Start extracting ssl_compute_master()
For now just moving code around, not changing indentation. Calling convention
and signature are going to be adjusted in upcoming commits.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 47f3751..87e3c7b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -658,78 +658,6 @@
}
/*
- * SSLv3:
- * master =
- * MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) +
- * MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) +
- * MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) )
- *
- * TLSv1+:
- * master = PRF( premaster, "master secret", randbytes )[0..47]
- */
- if( handshake->resume == 0 )
- {
- MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
- handshake->pmslen );
-
-#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
- if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED )
- {
- unsigned char session_hash[48];
- size_t hash_len;
-
- MBEDTLS_SSL_DEBUG_MSG( 3, ( "using extended master secret" ) );
-
- ssl->handshake->calc_verify( ssl, session_hash );
-
-#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
- if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
- {
-#if defined(MBEDTLS_SHA512_C)
- if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
- {
- hash_len = 48;
- }
- else
-#endif
- hash_len = 32;
- }
- else
-#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
- hash_len = 36;
-
- MBEDTLS_SSL_DEBUG_BUF( 3, "session hash", session_hash, hash_len );
-
- ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
- "extended master secret",
- session_hash, hash_len,
- session->master, 48 );
- if( ret != 0 )
- {
- MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
- return( ret );
- }
-
- }
- else
-#endif
- ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
- "master secret",
- handshake->randbytes, 64,
- session->master, 48 );
- if( ret != 0 )
- {
- MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
- return( ret );
- }
-
- mbedtls_platform_zeroize( handshake->premaster,
- sizeof(handshake->premaster) );
- }
- else
- MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) );
-
- /*
* Swap the client and server random values.
*/
memcpy( tmp, handshake->randbytes, 64 );
@@ -1165,6 +1093,90 @@
return( 0 );
}
+/*
+ * Compute master secret
+ */
+static int ssl_compute_master( mbedtls_ssl_context *ssl )
+{
+ int ret;
+ mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+ const mbedtls_ssl_ciphersuite_t *ciphersuite_info = handshake->ciphersuite_info;
+ mbedtls_ssl_session *session = ssl->session_negotiate;
+
+ /*
+ * SSLv3:
+ * master =
+ * MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) +
+ * MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) +
+ * MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) )
+ *
+ * TLSv1+:
+ * master = PRF( premaster, "master secret", randbytes )[0..47]
+ */
+ if( handshake->resume == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
+ handshake->pmslen );
+
+#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+ if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED )
+ {
+ unsigned char session_hash[48];
+ size_t hash_len;
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "using extended master secret" ) );
+
+ ssl->handshake->calc_verify( ssl, session_hash );
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+ if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
+ {
+#if defined(MBEDTLS_SHA512_C)
+ if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
+ {
+ hash_len = 48;
+ }
+ else
+#endif
+ hash_len = 32;
+ }
+ else
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+ hash_len = 36;
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "session hash", session_hash, hash_len );
+
+ ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
+ "extended master secret",
+ session_hash, hash_len,
+ session->master, 48 );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
+ return( ret );
+ }
+
+ }
+ else
+#endif
+ ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
+ "master secret",
+ handshake->randbytes, 64,
+ session->master, 48 );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
+ return( ret );
+ }
+
+ mbedtls_platform_zeroize( handshake->premaster,
+ sizeof(handshake->premaster) );
+ }
+ else
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) );
+
+ return( 0 );
+}
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
{
@@ -1181,6 +1193,13 @@
return( ret );
}
+ ret = ssl_compute_master( ssl );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "ssl_compute_master", ret );
+ return( ret );
+ }
+
return( ssl_populate_transform( ssl ) );
}