Add read_server_hello
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 633bb8d..054a45d 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -29,11 +29,14 @@
#include "mbedtls/debug.h"
#include "mbedtls/error.h"
+#include "mbedtls/platform.h"
#include "ssl_misc.h"
#include "ecdh_misc.h"
+#include "ssl_tls13_keys.h"
#define CLIENT_HELLO_RANDOM_LEN 32
+#define SERVER_HELLO_RANDOM_LEN 32
/* Write extensions */
@@ -92,6 +95,36 @@
return( 0 );
}
+static int ssl_tls1_3_parse_supported_versions_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ /* TODO: Implement full version and remove force version set in
+ * ssl_tls_parse_server_hello.
+ *
+ * From page 40,RFC 8446
+ * If supported_versions extension is present, clients MUST ignore the
+ * ServerHello.legacy_version value and MUST use only the
+ * "supported_versions" extension to determine the selected version. If
+ * the "supported_versions" extension in the ServerHello contains a
+ * version not offered by the client or contains a version prior to
+ * TLS 1.3, the client MUST abort the handshake with an
+ * "illegal_parameter" alert.
+ */
+
+ ((void) ssl);
+
+ if( len != 2 ||
+ buf[0] != MBEDTLS_SSL_MAJOR_VERSION_3 ||
+ buf[1] != MBEDTLS_SSL_MINOR_VERSION_4 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "unexpected version" ) );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ }
+
+ return( 0 );
+}
+
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
/*
@@ -452,6 +485,125 @@
return( ret );
}
+#if defined(MBEDTLS_ECDH_C)
+
+/* TODO: Code for MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED missing */
+static int ssl_tls1_3_check_ecdh_params( const mbedtls_ssl_context *ssl )
+{
+ const mbedtls_ecp_curve_info *curve_info;
+ mbedtls_ecp_group_id grp_id;
+#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
+ grp_id = ssl->handshake->ecdh_ctx.grp.id;
+#else
+ grp_id = ssl->handshake->ecdh_ctx.grp_id;
+#endif
+
+ curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
+ if( curve_info == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
+
+#if defined(MBEDTLS_ECP_C)
+ if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
+#else
+ if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
+ ssl->handshake->ecdh_ctx.grp.nbits > 521 )
+#endif
+ return( -1 );
+
+ MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
+ MBEDTLS_DEBUG_ECDH_QP );
+
+ return( 0 );
+}
+
+/* The ssl_tls1_3_parse_key_share_ext() function is used
+ * by the client to parse a KeyShare extension in
+ * a ServerHello message.
+ *
+ * The server only provides a single KeyShareEntry.
+ */
+static int ssl_tls1_3_read_public_ecdhe_share( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ ret = mbedtls_ecdh_tls1_3_read_public( &ssl->handshake->ecdh_ctx,
+ buf, len );
+ if( ret != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_tls13_read_public" ), ret );
+ return( ret );
+ }
+
+ if( ssl_tls1_3_check_ecdh_params( ssl ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "ssl_tls1_3_check_ecdh_params() failed!" ) );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ }
+
+ return( 0 );
+}
+#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
+
+/*
+ * Parse key_share extension in Server Hello
+ * struct {
+ * KeyShareEntry server_share;
+ * } KeyShareServerHello;
+ * struct {
+ * NamedGroup group;
+ * opaque key_exchange<1..2^16-1>;
+ * } KeyShareEntry;
+ */
+static int ssl_tls1_3_parse_key_share_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ const unsigned char *end )
+{
+ int ret = 0;
+ const unsigned char *p = buf;
+ uint16_t server_share_group, offered_group;
+
+ /* server_share_group (2 bytes) */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2);
+ server_share_group = MBEDTLS_GET_UINT16_BE( p, 0 );
+ p += 2;
+
+ /* Check that chosen group matches the one we offered. */
+ offered_group = ssl->handshake->offered_group_id;
+ if( offered_group != server_share_group )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1,
+ ( "Invalid server key share, our group %u, their group %u",
+ (unsigned) offered_group, (unsigned) server_share_group ) );
+ return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ }
+
+#if defined(MBEDTLS_ECDH_C)
+ if( mbedtls_ssl_tls13_named_group_is_ecdhe( server_share_group ) )
+ {
+ /* Complete ECDHE key agreement */
+ ret = ssl_tls1_3_read_public_ecdhe_share( ssl, p, end - p );
+ if( ret != 0 )
+ return( ret );
+ }
+#endif /* MBEDTLS_ECDH_C */
+ else if( 0 /* other KEMs? */ )
+ {
+ /* Do something */
+ }
+ else
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+
+ ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
+ return( ret );
+}
+
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
/* Write cipher_suites
@@ -738,13 +890,439 @@
}
/*
+ * Functions for parsing and processing ServerHello
+ */
+static int ssl_server_hello_is_hrr( unsigned const char *buf )
+{
+ const unsigned char magic_hrr_string[32] =
+ { 0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11,
+ 0xBE, 0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91,
+ 0xC2, 0xA2, 0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E,
+ 0x07, 0x9E, 0x09, 0xE2, 0xC8, 0xA8, 0x33 ,0x9C };
+
+ /* Check whether this message is a HelloRetryRequest ( HRR ) message.
+ *
+ * ServerHello and HRR are only distinguished by Random set to the
+ * special value of the SHA-256 of "HelloRetryRequest".
+ *
+ * struct {
+ * ProtocolVersion legacy_version = 0x0303;
+ * Random random;
+ * opaque legacy_session_id_echo<0..32>;
+ * CipherSuite cipher_suite;
+ * uint8 legacy_compression_method = 0;
+ * Extension extensions<6..2 ^ 16 - 1>;
+ * } ServerHello;
+ *
+ */
+ if( memcmp( buf + 2, magic_hrr_string,
+ sizeof( magic_hrr_string ) ) == 0 )
+ {
+ return( 1 );
+ }
+
+ return( 0 );
+}
+
+/* Fetch and preprocess
+ * Returns a negative value on failure, and otherwise
+ * - SSL_SERVER_HELLO_COORDINATE_HELLO or
+ * - SSL_SERVER_HELLO_COORDINATE_HRR
+ * to indicate which message is expected and to be parsed next. */
+#define SSL_SERVER_HELLO_COORDINATE_HELLO 0
+#define SSL_SERVER_HELLO_COORDINATE_HRR 1
+static int ssl_server_hello_coordinate( mbedtls_ssl_context *ssl,
+ unsigned char **buf,
+ size_t *buf_len )
+{
+ int ret;
+
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_read_record( ssl, 0 ) );
+
+ /* TBD: If we do an HRR, keep track of the number
+ * of ClientHello's we sent, and fail if it
+ * exceeds the configured threshold. */
+
+ if( ( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ) ||
+ ( ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "unexpected message" ) );
+
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+ MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+ return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+ }
+
+ *buf = ssl->in_msg + 4;
+ *buf_len = ssl->in_hslen - 4;
+
+ if( ssl_server_hello_is_hrr( ssl->in_msg + 4 ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "received HelloRetryRequest message" ) );
+ ret = SSL_SERVER_HELLO_COORDINATE_HRR;
+ }
+ else
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "received ServerHello message" ) );
+ ret = SSL_SERVER_HELLO_COORDINATE_HELLO;
+ }
+
+cleanup:
+
+ return( ret );
+}
+
+static int ssl_tls1_3_check_server_hello_session_id( mbedtls_ssl_context *ssl,
+ const unsigned char **buf,
+ const unsigned char *end )
+{
+ const unsigned char *p = *buf;
+ size_t recv_id_len;
+
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 );
+ recv_id_len = *p++ ;
+
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, recv_id_len );
+
+ /* legacy_session_id_echo */
+ if( ssl->session_negotiate->id_len != recv_id_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "Mismatch of session id length:"
+ " id_len = %" MBEDTLS_PRINTF_SIZET
+ " , recv_id_len = %" MBEDTLS_PRINTF_SIZET,
+ ssl->session_negotiate->id_len, recv_id_len ) );
+ return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ }
+
+ if( memcmp( ssl->session_negotiate->id, p , recv_id_len ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "Unexpected legacy_session_id_echo" ) );
+ MBEDTLS_SSL_DEBUG_BUF( 3, "Expected Session ID",
+ ssl->session_negotiate->id,
+ ssl->session_negotiate->id_len );
+ MBEDTLS_SSL_DEBUG_BUF( 3, "Received Session ID", p,
+ ssl->session_negotiate->id_len );
+ return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ }
+
+ p += recv_id_len;
+ *buf = p;
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "Session ID", ssl->session_negotiate->id,
+ recv_id_len );
+ return( 0 );
+}
+
+static int ssl_tls1_3_cipher_suite_is_offered( mbedtls_ssl_context *ssl,
+ uint16_t cipher_suite )
+{
+ /* Check whether we have offered this ciphersuite */
+ for ( int i = 0; ssl->conf->ciphersuite_list[i] != 0; i++ )
+ {
+ if( ssl->conf->ciphersuite_list[i] == cipher_suite )
+ {
+ return( 1 );
+ }
+ }
+ return( 0 );
+}
+
+/* Parse ServerHello message and configure context
+ *
+ * struct {
+ * ProtocolVersion legacy_version = 0x0303; // TLS 1.2
+ * Random random;
+ * opaque legacy_session_id_echo<0..32>;
+ * CipherSuite cipher_suite;
+ * uint8 legacy_compression_method = 0;
+ * Extension extensions<6..2 ^ 16 - 1>;
+ * } ServerHello;
+ */
+static int ssl_tls1_3_parse_server_hello( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ const unsigned char *end )
+{
+
+ int ret;
+ const unsigned char *p = buf;
+ size_t field_len; /* Length of field */
+ const unsigned char *ext_end; /* Pointer to end of individual extension */
+ uint16_t cipher_suite;
+ const mbedtls_ssl_ciphersuite_t* ciphersuite_info;
+
+ /*
+ * Check there is space for minimal fields
+ *
+ * - legacy_version ( 2 bytes)
+ * - random (32 bytes)
+ * - legacy_session_id_echo ( 1 byte ), minimum size
+ * - cipher_suite ( 2 bytes)
+ * - legacy_compression_method ( 1 byte )
+ */
+ if( mbedtls_ssl_chk_buf_ptr( p, end, 38 ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1,
+ ( "bad server hello message - min size not reached" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+ MBEDTLS_ERR_SSL_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+ }
+
+ MBEDTLS_SSL_DEBUG_BUF( 4, "server hello", p, end - p );
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", p, 2 );
+
+ /* legacy_version must be 0x0303 (TLS 1.2) */
+ if( !( p[0] == MBEDTLS_SSL_MAJOR_VERSION_3 &&
+ p[1] == MBEDTLS_SSL_MINOR_VERSION_3 ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "Unsupported version of TLS." ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION,
+ MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION );
+ return( MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION );
+ }
+ p += 2;
+ /* Internally we use the correct 1.3 version
+ * TODO: Remove below lines after supported_versions extension
+ * finished.
+ */
+ ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
+ ssl->minor_ver = MBEDTLS_SSL_MINOR_VERSION_4;
+
+ /* Store server-provided random values */
+ memcpy( ssl->handshake->randbytes + CLIENT_HELLO_RANDOM_LEN, p,
+ SERVER_HELLO_RANDOM_LEN );
+ MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes",
+ p, SERVER_HELLO_RANDOM_LEN );
+ p += SERVER_HELLO_RANDOM_LEN;
+
+ /* Read and store session id (legacy_session_id_echo) */
+ if( ssl_tls1_3_check_server_hello_session_id( ssl, &p, end ) != 0 )
+ {
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+ MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ }
+
+ /* Read server-selected ciphersuite,
+ Check if there is space for cipher_suite. */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2);
+ cipher_suite = MBEDTLS_GET_UINT16_BE( p, 0 );
+ p += 2;
+
+ /* Configure ciphersuites */
+ ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( cipher_suite );
+ ssl->handshake->ciphersuite_info = ciphersuite_info;
+ if( ciphersuite_info == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found",
+ cipher_suite ) );
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
+ MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+ }
+
+ mbedtls_ssl_optimize_checksum( ssl, ssl->handshake->ciphersuite_info );
+
+ ssl->session_negotiate->ciphersuite = cipher_suite;
+
+ ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( cipher_suite );
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: ( %04x ) - %s",
+ cipher_suite, ciphersuite_info->name ) );
+
+#if defined(MBEDTLS_HAVE_TIME)
+ ssl->session_negotiate->start = time( NULL );
+#endif /* MBEDTLS_HAVE_TIME */
+
+ /* Check whether we have offered this ciphersuite */
+ /* Via the force_ciphersuite version we may have instructed the client */
+ /* to use a difference ciphersuite. */
+ if( ssl_tls1_3_cipher_suite_is_offered( ssl, cipher_suite ) == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite(%04x) is not in offered list",
+ cipher_suite ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
+ MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ }
+
+ /* Ensure that compression method is set to zero
+ *
+ * legacy_compression_method == 0 ( 1 byte)
+ */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 );
+ if( p[0] != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+ MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+ }
+ p++;
+
+ /* Check there is space fore extensions_length */
+ if( mbedtls_ssl_chk_buf_ptr( p, end, 2 ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+ MBEDTLS_ERR_SSL_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+ }
+
+ /* Get length of extensions field (2 bytes)*/
+ MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
+ field_len = MBEDTLS_GET_UINT16_BE( p, 0 );
+ p += 2;
+ /* Check there is space for extensions_data */
+ if( mbedtls_ssl_chk_buf_ptr( p, end, field_len ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+ MBEDTLS_ERR_SSL_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+ }
+ /* Set end of extensions */
+ ext_end = p + field_len;
+
+ MBEDTLS_SSL_DEBUG_MSG( 3,
+ ( "server hello, total extension length: %" MBEDTLS_PRINTF_SIZET ,
+ field_len ) );
+
+ MBEDTLS_SSL_DEBUG_BUF( 3, "server hello extensions", p, field_len );
+
+ while ( p < ext_end )
+ {
+ unsigned int extension_type;
+ size_t extension_data_len;
+
+ /*
+ * ....
+ * Extension extensions<6..2 ^ 16 - 1>;
+ * ....
+ * struct {
+ * ExtensionType extension_type;
+ * opaque extension_data<0..2^16-1>;
+ * } Extension;
+ * extension_type (2 bytes)
+ * extension_data_length (2 bytes)
+ */
+ MBEDTLS_SSL_CHK_BUF_PTR( p, ext_end, 4 );
+ extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
+ extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
+ p += 4;
+
+ if( mbedtls_ssl_chk_buf_ptr( p, ext_end, extension_data_len ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+ MBEDTLS_ERR_SSL_DECODE_ERROR );
+ return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+ }
+
+ switch( extension_type )
+ {
+ case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
+ MBEDTLS_SSL_DEBUG_MSG( 3,
+ ( "found supported_versions extension" ) );
+
+ ret = ssl_tls1_3_parse_supported_versions_ext( ssl,
+ p, extension_data_len );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+ case MBEDTLS_TLS_EXT_PRE_SHARED_KEY:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found pre_shared_key extension." ) );
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "pre_shared_key:Not supported yet" ) );
+ break;
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+ case MBEDTLS_TLS_EXT_KEY_SHARE:
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found key_shares extension" ) );
+ if( ( ret = ssl_tls1_3_parse_key_share_ext( ssl,
+ p, p + extension_data_len ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1,
+ "ssl_tls1_3_parse_key_share_ext",
+ ret );
+ return( ret );
+ }
+ break;
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+
+ default:
+ MBEDTLS_SSL_DEBUG_MSG( 3,
+ ( "unknown extension found: %u ( ignoring )",
+ extension_type ) );
+ }
+
+ p += extension_data_len;
+ }
+
+ return( 0 );
+}
+
+static int ssl_tls13_finalize_server_hello( mbedtls_ssl_context *ssl )
+{
+ ((void) ssl);
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "postprocess hasn't been implemented" ) );
+ return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+}
+
+/*
+ * Wait and Parse ServerHello handshake message.
* Handler for MBEDTLS_SSL_SERVER_HELLO
*/
static int ssl_tls1_3_process_server_hello( mbedtls_ssl_context *ssl )
{
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS );
- return( 0 );
+ int ret = 0;
+ unsigned char *buf;
+ size_t buf_len;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> %s", __func__ ) );
+
+ /* Coordination step
+ * - Fetch record
+ * - Make sure it's either a ServerHello or a HRR.
+ * - Switch processing routine in case of HRR
+ */
+
+ ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
+ ssl->handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
+
+
+ ret = ssl_server_hello_coordinate( ssl, &buf, &buf_len );
+ /* Parsing step
+ * We know what message to expect by now and call
+ * the respective parsing function.
+ */
+ if( ret == SSL_SERVER_HELLO_COORDINATE_HELLO )
+ {
+ MBEDTLS_SSL_PROC_CHK( ssl_tls1_3_parse_server_hello( ssl, buf,
+ buf + buf_len ) );
+
+ mbedtls_ssl_tls1_3_add_hs_msg_to_checksum( ssl,
+ MBEDTLS_SSL_HS_SERVER_HELLO,
+ buf, buf_len );
+
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_server_hello( ssl ) );
+ }
+ else if( ret == SSL_SERVER_HELLO_COORDINATE_HRR )
+ {
+ /* TODO: Implement HRR in future #4915 */
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "HRR hasn't been implemented" ) );
+
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+ MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+ ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
+ }
+
+cleanup:
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= %s", __func__ ) );
+ return( ret );
}
/*