Re-construct the code to merge hello and hrr based on comments

Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
This commit is contained in:
XiaokangQian 2022-01-14 04:03:11 +00:00
parent 0b56a8f85c
commit b851da8a44

View File

@ -421,6 +421,69 @@ static int ssl_tls13_read_public_ecdhe_share( mbedtls_ssl_context *ssl,
}
#endif /* MBEDTLS_ECDH_C */
static int ssl_tls13_hrr_check_key_share_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
const unsigned char *end )
{
/* Variables for parsing the key_share */
const uint16_t* grp_id;
const mbedtls_ecp_curve_info *curve_info = NULL;
const unsigned char *p = buf;
int tls_id;
int found = 0;
const uint16_t *group_list = mbedtls_ssl_get_groups( ssl );
if( group_list == NULL )
return( MBEDTLS_ERR_SSL_BAD_CONFIG );
MBEDTLS_SSL_DEBUG_BUF( 3, "key_share extension", p, end - buf );
/* Read selected_group */
tls_id = MBEDTLS_GET_UINT16_BE( p, 0 );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected_group ( %d )", tls_id ) );
/* Upon receipt of this extension in a HelloRetryRequest, the client
* MUST first verify that the selected_group field corresponds to a
* group which was provided in the "supported_groups" extension in the
* original ClientHello.
* The supported_group was based on the info in ssl->conf->group_list.
*
* If the server provided a key share that was not sent in the ClientHello
* then the client MUST abort the handshake with an "illegal_parameter" alert.
*/
for ( ; *group_list != 0; group_list++ )
{
curve_info = mbedtls_ecp_curve_info_from_tls_id( *group_list );
if( curve_info == NULL || curve_info->tls_id != tls_id )
continue;
/* We found a match */
found = 1;
break;
}
/* Client MUST verify that the selected_group field does not
* correspond to a group which was provided in the "key_share"
* extension in the original ClientHello. If the server sent an
* HRR message with a key share already provided in the
* ClientHello then the client MUST abort the handshake with
* an "illegal_parameter" alert.
*/
if( found == 0 || tls_id == ssl->handshake->offered_group_id )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid key share in HRR" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT(
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
}
/* Remember server's preference for next ClientHello */
ssl->handshake->offered_group_id= tls_id;
return( 0 );
}
/*
* ssl_tls13_parse_key_share_ext()
* Parse key_share extension in Server Hello
@ -943,7 +1006,8 @@ static int ssl_tls13_cipher_suite_is_offered( mbedtls_ssl_context *ssl,
*/
static int ssl_tls13_parse_server_hello( mbedtls_ssl_context *ssl,
const unsigned char *buf,
const unsigned char *end )
const unsigned char *end,
int hrr )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const unsigned char *p = buf;
@ -951,6 +1015,10 @@ static int ssl_tls13_parse_server_hello( mbedtls_ssl_context *ssl,
const unsigned char *extensions_end;
uint16_t cipher_suite;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
#if defined(MBEDTLS_SSL_COOKIE_C)
size_t cookie_len;
unsigned char *cookie;
#endif /* MBEDTLS_SSL_COOKIE_C */
/*
* Check there is space for minimal fields
@ -1093,6 +1161,32 @@ static int ssl_tls13_parse_server_hello( mbedtls_ssl_context *ssl,
switch( extension_type )
{
#if defined(MBEDTLS_SSL_COOKIE_C)
case MBEDTLS_TLS_EXT_COOKIE:
/* Retrieve length field of cookie */
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 2 );
cookie_len = MBEDTLS_GET_UINT16_BE( p, 0 );
cookie = (unsigned char *) ( p + 2 );
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, cookie_len + 2 );
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie extension", cookie, cookie_len );
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "alloc failed ( %" MBEDTLS_PRINTF_SIZET " bytes )",
cookie_len ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
memcpy( ssl->handshake->verify_cookie, cookie, cookie_len );
ssl->handshake->verify_cookie_len = (unsigned char) cookie_len;
break;
#endif /* MBEDTLS_SSL_COOKIE_C */
case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "found supported_versions extension" ) );
@ -1116,8 +1210,13 @@ static int ssl_tls13_parse_server_hello( mbedtls_ssl_context *ssl,
#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_tls13_parse_key_share_ext( ssl,
p, p + extension_data_len ) ) != 0 )
if( hrr )
ret = ssl_tls13_hrr_check_key_share_ext( ssl,
p, p + extension_data_len );
else
ret = ssl_tls13_parse_key_share_ext( ssl,
p, p + extension_data_len );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1,
"ssl_tls13_parse_key_share_ext",
@ -1259,268 +1358,6 @@ cleanup:
return( ret );
}
static int ssl_hrr_parse( mbedtls_ssl_context *ssl,
const unsigned char *buf,
const unsigned char *end )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
int cipher_suite;
/* pointer to the end of the buffer for length checks */
const unsigned char *p = buf;
const unsigned char *extensions_end;
size_t extensions_len; /* stores length of all extensions */
const mbedtls_ssl_ciphersuite_t* ciphersuite_info; /* pointer to ciphersuite */
#if defined(MBEDTLS_SSL_COOKIE_C)
size_t cookie_len;
unsigned char *cookie;
#endif /* MBEDTLS_SSL_COOKIE_C */
/* Check for minimal length
* 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;
*
* 38 = 32 ( random bytes ) + 2 ( ciphersuite ) + 2 ( version ) +
* 1 ( legacy_compression_method ) +
* 1 ( minimum for legacy_session_id_echo )
*/
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 38 );
MBEDTLS_SSL_DEBUG_BUF( 4, "hello retry request", p, end - p );
MBEDTLS_SSL_DEBUG_BUF( 3, "hello retry request, version", p, 2 );
/* The version field must contain 0x303 */
if( MBEDTLS_GET_UINT16_BE( p, 0 ) != 0x303 )
{
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 );
}
/* skip version */
p += 2;
/* Internally we use the correct 1.3 version */
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 + MBEDTLS_SERVER_HELLO_RANDOM_LEN,
p, MBEDTLS_SERVER_HELLO_RANDOM_LEN );
MBEDTLS_SSL_DEBUG_BUF( 3, "hello retry request, random bytes",
p + 2, MBEDTLS_SERVER_HELLO_RANDOM_LEN );
/* skip random bytes */
p += MBEDTLS_SERVER_HELLO_RANDOM_LEN;
/* ...
* opaque legacy_session_id_echo<0..32>;
* ...
*/
if( ssl_tls13_check_server_hello_session_id_echo( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
}
/* read server-selected ciphersuite, which follows random bytes */
cipher_suite = MBEDTLS_GET_UINT16_BE( p, 0 );
/* skip ciphersuite */
p += 2;
/*
* Check whether we have offered this ciphersuite
* Via the force_ciphersuite version we may have instructed the client
* to use a difference ciphersuite.
*/
ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( cipher_suite );
if( ciphersuite_info == NULL ||
ssl_tls13_cipher_suite_is_offered( ssl, cipher_suite ) == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite(%04x) not found or not offered",
(unsigned int)cipher_suite ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
}
/* Configure ciphersuites */
mbedtls_ssl_optimize_checksum( ssl, ciphersuite_info );
ssl->handshake->ciphersuite_info = ciphersuite_info;
ssl->session_negotiate->ciphersuite = cipher_suite;
MBEDTLS_SSL_DEBUG_MSG( 3,
( "hello retry request, chosen ciphersuite: ( %04x ) - %s",
(unsigned int)cipher_suite, ciphersuite_info->name ) );
#if defined(MBEDTLS_HAVE_TIME)
ssl->session_negotiate->start = time( NULL );
#endif /* MBEDTLS_HAVE_TIME */
/* Ensure that compression method is set to zero */
if( p[0] != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad hello retry request message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
}
/* skip compression */
p++;
/* Are we reading beyond the message buffer? */
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
p += 2; /* skip extension length */
/* Are we reading beyond the message buffer? */
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
extensions_end = p + extensions_len;
MBEDTLS_SSL_DEBUG_MSG( 3,
( "hello retry request, total extension length: %"
MBEDTLS_PRINTF_SIZET , extensions_len ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "extensions", p, extensions_len );
while ( p < extensions_end )
{
unsigned int extension_type;
const unsigned char *extensions_data_end;
unsigned int extension_data_len; /* size of an individual extension */
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
extension_data_len = MBEDTLS_GET_UINT16_BE( p + 2, 0 );
p += 4;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
extensions_data_end = p + extension_data_len;
switch( extension_type )
{
#if defined(MBEDTLS_SSL_COOKIE_C)
case MBEDTLS_TLS_EXT_COOKIE:
/* Retrieve length field of cookie */
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_data_end, 2 );
cookie_len = MBEDTLS_GET_UINT16_BE( p, 0 );
cookie = (unsigned char *) ( p + 2 );
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_data_end, cookie_len + 2 );
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie extension", cookie, cookie_len );
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "alloc failed ( %" MBEDTLS_PRINTF_SIZET " bytes )",
cookie_len ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
memcpy( ssl->handshake->verify_cookie, cookie, cookie_len );
ssl->handshake->verify_cookie_len = (unsigned char) cookie_len;
break;
#endif /* MBEDTLS_SSL_COOKIE_C */
case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported_versions extension" ) );
ret = ssl_tls13_parse_supported_versions_ext( ssl,
p,
p + extension_data_len );
if( ret != 0 )
return( ret );
break;
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
case MBEDTLS_TLS_EXT_KEY_SHARE:
{
/* Variables for parsing the key_share */
const uint16_t* grp_id;
const mbedtls_ecp_curve_info *curve_info = NULL;
int tls_id;
int found = 0;
MBEDTLS_SSL_DEBUG_BUF( 3, "key_share extension", p, extension_data_len );
/* Read selected_group */
tls_id = MBEDTLS_GET_UINT16_BE( p, 0 );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected_group ( %d )", tls_id ) );
/* Upon receipt of this extension in a HelloRetryRequest, the client
* MUST first verify that the selected_group field corresponds to a
* group which was provided in the "supported_groups" extension in the
* original ClientHello.
* The supported_group was based on the info in ssl->conf->group_list.
*
* If the server provided a key share that was not sent in the ClientHello
* then the client MUST abort the handshake with an "illegal_parameter" alert.
*/
for( grp_id = ssl->conf->group_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
{
curve_info = mbedtls_ecp_curve_info_from_tls_id( *grp_id );
if( curve_info == NULL || curve_info->tls_id != tls_id )
continue;
/* We found a match */
found = 1;
break;
}
/* Client MUST verify that the selected_group field does not
* correspond to a group which was provided in the "key_share"
* extension in the original ClientHello. If the server sent an
* HRR message with a key share already provided in the
* ClientHello then the client MUST abort the handshake with
* an "illegal_parameter" alert.
*/
if( found == 0 || tls_id == ssl->handshake->offered_group_id )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid key share in HRR" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT(
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
}
/* Remember server's preference for next ClientHello */
ssl->handshake->offered_group_id= tls_id;
break;
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
default:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "unknown extension found: %u ( ignoring )",
extension_type ) );
}
/* Jump to next extension */
//extensions_len -= 4 + extension_data_len;
//ext += 4 + extension_data_len;
p += extension_data_len;
}
return( 0 );
}
static int ssl_hrr_postprocess( mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
@ -1575,6 +1412,7 @@ static int ssl_tls13_process_server_hello( mbedtls_ssl_context *ssl )
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char *buf = NULL;
size_t buf_len = 0;
int hrr = -1;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> %s", __func__ ) );
@ -1586,31 +1424,28 @@ static int ssl_tls13_process_server_hello( mbedtls_ssl_context *ssl )
ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
ssl->handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
ret = ssl_tls13_server_hello_coordinate( ssl, &buf, &buf_len );
hrr = ssl_tls13_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_tls13_parse_server_hello( ssl, buf,
buf + buf_len ) );
mbedtls_ssl_tls13_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 )
{
MBEDTLS_SSL_PROC_CHK( ssl_hrr_parse( ssl, buf, buf + buf_len ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( " hrr = %d ", hrr ) );
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_server_hello( ssl, buf,
buf + buf_len,
hrr ) );
if( hrr == SSL_SERVER_HELLO_COORDINATE_HRR )
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_reset_transcript_for_hrr( ssl ) );
mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
MBEDTLS_SSL_HS_SERVER_HELLO,
buf, buf_len );
mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
MBEDTLS_SSL_HS_SERVER_HELLO,
buf, buf_len );
if( hrr == SSL_SERVER_HELLO_COORDINATE_HELLO )
{
MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_server_hello( ssl ) );
}
else if( hrr == SSL_SERVER_HELLO_COORDINATE_HRR )
{
MBEDTLS_SSL_PROC_CHK( ssl_hrr_postprocess( ssl ) );
}