Drop support for parsing SSLv2 ClientHello.

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
This commit is contained in:
Mateusz Starzyk 2021-02-18 13:55:21 +01:00
parent e7e5252813
commit 9e9ca1a738
8 changed files with 2 additions and 314 deletions

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@ -0,0 +1,2 @@
API changes
* Drop support for parsing SSLv2 ClientHello (MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO).

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@ -1414,16 +1414,6 @@
*/
#define MBEDTLS_SSL_RENEGOTIATION
/**
* \def MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO
*
* Enable support for receiving and parsing SSLv2 Client Hello messages for the
* SSL Server module (MBEDTLS_SSL_SRV_C).
*
* Uncomment this macro to enable support for SSLv2 Client Hello messages.
*/
//#define MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO
/**
* \def MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE
*

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@ -861,14 +861,6 @@
#endif
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
#if defined(MBEDTLS_DEPRECATED_REMOVED)
#error "MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO is deprecated and will be removed in a future version of Mbed TLS"
#elif defined(MBEDTLS_DEPRECATED_WARNING)
#warning "MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO is deprecated and will be removed in a future version of Mbed TLS"
#endif
#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
#if defined(MBEDTLS_DEPRECATED_REMOVED)
#error "MBEDTLS_SSL_HW_RECORD_ACCEL is deprecated and will be removed in a future version of Mbed TLS"

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@ -1691,19 +1691,6 @@
*/
#define MBEDTLS_SSL_RENEGOTIATION
/**
* \def MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO
*
* Enable support for receiving and parsing SSLv2 Client Hello messages for the
* SSL Server module (MBEDTLS_SSL_SRV_C).
*
* \deprecated This option is deprecated and will be removed in a future
* version of Mbed TLS.
*
* Uncomment this macro to enable support for SSLv2 Client Hello messages.
*/
//#define MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO
/**
* \def MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE
*

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@ -1144,269 +1144,6 @@ static int ssl_ciphersuite_match( mbedtls_ssl_context *ssl, int suite_id,
return( 0 );
}
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
static int ssl_parse_client_hello_v2( mbedtls_ssl_context *ssl )
{
int ret, got_common_suite;
unsigned int i, j;
size_t n;
unsigned int ciph_len, sess_len, chal_len;
unsigned char *buf, *p;
const int *ciphersuites;
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
buf = ssl->in_hdr;
MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, 5 );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
buf[2] ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]",
buf[3], buf[4] ) );
/*
* SSLv2 Client Hello
*
* Record layer:
* 0 . 1 message length
*
* SSL layer:
* 2 . 2 message type
* 3 . 4 protocol version
*/
if( buf[2] != MBEDTLS_SSL_HS_CLIENT_HELLO ||
buf[3] != MBEDTLS_SSL_MAJOR_VERSION_3 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
if( n < 17 || n > 512 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
ssl->minor_ver = ( buf[4] <= ssl->conf->max_minor_ver )
? buf[4] : ssl->conf->max_minor_ver;
if( ssl->minor_ver < ssl->conf->min_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
" [%d:%d] < [%d:%d]",
ssl->major_ver, ssl->minor_ver,
ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
ssl->handshake->max_major_ver = buf[3];
ssl->handshake->max_minor_ver = buf[4];
if( ( ret = mbedtls_ssl_fetch_input( ssl, 2 + n ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
return( ret );
}
ssl->handshake->update_checksum( ssl, buf + 2, n );
buf = ssl->in_msg;
n = ssl->in_left - 5;
/*
* 0 . 1 ciphersuitelist length
* 2 . 3 session id length
* 4 . 5 challenge length
* 6 . .. ciphersuitelist
* .. . .. session id
* .. . .. challenge
*/
MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, n );
ciph_len = ( buf[0] << 8 ) | buf[1];
sess_len = ( buf[2] << 8 ) | buf[3];
chal_len = ( buf[4] << 8 ) | buf[5];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d",
ciph_len, sess_len, chal_len ) );
/*
* Make sure each parameter length is valid
*/
if( ciph_len < 3 || ( ciph_len % 3 ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( sess_len > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( chal_len < 8 || chal_len > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
if( n != 6 + ciph_len + sess_len + chal_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
buf + 6, ciph_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id",
buf + 6 + ciph_len, sess_len );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, challenge",
buf + 6 + ciph_len + sess_len, chal_len );
p = buf + 6 + ciph_len;
ssl->session_negotiate->id_len = sess_len;
memset( ssl->session_negotiate->id, 0,
sizeof( ssl->session_negotiate->id ) );
memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len );
p += sess_len;
memset( ssl->handshake->randbytes, 0, 64 );
memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len );
/*
* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
{
if( p[0] == 0 && p[1] == 0 && p[2] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
"during renegotiation" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
break;
}
}
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
{
if( p[0] == 0 &&
p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) &&
p[2] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE ) & 0xff ) )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "received FALLBACK_SCSV" ) );
if( ssl->minor_ver < ssl->conf->max_minor_ver )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
break;
}
}
#endif /* MBEDTLS_SSL_FALLBACK_SCSV */
got_common_suite = 0;
ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
ciphersuite_info = NULL;
#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
for( i = 0; ciphersuites[i] != 0; i++ )
#else
for( i = 0; ciphersuites[i] != 0; i++ )
for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
#endif
{
if( p[0] != 0 ||
p[1] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
p[2] != ( ( ciphersuites[i] ) & 0xFF ) )
continue;
got_common_suite = 1;
if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
&ciphersuite_info ) ) != 0 )
return( ret );
if( ciphersuite_info != NULL )
goto have_ciphersuite_v2;
}
if( got_common_suite )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
"but none of them usable" ) );
return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
}
have_ciphersuite_v2:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
ssl->session_negotiate->ciphersuite = ciphersuites[i];
ssl->handshake->ciphersuite_info = ciphersuite_info;
/*
* SSLv2 Client Hello relevant renegotiation security checks
*/
if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
ssl->in_left = 0;
ssl->state++;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
/* This function doesn't alert on errors that happen early during
ClientHello parsing because they might indicate that the client is
not talking SSL/TLS at all and would not understand our alert. */
@ -1461,14 +1198,6 @@ read_record_header:
buf = ssl->in_hdr;
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM )
#endif
if( ( buf[0] & 0x80 ) != 0 )
return( ssl_parse_client_hello_v2( ssl ) );
#endif
MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_in_hdr_len( ssl ) );
/*

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@ -501,9 +501,6 @@ static const char * const features[] = {
#if defined(MBEDTLS_SSL_RENEGOTIATION)
"MBEDTLS_SSL_RENEGOTIATION",
#endif /* MBEDTLS_SSL_RENEGOTIATION */
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
"MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO",
#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
"MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE",
#endif /* MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE */

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@ -1393,14 +1393,6 @@ int query_config( const char *config )
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
#if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
if( strcmp( "MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO", config ) == 0 )
{
MACRO_EXPANSION_TO_STR( MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO );
return( 0 );
}
#endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
#if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
if( strcmp( "MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE", config ) == 0 )
{

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@ -301,7 +301,6 @@ def crypto_adapter(adapter):
DEPRECATED = frozenset([
'MBEDTLS_SSL_PROTO_SSL3',
'MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO',
])
def no_deprecated_adapter(adapter):