Fix bugs in ECDHE_PSK key exchange
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 178393a..699bcb6 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1908,6 +1908,7 @@
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
unsigned char *p = ssl->handshake->premaster;
+ size_t zlen;
/*
* ECDHE_PSK key exchange: RFC 5489, section 2
@@ -1922,14 +1923,14 @@
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
i = 4;
- n = ssl->psk_identity_len;
- ssl->out_msg[4] = (unsigned char)( n >> 8 );
- ssl->out_msg[5] = (unsigned char)( n );
+ ssl->out_msg[i++] = (unsigned char)( ssl->psk_identity_len >> 8 );
+ ssl->out_msg[i++] = (unsigned char)( ssl->psk_identity_len );
- memcpy( ssl->out_msg + 6, ssl->psk_identity, ssl->psk_identity_len );
+ memcpy( ssl->out_msg + i, ssl->psk_identity, ssl->psk_identity_len );
+ i += ssl->psk_identity_len;
ret = ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
- &ssl->out_msg[8 + ssl->psk_identity_len], 512,
+ &ssl->out_msg[i], 1000,
ssl->f_rng, ssl->p_rng );
if( ret != 0 )
{
@@ -1937,9 +1938,6 @@
return( ret );
}
- ssl->out_msg[6 + ssl->psk_identity_len] = (unsigned char)( n >> 8 );
- ssl->out_msg[7 + ssl->psk_identity_len] = (unsigned char)( n );
-
SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
/*
@@ -1949,7 +1947,7 @@
* };
* with "other_secret" containing Z from ECDH
*/
- if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &n,
+ if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &zlen,
p + 2, POLARSSL_MPI_MAX_SIZE,
ssl->f_rng, ssl->p_rng ) ) != 0 )
{
@@ -1957,9 +1955,9 @@
return( ret );
}
- *(p++) = (unsigned char)( n >> 8 );
- *(p++) = (unsigned char)( n );
- p += n;
+ *(p++) = (unsigned char)( zlen >> 8 );
+ *(p++) = (unsigned char)( zlen );
+ p += zlen;
SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
@@ -1968,8 +1966,7 @@
memcpy( p, ssl->psk, ssl->psk_len );
p += ssl->psk_len;
- ssl->handshake->pmslen = 4 + n + ssl->psk_len;
- n = ssl->handshake->pmslen;
+ ssl->handshake->pmslen = p - ssl->handshake->premaster;
}
else
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index b128d9d..1588770 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2287,41 +2287,6 @@
#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
-#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
- defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
- defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
-static int ssl_parse_client_ecdh_public( ssl_context *ssl )
-{
- int ret;
- size_t n;
-
- /*
- * Receive client public key and calculate premaster
- */
- n = ssl->in_msg[3];
-
- if( n < 1 || n > mpi_size( &ssl->handshake->ecdh_ctx.grp.P ) * 2 + 2 ||
- n + 4 != ssl->in_hslen )
- {
- SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
- return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
- }
-
- if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
- ssl->in_msg + 4, n ) ) != 0 )
- {
- SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
- return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
- }
-
- SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
-
- return( ret );
-}
-#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
- POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
- POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
-
#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
static int ssl_parse_encrypted_pms_secret( ssl_context *ssl )
{
@@ -2522,12 +2487,24 @@
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA )
{
- if( ( ret = ssl_parse_client_ecdh_public( ssl ) ) != 0 )
+ size_t n = ssl->in_msg[3];
+
+ if( n < 1 || n > mpi_size( &ssl->handshake->ecdh_ctx.grp.P ) * 2 + 2 ||
+ n + 4 != ssl->in_hslen )
{
- SSL_DEBUG_RET( 1, ( "ssl_parse_client_ecdh_public" ), ret );
- return( ret );
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
+ if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
+ ssl->in_msg + 4, n ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
+ }
+
+ SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+
if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
&ssl->handshake->pmslen,
ssl->handshake->premaster,
@@ -2629,12 +2606,16 @@
SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
return( ret );
}
- if( ( ret = ssl_parse_client_ecdh_public( ssl ) ) != 0 )
+
+ if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
+ p, end - p ) ) != 0 )
{
- SSL_DEBUG_RET( 1, ( "ssl_parse_client_ecdh_public" ), ret );
- return( ret );
+ SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
}
+ SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+
// Set up the premaster secret
//
p = ssl->handshake->premaster;
@@ -2668,7 +2649,7 @@
{
if( ( ret = ssl_parse_encrypted_pms_secret( ssl ) ) != 0 )
{
- SSL_DEBUG_RET( 1, ( "ssl_parse_client_ecdh_public" ), ret );
+ SSL_DEBUG_RET( 1, ( "ssl_parse_parse_ecrypted_pms_secret" ), ret );
return( ret );
}
}