Split out SRP from tls_process_key_exchange()
Continuing from the previous commit. Refactor tls_process_key_exchange() to
split out into a separate function the SRP aspects.
Reviewed-by: Richard Levitte <levitte@openssl.org>
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index 7195379..48503d3 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1344,6 +1344,55 @@
#endif
}
+static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey, int *al)
+{
+#ifndef OPENSSL_NO_SRP
+ PACKET prime, generator, salt, server_pub;
+
+ if (!PACKET_get_length_prefixed_2(pkt, &prime)
+ || !PACKET_get_length_prefixed_2(pkt, &generator)
+ || !PACKET_get_length_prefixed_1(pkt, &salt)
+ || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
+ *al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
+ return 0;
+ }
+
+ if ((s->srp_ctx.N =
+ BN_bin2bn(PACKET_data(&prime),
+ PACKET_remaining(&prime), NULL)) == NULL
+ || (s->srp_ctx.g =
+ BN_bin2bn(PACKET_data(&generator),
+ PACKET_remaining(&generator), NULL)) == NULL
+ || (s->srp_ctx.s =
+ BN_bin2bn(PACKET_data(&salt),
+ PACKET_remaining(&salt), NULL)) == NULL
+ || (s->srp_ctx.B =
+ BN_bin2bn(PACKET_data(&server_pub),
+ PACKET_remaining(&server_pub), NULL)) == NULL) {
+ *al = SSL_AD_INTERNAL_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
+ return 0;
+ }
+
+ if (!srp_verify_server_param(s, al)) {
+ *al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_SRP_PARAMETERS);
+ return 0;
+ }
+
+ /* We must check if there is a certificate */
+ if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA|SSL_aDSS))
+ *pkey = X509_get0_pubkey(s->session->peer);
+
+ return 1;
+#else
+ SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
+ *al = SSL_AD_INTERNAL_ERROR;
+ return 0;
+#endif
+}
+
MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
{
EVP_MD_CTX *md_ctx;
@@ -1377,44 +1426,10 @@
/* Nothing else to do for plain PSK or RSAPSK */
if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
- }
-#ifndef OPENSSL_NO_SRP
- else if (alg_k & SSL_kSRP) {
- PACKET prime, generator, salt, server_pub;
- if (!PACKET_get_length_prefixed_2(pkt, &prime)
- || !PACKET_get_length_prefixed_2(pkt, &generator)
- || !PACKET_get_length_prefixed_1(pkt, &salt)
- || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
- SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);
- goto f_err;
- }
-
- if ((s->srp_ctx.N =
- BN_bin2bn(PACKET_data(&prime),
- PACKET_remaining(&prime), NULL)) == NULL
- || (s->srp_ctx.g =
- BN_bin2bn(PACKET_data(&generator),
- PACKET_remaining(&generator), NULL)) == NULL
- || (s->srp_ctx.s =
- BN_bin2bn(PACKET_data(&salt),
- PACKET_remaining(&salt), NULL)) == NULL
- || (s->srp_ctx.B =
- BN_bin2bn(PACKET_data(&server_pub),
- PACKET_remaining(&server_pub), NULL)) == NULL) {
- SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_BN_LIB);
+ } else if (alg_k & SSL_kSRP) {
+ if (!tls_process_ske_srp(s, pkt, &pkey, &al))
goto err;
- }
-
- if (!srp_verify_server_param(s, &al)) {
- SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_BAD_SRP_PARAMETERS);
- goto f_err;
- }
-
-/* We must check if there is a certificate */
- if (alg_a & (SSL_aRSA|SSL_aDSS))
- pkey = X509_get0_pubkey(s->session->peer);
}
-#endif /* !OPENSSL_NO_SRP */
#ifndef OPENSSL_NO_DH
else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
PACKET prime, generator, pub_key;
