / libglib2.0-dev", \
+		"HAVE_GLIB2=0")
+	$(call check_dep, \
+		"$(LIB)", \
+		$^, \
+		"openssl-devel / libssl-dev version >= 1.1.0", \
+		"HAVE_OPENSSL=0", \
+		"-I.")
+	$(call check_dep, \
+		"$(LIB)", \
+		"curl/curl.h", \
+		"libcurl-devel", \
+		"HAVE_LIBCURL=0")
+	touch $@
--- /dev/null
+++ b/libpv/cert.c
@@ -0,0 +1,1645 @@
+/*
+ * Certificate functions and definitions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+/* Must be included before any other header */
+#include "config.h"
+
+#include <openssl/pem.h>
+
+#include "libpv/cert.h"
+#include "libpv/crypto.h"
+#include "libpv/curl.h"
+
+/* Used for the caching of the downloaded CRLs */
+static GHashTable *cached_crls;
+
+void pv_cert_init(void)
+{
+	if (!cached_crls)
+		cached_crls = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
+						    (GDestroyNotify)X509_CRL_free);
+}
+
+void pv_cert_cleanup(void)
+{
+	g_clear_pointer(&cached_crls, g_hash_table_destroy);
+}
+
+PvX509WithPath *pv_x509_with_path_new(X509 *cert, const char *path)
+{
+	g_autoptr(PvX509WithPath) ret = g_new(PvX509WithPath, 1);
+
+	g_assert(cert && path);
+
+	if (X509_up_ref(cert) != 1)
+		g_abort();
+	ret->cert = cert;
+	ret->path = g_strdup(path);
+	return g_steal_pointer(&ret);
+}
+
+void pv_x509_with_path_free(PvX509WithPath *cert)
+{
+	if (!cert)
+		return;
+
+	X509_free(cert->cert);
+	g_free(cert->path);
+	g_free(cert);
+}
+
+PvX509Pair *pv_x509_pair_new_take(X509 **cert, STACK_OF_X509_CRL **crls)
+{
+	g_autoptr(PvX509Pair) ret = g_new0(PvX509Pair, 1);
+
+	g_assert(cert);
+	g_assert(crls);
+
+	ret->cert = g_steal_pointer(cert);
+	ret->crls = g_steal_pointer(crls);
+	return g_steal_pointer(&ret);
+}
+
+void pv_x509_pair_free(PvX509Pair *pair)
+{
+	if (!pair)
+		return;
+
+	sk_X509_CRL_pop_free(pair->crls, X509_CRL_free);
+	X509_free(pair->cert);
+	g_free(pair);
+}
+
+void STACK_OF_DIST_POINT_free(STACK_OF_DIST_POINT *stack)
+{
+	if (!stack)
+		return;
+
+	sk_DIST_POINT_pop_free(stack, DIST_POINT_free);
+}
+
+void STACK_OF_X509_free(STACK_OF_X509 *stack)
+{
+	if (!stack)
+		return;
+
+	sk_X509_pop_free(stack, X509_free);
+}
+
+void STACK_OF_X509_CRL_free(STACK_OF_X509_CRL *stack)
+{
+	if (!stack)
+		return;
+
+	sk_X509_CRL_pop_free(stack, X509_CRL_free);
+}
+
+static gboolean certificate_uses_elliptic_curve(EVP_PKEY *key, int nid, GError **error)
+{
+	g_autoptr(EC_KEY) ec = NULL;
+	int rc;
+
+	g_assert(key);
+
+	if (EVP_PKEY_id(key) != EVP_PKEY_EC) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_PARM, _("No EC key found"));
+		return FALSE;
+	}
+
+	ec = EVP_PKEY_get1_EC_KEY(key);
+	if (!ec) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_PARM, _("No EC key found"));
+		return FALSE;
+	}
+
+	if (EC_KEY_check_key(ec) != 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_PARM, _("Invalid EC key"));
+		return FALSE;
+	}
+
+	rc = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
+	if (rc != nid) {
+		/* maybe the NID is unset */
+		if (rc == 0) {
+			g_autoptr(EC_GROUP) grp = EC_GROUP_new_by_curve_name(nid);
+			const EC_POINT *pub = EC_KEY_get0_public_key(ec);
+			g_autoptr(BN_CTX) ctx = BN_CTX_new();
+
+			if (EC_POINT_is_on_curve(grp, pub, ctx) != 1) {
+				g_set_error_literal(error, PV_CERT_ERROR,
+						    PV_CERT_ERROR_INVALID_PARM,
+						    _("Invalid EC curve"));
+				return FALSE;
+			}
+		} else {
+			/* NID was set but doesn't match with the expected NID
+			 */
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_PARM,
+				    _("Wrong NID used: '%d'"),
+				    EC_GROUP_get_curve_name(EC_KEY_get0_group(ec)));
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+EVP_PKEY *pv_x509_get_ec_pubkey(X509 *cert, int nid, GError **error)
+{
+	g_autoptr(EVP_PKEY) ret = NULL;
+
+	ret = X509_get_pubkey(cert);
+	if (!ret) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_PARM,
+			    _("Failed to get public key from host-key document"));
+		return NULL;
+	}
+
+	if (!certificate_uses_elliptic_curve(ret, nid, error)) {
+		g_prefix_error(error, _("Host-key document does not use an elliptic EC curve"));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+GSList *pv_get_ec_pubkeys(PvCertWithPathList *certs_with_path, int nid, GError **error)
+{
+	g_autoslist(EVP_PKEY) ret = NULL;
+
+	for (GSList *iterator = certs_with_path; iterator; iterator = iterator->next) {
+		const PvX509WithPath *cert_with_path = iterator->data;
+		g_autoptr(EVP_PKEY) host_key = NULL;
+		X509 *cert = cert_with_path->cert;
+
+		host_key = pv_x509_get_ec_pubkey(cert, nid, error);
+		if (!host_key)
+			return NULL;
+
+		ret = g_slist_append(ret, g_steal_pointer(&host_key));
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+PvCertWithPathList *pv_load_certificates(char **cert_paths, GError **error)
+{
+	g_autoslist(PvX509WithPath) ret = NULL;
+
+	for (char **iterator = cert_paths; iterator != NULL && *iterator != NULL; iterator++) {
+		const char *cert_path = *iterator;
+		g_autoptr(X509) cert = NULL;
+
+		g_assert(cert_path);
+
+		cert = pv_load_first_cert_from_file(cert_path, error);
+		if (!cert)
+			return NULL;
+
+		ret = g_slist_append(ret, pv_x509_with_path_new(cert, cert_path));
+	}
+	if (!ret) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CERTIFICATE,
+			    _("no certificates specified"));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+X509 *pv_load_first_cert_from_file(const char *path, GError **error)
+{
+	g_autoptr(BIO) bio = BIO_new_file(path, "r");
+	g_autoptr(X509) cert = NULL;
+
+	if (!bio) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CERTIFICATE,
+			    _("unable to read certificate: '%s'"), path);
+		return NULL;
+	}
+
+	cert = PEM_read_bio_X509(bio, NULL, NULL, NULL);
+	if (cert)
+		return g_steal_pointer(&cert);
+	ERR_clear_error();
+	if (pv_BIO_reset(bio) < 0) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CERTIFICATE,
+			    _("unable to load certificate: '%s'"), path);
+		return NULL;
+	}
+
+	/* maybe the certificate is stored in DER format */
+	cert = d2i_X509_bio(bio, NULL);
+	if (cert)
+		return g_steal_pointer(&cert);
+
+	g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CERTIFICATE,
+		    _("unable to load certificate: '%s'"), path);
+	return NULL;
+}
+
+static X509_CRL *load_crl_from_bio(BIO *bio)
+{
+	g_autoptr(X509_CRL) crl = PEM_read_bio_X509_CRL(bio, NULL, NULL, NULL);
+	if (crl)
+		return g_steal_pointer(&crl);
+	ERR_clear_error();
+	if (pv_BIO_reset(bio) < 0)
+		return NULL;
+
+	/* maybe the CRL is stored in DER format */
+	crl = d2i_X509_CRL_bio(bio, NULL);
+	if (crl)
+		return g_steal_pointer(&crl);
+	return NULL;
+}
+
+/* This function reads in only the first CRL and ignores all other. This is only
+ * relevant for the PEM file format.
+ */
+X509_CRL *pv_load_first_crl_from_file(const char *path, GError **error)
+{
+	g_autoptr(BIO) bio = BIO_new_file(path, "r");
+	g_autoptr(X509_CRL) crl = NULL;
+
+	if (!bio) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CRL,
+			    _("unable to read CRL: '%s'"), path);
+		return NULL;
+	}
+
+	crl = load_crl_from_bio(bio);
+	if (!crl) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_READ_CRL,
+			    _("unable to load CRL: '%s'"), path);
+		return NULL;
+	}
+	return g_steal_pointer(&crl);
+}
+
+static char *pv_X509_NAME_oneline(const X509_NAME *name)
+{
+	g_autoptr(BIO) key_bio = BIO_new(BIO_s_mem());
+	g_autofree char *ret = NULL;
+	char *key = NULL;
+	long len;
+
+	if (X509_NAME_print_ex(key_bio, name, 0, XN_FLAG_RFC2253) == -1) {
+		g_warning(_("Cannot receive X509-NAME from CRL: %s"), pv_get_openssl_error());
+		return NULL;
+	}
+
+	len = BIO_get_mem_data(key_bio, &key);
+	if (len < 0) {
+		g_warning(_("Cannot receive X509-NAME from CRL"));
+		return NULL;
+	}
+
+	ret = g_malloc0((size_t)len + 1);
+	memcpy(ret, key, (size_t)len);
+	return g_steal_pointer(&ret);
+}
+
+static gboolean cache_crl(const X509_NAME *name, X509_CRL *crl)
+{
+	g_autofree char *key = NULL;
+
+	g_assert(name);
+
+	key = pv_X509_NAME_oneline(name);
+	if (!key) {
+		g_warning(_("Cannot receive X509-NAME from CRL"));
+		return FALSE;
+	}
+	if (X509_CRL_up_ref(crl) != 1)
+		g_abort();
+	return g_hash_table_insert(cached_crls, g_steal_pointer(&key), crl);
+}
+
+/* Caller is responsible for free'ing */
+static X509_CRL *lookup_crl(const X509_NAME *name)
+{
+	g_autoptr(X509_CRL) crl = NULL;
+	g_autofree char *key = NULL;
+
+	g_assert(name);
+
+	key = pv_X509_NAME_oneline(name);
+	if (!key)
+		return NULL;
+	crl = g_hash_table_lookup(cached_crls, key);
+	if (crl) {
+		if (X509_CRL_up_ref(crl) != 1)
+			g_abort();
+		return g_steal_pointer(&crl);
+	}
+	return NULL;
+}
+
+/* Returns empty stack if no CRL downloaded. */
+static STACK_OF_X509_CRL *crls_download_cb(const X509_STORE_CTX *ctx, const X509_NAME *nm)
+{
+	g_autoptr(STACK_OF_X509_CRL) crls = NULL;
+	g_autoptr(X509_CRL) crl = NULL;
+	/* must not be free'd */
+	X509 *cert = NULL;
+
+	crls = sk_X509_CRL_new_null();
+	if (!crls)
+		g_abort();
+	cert = pv_X509_STORE_CTX_get_current_cert(ctx);
+	if (!cert)
+		return g_steal_pointer(&crls);
+	g_assert(X509_NAME_cmp(X509_get_issuer_name(cert), nm) == 0);
+	crl = lookup_crl(nm);
+	if (!crl) {
+		/* ignore error */
+		crl = pv_load_first_crl_by_cert(cert, NULL);
+		if (!crl)
+			return g_steal_pointer(&crls);
+		g_assert_true(cache_crl(nm, crl));
+	}
+	if (sk_X509_CRL_push(crls, g_steal_pointer(&crl)) == 0)
+		g_abort();
+	return g_steal_pointer(&crls);
+}
+
+/* Downloaded CRLs have a higher precedence than the CRLs specified on the
+ * command line.
+ */
+static STACK_OF_X509_CRL *crls_cb(const X509_STORE_CTX *ctx, const X509_NAME *nm)
+{
+	g_autoptr(STACK_OF_X509_CRL) crls = crls_download_cb(ctx, nm);
+
+	if (sk_X509_CRL_num(crls) > 0)
+		return g_steal_pointer(&crls);
+	return pv_X509_STORE_CTX_get1_crls(ctx, nm);
+}
+
+/* Set up CRL lookup with download support */
+void pv_store_setup_crl_download(X509_STORE *st)
+{
+	pv_X509_STORE_set_lookup_crls(st, crls_cb);
+}
+
+static X509_CRL *GByteArray_to_X509_CRL(const GByteArray *data)
+{
+	g_autoptr(X509_CRL) ret = NULL;
+	g_autoptr(BIO) bio = NULL;
+
+	g_assert(data);
+
+	if (data->len > INT_MAX)
+		return NULL;
+
+	bio = BIO_new_mem_buf(data->data, (int)data->len);
+	if (!bio)
+		g_abort();
+
+	ret = load_crl_from_bio(bio);
+	if (!ret)
+		return NULL;
+
+	return g_steal_pointer(&ret);
+}
+
+static int load_crl_from_web(const char *url, X509_CRL **crl, GError **error)
+{
+	g_autoptr(X509_CRL) tmp_crl = NULL;
+	g_autoptr(GByteArray) data = NULL;
+	g_assert(crl);
+
+	data = curl_download(url, CRL_DOWNLOAD_TIMEOUT_MS, CRL_DOWNLOAD_MAX_SIZE, error);
+	if (!data) {
+		g_prefix_error(error, _("unable to download CRL: "));
+		return -1;
+	}
+	tmp_crl = GByteArray_to_X509_CRL(data);
+	if (!tmp_crl) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_CRL_DOWNLOAD_FAILED,
+			    _("unable to load CRL from '%s'"), url);
+		return -1;
+	}
+	*crl = g_steal_pointer(&tmp_crl);
+	return 0;
+}
+
+/* Get the first http[s] URL from a DIST_POINT */
+static const char *get_first_dp_url(DIST_POINT *dp)
+{
+	GENERAL_NAMES *general_names;
+
+	g_assert(dp);
+
+	if (!dp->distpoint || dp->distpoint->type != 0)
+		return NULL;
+
+	general_names = dp->distpoint->name.fullname;
+	for (int i = 0; i < sk_GENERAL_NAME_num(general_names); i++) {
+		GENERAL_NAME *name = sk_GENERAL_NAME_value(general_names, i);
+		g_autofree const char *uri_str = NULL;
+		ASN1_STRING *uri_asn1;
+		const char *uri_data;
+		int uri_data_len;
+		int type;
+
+		uri_asn1 = GENERAL_NAME_get0_value(name, &type);
+		if (type != GEN_URI)
+			continue;
+		uri_data_len = ASN1_STRING_length(uri_asn1);
+		if (uri_data_len < 0)
+			continue;
+		uri_data = (const char *)ASN1_STRING_get0_data(uri_asn1);
+		/* Make sure that uri_str is null-terminated as in general it
+		 * cannot be assumed that @uri_data is null-terminated.
+		 */
+		uri_str = g_strndup(uri_data, (size_t)uri_data_len);
+		if (g_str_has_prefix(uri_str, "http://"))
+			return uri_data;
+		if (g_str_has_prefix(uri_str, "https://"))
+			return uri_data;
+	}
+	return NULL;
+}
+
+/* Download a CRL using the URI specified in the distribution @crldp */
+static X509_CRL *load_crl_by_dist_point(DIST_POINT *crldp, GError **error)
+{
+	const char *uri = get_first_dp_url(crldp);
+	g_autoptr(X509_CRL) crl = NULL;
+
+	if (!uri) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			    _("no valid URL specified in distribution point"));
+		return NULL;
+	}
+
+	if (load_crl_from_web(uri, &crl, error) < 0)
+		return NULL;
+
+	return g_steal_pointer(&crl);
+}
+
+/* This function returns the first X509_CRL found from the CRL distribution
+ * points specified in @cert. This function could be optimized by filtering
+ * duplicate certificates and/or filtering duplicated URIs.
+ */
+X509_CRL *pv_load_first_crl_by_cert(X509 *cert, GError **error)
+{
+	g_autoptr(STACK_OF_DIST_POINT) crldps = NULL;
+	g_autoptr(X509_CRL) ret = NULL;
+
+	g_assert(cert);
+
+	crldps = X509_get_ext_d2i(cert, NID_crl_distribution_points, NULL, NULL);
+	if (!crldps || sk_DIST_POINT_num(crldps) == 0) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_CRLDP,
+			    _("no distribution point found"));
+		return NULL;
+	}
+
+	for (int i = 0; i < sk_DIST_POINT_num(crldps); i++) {
+		DIST_POINT *crldp = sk_DIST_POINT_value(crldps, i);
+
+		g_assert(crldp);
+
+		/* ignore error */
+		ret = load_crl_by_dist_point(crldp, NULL);
+		if (ret)
+			return g_steal_pointer(&ret);
+	}
+
+	g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_FAILED_DOWNLOAD_CRL,
+		    _("failed to download CRL"));
+	return NULL;
+}
+
+STACK_OF_X509_CRL *pv_try_load_crls_by_certs(GSList *certs_with_path)
+{
+	g_autoptr(STACK_OF_X509_CRL) ret = sk_X509_CRL_new_null();
+	if (!ret)
+		g_abort();
+
+	for (GSList *iterator = certs_with_path; iterator; iterator = iterator->next) {
+		PvX509WithPath *cert_with_path = iterator->data;
+		X509 *cert = cert_with_path->cert;
+		g_autoptr(X509_CRL) crl = NULL;
+		g_assert(cert);
+		/* ignore error */
+		crl = pv_load_first_crl_by_cert(cert, NULL);
+		if (!crl)
+			continue;
+		if (sk_X509_CRL_push(ret, g_steal_pointer(&crl)) == 0)
+			g_abort();
+	}
+	return g_steal_pointer(&ret);
+}
+
+#define DEFINE_GSLIST_MAP(t2, t1)                                                          \
+	typedef t1 *(*g_slist_map_func_##t2##_##t1)(const t2 *x, GError **error);          \
+	G_GNUC_UNUSED static GSList *g_slist_map_##t2##_##t1(                              \
+		const GSList *list, g_slist_map_func_##t2##_##t1 func, GError **error)     \
+	{                                                                                  \
+		g_autoslist(t1) ret = NULL;                                                \
+		for (const GSList *iterator = list; iterator; iterator = iterator->next) { \
+			const t2 *value = iterator->data;                                  \
+			t1 *new_value = NULL;                                              \
+			g_assert(value);                                                   \
+			new_value = func(value, error);                                    \
+			if (!new_value)                                                    \
+				return NULL;                                               \
+			ret = g_slist_append(ret, g_steal_pointer(&new_value));            \
+		}                                                                          \
+		return g_steal_pointer(&ret);                                              \
+	}
+
+#define DEFINE_GSLIST_TO_STACK(t1)                                                      \
+	G_GNUC_UNUSED static STACK_OF(t1) * g_slist_to_stack_of_##t1(GSList **list)     \
+	{                                                                               \
+		g_assert(list);                                                         \
+		g_autoptr(STACK_OF_##t1) ret = sk_##t1##_new_null();                    \
+		if (!ret)                                                               \
+			g_abort();                                                      \
+		for (GSList *iterator = *list; iterator; iterator = iterator->next) {   \
+			if (sk_##t1##_push(ret, g_steal_pointer(&iterator->data)) == 0) \
+				g_abort();                                              \
+		}                                                                       \
+		g_clear_pointer(list, g_slist_free);                                    \
+		return g_steal_pointer(&ret);                                           \
+	}
+
+DEFINE_GSLIST_MAP(PvX509WithPath, X509)
+DEFINE_GSLIST_TO_STACK(X509)
+
+static X509 *pv_x509_with_path_get_cert(const PvX509WithPath *cert_with_path,
+					G_GNUC_UNUSED GError **error)
+{
+	g_autoptr(X509) cert = NULL;
+
+	g_assert(cert_with_path && cert_with_path->cert);
+
+	cert = cert_with_path->cert;
+	if (X509_up_ref(cert) != 1)
+		g_abort();
+	return g_steal_pointer(&cert);
+}
+
+/* @crl_paths is allowed to be NULL */
+static int load_crls_to_store(X509_STORE *store, char **crl_paths, gboolean err_out_empty_crls,
+			      GError **error)
+{
+	for (char **iterator = crl_paths; iterator != NULL && *iterator != NULL; iterator++) {
+		X509_LOOKUP *lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
+		const char *crl_path = *iterator;
+		int count;
+
+		g_assert(crl_path);
+
+		if (!lookup) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+				    _("X509 store initialization failed"));
+			return -1;
+		}
+
+		/* support *.pem files containing multiple CRLs */
+		count = X509_load_crl_file(lookup, crl_path, X509_FILETYPE_PEM);
+		if (count > 0)
+			continue;
+
+		count = X509_load_crl_file(lookup, crl_path, X509_FILETYPE_ASN1);
+		if (count == 1)
+			continue;
+
+		if (err_out_empty_crls) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_LOAD_CRL,
+				    _("unable to load CRL from: '%s'"), crl_path);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+X509_STORE *pv_store_setup(char *root_ca_path, char **crl_paths, char **cert_with_crl_paths,
+			   GError **error)
+{
+	g_autoptr(X509_STORE) store = X509_STORE_new();
+	if (!store)
+		g_abort();
+
+	/* if @root_ca_path != NULL use the specified root CA only, otherwise use the
+	 * default root CAs found on the system
+	 */
+	if (root_ca_path) {
+		X509_LOOKUP *lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
+		int count;
+
+		if (!lookup) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+				    _("X509 store initialization failed"));
+			return NULL;
+		}
+
+		/* only the PEM format allows embedded CRLs so we've to
+		 * check for it only here and not in case of ASN1
+		 */
+		count = X509_load_cert_file(lookup, root_ca_path, X509_FILETYPE_PEM);
+		if (count > 0) {
+			/* Out of security reasons that it can be easily
+			 * overseen that there are multiple certificates located
+			 * in a PEM-file we raise an error
+			 */
+			if (count > 1) {
+				g_set_error(
+					error, PV_CERT_ERROR, PV_CERT_ERROR_LOAD_ROOT_CA,
+					_("multiple certificates in one PEM file is not supported: '%s'"),
+					root_ca_path);
+				return NULL;
+			}
+
+			/* PEM format so it's possible there are CRLs embedded
+			 */
+			(void)X509_load_crl_file(lookup, root_ca_path, X509_FILETYPE_PEM);
+		} else {
+			/* Maybe the root CA is stored in ASN1 format */
+			count = X509_load_cert_file(lookup, root_ca_path, X509_FILETYPE_ASN1);
+			if (count != 1) {
+				g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_LOAD_ROOT_CA,
+					    _("failed to load root certificate from '%s'"),
+					    root_ca_path);
+				return NULL;
+			}
+		}
+	} else {
+		/* Load certificates into @store from the hardcoded OpenSSL
+		 * default paths
+		 */
+		if (X509_STORE_set_default_paths(store) != 1) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_LOAD_DEFAULT_CA,
+				    _("failed to load system root certificates"));
+			return NULL;
+		}
+	}
+
+	/* Error out if a CRL file was provided that has not at least one CRL*/
+	if (load_crls_to_store(store, crl_paths, TRUE, error) < 0)
+		return NULL;
+
+	/* Try to load CRLs from the provided untrusted certificates */
+	if (load_crls_to_store(store, cert_with_crl_paths, FALSE, error) < 0)
+		return NULL;
+
+	return g_steal_pointer(&store);
+}
+
+STACK_OF_X509 *pv_get_x509_stack(const GSList *x509_with_path_list)
+{
+	g_autoslist(X509) certs = NULL;
+	g_autoptr(GError) error = NULL;
+
+	certs = g_slist_map_PvX509WithPath_X509(x509_with_path_list, pv_x509_with_path_get_cert,
+						&error);
+	g_assert_no_error(error);
+	return g_slist_to_stack_of_X509(&certs);
+}
+
+int pv_init_store_ctx(X509_STORE_CTX *ctx, X509_STORE *trusted, STACK_OF_X509 *chain,
+		      GError **error)
+{
+	pv_wrapped_g_assert(ctx);
+	pv_wrapped_g_assert(trusted);
+	pv_wrapped_g_assert(chain);
+
+	if (X509_STORE_CTX_init(ctx, trusted, NULL, chain) != 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			    _("X509 store initialization failed: %s"),
+			    X509_verify_cert_error_string(X509_STORE_CTX_get_error(ctx)));
+		return -1;
+	}
+	return 0;
+}
+
+X509_STORE_CTX *pv_create_store_ctx(X509_STORE *trusted, STACK_OF_X509 *chain, GError **error)
+{
+	g_autoptr(X509_STORE_CTX) ctx = X509_STORE_CTX_new();
+
+	pv_wrapped_g_assert(trusted);
+	pv_wrapped_g_assert(chain);
+
+	if (!ctx)
+		return NULL;
+
+	if (pv_init_store_ctx(ctx, trusted, chain, error) < 0)
+		return NULL;
+
+	return g_steal_pointer(&ctx);
+}
+
+int pv_store_set_verify_param(X509_STORE *store, GError **error)
+{
+	g_autoptr(X509_VERIFY_PARAM) param = NULL;
+	unsigned long flags = X509_V_FLAG_CRL_CHECK | X509_V_FLAG_CRL_CHECK_ALL |
+			      X509_V_FLAG_TRUSTED_FIRST | X509_V_FLAG_CHECK_SS_SIGNATURE |
+			      X509_V_FLAG_X509_STRICT | X509_V_FLAG_POLICY_CHECK;
+
+	/* Create a X509_VERIFY_PARAM structure, which specifies which checks
+	 * should be done by the certificate verification operation
+	 */
+	param = X509_VERIFY_PARAM_new();
+	if (!param)
+		g_abort();
+
+	/* The maximum depth level of the chain of trust for the verification of
+	 * the IBM Z signing key is 2, i.e. IBM Z signing key -> intermediate CA
+	 * -> root CA
+	 */
+	X509_VERIFY_PARAM_set_depth(param, 2);
+
+	/* Set minimum allowed security level to at least 112 bits. */
+	X509_VERIFY_PARAM_set_auth_level(param, PV_CERTS_SECURITY_LEVEL);
+
+	/* Set verification purpose to 'Any Purpose' and specify that the
+	 * associated trust setting of the default purpose should be used.
+	 */
+	if (X509_VERIFY_PARAM_set_purpose(param, X509_PURPOSE_ANY | X509_TRUST_DEFAULT) != 1)
+		goto error;
+
+	/* Each certificate from the chain of trust must be checked against a
+	 * CRL to see if it has been revoked. In addition, use trusted
+	 * certificates first mode, check signature of the last certificate,
+	 * strict mode, and verify the policies.
+	 */
+	if (X509_VERIFY_PARAM_set_flags(param, flags) != 1)
+		goto error;
+
+	if (X509_STORE_set1_param(store, param) != 1)
+		goto error;
+
+	return 0;
+
+error:
+	g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+		    _("X509 store initialization failed"));
+	return -1;
+}
+
+static int x509_name_entry_get0_data(X509_NAME_ENTRY *entry, const uint8_t **data, size_t *data_len)
+{
+	const ASN1_STRING *asn1_str;
+	int tmp_data_len;
+
+	g_assert(data);
+	g_assert(data_len);
+
+	asn1_str = X509_NAME_ENTRY_get_data(entry);
+	if (!asn1_str)
+		return -1;
+
+	tmp_data_len = ASN1_STRING_length(asn1_str);
+	if (tmp_data_len < 0)
+		return -1;
+
+	*data = ASN1_STRING_get0_data(asn1_str);
+	*data_len = (size_t)tmp_data_len;
+	return 0;
+}
+
+/* The caller must not free *data! */
+static int x509_name_get0_data_by_NID(X509_NAME *name, int nid, const uint8_t **data,
+				      size_t *data_len)
+{
+	X509_NAME_ENTRY *entry = NULL;
+	int lastpos = -1;
+
+	lastpos = X509_NAME_get_index_by_NID(name, nid, lastpos);
+	if (lastpos == -1)
+		return -1;
+
+	entry = X509_NAME_get_entry(name, lastpos);
+	if (!entry)
+		return -1;
+
+	if (x509_name_entry_get0_data(entry, data, data_len) < 0)
+		return -1;
+
+	return 0;
+}
+
+/* @y must be a NULL-terminated string */
+static gboolean x509_name_data_by_nid_equal(X509_NAME *name, int nid, const char *y)
+{
+	const uint8_t *data = NULL;
+	size_t y_len = strlen(y);
+	size_t data_len;
+
+	if (x509_name_get0_data_by_NID(name, nid, &data, &data_len) < 0)
+		return FALSE;
+
+	if (data_len != y_len)
+		return FALSE;
+
+	return memcmp(data, y, data_len) == 0;
+}
+
+/* Checks whether the subject of @cert is a IBM signing key subject. For this we
+ * must check that the subject is equal to: 'C = US, ST = New York, L =
+ * Poughkeepsie, O = International Business Machines Corporation, CN =
+ * International Business Machines Corporation' and the organization unit (OUT)
+ * must end with the suffix ' Key Signing Service'.
+ */
+static gboolean has_ibm_signing_subject(X509 *cert)
+{
+	X509_NAME *subject = X509_get_subject_name(cert);
+	/* X509_NAME_entry_count is safe to be used with NULL */
+	int entry_count = X509_NAME_entry_count(subject);
+	g_autofree char *data_str = NULL;
+	const uint8_t *data;
+	size_t data_len;
+
+	if (entry_count != PV_IMB_Z_SUBJECT_ENTRY_COUNT)
+		return FALSE;
+
+	if (!x509_name_data_by_nid_equal(subject, NID_countryName, PV_IBM_Z_SUBJECT_COUNTRY_NAME))
+		return FALSE;
+
+	if (!x509_name_data_by_nid_equal(subject, NID_stateOrProvinceName, PV_IBM_Z_SUBJECT_STATE))
+		return FALSE;
+
+	if (!x509_name_data_by_nid_equal(subject, NID_localityName, PV_IBM_Z_SUBJECT_LOCALITY_NAME))
+		return FALSE;
+
+	if (!x509_name_data_by_nid_equal(subject, NID_organizationName,
+					 PV_IBM_Z_SUBJECT_ORGANIZATION_NAME))
+		return FALSE;
+
+	if (!x509_name_data_by_nid_equal(subject, NID_commonName, PV_IBM_Z_SUBJECT_COMMON_NAME))
+		return FALSE;
+
+	if (x509_name_get0_data_by_NID(subject, NID_organizationalUnitName, &data, &data_len) < 0)
+		return FALSE;
+
+	/* Make sure that data_str is null-terminated as in general it cannot be
+	 * assumed that @data is null-terminated.
+	 */
+	data_str = g_strndup((const char *)data, data_len);
+	if (!g_str_has_suffix(data_str, PV_IBM_Z_SUBJECT_ORGANIZATIONAL_UNIT_NAME_SUFFIX))
+		return FALSE;
+
+	return TRUE;
+}
+
+/* Return a list of all IBM Z signing key certificates in @certs and remove them
+ * from the chain. Return empty stack if no IBM Z signing key is found.
+ */
+STACK_OF_X509 *pv_remove_ibm_signing_certs(STACK_OF_X509 *certs)
+{
+	g_autoptr(STACK_OF_X509) ret = sk_X509_new_null();
+
+	for (int i = 0; i < sk_X509_num(certs); i++) {
+		X509 *cert = sk_X509_value(certs, i);
+
+		g_assert(cert);
+
+		if (!has_ibm_signing_subject(cert))
+			continue;
+
+		/* Remove this certificate from the list and change i-- as the
+		 * array has changed - this is not beautiful, but right now the
+		 * easiest solution I came up with.
+		 */
+		if (sk_X509_delete(certs, i--) != cert)
+			g_abort();
+
+		if (sk_X509_push(ret, g_steal_pointer(&cert)) == 0)
+			g_abort();
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+static X509_NAME *x509_name_reorder_attributes(const X509_NAME *name, const int nids[],
+					       size_t nids_len)
+{
+	int entry_count = X509_NAME_entry_count(name);
+	g_autoptr(X509_NAME) ret = NULL;
+
+	if (entry_count < 0)
+		return NULL;
+
+	if (nids_len != (size_t)entry_count)
+		return NULL;
+
+	ret = X509_NAME_new();
+	if (!ret)
+		g_abort();
+
+	for (size_t i = 0; i < nids_len; i++) {
+		const X509_NAME_ENTRY *entry = NULL;
+		int nid = nids[i];
+		int lastpos = -1;
+
+		lastpos = X509_NAME_get_index_by_NID((X509_NAME *)name, nid, lastpos);
+		if (lastpos == -1)
+			return NULL;
+
+		entry = X509_NAME_get_entry(name, lastpos);
+		if (!entry)
+			return NULL;
+
+		if (X509_NAME_add_entry(ret, entry, -1, 0) != 1)
+			return NULL;
+	}
+	return g_steal_pointer(&ret);
+}
+
+X509_NAME *pv_c2b_name(const X509_NAME *name)
+{
+	int nids[] = { NID_countryName,	 NID_organizationName,	  NID_organizationalUnitName,
+		       NID_localityName, NID_stateOrProvinceName, NID_commonName };
+	g_autoptr(X509_NAME) broken_name = NULL;
+
+	g_assert(name);
+
+	/* Try to reorder the attributes */
+	broken_name = x509_name_reorder_attributes(name, nids, G_N_ELEMENTS(nids));
+	if (broken_name)
+		return g_steal_pointer(&broken_name);
+	return X509_NAME_dup((X509_NAME *)name);
+}
+
+static int security_level_to_bits(int level)
+{
+	static int security_bits[] = { 0, 80, 112, 128, 192, 256 };
+
+	g_assert(level > 0 && level < (int)G_N_ELEMENTS(security_bits));
+
+	return security_bits[level];
+}
+
+/* returns
+ *   0 when the certificate is valid,
+ *  -1 when not yet valid,
+ *   1 when expired
+ */
+static int check_validity_period(const ASN1_TIME *not_before, const ASN1_TIME *not_after)
+{
+	if (X509_cmp_current_time(not_before) != -1)
+		return -1;
+
+	if (X509_cmp_current_time(not_after) != 1)
+		return 1;
+
+	return 0;
+}
+
+static gboolean own_X509_NAME_ENTRY_equal(const X509_NAME_ENTRY *x, const X509_NAME_ENTRY *y)
+{
+	const ASN1_OBJECT *x_obj = X509_NAME_ENTRY_get_object(x);
+	const ASN1_STRING *x_data = X509_NAME_ENTRY_get_data(x);
+	const ASN1_OBJECT *y_obj = X509_NAME_ENTRY_get_object(y);
+	const ASN1_STRING *y_data = X509_NAME_ENTRY_get_data(y);
+	int x_len = ASN1_STRING_length(x_data);
+	int y_len = ASN1_STRING_length(y_data);
+
+	if (x_len < 0 || x_len != y_len)
+		return FALSE;
+
+	/* ASN1_STRING_cmp(x_data, y_data) == 0 doesn't work because it also
+	 * compares the type, which is sometimes different.
+	 */
+	return OBJ_cmp(x_obj, y_obj) == 0 &&
+	       memcmp(ASN1_STRING_get0_data(x_data), ASN1_STRING_get0_data(y_data),
+		      (unsigned long)x_len) == 0;
+}
+
+static gboolean own_X509_NAME_equal(const X509_NAME *x, const X509_NAME *y)
+{
+	int x_count = X509_NAME_entry_count(x);
+	int y_count = X509_NAME_entry_count(y);
+
+	if (x != y && (!x || !y))
+		return FALSE;
+
+	if (x_count != y_count)
+		return FALSE;
+
+	for (int i = 0; i < x_count; i++) {
+		const X509_NAME_ENTRY *entry_i = X509_NAME_get_entry(x, i);
+		gboolean entry_found = FALSE;
+
+		for (int j = 0; j < y_count; j++) {
+			const X509_NAME_ENTRY *entry_j = X509_NAME_get_entry(y, j);
+
+			if (own_X509_NAME_ENTRY_equal(entry_i, entry_j)) {
+				entry_found = TRUE;
+				break;
+			}
+		}
+
+		if (!entry_found)
+			return FALSE;
+	}
+	return TRUE;
+}
+
+/* Verify that the used public key algorithm matches the subject signature
+ * algorithm
+ */
+static int check_signature_algo_match(const EVP_PKEY *pkey, const X509 *subject, GError **error)
+{
+	int pkey_nid;
+
+	if (!pkey) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_PUBLIC_KEY, _("no public key"));
+		return -1;
+	}
+
+	if (OBJ_find_sigid_algs(X509_get_signature_nid(subject), NULL, &pkey_nid) != 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_SIGNATURE_ALGORITHM,
+			    _("unsupported signature algorithm"));
+		return -1;
+	}
+
+	if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey)) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_SIGNATURE_ALGORITHM_MISMATCH,
+			    _("signature algorithm mismatch"));
+		return -1;
+	}
+
+	return 0;
+}
+
+/* It's almost the same as X509_check_issed from OpenSSL does except that we
+ * don't check the key usage of the potential issuer. This means we check:
+ * 1. issuer_name(cert) == subject_name(issuer)
+ * 2. Check whether the akid(cert) (if available) matches the issuer skid
+ * 3. Check that the cert algrithm matches the subject algorithm
+ * 4. Verify the signature of certificate @cert is using the public key of
+ *    @issuer.
+ */
+static int check_host_key_issued(X509 *cert, X509 *issuer, GError **error)
+{
+	const X509_NAME *issuer_subject = X509_get_subject_name(issuer);
+	const X509_NAME *cert_issuer = X509_get_issuer_name(cert);
+	g_autoptr(AUTHORITY_KEYID) akid = NULL;
+
+	/* We cannot use X509_NAME_cmp() because it considers the order of the
+	 * X509_NAME_Entries.
+	 */
+	if (!own_X509_NAME_equal(issuer_subject, cert_issuer)) {
+		g_autofree char *issuer_subject_str = pv_X509_NAME_oneline(issuer_subject);
+		g_autofree char *cert_issuer_str = pv_X509_NAME_oneline(cert_issuer);
+
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_CERT_SUBJECT_ISSUER_MISMATCH,
+			    _("Subject issuer mismatch:\n'%s'\n'%s'"), issuer_subject_str,
+			    cert_issuer_str);
+		return -1;
+	}
+
+	akid = X509_get_ext_d2i(cert, NID_authority_key_identifier, NULL, NULL);
+	if (akid && X509_check_akid(issuer, akid) != X509_V_OK) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_SKID_AKID_MISMATCH,
+			    _("AKID mismatch"));
+		return -1;
+	}
+
+	if (check_signature_algo_match(X509_get0_pubkey(issuer), cert, error) < 0)
+		return -1;
+
+	if (X509_verify(cert, X509_get0_pubkey(issuer)) != 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_CERT_SIGNATURE_INVALID,
+			    _("Signature verification failed"));
+		return -1;
+	}
+
+	return 0;
+}
+
+static gboolean is_cert_revoked(X509 *cert, X509_CRL *crl)
+{
+	X509_REVOKED *revoked = NULL;
+	int rc;
+
+	if (!cert || !crl)
+		g_abort();
+
+	rc = X509_CRL_get0_by_serial(crl, &revoked, (ASN1_INTEGER *)X509_get0_serialNumber(cert));
+	if (rc == 0)
+		return FALSE;
+
+	if (revoked)
+		return TRUE;
+
+	return FALSE;
+}
+
+/* Assumptions are that the issuer_crt and issuer_crl is a trusted IBM Z
+ * signing certificate/revocation list. This function verifies a host-key
+ * document. To do so multiple steps are required:
+ *
+ * 1. issuer(host_key) == subject(issuer_crt)
+ * 2. Signature verification
+ * 3. @host_key must not be expired
+ * 4. @host_key must not be revoked
+ */
+int pv_verify_host_key(X509 *host_key, GSList *issuer_pairs, int verify_flags, int level,
+		       GError **error)
+{
+	const int exp_security_bits = security_level_to_bits(level);
+	EVP_PKEY *pkey;
+	gboolean successfully_checked = FALSE;
+	int pkey_security_bits;
+
+	g_assert(host_key);
+	pkey = X509_get0_pubkey(host_key);
+
+	if (!pkey) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			    _("failed to retrieve public key"));
+		return -1;
+	}
+
+	/* check key level, if necessary */
+	pkey_security_bits = EVP_PKEY_security_bits(pkey);
+	if (exp_security_bits > 0 && pkey_security_bits < exp_security_bits) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_VERIFICATION_FAILED,
+			    _("not enough bits of security (%d, %d expected)"), pkey_security_bits,
+			    exp_security_bits);
+		return -1;
+	}
+
+	if (!(verify_flags & X509_V_FLAG_NO_CHECK_TIME)) {
+		const ASN1_TIME *last = X509_get0_notBefore(host_key);
+		const ASN1_TIME *next = X509_get0_notAfter(host_key);
+
+		if (!last || !next || check_validity_period(last, next)) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_VALIDITY_PERIOD,
+				    _("validity period is not valid"));
+			return -1;
+		}
+	} else {
+		verify_flags &= ~X509_V_FLAG_NO_CHECK_TIME;
+	}
+
+	/* Verify that the host_key was issued by a certificate and that it
+	 * wasn't revoked.
+	 */
+	for (GSList *iterator = issuer_pairs; iterator; iterator = iterator->next) {
+		const PvX509Pair *pair = iterator->data;
+		STACK_OF_X509_CRL *issuer_crls = NULL;
+		X509 *issuer_cert = NULL;
+
+		g_assert(pair);
+
+		issuer_cert = pair->cert;
+		issuer_crls = pair->crls;
+
+		g_assert(issuer_cert);
+
+		/* Verify that the issuer(host_key) == subject(issuer_cert) and
+		 * that the signature is valid
+		 */
+		if (check_host_key_issued(host_key, issuer_cert, NULL) < 0)
+			continue;
+
+		/* Check against CRL */
+		if (verify_flags & X509_V_FLAG_CRL_CHECK) {
+			gboolean crl_checked = FALSE;
+
+			verify_flags &= ~X509_V_FLAG_CRL_CHECK;
+			for (int i = 0; i < sk_X509_CRL_num(issuer_crls); i++) {
+				X509_CRL *issuer_crl = sk_X509_CRL_value(issuer_crls, i);
+
+				g_assert(issuer_crl);
+
+				if (is_cert_revoked(host_key, issuer_crl)) {
+					g_set_error(error, PV_CERT_ERROR,
+						    PV_CERT_ERROR_CERT_REVOKED,
+						    _("certificate revoked"));
+					return -1;
+				}
+
+				crl_checked = TRUE;
+			}
+
+			if (!crl_checked) {
+				g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_CRL,
+					    _("no valid CRL found"));
+				return -1;
+			}
+			successfully_checked = TRUE;
+			break;
+		}
+	}
+
+	if (!successfully_checked) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_ISSUER_IBM_Z_FOUND,
+			    _("no IBM Z signing key that issued this host-key document found"));
+		return -1;
+	}
+
+	/* were some unsupported flags specified? */
+	g_assert(verify_flags == 0);
+	return 0;
+}
+
+int pv_verify_cert(X509_STORE_CTX *ctx, X509 *cert, GError **error)
+{
+	int rc;
+
+	pv_wrapped_g_assert(cert);
+	pv_wrapped_g_assert(ctx);
+
+	X509_STORE_CTX_set_cert(ctx, cert);
+	rc = X509_verify_cert(ctx);
+	if (rc != 1) {
+		X509 *tmp_cert = NULL;
+
+		tmp_cert = pv_X509_STORE_CTX_get_current_cert(ctx);
+		if (tmp_cert) {
+			g_autofree char *subj_name =
+				pv_X509_NAME_oneline(X509_get_subject_name(tmp_cert));
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_VERIFICATION_FAILED,
+				    _("failed to verify certificate '%s': %s"), subj_name,
+				    X509_verify_cert_error_string(X509_STORE_CTX_get_error(ctx)));
+		} else {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_VERIFICATION_FAILED,
+				    _("failed to verify certificate: %s"),
+				    X509_verify_cert_error_string(X509_STORE_CTX_get_error(ctx)));
+		}
+		return -1;
+	}
+	return 0;
+}
+
+/* Verify that: subject(issuer) == issuer(crl) and SKID(issuer) == AKID(crl) */
+static int check_crl_issuer(X509_CRL *crl, X509 *issuer, GError **error)
+{
+	const X509_NAME *crl_issuer = X509_CRL_get_issuer(crl);
+	const X509_NAME *issuer_subject = X509_get_subject_name(issuer);
+	AUTHORITY_KEYID *akid = NULL;
+
+	if (!own_X509_NAME_equal(issuer_subject, crl_issuer)) {
+		g_autofree char *issuer_subject_str = pv_X509_NAME_oneline(issuer_subject);
+		g_autofree char *crl_issuer_str = pv_X509_NAME_oneline(crl_issuer);
+
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_CRL_SUBJECT_ISSUER_MISMATCH,
+			    _("issuer mismatch:\n%s\n%s"), issuer_subject_str, crl_issuer_str);
+		return -1;
+	}
+
+	/* If AKID(@crl) is specified it must match with SKID(@issuer) */
+	akid = X509_CRL_get_ext_d2i(crl, NID_authority_key_identifier, NULL, NULL);
+	if (akid && X509_check_akid(issuer, akid) != X509_V_OK) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_SKID_AKID_MISMATCH,
+			    _("AKID mismatch"));
+		return -1;
+	}
+
+	return 0;
+}
+
+int pv_verify_crl(X509_CRL *crl, X509 *cert, int verify_flags, GError **error)
+{
+	EVP_PKEY *pkey = X509_get0_pubkey(cert);
+
+	g_assert(crl);
+
+	if (!pkey) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			    _("failed to retrieve public key from the certificate"));
+		return -1;
+	}
+
+	/* check that the @crl issuer matches with the subject name of @cert*/
+	if (check_crl_issuer(crl, cert, error) < 0)
+		return -1;
+
+	/* verify the validity period of the CRL */
+	if (!(verify_flags & X509_V_FLAG_NO_CHECK_TIME)) {
+		const ASN1_TIME *last = X509_CRL_get0_lastUpdate(crl);
+		const ASN1_TIME *next = X509_CRL_get0_nextUpdate(crl);
+
+		if (!last || !next || check_validity_period(last, next)) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INVALID_VALIDITY_PERIOD,
+				    _("validity period is not valid"));
+			return -1;
+		}
+	} else {
+		verify_flags &= ~X509_V_FLAG_NO_CHECK_TIME;
+	}
+
+	/* verify the signature */
+	if (X509_CRL_verify(crl, pkey) != 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_CRL_SIGNATURE_INVALID,
+			    _("signature is not valid"));
+		return -1;
+	}
+	g_assert(verify_flags == 0);
+	return 0;
+}
+
+int pv_check_chain_parameters(const STACK_OF_X509 *chain, GError **error)
+{
+	const X509_NAME *ca_x509_subject = NULL;
+	g_autofree char *ca_subject = NULL;
+	int len = sk_X509_num(chain);
+	X509 *ca = NULL;
+
+	if (len < 2) {
+		g_set_error(
+			error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			_("there must be at least one root and one leaf certificate in the chain of trust"));
+		return -1;
+	}
+
+	/* get the root certificate of the chain of trust */
+	ca = sk_X509_value(chain, len - 1);
+	if (!ca) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_INTERNAL,
+			    _("no root certificate found"));
+		return -1;
+	}
+
+	ca_x509_subject = X509_get_subject_name(ca);
+	if (!ca_x509_subject) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("subject of the root CA cannot be retrieved"));
+		return -1;
+	}
+
+	ca_subject = pv_X509_NAME_oneline(ca_x509_subject);
+	if (!ca_subject) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("subject name of the root CA cannot be retrieved"));
+		return -1;
+	}
+	g_info(_("Root CA used: '%s'"), ca_subject);
+
+	return 0;
+}
+
+/* Given a certificate @cert try to find valid revocation lists in @ctx. If no
+ * valid CRL was found NULL is returned.
+ */
+STACK_OF_X509_CRL *pv_store_ctx_find_valid_crls(X509_STORE_CTX *ctx, X509 *cert, GError **error)
+{
+	g_autoptr(STACK_OF_X509_CRL) ret = NULL;
+	const int verify_flags = 0;
+	X509_NAME *subject = NULL;
+
+	pv_wrapped_g_assert(ctx);
+	pv_wrapped_g_assert(cert);
+
+	subject = X509_get_subject_name(cert);
+	if (!subject) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_MALFORMED_CERTIFICATE,
+			    _("certificate is malformed"));
+		return NULL;
+	}
+
+	ret = pv_X509_STORE_CTX_get1_crls(ctx, subject);
+	if (!ret) {
+		/* Workaround to fix the mismatch between issuer name of the
+		 * IBM Z signing CRLs and the IBM Z signing key subject name.
+		 */
+		g_autoptr(X509_NAME) broken_subject = pv_c2b_name(subject);
+
+		ret = pv_X509_STORE_CTX_get1_crls(ctx, broken_subject);
+		if (!ret) {
+			g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_CRL, _("no CRL found"));
+			g_info("ERROR: %s", (*error)->message);
+			return NULL;
+		}
+	}
+
+	/* Filter out non-valid CRLs for @cert */
+	for (int i = 0; i < sk_X509_CRL_num(ret); i++) {
+		X509_CRL *crl = sk_X509_CRL_value(ret, i);
+
+		g_assert(crl);
+
+		/* If @crl is not valid remove it from the array and log a
+		 * warning.
+		 */
+		if (pv_verify_crl(crl, cert, verify_flags, error) < 0) {
+			g_assert(error);
+			g_warning(_("CRL is not valid: %s"), (*error)->message);
+			g_clear_error(error);
+
+			/* Remove this certificate from the list and change i-- as the
+			 * array has changed - this is not beautfiul, but right now the
+			 * easiest solution I came up with
+			 */
+			if (sk_X509_CRL_delete(ret, i--) != crl)
+				g_abort();
+
+			g_clear_pointer(&crl, X509_CRL_free);
+		}
+	}
+
+	if (sk_X509_CRL_num(ret) < 1) {
+		g_set_error(error, PV_CERT_ERROR, PV_CERT_ERROR_NO_CRL, _("no valid CRL found"));
+		return NULL;
+	}
+	return g_steal_pointer(&ret);
+}
+
+/*
+ * Finds the IBM signing key in the stack.
+ * Error out, if there is not exactly one IBM signing key.
+ */
+static STACK_OF_X509 *get_ibm_signing_certs(STACK_OF_X509 *certs, GError **error)
+{
+	g_autoptr(STACK_OF_X509) ibm_signing_certs = NULL;
+	int ibm_signing_certs_count;
+
+	/* Find all IBM Z signing keys and remove them from the chain as we
+	 * have to verify that they're valid. The last step of the chain of
+	 * trust verification must be done manually, as the IBM Z signing keys
+	 * are not marked as (intermediate) CA and therefore the standard
+	 * `X509_verify_cert` function of OpenSSL cannot be used to verify the
+	 * actual host-key documents.
+	 */
+	ibm_signing_certs = pv_remove_ibm_signing_certs(certs);
+	ibm_signing_certs_count = sk_X509_num(ibm_signing_certs);
+	if (ibm_signing_certs_count < 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_NO_IBM_Z_SIGNING_KEY,
+			    _("Specify at least one IBM Z signing key"));
+		return NULL;
+	} else if (ibm_signing_certs_count > 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_NO_IBM_Z_SIGNING_KEY,
+			    _("Specify only one IBM Z signing key"));
+		return NULL;
+	}
+	g_assert(ibm_signing_certs_count == 1);
+
+	return g_steal_pointer(&ibm_signing_certs);
+}
+
+static gboolean download_crls(X509_STORE *trusted, PvCertWithPathList *host_key_certs_with_path,
+			      GError **error)
+{
+	g_autoptr(STACK_OF_X509_CRL) downloaded_ibm_signing_crls = NULL;
+
+	/* Set up the download routine for the lookup of CRLs. */
+	pv_store_setup_crl_download(trusted);
+
+	/* Try to download the CRLs of the IBM Z signing certificates
+	 * specified in the host-key documents. Ignore download errors
+	 * as it's still possible that a CRL is specified via command
+	 * line.
+	 */
+	downloaded_ibm_signing_crls = pv_try_load_crls_by_certs(host_key_certs_with_path);
+
+	/* Add the downloaded CRLs to the store so they can be used for
+	 * the verification later.
+	 */
+	for (int i = 0; i < sk_X509_CRL_num(downloaded_ibm_signing_crls); i++) {
+		X509_CRL *crl = sk_X509_CRL_value(downloaded_ibm_signing_crls, i);
+
+		if (X509_STORE_add_crl(trusted, crl) != 1) {
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    _("failed to load CRL"));
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+
+gboolean pv_verify_host_key_doc(PvCertWithPathList *host_key_certs_with_path, X509_STORE *trusted,
+				STACK_OF_X509 *untrusted_certs, gboolean online, GError **error)
+{
+	g_autoslist(PvX509Pair) ibm_z_pairs = NULL;
+	g_autoptr(STACK_OF_X509) ibm_signing_certs = NULL;
+	g_autoptr(X509_STORE_CTX) ctx = NULL;
+
+	pv_wrapped_g_assert(host_key_certs_with_path);
+	pv_wrapped_g_assert(trusted);
+	pv_wrapped_g_assert(untrusted_certs);
+
+	if (online && !download_crls(trusted, host_key_certs_with_path, error))
+		return -1;
+
+	/* Find all IBM Z signing keys and remove them from the chain as we
+	 * have to verify that they're valid. The last step of the chain of
+	 * trust verification must be done manually, as the IBM Z signing keys
+	 * are not marked as (intermediate) CA and therefore the standard
+	 * `X509_verify_cert` function of OpenSSL cannot be used to verify the
+	 * actual host-key documents.
+	 */
+	ibm_signing_certs = get_ibm_signing_certs(untrusted_certs, error);
+	if (!ibm_signing_certs)
+		return -1;
+
+	if (pv_store_set_verify_param(trusted, error) < 0)
+		return -1;
+
+	ctx = pv_create_store_ctx(trusted, untrusted_certs, error);
+	if (!ctx)
+		return -1;
+	/*
+	 * Get all IBM-signing-[key,crls] pairs.
+	 * NOTE: Currently there is only one signing-key allowed
+	 */
+	for (int i = 0; i < sk_X509_num(ibm_signing_certs); i++) {
+		g_autoptr(X509) ibm_signing_cert = sk_X509_pop(ibm_signing_certs);
+		g_autoptr(STACK_OF_X509_CRL) ibm_signing_crls = NULL;
+		PvX509Pair *ibm_z_pair = NULL;
+
+		/*
+		 * Get CRLs for the IBM signing cert
+		 */
+		ibm_signing_crls = pv_store_ctx_find_valid_crls(ctx, ibm_signing_cert, error);
+		if (!ibm_signing_crls) {
+			g_prefix_error(error, _("IBM Z signing key: "));
+			return -1;
+		}
+
+		/* build the pair and add it to the list */
+		ibm_z_pair = pv_x509_pair_new_take(&ibm_signing_cert, &ibm_signing_crls);
+		g_assert(!ibm_signing_cert);
+		g_assert(!ibm_signing_crls);
+		ibm_z_pairs = g_slist_append(ibm_z_pairs, ibm_z_pair);
+	}
+
+	/* Verify host-key documents by using the IBM Z signing
+	 * certificates and the corresponding certificate revocation
+	 * lists.
+	 */
+	for (GSList *iterator = host_key_certs_with_path; iterator; iterator = iterator->next) {
+		PvX509WithPath *host_key_with_path = iterator->data;
+		const char *host_key_path = host_key_with_path->path;
+		X509 *host_key = host_key_with_path->cert;
+		int flags = X509_V_FLAG_CRL_CHECK;
+
+		if (pv_verify_host_key(host_key, ibm_z_pairs, flags, PV_CERTS_SECURITY_LEVEL,
+				       error) < 0) {
+			g_prefix_error(error, "'%s': ", host_key_path);
+			return -1;
+		}
+	}
+
+	/* Verify that all IBM Z signing keys are trustable.
+	 * For this we must check:
+	 *
+	 * 1. Can a chain of trust be established ending in a root CA
+	 * 2. Is the correct root CA used? It has either to be the
+	 *    System CA or the root CA specified via command line.
+	 */
+	for (GSList *iterator = ibm_z_pairs; iterator; iterator = iterator->next) {
+		const PvX509Pair *ibm_z_pair = iterator->data;
+
+		if (pv_verify_cert(ctx, ibm_z_pair->cert, error) < 0)
+			return -1;
+		if (pv_check_chain_parameters(X509_STORE_CTX_get0_chain(ctx), error) < 0)
+			return -1;
+		/* re-init ctx for the next verification */
+		X509_STORE_CTX_cleanup(ctx);
+		if (pv_init_store_ctx(ctx, trusted, untrusted_certs, error) != 0)
+			return -1;
+	}
+	return 0;
+}
+
+int pv_verify_host_key_docs_by_path(char **host_key_paths, char *optional_root_ca_path,
+				    char **crl_paths, char **untrusted_cert_paths, gboolean online,
+				    GError **error)
+{
+	g_autoslist(PvX509WithPath) untrusted_certs_with_path = NULL, host_key_certs = NULL;
+	g_autoptr(STACK_OF_X509) untrusted_certs = NULL;
+	g_autoptr(X509_STORE) trusted = NULL;
+
+	pv_wrapped_g_assert(host_key_paths);
+	pv_wrapped_g_assert(untrusted_cert_paths);
+
+	/* Load trusted root CAs of the system if and only if @root_ca_path is
+	 * NULL, otherwise use the root CA specified by @root_ca_path.
+	 */
+	trusted = pv_store_setup(optional_root_ca_path, crl_paths, untrusted_cert_paths, error);
+	if (!trusted)
+		return -1;
+
+	/* Load all untrusted certificates (e.g. IBM Z signing key and
+	 * intermediate CA) that are required to establish a chain of
+	 * trust starting from the host-key document up to the root CA (if not
+	 * otherwise specified that can be one of the system wide installed
+	 * root CAs, e.g. DigiCert).
+	 */
+	untrusted_certs_with_path = pv_load_certificates(untrusted_cert_paths, error);
+	if (!untrusted_certs_with_path)
+		return -1;
+	/* Convert to STACK_OF(X509) */
+	untrusted_certs = pv_get_x509_stack(untrusted_certs_with_path);
+
+	host_key_certs = pv_load_certificates(host_key_paths, error);
+	if (!host_key_certs)
+		return -1;
+
+	return pv_verify_host_key_doc(host_key_certs, trusted, untrusted_certs, online, error);
+}
--- /dev/null
+++ b/libpv/common.c
@@ -0,0 +1,45 @@
+/*
+ * Libpv common functions.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ */
+/* Must be included before any other header */
+#include "config.h"
+
+#include "libpv/common.h"
+#include "libpv/cert.h"
+#include "libpv/curl.h"
+
+/* setup and tear down */
+int pv_init(void)
+{
+	static size_t openssl_initalized;
+
+	if (g_once_init_enter(&openssl_initalized)) {
+		if (OPENSSL_VERSION_NUMBER < 0x1000100fL)
+			g_assert_not_reached();
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+		SSL_library_init();
+		SSL_load_error_strings();
+#else
+		OPENSSL_init_crypto(0, NULL);
+#endif
+
+		if (pv_curl_init() != 0)
+			return -1;
+
+		pv_cert_init();
+		g_once_init_leave(&openssl_initalized, 1);
+	}
+	return 0;
+}
+
+void pv_cleanup(void)
+{
+	pv_cert_cleanup();
+	pv_curl_cleanup();
+}
--- /dev/null
+++ b/libpv/config.h
@@ -0,0 +1,15 @@
+/*
+ * Config file.
+ * Must be include before any other header.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ *
+ */
+#ifndef LIBPV_CONFIG_H
+#define LIBPV_CONFIG_H
+#define GETTEXT_PACKAGE "libpv"
+
+#endif /* LIBPV_CONFIG_H */
--- /dev/null
+++ b/libpv/crypto.c
@@ -0,0 +1,529 @@
+/*
+ * Cryptography functions
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+/* Must be included before any other header */
+#include "config.h"
+
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include <openssl/kdf.h>
+
+#include "lib/zt_common.h"
+#include "libpv/crypto.h"
+#include "libpv/glib-helper.h"
+#include "libpv/hash.h"
+
+const char *pv_get_openssl_error(void)
+{
+	const char *ret;
+	BIO *bio;
+	char *buf;
+	long len;
+
+	bio = BIO_new(BIO_s_mem());
+	ERR_print_errors(bio);
+	len = BIO_get_mem_data(bio, &buf);
+	if (len < 0)
+		ret = "Cannot receive OpenSSL error message.";
+	else
+		ret = g_strndup(buf, (size_t)len);
+	BIO_free(bio);
+	return ret;
+}
+
+int pv_BIO_reset(BIO *b)
+{
+	int rc = BIO_reset(b);
+
+	if (rc != 1 && (BIO_method_type(b) == BIO_TYPE_FILE && rc != 0))
+		return -1;
+	return 1;
+}
+
+GBytes *pv_generate_rand_data(size_t size, GError **error)
+{
+	g_autofree uint8_t *data = NULL;
+
+	if (size > INT_MAX) {
+		g_set_error_literal(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_RANDOMIZATION,
+				    "Too many random data requested. Split it up");
+		OPENSSL_clear_free(data, size);
+		return NULL;
+	}
+
+	data = g_malloc(size);
+	if (RAND_bytes(data, (int)size) != 1) {
+		g_set_error_literal(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_RANDOMIZATION,
+				    "The required amount of random data is not available");
+		return NULL;
+	}
+
+	return pv_sec_gbytes_new_take(g_steal_pointer(&data), size);
+}
+
+GBytes *pv_generate_key(const EVP_CIPHER *cipher, GError **error)
+{
+	int size;
+
+	pv_wrapped_g_assert(cipher);
+
+	size = EVP_CIPHER_key_length(cipher);
+	if (size <= 0) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_KEYGENERATION,
+			    "Unknown cipher");
+		return NULL;
+	}
+
+	return pv_generate_rand_data((guint)size, error);
+}
+
+GBytes *pv_generate_iv(const EVP_CIPHER *cipher, GError **error)
+{
+	int size;
+
+	pv_wrapped_g_assert(cipher);
+
+	size = EVP_CIPHER_iv_length(cipher);
+	if (size <= 0) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_KEYGENERATION,
+			    "Unknown cipher");
+		return NULL;
+	}
+
+	return pv_generate_rand_data((guint)size, error);
+}
+
+static int64_t pv_gcm_encrypt_decrypt(GBytes *input, GBytes *aad, const PvCipherParms *parms,
+				      GBytes **output, GBytes **tagp, enum PvCryptoMode mode,
+				      GError **error)
+{
+	const uint8_t *in_data, *aad_data = NULL, *iv_data, *key_data;
+	size_t in_size, aad_size = 0, iv_size, key_size, out_size;
+	const EVP_CIPHER *cipher = parms->cipher;
+	const size_t tag_size = parms->tag_size;
+	gboolean encrypt = mode == PV_ENCRYPT;
+	g_autoptr(EVP_CIPHER_CTX) ctx = NULL;
+	g_autofree uint8_t *out_data = NULL;
+	g_autofree uint8_t *tag_data = NULL;
+	const GBytes *key = parms->key;
+	const GBytes *iv = parms->iv;
+	int cipher_block_size;
+	int64_t ret = -1;
+	int len = -1;
+	GBytes *tag;
+
+	g_assert(tagp);
+	g_assert(cipher);
+	g_assert(key);
+	g_assert(iv);
+
+	tag = *tagp;
+	in_data = g_bytes_get_data((GBytes *)input, &in_size);
+	if (aad)
+		aad_data = g_bytes_get_data((GBytes *)aad, &aad_size);
+	iv_data = g_bytes_get_data((GBytes *)iv, &iv_size);
+	key_data = g_bytes_get_data((GBytes *)key, &key_size);
+	out_size = in_size;
+	cipher_block_size = EVP_CIPHER_block_size(cipher);
+
+	/* Checks for later casts */
+	g_assert(aad_size <= INT_MAX);
+	g_assert(in_size <= INT_MAX);
+	g_assert(iv_size <= INT_MAX);
+	g_assert(cipher_block_size > 0);
+
+	ctx = EVP_CIPHER_CTX_new();
+	if (!ctx)
+		g_abort();
+
+	if (tag_size == 0 || (tag_size % (size_t)cipher_block_size != 0)) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "Passed tag size is incorrect");
+		return -1;
+	}
+
+	/* Has the passed key the correct size? */
+	if (EVP_CIPHER_key_length(cipher) != (int)key_size) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "Passed key has incorrect size: %ld != %d", key_size,
+			    EVP_CIPHER_key_length(cipher));
+		return -1;
+	}
+
+	/* First, set the cipher algorithm so we can verify our key/IV lengths
+	 */
+	if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, encrypt) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "EVP_CIPHER_CTX_new failed");
+		return -1;
+	}
+
+	/* Set IV length */
+	if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, (int)iv_size, NULL) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "EVP_CIPHER_CTX_ex failed");
+		return -1;
+	}
+
+	/* Initialise key and IV */
+	if (EVP_CipherInit_ex(ctx, NULL, NULL, key_data, iv_data, encrypt) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "EVP_CipherInit_ex failed");
+		return -1;
+	}
+
+	/* Allocate output data */
+	out_data = g_malloc0(out_size);
+	if (encrypt)
+		tag_data = g_malloc0(tag_size);
+
+	if (aad_size > 0) {
+		/* Provide any AAD data */
+		if (EVP_CipherUpdate(ctx, NULL, &len, aad_data, (int)aad_size) != 1) {
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    "EVP_CipherUpdate failed");
+			return -1;
+		}
+		g_assert(len == (int)aad_size);
+	}
+
+	/* Provide data to be en/decrypted */
+	if (EVP_CipherUpdate(ctx, out_data, &len, in_data, (int)in_size) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    "EVP_CipherUpdate failed");
+		return -1;
+	}
+	ret = len;
+
+	if (!encrypt) {
+		const uint8_t *tmp_tag_data = NULL;
+		size_t tmp_tag_size = 0;
+
+		if (tag)
+			tmp_tag_data = g_bytes_get_data(tag, &tmp_tag_size);
+		if (tag_size != tmp_tag_size) {
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    "Getting the GCM tag failed");
+			return -1;
+		}
+
+		/* Set expected tag value */
+		if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, (int)tmp_tag_size,
+					(uint8_t *)tmp_tag_data) != 1) {
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    "Setting the GCM tag failed");
+			return -1;
+		}
+	}
+
+	/* Finalize the en/decryption */
+	if (EVP_CipherFinal_ex(ctx, (uint8_t *)out_data + len, &len) != 1) {
+		if (encrypt)
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    "Encrypting failed (EVP_CipherFinal_ex)");
+		else
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_NO_MATCH_TAG,
+				    "Verifying the GCM tag failed");
+		return -1;
+	}
+	ret += len;
+
+	if (encrypt) {
+		/* Get the tag */
+		if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, (int)tag_size, tag_data) != 1) {
+			g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+				    "Getting the GCM tag failed");
+			return -1;
+		}
+
+		g_assert(!*tagp);
+		*tagp = g_bytes_new_take(g_steal_pointer(&tag_data), tag_size);
+	}
+	g_assert(ret == (int)out_size);
+	g_assert(out_size == in_size);
+
+	g_assert(!*output);
+	*output = pv_sec_gbytes_new_take(g_steal_pointer(&out_data), out_size);
+	return ret;
+}
+
+int64_t pv_gcm_encrypt(GBytes *plain, GBytes *aad, const PvCipherParms *parms, GBytes **cipher,
+		       GBytes **tag, GError **error)
+{
+	pv_wrapped_g_assert(plain);
+	pv_wrapped_g_assert(parms);
+	pv_wrapped_g_assert(cipher);
+	pv_wrapped_g_assert(tag);
+
+	return pv_gcm_encrypt_decrypt(plain, aad, parms, cipher, tag, PV_ENCRYPT, error);
+}
+
+int64_t pv_gcm_decrypt(GBytes *cipher, GBytes *aad, GBytes *tag, const PvCipherParms *parms,
+		       GBytes **plain, GError **error)
+{
+	pv_wrapped_g_assert(cipher);
+	pv_wrapped_g_assert(tag);
+	pv_wrapped_g_assert(parms);
+	pv_wrapped_g_assert(plain);
+
+	return pv_gcm_encrypt_decrypt(cipher, aad, parms, plain, &tag, PV_DECRYPT, error);
+}
+
+GBytes *pv_hkdf_extract_and_expand(size_t derived_key_len, GBytes *key, GBytes *salt, GBytes *info,
+				   const EVP_MD *md, G_GNUC_UNUSED GError **error)
+{
+	const unsigned char *salt_data, *key_data, *info_data;
+	g_autoptr(EVP_PKEY_CTX) ctx = NULL;
+	size_t salt_len, key_len, info_len;
+	g_autofree unsigned char *derived_key = NULL;
+
+	g_assert(derived_key_len > 0);
+	pv_wrapped_g_assert(key);
+	pv_wrapped_g_assert(salt);
+	pv_wrapped_g_assert(info);
+	pv_wrapped_g_assert(md);
+
+	ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
+	if (!ctx)
+		g_abort();
+
+	if (EVP_PKEY_derive_init(ctx) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_hkdf_mode(ctx, EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_set_hkdf_md(ctx, md) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	salt_data = g_bytes_get_data(salt, &salt_len);
+	if (salt_len > INT_MAX) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_set1_hkdf_salt(ctx, salt_data, (int)salt_len) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	key_data = g_bytes_get_data(key, &key_len);
+	if (key_len > INT_MAX) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_set1_hkdf_key(ctx, key_data, (int)key_len) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	info_data = g_bytes_get_data(info, &info_len);
+	if (info_len > INT_MAX) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_add1_hkdf_info(ctx, (unsigned char *)info_data, (int)info_len) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		return NULL;
+	}
+
+	derived_key = g_malloc0(derived_key_len);
+	if (EVP_PKEY_derive(ctx, derived_key, &derived_key_len) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_HKDF_FAIL,
+			    "FAILED to derive key via HKDF");
+		printf("%s\n", pv_get_openssl_error());
+		return NULL;
+	}
+
+	return pv_sec_gbytes_new_take(g_steal_pointer(&derived_key), derived_key_len);
+}
+
+EVP_PKEY *pv_generate_ec_key(int nid, GError **error)
+{
+	g_autoptr(EVP_PKEY_CTX) ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL);
+	g_autoptr(EVP_PKEY) ret = NULL;
+
+	g_assert(ctx);
+
+	if (EVP_PKEY_keygen_init(ctx) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_KEYGENERATION,
+			    _("EC key could not be auto-generated"));
+		return NULL;
+	}
+
+	if (EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_KEYGENERATION,
+			    _("EC key could not be auto-generated"));
+		return NULL;
+	}
+
+	if (EVP_PKEY_keygen(ctx, &ret) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_KEYGENERATION,
+			    _("EC key could not be auto-generated"));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+/* Convert a EVP_PKEY to the key format used in the PV header */
+PvEcdhPubKey *pv_evp_pkey_to_ecdh_pub_key(EVP_PKEY *key, GError **error)
+{
+	g_autofree PvEcdhPubKey *ret = g_new0(PvEcdhPubKey, 1);
+	g_autoptr(BIGNUM) pub_x_big = NULL, pub_y_big = NULL;
+	g_autoptr(EC_KEY) ec_key = NULL;
+	const EC_POINT *pub_key;
+	const EC_GROUP *grp;
+
+	pv_wrapped_g_assert(key);
+
+	ec_key = EVP_PKEY_get1_EC_KEY(key);
+	if (!ec_key) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Key has the wrong type"));
+		return NULL;
+	}
+
+	pub_key = EC_KEY_get0_public_key(ec_key);
+	if (!pub_key) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Failed to get public key"));
+		return NULL;
+	}
+
+	grp = EC_KEY_get0_group(ec_key);
+	if (!grp) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Failed to get EC group"));
+		return NULL;
+	}
+
+	pub_x_big = BN_new();
+	if (!pub_x_big)
+		g_abort();
+
+	pub_y_big = BN_new();
+	if (!pub_y_big)
+		g_abort();
+
+	if (EC_POINT_get_affine_coordinates_GFp(grp, pub_key, pub_x_big, pub_y_big, NULL) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Cannot convert key to internal format"));
+		return NULL;
+	}
+
+	if (BN_bn2binpad(pub_x_big, ret->x, sizeof(ret->x)) < 0) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Cannot convert key to internal format"));
+		return NULL;
+	}
+
+	if (BN_bn2binpad(pub_y_big, ret->y, sizeof(ret->y)) < 0) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Cannot convert key to internal format"));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ret);
+}
+
+static GBytes *derive_key(EVP_PKEY *key1, EVP_PKEY *key2, GError **error)
+{
+	g_autoptr(EVP_PKEY_CTX) ctx = NULL;
+	uint8_t *data = NULL;
+	size_t data_size, key_size;
+
+	ctx = EVP_PKEY_CTX_new(key1, NULL);
+	if (!ctx)
+		g_abort();
+
+	if (EVP_PKEY_derive_init(ctx) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Key derivation failed"));
+		return NULL;
+	}
+
+	if (EVP_PKEY_derive_set_peer(ctx, key2) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_INTERNAL,
+			    _("Key derivation failed"));
+		return NULL;
+	}
+
+	/* Determine buffer length */
+	if (EVP_PKEY_derive(ctx, NULL, &key_size) != 1) {
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_DERIVE,
+			    _("Key derivation failed"));
+		return NULL;
+	}
+
+	data_size = key_size;
+	data = OPENSSL_malloc(data_size);
+	if (!data)
+		g_abort();
+	if (EVP_PKEY_derive(ctx, data, &data_size) != 1) {
+		OPENSSL_clear_free(data, data_size);
+		g_set_error(error, PV_CRYPTO_ERROR, PV_CRYPTO_ERROR_DERIVE,
+			    _("Key derivation failed"));
+		return NULL;
+	}
+
+	g_assert(data_size == key_size);
+	return pv_sec_gbytes_new_take(g_steal_pointer(&data), data_size);
+}
+
+GBytes *pv_derive_exchange_key(EVP_PKEY *cust, EVP_PKEY *host, GError **error)
+{
+	const guint8 append[] = { 0x00, 0x00, 0x00, 0x01 };
+	g_autoptr(GBytes) derived_key = NULL, ret = NULL;
+	g_autoptr(GByteArray) der_key_ga = NULL;
+	g_autofree uint8_t *raw = NULL;
+	size_t raw_len;
+
+	pv_wrapped_g_assert(cust);
+	pv_wrapped_g_assert(host);
+
+	derived_key = derive_key(cust, host, error);
+	if (!derived_key)
+		return NULL;
+
+	der_key_ga = g_bytes_unref_to_array(g_steal_pointer(&derived_key));
+	/* ANSI X.9.63-2011: 66 bytes x with leading 7 bits and
+	 * concatenate 32 bit int '1'
+	 */
+	der_key_ga = g_byte_array_append(der_key_ga, append, sizeof(append));
+	/* free GBytesArray and get underlying data */
+	raw_len = der_key_ga->len;
+	raw = g_byte_array_free(g_steal_pointer(&der_key_ga), FALSE);
+
+	ret = pv_sha256_hash(raw, raw_len, error);
+	OPENSSL_cleanse(raw, raw_len);
+	return g_steal_pointer(&ret);
+}
+
+GQuark pv_crypto_error_quark(void)
+{
+	return g_quark_from_static_string("pv-crypto-error-quark");
+}
--- /dev/null
+++ b/libpv/curl.c
@@ -0,0 +1,116 @@
+/*
+ * Libcurl utils
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+/* Must be included before any other header */
+#include "config.h"
+
+#include <curl/curl.h>
+#include <stdio.h>
+
+#include "lib/zt_common.h"
+#include "libpv/curl.h"
+
+struct UserData {
+	GByteArray *buffer;
+	uint max_size;
+};
+
+static size_t write_callback(char *ptr, size_t size, size_t nmemb, void *userdata)
+{
+	g_assert(userdata);
+	struct UserData *data = (struct UserData *)userdata;
+	GByteArray *buffer = data->buffer;
+	uint64_t actual_size;
+	size_t err;
+
+	g_assert(buffer);
+
+	if (!g_uint64_checked_mul(&actual_size, size, nmemb))
+		g_abort();
+
+	/* Signal an error condition by returning a amount that differs
+	 * from the amount passed to the callback. This results in a
+	 * CURLE_WRITE_ERROR.
+	 */
+	err = actual_size + 1;
+
+	if (actual_size > G_MAXUINT)
+		return err;
+
+	data->buffer = g_byte_array_append(buffer, (uint8_t *)ptr, (uint)actual_size);
+	if (data->buffer->len > data->max_size)
+		return err;
+
+	return actual_size;
+}
+
+int pv_curl_init(void)
+{
+	if (curl_global_init(CURL_GLOBAL_ALL) != 0)
+		return -1;
+	return 0;
+}
+
+void pv_curl_cleanup(void)
+{
+	curl_global_cleanup();
+}
+
+GByteArray *curl_download(const char *url, long timeout_ms, uint max_size, GError **err)
+{
+	g_autoptr(GByteArray) ret = NULL;
+	g_autoptr(CURL) handle = NULL;
+	g_autofree char *agent = NULL;
+	struct UserData userdata;
+	CURLcode rc;
+
+	/* set up curl session */
+	handle = curl_easy_init();
+	if (!handle)
+		g_abort();
+
+	/* follow redirection */
+	rc = curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1L);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	rc = curl_easy_setopt(handle, CURLOPT_TIMEOUT_MS, timeout_ms);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	rc = curl_easy_setopt(handle, CURLOPT_NOSIGNAL, 1L);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	agent = g_strdup_printf("%s/%s", GETTEXT_PACKAGE, RELEASE_STRING);
+	rc = curl_easy_setopt(handle, CURLOPT_USERAGENT, agent);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	rc = curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, write_callback);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	ret = g_byte_array_new();
+	userdata.buffer = ret;
+	userdata.max_size = max_size;
+	rc = curl_easy_setopt(handle, CURLOPT_WRITEDATA, (void *)&userdata);
+	if (rc != CURLE_OK)
+		goto curl_err;
+	rc = curl_easy_setopt(handle, CURLOPT_URL, url);
+	if (rc != CURLE_OK)
+		goto curl_err;
+
+	rc = curl_easy_perform(handle);
+	if (rc != CURLE_OK) {
+		g_set_error(err, PV_CURL_ERROR, PV_CURL_ERROR_DOWNLOAD_FAILED,
+			    _("download failed: %s"), curl_easy_strerror(rc));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ret);
+curl_err:
+	g_set_error(err, PV_CURL_ERROR, PV_CURL_ERROR_CURL_INIT_FAILED,
+		    _("cURL initialization failed: %s"), curl_easy_strerror(rc));
+	return NULL;
+}
--- /dev/null
+++ b/libpv/glib-helper.c
@@ -0,0 +1,179 @@
+/*
+ * Glib convenience functions
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+/* Must be included before any other header */
+#include "config.h"
+
+#include <errno.h>
+#include <openssl/crypto.h>
+
+#include "libpv/glib-helper.h"
+
+struct __data {
+	void *data;
+	size_t size;
+	GFreeFunc free_func;
+};
+
+static void __data_clear_and_free(void *p)
+{
+	struct __data *ptr = p;
+
+	if (!ptr)
+		return;
+
+	if (ptr->data) {
+		OPENSSL_cleanse(ptr->data, ptr->size);
+		ptr->free_func(ptr->data);
+	}
+	g_free(ptr);
+}
+
+static GBytes *pv_sec_gbytes_new_take_func(void *data, size_t size, GFreeFunc free_func)
+{
+	struct __data *tmp = g_new(struct __data, 1);
+
+	tmp->data = data;
+	tmp->size = size;
+	tmp->free_func = free_func;
+
+	return g_bytes_new_with_free_func(data, size, __data_clear_and_free, tmp);
+}
+
+GBytes *pv_sec_gbytes_new_take(void *data, size_t size)
+{
+	return pv_sec_gbytes_new_take_func(data, size, g_free);
+}
+
+GBytes *pv_sec_gbytes_new(const void *data, size_t size)
+{
+	g_autofree void *tmp_data = NULL;
+
+	g_return_val_if_fail(data || size != 0, NULL);
+
+	tmp_data = g_malloc(size);
+	memcpy(tmp_data, data, size);
+	return pv_sec_gbytes_new_take(g_steal_pointer(&tmp_data), size);
+}
+
+int pv_file_seek(FILE *file, long offset, int whence, GError **error)
+{
+	int cached_errno;
+	int ret = fseek(file, offset, whence);
+
+	if (ret) {
+		cached_errno = errno;
+		g_set_error(error, PV_GLIB_HELPER_ERROR, PV_GLIB_HELPER_FILE_ERROR,
+			    "Cannot seek: %s", g_strerror(cached_errno));
+	}
+	return ret;
+}
+
+size_t pv_file_write(FILE *file, const void *ptr, size_t size, GError **error)
+{
+	int cached_errno;
+	size_t n = fwrite(ptr, 1, size, file);
+
+	if (n != size) {
+		cached_errno = errno;
+		g_set_error(error, PV_GLIB_HELPER_ERROR, PV_GLIB_HELPER_FILE_ERROR,
+			    "Cannot write: %s", g_strerror(cached_errno));
+	}
+	return n;
+}
+
+long pv_file_close(FILE *file, GError **error)
+{
+	int cached_errno;
+	int ret = fclose(file);
+
+	if (ret) {
+		cached_errno = errno;
+		g_set_error(error, PV_GLIB_HELPER_ERROR, PV_GLIB_HELPER_FILE_ERROR,
+			    "Cannot close: %s", g_strerror(cached_errno));
+	}
+	return ret;
+}
+
+void pv_auto_close_file(FILE *file)
+{
+	if (!file)
+		return;
+
+	(void)pv_file_close(file, NULL);
+}
+
+long pv_file_tell(FILE *file, GError **error)
+{
+	int cached_errno;
+	long n = ftell(file);
+
+	if (n < 0) {
+		cached_errno = errno;
+		g_set_error(error, PV_GLIB_HELPER_ERROR, PV_GLIB_HELPER_FILE_ERROR,
+			    "Cannot tell: %s", g_strerror(cached_errno));
+	}
+	return n;
+}
+
+FILE *pv_file_open(const char *filename, const char *mode, GError **error)
+{
+	FILE *file = fopen(filename, mode);
+	int cached_errno;
+
+	if (!file) {
+		cached_errno = errno;
+		g_set_error(error, PV_GLIB_HELPER_ERROR, PV_GLIB_HELPER_FILE_ERROR,
+			    "Cannot open '%s'. %s", filename, g_strerror(cached_errno));
+		return NULL;
+	}
+	return file;
+}
+
+GBytes *pv_file_get_content_as_g_bytes(const char *filename, GError **error)
+{
+	g_autofree char *data = NULL;
+	size_t data_size;
+
+	if (!g_file_get_contents(filename, &data, &data_size, error))
+		return NULL;
+
+	return g_bytes_new_take(g_steal_pointer(&data), data_size);
+}
+
+GBytes *pv_file_get_content_as_secure_bytes(const char *filename)
+{
+	g_autoptr(FILE) f = fopen(filename, "rb");
+	g_autofree char *data = NULL;
+	ssize_t file_size;
+	size_t data_size;
+
+	if (!f)
+		return NULL;
+
+	fseek(f, 0, SEEK_END);
+	file_size = ftell(f);
+	if (file_size < 0)
+		return NULL;
+	data_size = (size_t)file_size;
+	fseek(f, 0, SEEK_SET);
+	data = g_malloc0(data_size);
+	if (data_size != fread(data, 1, data_size, f))
+		return NULL;
+	return pv_sec_gbytes_new_take(g_steal_pointer(&data), data_size);
+}
+
+void *pv_gbytes_memcpy(void *dst, size_t dst_size, GBytes *src)
+{
+	size_t src_size;
+	const void *src_data = g_bytes_get_data(src, &src_size);
+
+	if (dst_size < src_size)
+		return NULL;
+	return memcpy(dst, src_data, src_size);
+}
--- /dev/null
+++ b/libpv/hash.c
@@ -0,0 +1,147 @@
+/*
+ * Hashing functions.
+
+ * Copyright IBM Corp. 2022
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+/* Must be included before any other header */
+#include "config.h"
+
+#include "libpv/crypto.h"
+#include "libpv/hash.h"
+
+GBytes *pv_sha256_hash(uint8_t *buf, size_t size, GError **error)
+{
+	g_autoptr(EVP_MD_CTX) ctx = NULL;
+
+	ctx = pv_digest_ctx_new(EVP_sha256(), error);
+	if (!ctx)
+		return NULL;
+
+	if (pv_digest_ctx_update_raw(ctx, buf, size, error) != 0)
+		return NULL;
+
+	return pv_digest_ctx_finalize(ctx, error);
+}
+
+EVP_MD_CTX *pv_digest_ctx_new(const EVP_MD *md, GError **error)
+{
+	g_autoptr(EVP_MD_CTX) ctx = EVP_MD_CTX_new();
+
+	if (!ctx) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    _("Hash context generation failed"));
+		return NULL;
+	}
+
+	if (EVP_DigestInit_ex(ctx, md, NULL) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    _("EVP_DigestInit_ex failed"));
+		return NULL;
+	}
+
+	return g_steal_pointer(&ctx);
+}
+
+int pv_digest_ctx_update_raw(EVP_MD_CTX *ctx, const uint8_t *buf, size_t size, GError **error)
+{
+	if (!buf || size == 0)
+		return 0;
+
+	if (EVP_DigestUpdate(ctx, buf, size) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    _("EVP_DigestUpdate failed"));
+		return -1;
+	}
+	return 0;
+}
+
+int pv_digest_ctx_update(EVP_MD_CTX *ctx, GBytes *data, GError **error)
+{
+	const uint8_t *buf;
+	size_t buf_size;
+
+	if (!data)
+		return 0;
+	buf = g_bytes_get_data((GBytes *)data, &buf_size);
+	return pv_digest_ctx_update_raw(ctx, buf, buf_size, error);
+}
+
+GBytes *pv_digest_ctx_finalize(EVP_MD_CTX *ctx, GError **error)
+{
+	int md_size = EVP_MD_size(EVP_MD_CTX_md(ctx));
+	g_autofree uint8_t *digest = NULL;
+	unsigned int digest_size;
+
+	g_assert(md_size > 0);
+
+	digest = g_malloc0((uint)md_size);
+	if (EVP_DigestFinal_ex(ctx, digest, &digest_size) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    _("EVP_DigestFinal_ex failed"));
+		return NULL;
+	}
+
+	g_assert(digest_size == (uint)md_size);
+	return g_bytes_new_take(g_steal_pointer(&digest), digest_size);
+}
+
+HMAC_CTX *pv_hmac_ctx_new(GBytes *key, const EVP_MD *md, GError **error)
+{
+	g_autoptr(HMAC_CTX) ctx = HMAC_CTX_new();
+	const uint8_t *key_data;
+	size_t key_size;
+
+	key_data = g_bytes_get_data(key, &key_size);
+
+	if (HMAC_Init_ex(ctx, key_data, (int)key_size, md, NULL) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    "unable to create HMAC context: %s", pv_get_openssl_error());
+		return NULL;
+	}
+	return g_steal_pointer(&ctx);
+}
+
+int pv_hmac_ctx_update_raw(HMAC_CTX *ctx, const void *buf, size_t size, GError **error)
+{
+	if (!buf || size == 0)
+		return 0;
+
+	if (HMAC_Update(ctx, buf, size) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    "unable to add data to HMAC context: %s", pv_get_openssl_error());
+		return -1;
+	}
+	return 0;
+}
+
+int pv_hmac_ctx_update(HMAC_CTX *ctx, GBytes *data, GError **error)
+{
+	const uint8_t *buf;
+	size_t buf_size;
+
+	if (!data)
+		return 0;
+	buf = g_bytes_get_data((GBytes *)data, &buf_size);
+	return pv_hmac_ctx_update_raw(ctx, buf, buf_size, error);
+}
+
+GBytes *pv_hamc_ctx_finalize(HMAC_CTX *ctx, GError **error)
+{
+	int md_size = EVP_MD_size(HMAC_CTX_get_md(ctx));
+	g_autofree uint8_t *hmac = NULL;
+	unsigned int hmac_size = 0;
+
+	g_assert(md_size > 0);
+
+	hmac = g_malloc0((unsigned int)md_size);
+
+	if (HMAC_Final(ctx, hmac, &hmac_size) != 1) {
+		g_set_error(error, PV_HASH_ERROR, PV_HASH_ERROR_INTERNAL,
+			    "unable to calculate HMAC: %s", pv_get_openssl_error());
+		return NULL;
+	}
+	return g_bytes_new_take(g_steal_pointer(&hmac), hmac_size);
+}
