Add TLS1.3 process certificate request

Signed-off-by: Xiaofei Bai <xiaofei.bai@arm.com>
This commit is contained in:
Xiaofei Bai 2021-12-23 12:09:05 +00:00
parent f51b79c297
commit e1e344213a
3 changed files with 397 additions and 7 deletions

View File

@ -556,6 +556,13 @@ struct mbedtls_ssl_handshake_params
#if defined(MBEDTLS_SSL_PROTO_DTLS)
unsigned char retransmit_state; /*!< Retransmission state */
#endif
/*
* Handshake specific crypto variables
*/
#if defined(MBEDTLS_X509_CRT_PARSE_C)
int recv_sig_schemes_list[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
/*!< Received signature algorithms */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if !defined(MBEDTLS_DEPRECATED_REMOVED)
unsigned char group_list_heap_allocated;
@ -802,6 +809,12 @@ struct mbedtls_ssl_handshake_params
represents an extension and defined
as \c MBEDTLS_SSL_EXT_XXX */
#if defined(MBEDTLS_ECDSA_C)
unsigned char cert_req_ctx_len; /*!< certificate request context
length */
unsigned char* cert_req_ctx; /*!< certificate request context */
#endif
union
{
unsigned char early [MBEDTLS_TLS1_3_MD_MAX_SIZE];
@ -1687,6 +1700,11 @@ int mbedtls_ssl_tls13_start_handshake_msg( mbedtls_ssl_context *ssl,
unsigned char **buf,
size_t *buf_len );
/*
* Handler of TLS 1.3 server certificate request message
*/
int mbedtls_ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl );
/*
* Handler of TLS 1.3 server certificate message
*/

View File

@ -1415,10 +1415,9 @@ static int ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
if( ( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) &&
( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CertificateRequest not supported" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
ret = mbedtls_ssl_tls13_process_certificate_request( ssl );
if( ret != 0 )
return( ret );
}
ssl->keep_current_message = 1;

View File

@ -136,6 +136,379 @@ void mbedtls_ssl_tls13_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
}
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
/*
* mbedtls_ssl_tls13_write_sig_alg_ext( )
*
* enum {
* ....
* ecdsa_secp256r1_sha256( 0x0403 ),
* ecdsa_secp384r1_sha384( 0x0503 ),
* ecdsa_secp521r1_sha512( 0x0603 ),
* ....
* } SignatureScheme;
*
* struct {
* SignatureScheme supported_signature_algorithms<2..2^16-2>;
* } SignatureSchemeList;
*
* Only if we handle at least one key exchange that needs signatures.
*/
int mbedtls_ssl_tls13_write_sig_alg_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
unsigned char *end,
size_t *out_len )
{
unsigned char *p = buf;
unsigned char *supported_sig_alg; /* Start of supported_signature_algorithms */
size_t supported_sig_alg_len = 0; /* Length of supported_signature_algorithms */
*out_len = 0;
/* Skip the extension on the client if all allowed key exchanges
* are PSK-based. */
#if defined(MBEDTLS_SSL_CLI_C)
if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
!mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
{
return( 0 );
}
#endif /* MBEDTLS_SSL_CLI_C */
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding signature_algorithms extension" ) );
/* Check if we have space for header and length field:
* - extension_type (2 bytes)
* - extension_data_length (2 bytes)
* - supported_signature_algorithms_length (2 bytes)
*/
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 );
p += 6;
/*
* Write supported_signature_algorithms
*/
supported_sig_alg = p;
for( const uint16_t *sig_alg = ssl->conf->tls13_sig_algs;
*sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++ )
{
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
MBEDTLS_PUT_UINT16_BE( *sig_alg, p, 0 );
p += 2;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "signature scheme [%x]", *sig_alg ) );
}
/* Length of supported_signature_algorithms */
supported_sig_alg_len = p - supported_sig_alg;
if( supported_sig_alg_len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "No signature algorithms defined." ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/* Write extension_type */
MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SIG_ALG, buf, 0 );
/* Write extension_data_length */
MBEDTLS_PUT_UINT16_BE( supported_sig_alg_len + 2, buf, 2 );
/* Write length of supported_signature_algorithms */
MBEDTLS_PUT_UINT16_BE( supported_sig_alg_len, buf, 4 );
/* Output the total length of signature algorithms extension. */
*out_len = p - buf;
ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SIG_ALG;
return( 0 );
}
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_tls13_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
const unsigned char *end )
{
size_t sig_alg_list_size; /* size of receive signature algorithms list */
const unsigned char *p; /* pointer to individual signature algorithm */
const uint16_t *sig_alg; /* iterate through configured signature schemes */
unsigned int signature_scheme; /* store received signature algorithm scheme */
uint32_t common_idx = 0; /* iterate through received_signature_schemes_list */
size_t buf_len = end - buf;
MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 );
sig_alg_list_size = MBEDTLS_GET_UINT16_BE( buf, 0 );
if( sig_alg_list_size + 2 != buf_len ||
sig_alg_list_size % 2 != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad signature_algorithms extension" ) );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
memset( ssl->handshake->recv_sig_schemes_list, 0,
sizeof( ssl->handshake->recv_sig_schemes_list ) );
for( p = buf + 2; p < end && common_idx + 1 < MBEDTLS_PK_SIGNATURE_MAX_SIZE; p += 2 )
{
signature_scheme = MBEDTLS_GET_UINT16_BE( p, 0 );
MBEDTLS_SSL_DEBUG_MSG( 4, ( "received signature algorithm: 0x%x",
signature_scheme ) );
for( sig_alg = ssl->conf->tls13_sig_algs;
*sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++ )
{
if( *sig_alg == signature_scheme )
{
ssl->handshake->recv_sig_schemes_list[common_idx] = signature_scheme;
common_idx++;
break;
}
}
}
if( common_idx == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no signature algorithm in common" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
}
ssl->handshake->recv_sig_schemes_list[common_idx] = MBEDTLS_TLS1_3_SIG_NONE;
return( 0 );
}
#endif
/*
*
* STATE HANDLING: CertificateRequest
*
*/
/*
* Overview
*/
/* Coordination:
* Deals with the ambiguity of not knowing if a CertificateRequest
* will be sent. Returns a negative code on failure, or
* - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST
* - SSL_CERTIFICATE_REQUEST_SKIP
* indicating if a Certificate Request is expected or not.
*/
#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0
#define SSL_CERTIFICATE_REQUEST_SKIP 1
/*
* Implementation
*/
static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
{
int ret;
if( mbedtls_ssl_tls13_psk_enabled( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip parse certificate request" ) );
return( SSL_CERTIFICATE_REQUEST_SKIP );
}
if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
ssl->keep_current_message = 1;
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
return( SSL_CERTIFICATE_REQUEST_SKIP );
}
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_tls13_parse_certificate_request( mbedtls_ssl_context *ssl,
const unsigned char *buf,
const unsigned char *end )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const unsigned char *p = buf;
const unsigned char *ext = NULL;
size_t ext_len = 0;
size_t context_len = 0;
/*
* struct {
* opaque certificate_request_context<0..2^8-1>;
* Extension extensions<2..2^16-1>;
* } CertificateRequest;
*/
/*
* Parse certificate_request_context
*/
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
context_len = (size_t) p[0];
/* skip context_len */
p++;
/* Fixed length fields are:
* - 1 for length of context
* - 2 for length of extensions
* -----
* 3 bytes
*/
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 3 );
/* store context ( if necessary ) */
if( context_len > 0 )
{
MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
p, context_len );
ssl->handshake->cert_req_ctx = mbedtls_calloc( context_len, 1 );
if( ssl->handshake->cert_req_ctx == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return ( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
memcpy( ssl->handshake->cert_req_ctx, p, context_len );
/* jump over certificate_request_context */
p += context_len;
}
/*
* Parse extensions
*/
ext_len = MBEDTLS_GET_UINT16_BE( p, 0 );
/* At least one extension needs to be present,
* namely signature_algorithms ext. */
if( ext_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
MBEDTLS_ERR_SSL_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
/* skip total extension length */
p += 2;
ext = p; /* jump to extensions */
while( ext_len )
{
size_t ext_id = MBEDTLS_GET_UINT16_BE( ext, 0 );
size_t ext_size = MBEDTLS_GET_UINT16_BE( ext, 1 );
if( ext_size + 4 > ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
MBEDTLS_ERR_SSL_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
switch( ext_id )
{
case MBEDTLS_TLS_EXT_SIG_ALG:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "found signature_algorithms extension" ) );
if( ( ret = ssl_tls13_parse_signature_algorithms_ext( ssl,
ext + 4, ext + 4 + ext_size ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1,
"ssl_tls13_parse_signature_algorithms_ext", ret );
MBEDTLS_SSL_PEND_FATAL_ALERT(
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, ret );
return( ret );
}
break;
default:
MBEDTLS_SSL_DEBUG_MSG( 3,
( "unknown extension found: %" MBEDTLS_PRINTF_SIZET " ( ignoring )",
ext_id ) );
break;
}
ext_len -= 4 + ext_size;
ext += 4 + ext_size;
if( ( ext_len > 0 ) && ( ext_len < 4 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
MBEDTLS_ERR_SSL_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
}
}
ssl->client_auth = 1;
return( 0 );
}
#endif /* ( MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
/* Main entry point; orchestrates the other functions */
int mbedtls_ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
/* Coordination step
* - Fetch record
* - Make sure it's either a CertificateRequest or a ServerHelloDone
*/
MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
if( ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST )
{
unsigned char *buf;
size_t buf_len;
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
&buf, &buf_len ) );
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_request( ssl,
buf, buf + buf_len ) );
mbedtls_ssl_tls13_add_hs_msg_to_checksum(
ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, buf_len );
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
ssl->client_auth ? "a" : "no" ) );
cleanup:
/* In the MPS one would close the read-port here to
* ensure there's no overlap of reading and writing. */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
return( ret );
}
/*
* STATE HANDLING: Read CertificateVerify
*/
@ -487,20 +860,20 @@ static int ssl_tls13_parse_certificate( mbedtls_ssl_context *ssl,
const unsigned char *end )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t certificate_request_context_len = 0;
size_t cert_req_ctx_len = 0;
size_t certificate_list_len = 0;
const unsigned char *p = buf;
const unsigned char *certificate_list_end;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
certificate_request_context_len = p[0];
cert_req_ctx_len = p[0];
certificate_list_len = MBEDTLS_GET_UINT24_BE( p, 1 );
p += 4;
/* In theory, the certificate list can be up to 2^24 Bytes, but we don't
* support anything beyond 2^16 = 64K.
*/
if( ( certificate_request_context_len != 0 ) ||
if( ( cert_req_ctx_len != 0 ) ||
( certificate_list_len >= 0x10000 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );