SSL: rework restart state handling
As done by previous commits for ECC and ECDSA:
- use explicit state assignments rather than increment
- always place the state update right before the operation label
This will make it easier to add restart support for other operations later if
desired.
SSL-specific changes:
- remove useless states: when the last restartable operation on a message is
complete, ssl->state is incremented already, so we don't need any additional
state update: ecrs_state is only meant to complement ssl->state
- rename remaining states consistently as <message>_<operation>
- move some labels closer to the actual operation when possible (no assignment
to variables used after the label between its previous and current position)
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index d53f7b2..cf83e8f 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2305,9 +2305,9 @@
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled &&
- ssl->handshake->ecrs_state == ssl_ecrs_ske_read )
+ ssl->handshake->ecrs_state == ssl_ecrs_ske_start_processing )
{
- goto ske_process;
+ goto start_processing;
}
#endif
@@ -2317,12 +2317,6 @@
return( ret );
}
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
- if( ssl->handshake->ecrs_enabled )
- ssl->handshake->ecrs_state++;
-
-ske_process:
-#endif
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
@@ -2354,6 +2348,12 @@
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+ if( ssl->handshake->ecrs_enabled )
+ ssl->handshake->ecrs_state = ssl_ecrs_ske_start_processing;
+
+start_processing:
+#endif
p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
end = ssl->in_msg + ssl->in_hslen;
MBEDTLS_SSL_DEBUG_BUF( 3, "server key exchange", p, end - p );
@@ -2630,11 +2630,6 @@
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
return( ret );
}
-
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
- if( ssl->handshake->ecrs_enabled )
- ssl->handshake->ecrs_state++;
-#endif
}
#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
@@ -2901,7 +2896,7 @@
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
{
- if( ssl->handshake->ecrs_state == ssl_ecrs_ecdh_public_done )
+ if( ssl->handshake->ecrs_state == ssl_ecrs_ske_ecdh_calc_secret )
goto ecdh_calc_secret;
mbedtls_ecdh_enable_restart( &ssl->handshake->ecdh_ctx );
@@ -2924,7 +2919,7 @@
if( ssl->handshake->ecrs_enabled )
{
ssl->handshake->ecrs_n = n;
- ssl->handshake->ecrs_state++;
+ ssl->handshake->ecrs_state = ssl_ecrs_ske_ecdh_calc_secret;
}
ecdh_calc_secret:
@@ -2942,11 +2937,6 @@
}
MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
-
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
- if( ssl->handshake->ecrs_enabled )
- ssl->handshake->ecrs_state++;
-#endif
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
@@ -3167,9 +3157,9 @@
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled &&
- ssl->handshake->ecrs_state == ssl_ecrs_keys_derived )
+ ssl->handshake->ecrs_state == ssl_ecrs_crt_vrfy_sign )
{
- goto keys_derived;
+ goto sign;
}
#endif
@@ -3179,12 +3169,6 @@
return( ret );
}
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
- if( ssl->handshake->ecrs_enabled )
- ssl->handshake->ecrs_state++;
-
-keys_derived:
-#endif
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
@@ -3210,8 +3194,15 @@
}
/*
- * Make an RSA signature of the handshake digests
+ * Make a signature of the handshake digests
*/
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+ if( ssl->handshake->ecrs_enabled )
+ ssl->handshake->ecrs_state = ssl_ecrs_crt_vrfy_sign;
+
+sign:
+#endif
+
ssl->handshake->calc_verify( ssl, hash );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
@@ -3302,11 +3293,6 @@
return( ret );
}
-#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
- if( ssl->handshake->ecrs_enabled )
- ssl->handshake->ecrs_state++;
-#endif
-
ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 );
ssl->out_msg[5 + offset] = (unsigned char)( n );
