Add support for ECDHE_PSK key exchange
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 81d8e88..178393a 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1106,7 +1106,8 @@
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_ECDSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
static int ssl_parse_server_ecdh_params( ssl_context *ssl,
unsigned char **p,
unsigned char *end )
@@ -1143,10 +1144,12 @@
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
- POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+ POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) || \
- defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+ defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
static int ssl_parse_server_psk_hint( ssl_context *ssl,
unsigned char **p,
unsigned char *end )
@@ -1177,7 +1180,8 @@
return( ret );
}
#endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED ||
- POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+ POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED
+ POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
#if defined(POLARSSL_SSL_PROTO_TLS1_2)
#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
@@ -1254,7 +1258,8 @@
ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_ECDHE_RSA &&
ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA &&
ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_PSK &&
- ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_DHE_PSK )
+ ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_DHE_PSK &&
+ ciphersuite_info->key_exchange != POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
ssl->state++;
@@ -1352,6 +1357,25 @@
}
else
#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
+ if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE );
}
@@ -1880,6 +1904,75 @@
}
else
#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ unsigned char *p = ssl->handshake->premaster;
+
+ /*
+ * ECDHE_PSK key exchange: RFC 5489, section 2
+ *
+ * opaque psk_identity<0..2^16-1>;
+ * ClientECDiffieHellmanPublic public;
+ */
+ if( ssl->psk == NULL )
+ return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
+
+ if( sizeof(ssl->handshake->premaster) < 4 + ssl->psk_identity_len )
+ 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 );
+
+ memcpy( ssl->out_msg + 6, ssl->psk_identity, ssl->psk_identity_len );
+
+ ret = ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
+ &ssl->out_msg[8 + ssl->psk_identity_len], 512,
+ ssl->f_rng, ssl->p_rng );
+ if( ret != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_make_public", ret );
+ 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 );
+
+ /*
+ * PMS = struct {
+ * opaque other_secret<0..2^16-1>;
+ * opaque psk<0..2^16-1>;
+ * };
+ * with "other_secret" containing Z from ECDH
+ */
+ if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &n,
+ p + 2, POLARSSL_MPI_MAX_SIZE,
+ ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret );
+ return( ret );
+ }
+
+ *(p++) = (unsigned char)( n >> 8 );
+ *(p++) = (unsigned char)( n );
+ p += n;
+
+ SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
+
+ *(p++) = (unsigned char)( ssl->psk_len >> 8 );
+ *(p++) = (unsigned char)( ssl->psk_len );
+ memcpy( p, ssl->psk, ssl->psk_len );
+ p += ssl->psk_len;
+
+ ssl->handshake->pmslen = 4 + n + ssl->psk_len;
+ n = ssl->handshake->pmslen;
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA )
{