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Refine encrypted extensions parse function

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Change arguments of API.
Send different messages base on extensions types.

Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
This commit is contained in:
XiaokangQian 2021-10-09 10:12:11 +00:00
parent 140f0459ed
commit 08da26c58f
1 changed files with 47 additions and 36 deletions
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83
library/ssl_tls13_client.c
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@ -1411,8 +1411,8 @@ cleanup:
static int ssl_tls1_3_process_encrypted_extensions( mbedtls_ssl_context *ssl );
static int ssl_tls1_3_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t buf_len );
const unsigned char *buf,
const unsigned char *end );
static int ssl_tls1_3_postprocess_encrypted_extensions( mbedtls_ssl_context *ssl );
/*
@ -1431,7 +1431,7 @@ static int ssl_tls1_3_process_encrypted_extensions( mbedtls_ssl_context *ssl )
&buf, &buf_len ) );
/* Process the message contents */
MBEDTLS_SSL_PROC_CHK( ssl_tls1_3_parse_encrypted_extensions( ssl, buf, buf_len ) );
MBEDTLS_SSL_PROC_CHK( ssl_tls1_3_parse_encrypted_extensions( ssl, buf, ( buf + buf_len ) ) );
mbedtls_ssl_tls1_3_add_hs_msg_to_checksum(
ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSION, buf, buf_len );
@ -1445,32 +1445,27 @@ cleanup:
}
/* Parse EncryptedExtensions message
* struct {
* Extension extensions<0..2^16-1>;
* } EncryptedExtensions;
*/
static int ssl_tls1_3_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t buf_len )
const unsigned char *buf,
const unsigned char *end )
{
int ret = 0;
size_t p_ext_len;
const unsigned char *end = buf + buf_len;
size_t extensions_len;
const unsigned char *p = buf;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2);
p_ext_len = MBEDTLS_GET_UINT16_BE(buf, 0);
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
extensions_len = MBEDTLS_GET_UINT16_BE(p, 0);
p += 2; /* skip extension length */
/* Checking for an extension length that is too short */
if( p_ext_len > 0 && p_ext_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "EncryptedExtension message too short" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
MBEDTLS_ERR_SSL_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
p += 2;
/* Checking for an extension length that isn't aligned with the rest
* of the message */
if( buf_len != 2 + p_ext_len )
if( p + extensions_len != end )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "EncryptedExtension lengths misaligned" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
@ -1478,31 +1473,47 @@ static int ssl_tls1_3_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "encrypted extensions extensions", p, p_ext_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "encrypted extensions extensions", p, extensions_len );
while( p_ext_len )
while( p < end )
{
unsigned int ext_id = MBEDTLS_GET_UINT16_BE(p, 0);
size_t ext_size = MBEDTLS_GET_UINT16_BE(p, 2);
unsigned int extension_type;
size_t extension_data_len;
if( ext_size + 4 > p_ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad encrypted extensions message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
MBEDTLS_ERR_SSL_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
/*
* struct {
* ExtensionType extension_type; (2 bytes)
* opaque extension_data<0..2^16-1>;
* } Extension;
*/
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
p += 4;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extension_data_len );
/* TBD: The client MUST check EncryptedExtensions for the
* presence of any forbidden extensions and if any are found MUST abort
* the handshake with an "illegal_parameter" alert.
* the handshake with an "unsupported_extension" alert.
*/
((void) ext_id);
switch( extension_type )
{
p_ext_len -= 4 + ext_size;
p += 4 + ext_size;
case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extensions supported groups" ) );
break;
if( p_ext_len > 0 && p_ext_len < 4 )
default:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unsupported extension found: %d ( ignoring )", extension_type) );
break;
}
extensions_len -= 4 + extension_data_len;
p += extension_data_len;
/* Checking for an extension length that is too short */
if( extensions_len > 0 && extensions_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad encrypted extensions message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \