Add writing CertificateRequest msg on server side

Signed-off-by: Xiaofei Bai <xiaofei.bai@arm.com>
This commit is contained in:
Xiaofei Bai 2022-02-14 12:57:18 +00:00 committed by XiaokangQian
parent 612615fa5e
commit 9ca09d497f

View File

@ -25,6 +25,10 @@
#include "mbedtls/error.h"
#include "mbedtls/platform.h"
#include "ssl_misc.h"
#include "ssl_tls13_keys.h"
#include "ssl_debug_helpers.h"
#if defined(MBEDTLS_ECP_C)
#include "mbedtls/ecp.h"
#endif /* MBEDTLS_ECP_C */
@ -729,6 +733,136 @@ cleanup:
return( ret );
}
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
#define SSL_CERTIFICATE_REQUEST_SEND_REQUEST 0
#define SSL_CERTIFICATE_REQUEST_SKIP 1
/* Coordination:
* Check whether a CertificateRequest message should be written.
* Returns a negative code on failure, or
* - SSL_CERTIFICATE_REQUEST_SEND_REQUEST
* - SSL_CERTIFICATE_REQUEST_SKIP
* indicating if the writing of the CertificateRequest
* should be skipped or not.
*/
static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
{
int authmode;
if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip write certificate request" ) );
return( SSL_CERTIFICATE_REQUEST_SKIP );
}
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
if( ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET )
authmode = ssl->handshake->sni_authmode;
else
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
authmode = ssl->conf->authmode;
if( authmode == MBEDTLS_SSL_VERIFY_NONE )
return( SSL_CERTIFICATE_REQUEST_SKIP );
return( SSL_CERTIFICATE_REQUEST_SEND_REQUEST );
}
/*
* struct {
* opaque certificate_request_context<0..2^8-1>;
* Extension extensions<2..2^16-1>;
* } CertificateRequest;
*
*/
static int ssl_tls13_write_certificate_request( mbedtls_ssl_context *ssl,
unsigned char *buf,
const unsigned char *end,
size_t *out_len )
{
int ret;
size_t ext_size = 0;
unsigned char *p = buf;
*out_len = 0;
/* Check if we have enough space:
* - certificate_request_context (1 byte)
* - extensions (2 bytes)
*/
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 3 );
/*
* Write certificate_request_context
*/
/*
* We use a zero length context for the normal handshake
* messages. For post-authentication handshake messages
* this request context would be set to a non-zero value.
*/
*p++ = 0x0;
/*
* Write extensions
*/
/* The extensions must contain the signature_algorithms. */
ret = mbedtls_ssl_write_sig_alg_ext( ssl, p + 2, end, &ext_size );
if( ret != 0 )
return( ret );
/* length field for all extensions */
MBEDTLS_PUT_UINT16_BE( ext_size, p, 0 );
p += 2 + ext_size;
*out_len = p - buf;
return( ret );
}
static int ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
if( ret == SSL_CERTIFICATE_REQUEST_SEND_REQUEST )
{
unsigned char *buf;
size_t buf_len, msg_len;
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, &buf, &buf_len ) );
MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate_request(
ssl, buf, buf + buf_len, &msg_len ) );
mbedtls_ssl_tls13_add_hs_msg_to_checksum(
ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, msg_len );
/* TODO: Logically this should come at the end, but the non-MPS msg
* layer impl'n of mbedtls_ssl_tls13_finish_handshake_msg() can fail. */
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
ssl, buf_len, msg_len ) );
}
else if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
ret = 0;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );
cleanup:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
/*
* Handler for MBEDTLS_SSL_SERVER_HELLO
*/
@ -1195,6 +1329,12 @@ int mbedtls_ssl_tls13_handshake_server_step( mbedtls_ssl_context *ssl )
}
break;
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
case MBEDTLS_SSL_CERTIFICATE_REQUEST:
ret = ssl_tls13_process_certificate_request( ssl );
break;
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );