Index: openssl-0.9.7g/crypto/cryptlib.c
===================================================================
--- openssl-0.9.7g.orig/crypto/cryptlib.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/crypto/cryptlib.c	2014-11-28 18:27:22.794831105 +0100
@@ -512,6 +512,19 @@ void OpenSSLDie(const char *file,int lin
 	abort();
 	}
 
+int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len)
+{
+	size_t i;
+	const unsigned char *a = in_a;
+	const unsigned char *b = in_b;
+	unsigned char x = 0;
+
+	for (i = 0; i < len; i++)
+		x |= a[i] ^ b[i];
+
+	return x;
+}
+
 #ifdef OPENSSL_FIPS
 static int fips_started = 0;
 static int fips_mode = 0;
Index: openssl-0.9.7g/crypto/crypto.h
===================================================================
--- openssl-0.9.7g.orig/crypto/crypto.h	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/crypto/crypto.h	2014-11-28 18:27:22.794831105 +0100
@@ -493,6 +493,13 @@ void *FIPS_rand_check(void);
 
 #endif /* def OPENSSL_FIPS */
 
+/* CRYPTO_memcmp returns zero iff the |len| bytes at |a| and |b| are equal. It
+ * takes an amount of time dependent on |len|, but independent of the contents
+ * of |a| and |b|. Unlike memcmp, it cannot be used to put elements into a
+ * defined order as the return value when a != b is undefined, other than to be
+ * non-zero. */
+int CRYPTO_memcmp(const void *a, const void *b, size_t len);
+
 /* BEGIN ERROR CODES */
 /* The following lines are auto generated by the script mkerr.pl. Any changes
  * made after this point may be overwritten when the script is next run.
Index: openssl-0.9.7g/crypto/rsa/rsa_oaep.c
===================================================================
--- openssl-0.9.7g.orig/crypto/rsa/rsa_oaep.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/crypto/rsa/rsa_oaep.c	2014-11-28 18:27:22.794831105 +0100
@@ -136,7 +136,7 @@ int RSA_padding_check_PKCS1_OAEP(unsigne
 
 	EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL);
 
-	if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
+	if (CRYPTO_memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
 		goto decoding_err;
 	else
 		{
Index: openssl-0.9.7g/ssl/s2_clnt.c
===================================================================
--- openssl-0.9.7g.orig/ssl/s2_clnt.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/s2_clnt.c	2014-11-28 18:27:22.795831117 +0100
@@ -953,7 +953,7 @@ static int get_server_verify(SSL *s)
 		s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* SERVER-VERIFY */
 	p += 1;
 
-	if (memcmp(p,s->s2->challenge,s->s2->challenge_length) != 0)
+	if (CRYPTO_memcmp(p,s->s2->challenge,s->s2->challenge_length) != 0)
 		{
 		ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
 		SSLerr(SSL_F_GET_SERVER_VERIFY,SSL_R_CHALLENGE_IS_DIFFERENT);
Index: openssl-0.9.7g/ssl/s2_pkt.c
===================================================================
--- openssl-0.9.7g.orig/ssl/s2_pkt.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/s2_pkt.c	2014-11-28 18:27:22.795831117 +0100
@@ -267,8 +267,7 @@ static int ssl2_read_internal(SSL *s, vo
 			s->s2->ract_data_length-=mac_size;
 			ssl2_mac(s,mac,0);
 			s->s2->ract_data_length-=s->s2->padding;
-			if (	(memcmp(mac,s->s2->mac_data,
-				(unsigned int)mac_size) != 0) ||
+			if (    (CRYPTO_memcmp(mac,s->s2->mac_data,mac_size) != 0) ||
 				(s->s2->rlength%EVP_CIPHER_CTX_block_size(s->enc_read_ctx) != 0))
 				{
 				SSLerr(SSL_F_SSL2_READ_INTERNAL,SSL_R_BAD_MAC_DECODE);
Index: openssl-0.9.7g/ssl/s3_both.c
===================================================================
--- openssl-0.9.7g.orig/ssl/s3_both.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/s3_both.c	2014-11-28 18:27:22.795831117 +0100
@@ -220,7 +220,7 @@ int ssl3_get_finished(SSL *s, int a, int
 		goto f_err;
 		}
 
-	if (memcmp(p, s->s3->tmp.peer_finish_md, i) != 0)
+	if (CRYPTO_memcmp(p, s->s3->tmp.peer_finish_md, i) != 0)
 		{
 		al=SSL_AD_DECRYPT_ERROR;
 		SSLerr(SSL_F_SSL3_GET_FINISHED,SSL_R_DIGEST_CHECK_FAILED);
Index: openssl-0.9.7g/ssl/s3_pkt.c
===================================================================
--- openssl-0.9.7g.orig/ssl/s3_pkt.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/s3_pkt.c	2014-11-28 18:27:22.795831117 +0100
@@ -235,11 +235,8 @@ static int ssl3_get_record(SSL *s)
 	unsigned char *p;
 	unsigned char md[EVP_MAX_MD_SIZE];
 	short version;
-	unsigned int mac_size;
-	int clear=0;
+	unsigned mac_size;
 	size_t extra;
-	int decryption_failed_or_bad_record_mac = 0;
-	unsigned char *mac = NULL;
 
 	rr= &(s->s3->rrec);
 	sess=s->session;
@@ -347,20 +344,19 @@ again:
 
 	/* decrypt in place in 'rr->input' */
 	rr->data=rr->input;
+	rr->orig_len=rr->length;
 
 	enc_err = s->method->ssl3_enc->enc(s,0);
-	if (enc_err <= 0)
-		{
-		if (enc_err == 0)
-			/* SSLerr() and ssl3_send_alert() have been called */
-			goto err;
-
-		/* Otherwise enc_err == -1, which indicates bad padding
-		 * (rec->length has not been changed in this case).
-		 * To minimize information leaked via timing, we will perform
-		 * the MAC computation anyway. */
-		decryption_failed_or_bad_record_mac = 1;
-		}
+	/* enc_err is:
+	 * 	0: (in non-constant time) if the record is publically invalid.
+	 * 	1: if the padding is valid
+	 * 	-1: if the padding is invalid */
+	if (enc_err == 0)
+	{
+		al=SSL_AD_DECRYPTION_FAILED;
+		SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
+		goto f_err;
+	}
 
 #ifdef TLS_DEBUG
 printf("dec %d\n",rr->length);
@@ -369,51 +365,59 @@ printf("\n");
 #endif
 
 	/* r->length is now the compressed data plus mac */
-	if (	(sess == NULL) ||
-		(s->enc_read_ctx == NULL) ||
-		(s->read_hash == NULL))
-		clear=1;
-
-	if (!clear)
-		{
-		mac_size=EVP_MD_size(s->read_hash);
-
-		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
+	if ((sess != NULL) &&
+			(s->enc_read_ctx != NULL) &&
+			(s->read_hash != NULL))
+		{
+			/* s->read_hash != NULL => mac_size != -1 */
+			unsigned char *mac = NULL;
+			unsigned char mac_tmp[EVP_MAX_MD_SIZE];
+			mac_size=EVP_MD_size(s->read_hash);
+			OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+			/* orig_len is the length of the record before any padding was
+			 * removed. This is public information, as is the MAC in use,
+			 * therefore we can safely process the record in a different
+			 * amount of time if it's too short to possibly contain a MAC.
+			 */
+			if (rr->orig_len < mac_size ||
+					/* CBC records must have a padding length byte too. */
+					(EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+					 rr->orig_len < mac_size+1))
 			{
-#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
-			al=SSL_AD_RECORD_OVERFLOW;
-			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
-			goto f_err;
-#else
-			decryption_failed_or_bad_record_mac = 1;
-#endif			
+				al=SSL_AD_DECODE_ERROR;
+				SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
+				goto f_err;
 			}
-		/* check the MAC for rr->input (it's in mac_size bytes at the tail) */
-		if (rr->length >= mac_size)
+
+			if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 			{
-			rr->length -= mac_size;
-			mac = &rr->data[rr->length];
+				/* We update the length so that the TLS header bytes
+				 * can be constructed correctly but we need to extract
+				 * the MAC in constant time from within the record,
+				 * without leaking the contents of the padding bytes.
+				 */
+				mac = mac_tmp;
+				ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
+				rr->length -= mac_size;
 			}
 		else
 			{
-			/* record (minus padding) is too short to contain a MAC */
-#if 0 /* OK only for stream ciphers */
-			al=SSL_AD_DECODE_ERROR;
-			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
-			goto f_err;
-#else
-			decryption_failed_or_bad_record_mac = 1;
-			rr->length = 0;
-#endif
-			}
-		i=s->method->ssl3_enc->mac(s,md,0);
-		if (mac == NULL || memcmp(md, mac, mac_size) != 0)
-			{
-			decryption_failed_or_bad_record_mac = 1;
+				/* In this case there's no padding, so |rec->orig_len|
+				 * equals |rec->length| and we checked that there's
+				 * enough bytes for |mac_size| above. */
+				rr->length -= mac_size;
+				mac = &rr->data[rr->length];
 			}
+
+		i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
+		if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
+			enc_err = -1;
+		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
+			enc_err = -1;
 		}
 
-	if (decryption_failed_or_bad_record_mac)
+		if (enc_err < 0)
 		{
 		/* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 		 * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
Index: openssl-0.9.7g/ssl/Makefile
===================================================================
--- openssl-0.9.7g.orig/ssl/Makefile	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/Makefile	2014-11-28 18:27:22.796831130 +0100
@@ -27,7 +27,7 @@ LIB=$(TOP)/libssl.a
 SHARED_LIB= libssl$(SHLIB_EXT)
 LIBSRC=	\
 	s2_meth.c   s2_srvr.c s2_clnt.c  s2_lib.c  s2_enc.c s2_pkt.c \
-	s3_meth.c   s3_srvr.c s3_clnt.c  s3_lib.c  s3_enc.c s3_pkt.c s3_both.c \
+	s3_meth.c   s3_srvr.c s3_clnt.c  s3_lib.c  s3_enc.c s3_pkt.c s3_both.c s3_cbc.c \
 	s23_meth.c s23_srvr.c s23_clnt.c s23_lib.c          s23_pkt.c \
 	t1_meth.c   t1_srvr.c t1_clnt.c  t1_lib.c  t1_enc.c \
 	ssl_lib.c ssl_err2.c ssl_cert.c ssl_sess.c \
@@ -36,7 +36,7 @@ LIBSRC=	\
 	bio_ssl.c ssl_err.c kssl.c
 LIBOBJ= \
 	s2_meth.o  s2_srvr.o  s2_clnt.o  s2_lib.o  s2_enc.o s2_pkt.o \
-	s3_meth.o  s3_srvr.o  s3_clnt.o  s3_lib.o  s3_enc.o s3_pkt.o s3_both.o \
+	s3_meth.o  s3_srvr.o  s3_clnt.o  s3_lib.o  s3_enc.o s3_pkt.o s3_both.o s3_cbc.o \
 	s23_meth.o s23_srvr.o s23_clnt.o s23_lib.o          s23_pkt.o \
 	t1_meth.o   t1_srvr.o t1_clnt.o  t1_lib.o  t1_enc.o \
 	ssl_lib.o ssl_err2.o ssl_cert.o ssl_sess.o \
Index: openssl-0.9.7g/ssl/s3_enc.c
===================================================================
--- openssl-0.9.7g.orig/ssl/s3_enc.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/s3_enc.c	2014-11-28 18:27:22.796831130 +0100
@@ -417,12 +417,21 @@ void ssl3_cleanup_key_block(SSL *s)
 	s->s3->tmp.key_block_length=0;
 	}
 
+/* ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
+ *
+ * Returns:
+ * 0: (in non-constant time) if the record is publically invalid (i.e. too
+ * 	short etc).
+ * 1: if the record's padding is valid / the encryption was successful.
+ * -1: if the record's padding is invalid or, if sending, an internal error
+ *  	occured.
+ */
 int ssl3_enc(SSL *s, int send)
 	{
 	SSL3_RECORD *rec;
 	EVP_CIPHER_CTX *ds;
 	unsigned long l;
-	int bs,i;
+	int bs,i,mac_size=0;
 	const EVP_CIPHER *enc;
 
 	if (send)
@@ -470,32 +479,18 @@ int ssl3_enc(SSL *s, int send)
 		if (!send)
 			{
 			if (l == 0 || l%bs != 0)
-				{
-				SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
-				ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
 				return 0;
-				}
 			/* otherwise, rec->length >= bs */
 			}
 		
 		EVP_Cipher(ds,rec->data,rec->input,l);
 
+		rec->orig_len = rec->length;
+
+		if (s->read_hash != NULL)
+			mac_size = EVP_MD_size(s->read_hash);
 		if ((bs != 1) && !send)
-			{
-			i=rec->data[l-1]+1;
-			/* SSL 3.0 bounds the number of padding bytes by the block size;
-			 * padding bytes (except the last one) are arbitrary */
-			if (i > bs)
-				{
-				/* Incorrect padding. SSLerr() and ssl3_alert are done
-				 * by caller: we don't want to reveal whether this is
-				 * a decryption error or a MAC verification failure
-				 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
-				return -1;
-				}
-			/* now i <= bs <= rec->length */
-			rec->length-=i;
-			}
+			return ssl3_cbc_remove_padding(s, rec, bs, mac_size);
 		}
 	return(1);
 	}
@@ -571,7 +566,7 @@ int ssl3_mac(SSL *ssl, unsigned char *md
 	EVP_MD_CTX md_ctx;
 	const EVP_MD *hash;
 	unsigned char *p,rec_char;
-	unsigned int md_size;
+	size_t md_size;
 	int npad,i;
 
 	if (send)
@@ -592,29 +587,69 @@ int ssl3_mac(SSL *ssl, unsigned char *md
 	md_size=EVP_MD_size(hash);
 	npad=(48/md_size)*md_size;
 
-	/* Chop the digest off the end :-) */
-	EVP_MD_CTX_init(&md_ctx);
-
-	EVP_DigestInit_ex(  &md_ctx,hash, NULL);
-	EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
-	EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad);
-	EVP_DigestUpdate(&md_ctx,seq,8);
-	rec_char=rec->type;
-	EVP_DigestUpdate(&md_ctx,&rec_char,1);
-	p=md;
-	s2n(rec->length,p);
-	EVP_DigestUpdate(&md_ctx,md,2);
-	EVP_DigestUpdate(&md_ctx,rec->input,rec->length);
-	EVP_DigestFinal_ex( &md_ctx,md,NULL);
-
-	EVP_DigestInit_ex(  &md_ctx,hash, NULL);
-	EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
-	EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad);
-	EVP_DigestUpdate(&md_ctx,md,md_size);
-	EVP_DigestFinal_ex( &md_ctx,md,&md_size);
 
-	EVP_MD_CTX_cleanup(&md_ctx);
+	if (!send &&
+			EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+			ssl3_cbc_record_digest_supported(hash))
+	{
+		/* This is a CBC-encrypted record. We must avoid leaking any
+		 * timing-side channel information about how many blocks of
+		 * data we are hashing because that gives an attacker a
+		 * timing-oracle. */
+
+		/* npad is, at most, 48 bytes and that's with MD5:
+		 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
+		 *
+		 * With SHA-1 (the largest hash speced for SSLv3) the hash size
+		 * goes up 4, but npad goes down by 8, resulting in a smaller
+		 * total size. */
+		unsigned char header[75];
+		unsigned j = 0;
+		memcpy(header+j, mac_sec, md_size);
+		j += md_size;
+		memcpy(header+j, ssl3_pad_1, npad);
+		j += npad;
+		memcpy(header+j, seq, 8);
+		j += 8;
+		header[j++] = rec->type;
+		header[j++] = rec->length >> 8;
+		header[j++] = rec->length & 0xff;
+
+		ssl3_cbc_digest_record(
+				hash,
+				md, &md_size,
+				header, rec->input,
+				rec->length + md_size, rec->orig_len,
+				mac_sec, md_size,
+				1 /* is SSLv3 */);
+	}
+	else
+	{
+		unsigned int md_size_u;
+		/* Chop the digest off the end :-) */
+		EVP_MD_CTX_init(&md_ctx);
+
+		EVP_DigestInit_ex( &md_ctx,hash, NULL);
+		EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
+		EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad);
+		EVP_DigestUpdate(&md_ctx,seq,8);
+		rec_char=rec->type;
+		EVP_DigestUpdate(&md_ctx,&rec_char,1);
+		p=md;
+		s2n(rec->length,p);
+		EVP_DigestUpdate(&md_ctx,md,2);
+		EVP_DigestUpdate(&md_ctx,rec->input,rec->length);
+		EVP_DigestFinal_ex( &md_ctx,md,NULL);
+
+		EVP_DigestInit_ex( &md_ctx,hash, NULL);
+		EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
+		EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad);
+		EVP_DigestUpdate(&md_ctx,md,md_size);
+		EVP_DigestFinal_ex( &md_ctx,md,&md_size_u);
+		md_size = md_size_u;
 
+		EVP_MD_CTX_cleanup(&md_ctx);
+	}
 	for (i=7; i>=0; i--)
 		{
 		++seq[i];
Index: openssl-0.9.7g/ssl/ssl3.h
===================================================================
--- openssl-0.9.7g.orig/ssl/ssl3.h	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/ssl3.h	2014-11-28 18:27:22.796831130 +0100
@@ -289,6 +289,10 @@ typedef struct ssl3_record_st
 /*rw*/	unsigned char *data;    /* pointer to the record data */
 /*rw*/	unsigned char *input;   /* where the decode bytes are */
 /*r */	unsigned char *comp;    /* only used with decompression - malloc()ed */
+/*rw*/  unsigned int orig_len;  /* How many bytes were available before padding
+				  was removed? This is used to implement the
+				  MAC check in constant time for CBC records.
+				  */
 	} SSL3_RECORD;
 
 typedef struct ssl3_buffer_st
Index: openssl-0.9.7g/ssl/ssl_locl.h
===================================================================
--- openssl-0.9.7g.orig/ssl/ssl_locl.h	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/ssl_locl.h	2014-11-28 18:27:22.796831130 +0100
@@ -128,6 +128,7 @@
 #include <openssl/err.h>
 #include <openssl/ssl.h>
 #include <openssl/symhacks.h>
+#include <hmac/hmac.h>
 
 #ifdef OPENSSL_BUILD_SHLIBSSL
 # undef OPENSSL_EXTERN
@@ -172,6 +173,15 @@
 			 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
 			 *((c)++)=(unsigned char)(((l)    )&0xff))
 
+#define l2n8(l,c)      (*((c)++)=(unsigned char)(((l)>>56)&0xff), \
+		*((c)++)=(unsigned char)(((l)>>48)&0xff), \
+		*((c)++)=(unsigned char)(((l)>>40)&0xff), \
+		*((c)++)=(unsigned char)(((l)>>32)&0xff), \
+		*((c)++)=(unsigned char)(((l)>>24)&0xff), \
+		*((c)++)=(unsigned char)(((l)>>16)&0xff), \
+		*((c)++)=(unsigned char)(((l)>> 8)&0xff), \
+		*((c)++)=(unsigned char)(((l)    )&0xff))
+
 /* NOTE - c is not incremented as per l2c */
 #define l2cn(l1,l2,c,n)	{ \
 			c+=n; \
@@ -470,6 +480,34 @@ OPENSSL_EXTERN SSL_CIPHER ssl3_ciphers[]
 #undef SSL_COMP_get_compression_methods
 #define SSL_COMP_get_compression_methods	SSL_COMP_get_compress_methods
 #endif
+/* s3_cbc.c */
+void ssl3_cbc_copy_mac(unsigned char* out,
+		const SSL3_RECORD *rec,
+		unsigned md_size);
+int ssl3_cbc_remove_padding(const SSL* s,
+		SSL3_RECORD *rec,
+		unsigned block_size,
+		unsigned mac_size);
+int tls1_cbc_remove_padding(const SSL* s,
+		SSL3_RECORD *rec,
+		unsigned block_size,
+		unsigned mac_size);
+char ssl3_cbc_record_digest_supported(const EVP_MD *hash);
+void ssl3_cbc_digest_record(
+		const EVP_MD *hash,
+		unsigned char* md_out,
+		size_t* md_out_size,
+		const unsigned char header[13],
+		const unsigned char *data,
+		size_t data_plus_mac_size,
+		size_t data_plus_mac_plus_padding_size,
+		const unsigned char *mac_secret,
+		unsigned mac_secret_length,
+		char is_sslv3);
+
+void tls_fips_digest_extra(
+		const EVP_CIPHER_CTX *cipher_ctx, const EVP_MD *hash, HMAC_CTX *hctx,
+		const unsigned char *data, size_t data_len, size_t orig_len);
 
 
 SSL_METHOD *ssl_bad_method(int ver);
Index: openssl-0.9.7g/ssl/t1_enc.c
===================================================================
--- openssl-0.9.7g.orig/ssl/t1_enc.c	2014-11-28 18:27:21.022809252 +0100
+++ openssl-0.9.7g/ssl/t1_enc.c	2014-11-28 18:27:22.797831142 +0100
@@ -510,12 +510,21 @@ err:
 	return(0);
 	}
 
+/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
+ *
+ * Returns:
+ * 0: (in non-constant time) if the record is publically invalid (i.e. too
+ * 	short etc).
+ * 1: if the record's padding is valid / the encryption was successful.
+ * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
+ *  	an internal error occured.
+ */
 int tls1_enc(SSL *s, int send)
 	{
 	SSL3_RECORD *rec;
 	EVP_CIPHER_CTX *ds;
 	unsigned long l;
-	int bs,i,ii,j,k,n=0;
+	int bs,i,j,k,n=0, pad=0, ret, mac_size=0;
 	const EVP_CIPHER *enc;
 
 	if (send)
@@ -545,11 +554,11 @@ int tls1_enc(SSL *s, int send)
 	printf("tls1_enc(%d)\n", send);
 #endif    /* KSSL_DEBUG */
 
-	if ((s->session == NULL) || (ds == NULL) ||
-		(enc == NULL))
+	if ((s->session == NULL) || (ds == NULL) || (enc == NULL))
 		{
 		memmove(rec->data,rec->input,rec->length);
 		rec->input=rec->data;
+		ret = 1;
 		}
 	else
 		{
@@ -579,11 +588,11 @@ int tls1_enc(SSL *s, int send)
 		{
                 unsigned long ui;
 		printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
-                        ds,rec->data,rec->input,l);
+				ds,rec->data,rec->input,l);
 		printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
-                        ds->buf_len, ds->cipher->key_len,
-                        DES_KEY_SZ, DES_SCHEDULE_SZ,
-                        ds->cipher->iv_len);
+				ds->buf_len, ds->cipher->key_len,
+				DES_KEY_SZ, DES_SCHEDULE_SZ,
+				ds->cipher->iv_len);
 		printf("\t\tIV: ");
 		for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
 		printf("\n");
@@ -596,11 +605,7 @@ int tls1_enc(SSL *s, int send)
 		if (!send)
 			{
 			if (l == 0 || l%bs != 0)
-				{
-				SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
-				ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
 				return 0;
-				}
 			}
 		
 		EVP_Cipher(ds,rec->data,rec->input,l);
@@ -614,41 +619,15 @@ int tls1_enc(SSL *s, int send)
                 }
 #endif	/* KSSL_DEBUG */
 
+		ret = 1;
+		if (s->read_hash != NULL)
+			mac_size = EVP_MD_size(s->read_hash);
 		if ((bs != 1) && !send)
-			{
-			ii=i=rec->data[l-1]; /* padding_length */
-			i++;
-			if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG)
-				{
-				/* First packet is even in size, so check */
-				if ((memcmp(s->s3->read_sequence,
-					"\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1))
-					s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG;
-				if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
-					i--;
-				}
-			/* TLS 1.0 does not bound the number of padding bytes by the block size.
-			 * All of them must have value 'padding_length'. */
-			if (i > (int)rec->length)
-				{
-				/* Incorrect padding. SSLerr() and ssl3_alert are done
-				 * by caller: we don't want to reveal whether this is
-				 * a decryption error or a MAC verification failure
-				 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
-				return -1;
-				}
-			for (j=(int)(l-i); j<(int)l; j++)
-				{
-				if (rec->data[j] != ii)
-					{
-					/* Incorrect padding */
-					return -1;
-					}
-				}
-			rec->length-=i;
-			}
+			ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
+		if (pad && !send)
+			rec->length -= pad;
 		}
-	return(1);
+	return ret;
 	}
 
 int tls1_cert_verify_mac(SSL *s, EVP_MD_CTX *in_ctx, unsigned char *out)
@@ -696,10 +675,10 @@ int tls1_mac(SSL *ssl, unsigned char *md
 	SSL3_RECORD *rec;
 	unsigned char *mac_sec,*seq;
 	const EVP_MD *hash;
-	unsigned int md_size;
+	size_t md_size;
 	int i;
 	HMAC_CTX hmac;
-	unsigned char buf[5]; 
+	unsigned char header[13];
 
 	if (send)
 		{
@@ -718,21 +697,53 @@ int tls1_mac(SSL *ssl, unsigned char *md
 
 	md_size=EVP_MD_size(hash);
 
-	buf[0]=rec->type;
-	buf[1]=TLS1_VERSION_MAJOR;
-	buf[2]=TLS1_VERSION_MINOR;
-	buf[3]=rec->length>>8;
-	buf[4]=rec->length&0xff;
-
 	/* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
 	HMAC_CTX_init(&hmac);
 	HMAC_Init_ex(&hmac,mac_sec,EVP_MD_size(hash),hash,NULL);
-	HMAC_Update(&hmac,seq,8);
-	HMAC_Update(&hmac,buf,5);
-	HMAC_Update(&hmac,rec->input,rec->length);
-	HMAC_Final(&hmac,md,&md_size);
-	HMAC_CTX_cleanup(&hmac);
+	memcpy(header, seq, 8);
 
+	header[8]=rec->type;
+	header[9]=(unsigned char)(ssl->version>>8);
+	header[10]=(unsigned char)(ssl->version);
+	header[11]=(rec->length)>>8;
+	header[12]=(rec->length)&0xff;
+
+	if (!send &&
+			EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+			ssl3_cbc_record_digest_supported(hash))
+	{
+		/* This is a CBC-encrypted record. We must avoid leaking any
+		 * timing-side channel information about how many blocks of
+		 * data we are hashing because that gives an attacker a
+		 * timing-oracle. */
+		ssl3_cbc_digest_record(
+				hash,
+				md, &md_size,
+				header, rec->input,
+				rec->length + md_size, rec->orig_len,
+				ssl->s3->read_mac_secret,
+				EVP_MD_size(ssl->read_hash),
+				0 /* not SSLv3 */);
+	}
+	else
+	{
+		unsigned mds;
+
+		HMAC_Update(&hmac,header,sizeof(header));
+		HMAC_Update(&hmac,rec->input,rec->length);
+		HMAC_Final(&hmac,md,&mds);
+		md_size = mds;
+#ifdef OPENSSL_FIPS
+		if (!send && FIPS_mode())
+			tls_fips_digest_extra(
+					ssl->enc_read_ctx,
+					hash,
+					&hmac, rec->input,
+					rec->length, rec->orig_len);
+#endif
+	}
+
+	HMAC_CTX_cleanup(&hmac);
 #ifdef TLS_DEBUG
 printf("sec=");
 {unsigned int z; for (z=0; z<md_size; z++) printf("%02X ",mac_sec[z]); printf("\n"); }
Index: openssl-0.9.7g/ssl/s3_cbc.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ openssl-0.9.7g/ssl/s3_cbc.c	2014-11-28 18:28:30.564666964 +0100
@@ -0,0 +1,692 @@
+/* ssl/s3_cbc.c */
+/* ====================================================================
+ * Copyright (c) 2012 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+#include "ssl_locl.h"
+
+#include <openssl/md5.h>
+#include <openssl/sha.h>
+
+/* MAX_HASH_BIT_COUNT_BYTES is the maximum number of bytes in the hash's length
+ * field. (SHA-384/512 have 128-bit length.) */
+#define MAX_HASH_BIT_COUNT_BYTES 16
+
+/* MAX_HASH_BLOCK_SIZE is the maximum hash block size that we'll support.
+ * Currently SHA-384/512 has a 128-byte block size and that's the largest
+ * supported by TLS.) */
+#define MAX_HASH_BLOCK_SIZE 128
+
+/* Some utility functions are needed:
+ *
+ * These macros return the given value with the MSB copied to all the other
+ * bits. They use the fact that arithmetic shift shifts-in the sign bit.
+ * However, this is not ensured by the C standard so you may need to replace
+ * them with something else on odd CPUs. */
+#define DUPLICATE_MSB_TO_ALL(x) ( (unsigned)( (int)(x) >> (sizeof(int)*8-1) ) )
+#define DUPLICATE_MSB_TO_ALL_8(x) ((unsigned char)(DUPLICATE_MSB_TO_ALL(x)))
+
+/* constant_time_ge returns 0xff if a>=b and 0x00 otherwise. */
+static unsigned constant_time_ge(unsigned a, unsigned b)
+	{
+	a -= b;
+	return DUPLICATE_MSB_TO_ALL(~a);
+	}
+
+/* constant_time_eq_8 returns 0xff if a==b and 0x00 otherwise. */
+static unsigned char constant_time_eq_8(unsigned char a, unsigned char b)
+	{
+	unsigned c = a ^ b;
+	c--;
+	return DUPLICATE_MSB_TO_ALL_8(c);
+	}
+
+/* ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
+ * record in |rec| by updating |rec->length| in constant time.
+ *
+ * block_size: the block size of the cipher used to encrypt the record.
+ * returns:
+ *   0: (in non-constant time) if the record is publicly invalid.
+ *   1: if the padding was valid
+ *  -1: otherwise. */
+int ssl3_cbc_remove_padding(const SSL* s,
+			    SSL3_RECORD *rec,
+			    unsigned block_size,
+			    unsigned mac_size)
+	{
+	unsigned padding_length, good;
+	const unsigned overhead = 1 /* padding length byte */ + mac_size;
+
+	/* These lengths are all public so we can test them in non-constant
+	 * time. */
+	if (overhead > rec->length)
+		return 0;
+
+	padding_length = rec->data[rec->length-1];
+	good = constant_time_ge(rec->length, padding_length+overhead);
+	/* SSLv3 requires that the padding is minimal. */
+	good &= constant_time_ge(block_size, padding_length+1);
+	rec->length -= good & (padding_length+1);
+	return (int)((good & 1) | (~good & -1));
+}
+
+/* tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
+ * record in |rec| in constant time and returns 1 if the padding is valid and
+ * -1 otherwise. It also removes any explicit IV from the start of the record
+ * without leaking any timing about whether there was enough space after the
+ * padding was removed.
+ *
+ * block_size: the block size of the cipher used to encrypt the record.
+ * returns:
+ *   0: (in non-constant time) if the record is publicly invalid.
+ *   1: if the padding was valid
+ *  -1: otherwise. */
+int tls1_cbc_remove_padding(const SSL* s,
+			    SSL3_RECORD *rec,
+			    unsigned block_size,
+			    unsigned mac_size)
+	{
+	unsigned padding_length, good, to_check, i;
+	const char has_explicit_iv = 0;
+	const unsigned overhead = 1 /* padding length byte */ +
+				  mac_size +
+				  (has_explicit_iv ? block_size : 0);
+
+	/* These lengths are all public so we can test them in non-constant
+	 * time. */
+	if (overhead > rec->length)
+		return 0;
+
+	padding_length = rec->data[rec->length-1];
+
+	/* NB: if compression is in operation the first packet may not be of
+	 * even length so the padding bug check cannot be performed. This bug
+	 * workaround has been around since SSLeay so hopefully it is either
+	 * fixed now or no buggy implementation supports compression [steve]
+	 */
+	if ( (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) && !s->expand)
+		{
+		/* First packet is even in size, so check */
+		if ((memcmp(s->s3->read_sequence, "\0\0\0\0\0\0\0\0",8) == 0) &&
+		    !(padding_length & 1))
+			{
+			s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG;
+			}
+		if ((s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) &&
+		    padding_length > 0)
+			{
+			padding_length--;
+			}
+		}
+
+	good = constant_time_ge(rec->length, overhead+padding_length);
+	/* The padding consists of a length byte at the end of the record and
+	 * then that many bytes of padding, all with the same value as the
+	 * length byte. Thus, with the length byte included, there are i+1
+	 * bytes of padding.
+	 *
+	 * We can't check just |padding_length+1| bytes because that leaks
+	 * decrypted information. Therefore we always have to check the maximum
+	 * amount of padding possible. (Again, the length of the record is
+	 * public information so we can use it.) */
+	to_check = 255; /* maximum amount of padding. */
+	if (to_check > rec->length-1)
+		to_check = rec->length-1;
+
+	for (i = 0; i < to_check; i++)
+		{
+		unsigned char mask = constant_time_ge(padding_length, i);
+		unsigned char b = rec->data[rec->length-1-i];
+		/* The final |padding_length+1| bytes should all have the value
+		 * |padding_length|. Therefore the XOR should be zero. */
+		good &= ~(mask&(padding_length ^ b));
+		}
+
+	/* If any of the final |padding_length+1| bytes had the wrong value,
+	 * one or more of the lower eight bits of |good| will be cleared. We
+	 * AND the bottom 8 bits together and duplicate the result to all the
+	 * bits. */
+	good &= good >> 4;
+	good &= good >> 2;
+	good &= good >> 1;
+	good <<= sizeof(good)*8-1;
+	good = DUPLICATE_MSB_TO_ALL(good);
+
+	rec->length -= good & (padding_length+1);
+
+	/* We can always safely skip the explicit IV. We check at the beginning
+	 * of this function that the record has at least enough space for the
+	 * IV, MAC and padding length byte. (These can be checked in
+	 * non-constant time because it's all public information.) So, if the
+	 * padding was invalid, then we didn't change |rec->length| and this is
+	 * safe. If the padding was valid then we know that we have at least
+	 * overhead+padding_length bytes of space and so this is still safe
+	 * because overhead accounts for the explicit IV. */
+	if (has_explicit_iv)
+		{
+		rec->data += block_size;
+		rec->input += block_size;
+		rec->length -= block_size;
+		rec->orig_len -= block_size;
+		}
+
+	return (int)((good & 1) | (~good & -1));
+	}
+
+#if defined(_M_AMD64) || defined(__x86_64__)
+/*FIXME: this causes stack corruption!
+#define CBC_MAC_ROTATE_IN_PLACE
+*/
+#endif
+
+/* ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
+ * constant time (independent of the concrete value of rec->length, which may
+ * vary within a 256-byte window).
+ *
+ * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
+ * this function.
+ *
+ * On entry:
+ *   rec->orig_len >= md_size
+ *   md_size <= EVP_MAX_MD_SIZE
+ *
+ * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
+ * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
+ * a single cache-line, then the variable memory accesses don't actually affect
+ * the timing. This has been tested to be true on Intel amd64 chips.
+ */
+void ssl3_cbc_copy_mac(unsigned char* out,
+		       const SSL3_RECORD *rec,
+		       unsigned md_size)
+	{
+#if defined(CBC_MAC_ROTATE_IN_PLACE)
+	unsigned char rotated_mac_buf[EVP_MAX_MD_SIZE*2];
+	unsigned char *rotated_mac;
+#else
+	unsigned char rotated_mac[EVP_MAX_MD_SIZE];
+#endif
+
+	/* mac_end is the index of |rec->data| just after the end of the MAC. */
+	unsigned mac_end = rec->length;
+	unsigned mac_start = mac_end - md_size;
+	/* scan_start contains the number of bytes that we can ignore because
+	 * the MAC's position can only vary by 255 bytes. */
+	unsigned scan_start = 0;
+	unsigned i, j;
+	unsigned div_spoiler;
+	unsigned rotate_offset;
+
+	OPENSSL_assert(rec->orig_len >= md_size);
+	OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
+
+#if defined(CBC_MAC_ROTATE_IN_PLACE)
+	rotated_mac = (unsigned char*) (((intptr_t)(rotated_mac_buf + 64)) & ~63);
+#endif
+
+	/* This information is public so it's safe to branch based on it. */
+	if (rec->orig_len > md_size + 255 + 1)
+		scan_start = rec->orig_len - (md_size + 255 + 1);
+	/* div_spoiler contains a multiple of md_size that is used to cause the
+	 * modulo operation to be constant time. Without this, the time varies
+	 * based on the amount of padding when running on Intel chips at least.
+	 *
+	 * The aim of right-shifting md_size is so that the compiler doesn't
+	 * figure out that it can remove div_spoiler as that would require it
+	 * to prove that md_size is always even, which I hope is beyond it. */
+	div_spoiler = md_size >> 1;
+	div_spoiler <<= (sizeof(div_spoiler)-1)*8;
+	rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
+
+	memset(rotated_mac, 0, md_size);
+	for (i = scan_start; i < rec->orig_len;)
+		{
+		for (j = 0; j < md_size && i < rec->orig_len; i++, j++)
+			{
+			unsigned char mac_started = constant_time_ge(i, mac_start);
+			unsigned char mac_ended = constant_time_ge(i, mac_end);
+			unsigned char b = 0;
+			b = rec->data[i];
+			rotated_mac[j] |= b & mac_started & ~mac_ended;
+			}
+		}
+
+	/* Now rotate the MAC */
+#if defined(CBC_MAC_ROTATE_IN_PLACE)
+	j = 0;
+	for (i = 0; i < md_size; i++)
+		{
+		unsigned char offset = (div_spoiler + rotate_offset + i) % md_size;
+		out[j++] = rotated_mac[offset];
+		}
+#else
+	memset(out, 0, md_size);
+	for (i = 0; i < md_size; i++)
+		{
+		unsigned char offset = (div_spoiler + md_size - rotate_offset + i) % md_size;
+		for (j = 0; j < md_size; j++)
+			out[j] |= rotated_mac[i] & constant_time_eq_8(j, offset);
+		}
+#endif
+	}
+
+/* These functions serialize the state of a hash and thus perform the standard
+ * "final" operation without adding the padding and length that such a function
+ * typically does. */
+static void tls1_md5_final_raw(void* ctx, unsigned char *md_out)
+	{
+	MD5_CTX *md5 = ctx;
+	l2n(md5->A, md_out);
+	l2n(md5->B, md_out);
+	l2n(md5->C, md_out);
+	l2n(md5->D, md_out);
+	}
+
+static void tls1_sha1_final_raw(void* ctx, unsigned char *md_out)
+	{
+	SHA_CTX *sha1 = ctx;
+	l2n(sha1->h0, md_out);
+	l2n(sha1->h1, md_out);
+	l2n(sha1->h2, md_out);
+	l2n(sha1->h3, md_out);
+	l2n(sha1->h4, md_out);
+	}
+
+#define LARGEST_DIGEST_CTX SHA_CTX
+
+/* ssl3_cbc_record_digest_supported returns 1 iff |ctx| uses a hash function
+ * which ssl3_cbc_digest_record supports. */
+char ssl3_cbc_record_digest_supported(const EVP_MD *digest)
+{
+#ifdef OPENSSL_FIPS
+	if (FIPS_mode())
+		return 0;
+#endif
+	switch (EVP_MD_type(digest))
+		{
+		case NID_md5:
+		case NID_sha1:
+			return 1;
+		default:
+			return 0;
+		}
+	}
+
+/* ssl3_cbc_digest_record computes the MAC of a decrypted, padded SSLv3/TLS
+ * record.
+ *
+ *   ctx: the EVP_MD_CTX from which we take the hash function.
+ *     ssl3_cbc_record_digest_supported must return true for this EVP_MD_CTX.
+ *   md_out: the digest output. At most EVP_MAX_MD_SIZE bytes will be written.
+ *   md_out_size: if non-NULL, the number of output bytes is written here.
+ *   header: the 13-byte, TLS record header.
+ *   data: the record data itself, less any preceeding explicit IV.
+ *   data_plus_mac_size: the secret, reported length of the data and MAC
+ *     once the padding has been removed.
+ *   data_plus_mac_plus_padding_size: the public length of the whole
+ *     record, including padding.
+ *   is_sslv3: non-zero if we are to use SSLv3. Otherwise, TLS.
+ *
+ * On entry: by virtue of having been through one of the remove_padding
+ * functions, above, we know that data_plus_mac_size is large enough to contain
+ * a padding byte and MAC. (If the padding was invalid, it might contain the
+ * padding too. ) */
+void ssl3_cbc_digest_record(
+	const EVP_MD *digest,
+	unsigned char* md_out,
+	size_t* md_out_size,
+	const unsigned char header[13],
+	const unsigned char *data,
+	size_t data_plus_mac_size,
+	size_t data_plus_mac_plus_padding_size,
+	const unsigned char *mac_secret,
+	unsigned mac_secret_length,
+	char is_sslv3)
+	{
+	union { double align;
+		unsigned char c[sizeof(LARGEST_DIGEST_CTX)]; } md_state;
+	void (*md_final_raw)(void *ctx, unsigned char *md_out);
+	void (*md_transform)(void *ctx, const unsigned char *block);
+	unsigned md_size, md_block_size = 64;
+	unsigned sslv3_pad_length = 40, header_length, variance_blocks,
+		 len, max_mac_bytes, num_blocks,
+		 num_starting_blocks, k, mac_end_offset, c, index_a, index_b;
+	unsigned int bits;      /* at most 18 bits */
+	unsigned char length_bytes[MAX_HASH_BIT_COUNT_BYTES];
+	/* hmac_pad is the masked HMAC key. */
+	unsigned char hmac_pad[MAX_HASH_BLOCK_SIZE];
+	unsigned char first_block[MAX_HASH_BLOCK_SIZE];
+	unsigned char mac_out[EVP_MAX_MD_SIZE];
+	unsigned i, j, md_out_size_u;
+	EVP_MD_CTX md_ctx;
+	/* mdLengthSize is the number of bytes in the length field that terminates
+	* the hash. */
+	unsigned md_length_size = 8;
+
+	/* This is a, hopefully redundant, check that allows us to forget about
+	 * many possible overflows later in this function. */
+	OPENSSL_assert(data_plus_mac_plus_padding_size < 1024*1024);
+
+	switch (EVP_MD_type(digest))
+		{
+		case NID_md5:
+			MD5_Init((MD5_CTX*)md_state.c);
+			md_final_raw = tls1_md5_final_raw;
+			md_transform = (void(*)(void *ctx, const unsigned char *block)) MD5_Transform;
+			md_size = 16;
+			sslv3_pad_length = 48;
+			break;
+		case NID_sha1:
+			SHA1_Init((SHA_CTX*)md_state.c);
+			md_final_raw = tls1_sha1_final_raw;
+			md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA1_Transform;
+			md_size = 20;
+			break;
+		default:
+			/* ssl3_cbc_record_digest_supported should have been
+			 * called first to check that the hash function is
+			 * supported. */
+			OPENSSL_assert(0);
+			if (md_out_size)
+				*md_out_size = -1;
+			return;
+		}
+
+	OPENSSL_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES);
+	OPENSSL_assert(md_block_size <= MAX_HASH_BLOCK_SIZE);
+	OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
+
+	header_length = 13;
+	if (is_sslv3)
+		{
+		header_length =
+			mac_secret_length +
+			sslv3_pad_length +
+			8 /* sequence number */ +
+			1 /* record type */ +
+			2 /* record length */;
+		}
+
+	/* variance_blocks is the number of blocks of the hash that we have to
+	 * calculate in constant time because they could be altered by the
+	 * padding value.
+	 *
+	 * In SSLv3, the padding must be minimal so the end of the plaintext
+	 * varies by, at most, 15+20 = 35 bytes. (We conservatively assume that
+	 * the MAC size varies from 0..20 bytes.) In case the 9 bytes of hash
+	 * termination (0x80 + 64-bit length) don't fit in the final block, we
+	 * say that the final two blocks can vary based on the padding.
+	 *
+	 * TLSv1 has MACs up to 48 bytes long (SHA-384) and the padding is not
+	 * required to be minimal. Therefore we say that the final six blocks
+	 * can vary based on the padding.
+	 *
+	 * Later in the function, if the message is short and there obviously
+	 * cannot be this many blocks then variance_blocks can be reduced. */
+	variance_blocks = is_sslv3 ? 2 : 6;
+	/* From now on we're dealing with the MAC, which conceptually has 13
+	 * bytes of `header' before the start of the data (TLS) or 71/75 bytes
+	 * (SSLv3) */
+	len = data_plus_mac_plus_padding_size + header_length;
+	/* max_mac_bytes contains the maximum bytes of bytes in the MAC, including
+	* |header|, assuming that there's no padding. */
+	max_mac_bytes = len - md_size - 1;
+	/* num_blocks is the maximum number of hash blocks. */
+	num_blocks = (max_mac_bytes + 1 + md_length_size + md_block_size - 1) / md_block_size;
+	/* In order to calculate the MAC in constant time we have to handle
+	 * the final blocks specially because the padding value could cause the
+	 * end to appear somewhere in the final |variance_blocks| blocks and we
+	 * can't leak where. However, |num_starting_blocks| worth of data can
+	 * be hashed right away because no padding value can affect whether
+	 * they are plaintext. */
+	num_starting_blocks = 0;
+	/* k is the starting byte offset into the conceptual header||data where
+	 * we start processing. */
+	k = 0;
+	/* mac_end_offset is the index just past the end of the data to be
+	 * MACed. */
+	mac_end_offset = data_plus_mac_size + header_length - md_size;
+	/* c is the index of the 0x80 byte in the final hash block that
+	 * contains application data. */
+	c = mac_end_offset % md_block_size;
+	/* index_a is the hash block number that contains the 0x80 terminating
+	 * value. */
+	index_a = mac_end_offset / md_block_size;
+	/* index_b is the hash block number that contains the 64-bit hash
+	 * length, in bits. */
+	index_b = (mac_end_offset + md_length_size) / md_block_size;
+	/* bits is the hash-length in bits. It includes the additional hash
+	 * block for the masked HMAC key, or whole of |header| in the case of
+	 * SSLv3. */
+
+	/* For SSLv3, if we're going to have any starting blocks then we need
+	 * at least two because the header is larger than a single block. */
+	if (num_blocks > variance_blocks + (is_sslv3 ? 1 : 0))
+		{
+		num_starting_blocks = num_blocks - variance_blocks;
+		k = md_block_size*num_starting_blocks;
+		}
+
+	bits = 8*mac_end_offset;
+	if (!is_sslv3)
+		{
+		/* Compute the initial HMAC block. For SSLv3, the padding and
+		 * secret bytes are included in |header| because they take more
+		 * than a single block. */
+		bits += 8*md_block_size;
+		memset(hmac_pad, 0, md_block_size);
+		OPENSSL_assert(mac_secret_length <= sizeof(hmac_pad));
+		memcpy(hmac_pad, mac_secret, mac_secret_length);
+		for (i = 0; i < md_block_size; i++)
+			hmac_pad[i] ^= 0x36;
+
+		md_transform(md_state.c, hmac_pad);
+		}
+
+	memset(length_bytes,0,md_length_size-4);
+	length_bytes[md_length_size-4] = (unsigned char)(bits>>24);
+	length_bytes[md_length_size-3] = (unsigned char)(bits>>16);
+	length_bytes[md_length_size-2] = (unsigned char)(bits>>8);
+	length_bytes[md_length_size-1] = (unsigned char)bits;
+
+	if (k > 0)
+		{
+		if (is_sslv3)
+			{
+			/* The SSLv3 header is larger than a single block.
+			 * overhang is the number of bytes beyond a single
+			 * block that the header consumes: either 7 bytes
+			 * (SHA1) or 11 bytes (MD5). */
+			unsigned overhang = header_length-md_block_size;
+			md_transform(md_state.c, header);
+			memcpy(first_block, header + md_block_size, overhang);
+			memcpy(first_block + overhang, data, md_block_size-overhang);
+			md_transform(md_state.c, first_block);
+			for (i = 1; i < k/md_block_size - 1; i++)
+				md_transform(md_state.c, data + md_block_size*i - overhang);
+			}
+		else
+			{
+			/* k is a multiple of md_block_size. */
+			memcpy(first_block, header, 13);
+			memcpy(first_block+13, data, md_block_size-13);
+			md_transform(md_state.c, first_block);
+			for (i = 1; i < k/md_block_size; i++)
+				md_transform(md_state.c, data + md_block_size*i - 13);
+			}
+		}
+
+	memset(mac_out, 0, sizeof(mac_out));
+
+	/* We now process the final hash blocks. For each block, we construct
+	 * it in constant time. If the |i==index_a| then we'll include the 0x80
+	 * bytes and zero pad etc. For each block we selectively copy it, in
+	 * constant time, to |mac_out|. */
+	for (i = num_starting_blocks; i <= num_starting_blocks+variance_blocks; i++)
+		{
+		unsigned char block[MAX_HASH_BLOCK_SIZE];
+		unsigned char is_block_a = constant_time_eq_8(i, index_a);
+		unsigned char is_block_b = constant_time_eq_8(i, index_b);
+		for (j = 0; j < md_block_size; j++)
+			{
+			unsigned char b = 0, is_past_c, is_past_cp1;
+			if (k < header_length)
+				b = header[k];
+			else if (k < data_plus_mac_plus_padding_size + header_length)
+				b = data[k-header_length];
+			k++;
+
+			is_past_c = is_block_a & constant_time_ge(j, c);
+			is_past_cp1 = is_block_a & constant_time_ge(j, c+1);
+			/* If this is the block containing the end of the
+			 * application data, and we are at the offset for the
+			 * 0x80 value, then overwrite b with 0x80. */
+			b = (b&~is_past_c) | (0x80&is_past_c);
+			/* If this the the block containing the end of the
+			 * application data and we're past the 0x80 value then
+			 * just write zero. */
+			b = b&~is_past_cp1;
+			/* If this is index_b (the final block), but not
+			 * index_a (the end of the data), then the 64-bit
+			 * length didn't fit into index_a and we're having to
+			 * add an extra block of zeros. */
+			b &= ~is_block_b | is_block_a;
+
+			/* The final bytes of one of the blocks contains the
+			 * length. */
+			if (j >= md_block_size - md_length_size)
+				{
+				/* If this is index_b, write a length byte. */
+				b = (b&~is_block_b) | (is_block_b&length_bytes[j-(md_block_size-md_length_size)]);
+				}
+			block[j] = b;
+			}
+
+		md_transform(md_state.c, block);
+		md_final_raw(md_state.c, block);
+		/* If this is index_b, copy the hash value to |mac_out|. */
+		for (j = 0; j < md_size; j++)
+			mac_out[j] |= block[j]&is_block_b;
+		}
+
+	EVP_MD_CTX_init(&md_ctx);
+	EVP_DigestInit_ex(&md_ctx, digest, NULL /* engine */);
+	if (is_sslv3)
+		{
+		/* We repurpose |hmac_pad| to contain the SSLv3 pad2 block. */
+		memset(hmac_pad, 0x5c, sslv3_pad_length);
+
+		EVP_DigestUpdate(&md_ctx, mac_secret, mac_secret_length);
+		EVP_DigestUpdate(&md_ctx, hmac_pad, sslv3_pad_length);
+		EVP_DigestUpdate(&md_ctx, mac_out, md_size);
+		}
+	else
+		{
+		/* Complete the HMAC in the standard manner. */
+		for (i = 0; i < md_block_size; i++)
+			hmac_pad[i] ^= 0x6a;
+
+		EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size);
+		EVP_DigestUpdate(&md_ctx, mac_out, md_size);
+		}
+	EVP_DigestFinal(&md_ctx, md_out, &md_out_size_u);
+	if (md_out_size)
+		*md_out_size = md_out_size_u;
+	EVP_MD_CTX_cleanup(&md_ctx);
+	}
+
+#ifdef OPENSSL_FIPS
+
+/* Due to the need to use EVP in FIPS mode we can't reimplement digests but
+ * we can ensure the number of blocks processed is equal for all cases
+ * by digesting additional data.
+ */
+
+void tls_fips_digest_extra(
+		const EVP_CIPHER_CTX *cipher_ctx, const EVP_MD *hash, HMAC_CTX *hctx,
+		const unsigned char *data, size_t data_len, size_t orig_len)
+{
+	size_t block_size, digest_pad, blocks_data, blocks_orig;
+	if (EVP_CIPHER_CTX_mode(cipher_ctx) != EVP_CIPH_CBC_MODE)
+		return;
+	block_size = EVP_MD_block_size(hash);
+	/* We are in FIPS mode if we get this far so we know we have only SHA*
+	 * digests and TLS to deal with.
+	 * Minimum digest padding length is 17 for SHA384/SHA512 and 9
+	 * otherwise.
+	 * Additional header is 13 bytes. To get the number of digest blocks
+	 * processed round up the amount of data plus padding to the nearest
+	 * block length. Block length is 128 for SHA384/SHA512 and 64 otherwise.
+	 * So we have:
+	 * blocks = (payload_len + digest_pad + 13 + block_size - 1)/block_size
+	 * equivalently:
+	 * blocks = (payload_len + digest_pad + 12)/block_size + 1
+	 * HMAC adds a constant overhead.
+	 * We're ultimately only interested in differences so this becomes
+	 * blocks = (payload_len + 29)/128
+	 * for SHA384/SHA512 and
+	 * blocks = (payload_len + 21)/64
+	 * otherwise.
+	 */
+	digest_pad = block_size == 64 ? 21 : 29;
+	blocks_orig = (orig_len + digest_pad)/block_size;
+	blocks_data = (data_len + digest_pad)/block_size;
+	/* MAC enough blocks to make up the difference between the original
+	 * and actual lengths plus one extra block to ensure this is never a
+	 * no op. The "data" pointer should always have enough space to
+	 * perform this operation as it is large enough for a maximum
+	 * length TLS buffer.
+	 */
+	HMAC_Update(hctx, data,
+			(blocks_orig - blocks_data + 1) * block_size);
+}
+#endif
