Merge fix for IE Certificate Compatibility
diff --git a/library/error.c b/library/error.c
index 71d4faa..dd2db0c 100644
--- a/library/error.c
+++ b/library/error.c
@@ -435,6 +435,10 @@
             mbedtls_snprintf( buf, buflen, "SSL - The client initiated a reconnect from the same port" );
         if( use_ret == -(MBEDTLS_ERR_SSL_UNEXPECTED_RECORD) )
             mbedtls_snprintf( buf, buflen, "SSL - Record header looks valid but is not expected" );
+        if( use_ret == -(MBEDTLS_ERR_SSL_NON_FATAL) )
+            mbedtls_snprintf( buf, buflen, "SSL - The alert message received indicates a non-fatal error" );
+        if( use_ret == -(MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH) )
+            mbedtls_snprintf( buf, buflen, "SSL - Couldn't set the hash for verifying CertificateVerify" );
 #endif /* MBEDTLS_SSL_TLS_C */
 
 #if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 39fcd6c..223823b 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2639,6 +2639,15 @@
     {
         size_t sig_alg_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] <<  8 )
                              | ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n]       ) );
+#if defined(MBEDTLS_DEBUG_C)
+        unsigned char* sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
+        size_t i;
+
+        for( i = 0; i < sig_alg_len; i += 2 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d,%d", sig_alg[i], sig_alg[i + 1]  ) );
+        }
+#endif
 
         n += 2 + sig_alg_len;
 
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 4b0f997..fc0d2d7 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -1043,7 +1043,6 @@
 
     ssl->session_negotiate->ciphersuite = ciphersuites[i];
     ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
-    mbedtls_ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
 
     /*
      * SSLv2 Client Hello relevant renegotiation security checks
@@ -1840,7 +1839,6 @@
 
     ssl->session_negotiate->ciphersuite = ciphersuites[i];
     ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
-    mbedtls_ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
 
     ssl->state++;
 
@@ -2556,29 +2554,27 @@
      */
     if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
     {
-        /*
-         * Only use current running hash algorithm that is already required
-         * for requested ciphersuite.
-         */
-        ssl->handshake->verify_sig_alg = MBEDTLS_SSL_HASH_SHA256;
-
-        if( ssl->transform_negotiate->ciphersuite_info->mac ==
-            MBEDTLS_MD_SHA384 )
-        {
-            ssl->handshake->verify_sig_alg = MBEDTLS_SSL_HASH_SHA384;
-        }
+        const int *cur;
 
         /*
          * Supported signature algorithms
          */
+        for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ )
+        {
+            unsigned char hash = mbedtls_ssl_hash_from_md_alg( *cur );
+
+            if( MBEDTLS_SSL_HASH_NONE == hash || mbedtls_ssl_set_calc_verify_md( ssl, hash ) )
+                continue;
+
 #if defined(MBEDTLS_RSA_C)
-        p[2 + sa_len++] = ssl->handshake->verify_sig_alg;
-        p[2 + sa_len++] = MBEDTLS_SSL_SIG_RSA;
+            p[2 + sa_len++] = hash;
+            p[2 + sa_len++] = MBEDTLS_SSL_SIG_RSA;
 #endif
 #if defined(MBEDTLS_ECDSA_C)
-        p[2 + sa_len++] = ssl->handshake->verify_sig_alg;
-        p[2 + sa_len++] = MBEDTLS_SSL_SIG_ECDSA;
+            p[2 + sa_len++] = hash;
+            p[2 + sa_len++] = MBEDTLS_SSL_SIG_ECDSA;
 #endif
+        }
 
         p[0] = (unsigned char)( sa_len >> 8 );
         p[1] = (unsigned char)( sa_len      );
@@ -3581,17 +3577,28 @@
         return( 0 );
     }
 
-    /* Needs to be done before read_record() to exclude current message */
-    ssl->handshake->calc_verify( ssl, hash );
+    /* Read the message without adding it to the checksum */
+    do {
 
-    if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
+        if( ( ret = mbedtls_ssl_read_record_layer( ssl ) ) != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record_layer" ), ret );
+            return( ret );
+        }
+
+        ret = mbedtls_ssl_handle_message_type( ssl );
+
+    } while( MBEDTLS_ERR_SSL_NON_FATAL == ret );
+
+    if( 0 != ret )
     {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
+        MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret );
         return( ret );
     }
 
     ssl->state++;
 
+    /* Process the message contents */
     if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
         ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE_VERIFY )
     {
@@ -3638,14 +3645,19 @@
         /*
          * Hash
          */
-        if( ssl->in_msg[i] != ssl->handshake->verify_sig_alg )
+        md_alg = mbedtls_ssl_md_alg_from_hash( ssl->in_msg[i] );
+
+        if( md_alg == MBEDTLS_MD_NONE || mbedtls_ssl_set_calc_verify_md( ssl, ssl->in_msg[i] ) )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
                                 " for verify message" ) );
             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
         }
 
-        md_alg = mbedtls_ssl_md_alg_from_hash( ssl->handshake->verify_sig_alg );
+#if !defined(MBEDTLS_MD_SHA1)
+        if( MBEDTLS_MD_SHA1 == md_alg )
+            hash_start += 16;
+#endif
 
         /* Info from md_alg will be used instead */
         hashlen = 0;
@@ -3696,6 +3708,9 @@
         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
     }
 
+    /* Calculate hash and verify signature */
+    ssl->handshake->calc_verify( ssl, hash );
+
     if( ( ret = mbedtls_pk_verify( &ssl->session_negotiate->peer_cert->pk,
                            md_alg, hash_start, hashlen,
                            ssl->in_msg + i, sig_len ) ) != 0 )
@@ -3704,6 +3719,8 @@
         return( ret );
     }
 
+    mbedtls_ssl_update_handshake_status( ssl );
+
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
 
     return( ret );
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index df7b734..5272318 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3082,7 +3082,7 @@
 }
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
-static int ssl_prepare_handshake_record( mbedtls_ssl_context *ssl )
+int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl )
 {
     if( ssl->in_msglen < mbedtls_ssl_hs_hdr_len( ssl ) )
     {
@@ -3164,6 +3164,12 @@
         return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
     }
 
+    return( 0 );
+}
+
+void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl )
+{
+
     if( ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER &&
         ssl->handshake != NULL )
     {
@@ -3178,8 +3184,6 @@
         ssl->handshake->in_msg_seq++;
     }
 #endif
-
-    return( 0 );
 }
 
 /*
@@ -3735,6 +3739,38 @@
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> read record" ) );
 
+    do {
+
+        if( ( ret = mbedtls_ssl_read_record_layer( ssl ) ) != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record_layer" ), ret );
+            return( ret );
+        }
+
+        ret = mbedtls_ssl_handle_message_type( ssl );
+
+    } while( MBEDTLS_ERR_SSL_NON_FATAL == ret );
+
+    if( 0 != ret )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret );
+        return( ret );
+    }
+
+    if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
+    {
+        mbedtls_ssl_update_handshake_status( ssl );
+    }
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) );
+
+    return( 0 );
+}
+
+int mbedtls_ssl_read_record_layer( mbedtls_ssl_context *ssl )
+{
+    int ret;
+
     if( ssl->in_hslen != 0 && ssl->in_hslen < ssl->in_msglen )
     {
         /*
@@ -3748,9 +3784,6 @@
         MBEDTLS_SSL_DEBUG_BUF( 4, "remaining content in record",
                            ssl->in_msg, ssl->in_msglen );
 
-        if( ( ret = ssl_prepare_handshake_record( ssl ) ) != 0 )
-            return( ret );
-
         return( 0 );
     }
 
@@ -3759,7 +3792,10 @@
     /*
      * Read the record header and parse it
      */
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
 read_record_header:
+#endif
+
     if( ( ret = mbedtls_ssl_fetch_input( ssl, mbedtls_ssl_hdr_len( ssl ) ) ) != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
@@ -3913,13 +3949,22 @@
     }
 #endif
 
+    return( 0 );
+}
+
+int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl )
+{
+    int ret;
+
     /*
      * Handle particular types of records
      */
     if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE )
     {
-        if( ( ret = ssl_prepare_handshake_record( ssl ) ) != 0 )
+        if( ( ret = mbedtls_ssl_prepare_handshake_record( ssl ) ) != 0 )
+        {
             return( ret );
+        }
     }
 
     if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT )
@@ -3967,11 +4012,9 @@
 #endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */
 
         /* Silently ignore: fetch new message */
-        goto read_record_header;
+        return MBEDTLS_ERR_SSL_NON_FATAL;
     }
 
-    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= read record" ) );
-
     return( 0 );
 }
 
@@ -7602,4 +7645,47 @@
     }
 }
 
+int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md )
+{
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+    if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
+        return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
+
+    switch( md )
+    {
+#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1)
+#if defined(MBEDTLS_MD5_C)
+        case MBEDTLS_SSL_HASH_MD5:
+            ssl->handshake->calc_verify = ssl_calc_verify_tls;
+            break;
+#endif
+#if defined(MBEDTLS_SHA1_C)
+        case MBEDTLS_SSL_HASH_SHA1:
+            ssl->handshake->calc_verify = ssl_calc_verify_tls;
+            break;
+#endif
+#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 */
+#if defined(MBEDTLS_SHA512_C)
+        case MBEDTLS_SSL_HASH_SHA384:
+            ssl->handshake->calc_verify = ssl_calc_verify_tls_sha384;
+            break;
+#endif
+#if defined(MBEDTLS_SHA256_C)
+        case MBEDTLS_SSL_HASH_SHA256:
+            ssl->handshake->calc_verify = ssl_calc_verify_tls_sha256;
+            break;
+#endif
+        default:
+            return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
+    }
+
+    return 0;
+#else /* !MBEDTLS_SSL_PROTO_TLS1_2 */
+    (void) ssl;
+    (void) md;
+
+    return MBEDTLS_ERR_SSL_INVALID_VERIFY_HASH;
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+}
+
 #endif /* MBEDTLS_SSL_TLS_C */