Simplify server kex exchange signature generation.

Everything can go through the single EVP_Sign* code path.

ok inoguchi@ tb@

diff --git a/lib/libssl/ssl_srvr.c b/lib/libssl/ssl_srvr.c
index ff5b020..3d20f0f 100644 (file)
--- a/lib/libssl/ssl_srvr.c
+++ b/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.35 2018/06/10 13:50:39 jsing Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.36 2018/08/10 17:44:16 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1504,13 +1504,10 @@ ssl3_send_server_key_exchange(SSL *s)
        CBB cbb;
        unsigned char *params = NULL;
        size_t params_len;
-       unsigned char *q;
-       unsigned char md_buf[MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH];
-       unsigned int u;
        EVP_PKEY *pkey;
        const EVP_MD *md = NULL;
        unsigned char *p, *d;
-       int al, i, j, n, kn;
+       int al, i, n, kn;
        unsigned long type;
        BUF_MEM *buf;
        EVP_MD_CTX md_ctx;
@@ -1570,68 +1567,43 @@ ssl3_send_server_key_exchange(SSL *s)
                n = params_len;
                p += params_len;
 
-               /* not anonymous */
+               /* Add signature unless anonymous. */
                if (pkey != NULL) {
-                       /*
-                        * n is the length of the params, they start at &(d[4])
-                        * and p points to the space at the end.
-                        */
-                       if (pkey->type == EVP_PKEY_RSA && !SSL_USE_SIGALGS(s)) {
-                               q = md_buf;
-                               j = 0;
-                               if (!EVP_DigestInit_ex(&md_ctx, EVP_md5_sha1(),
-                                   NULL))
-                                       goto err;
-                               EVP_DigestUpdate(&md_ctx, s->s3->client_random,
-                                   SSL3_RANDOM_SIZE);
-                               EVP_DigestUpdate(&md_ctx, s->s3->server_random,
-                                   SSL3_RANDOM_SIZE);
-                               EVP_DigestUpdate(&md_ctx, d, n);
-                               EVP_DigestFinal_ex(&md_ctx, q,
-                                   (unsigned int *)&i);
-                               q += i;
-                               j += i;
-                               if (RSA_sign(NID_md5_sha1, md_buf, j,
-                                   &(p[2]), &u, pkey->pkey.rsa) <= 0) {
-                                       SSLerror(s, ERR_R_RSA_LIB);
-                                       goto err;
-                               }
-                               s2n(u, p);
-                               n += u + 2;
-                       } else if (md) {
-                               /* Send signature algorithm. */
-                               if (SSL_USE_SIGALGS(s)) {
-                                       if (!tls12_get_sigandhash(p, pkey, md)) {
-                                               /* Should never happen */
-                                               al = SSL_AD_INTERNAL_ERROR;
-                                               SSLerror(s, ERR_R_INTERNAL_ERROR);
-                                               goto f_err;
-                                       }
-                                       p += 2;
-                               }
-                               EVP_SignInit_ex(&md_ctx, md, NULL);
-                               EVP_SignUpdate(&md_ctx,
-                                   s->s3->client_random,
-                                   SSL3_RANDOM_SIZE);
-                               EVP_SignUpdate(&md_ctx,
-                                   s->s3->server_random,
-                                   SSL3_RANDOM_SIZE);
-                               EVP_SignUpdate(&md_ctx, d, n);
-                               if (!EVP_SignFinal(&md_ctx, &p[2],
-                                       (unsigned int *)&i, pkey)) {
-                                       SSLerror(s, ERR_R_EVP_LIB);
-                                       goto err;
-                               }
-                               s2n(i, p);
-                               n += i + 2;
-                               if (SSL_USE_SIGALGS(s))
-                                       n += 2;
-                       } else {
+                       if (pkey->type == EVP_PKEY_RSA && !SSL_USE_SIGALGS(s))
+                               md = EVP_md5_sha1();
+               
+                       if (md == NULL) {
                                /* Is this error check actually needed? */
                                al = SSL_AD_HANDSHAKE_FAILURE;
                                SSLerror(s, SSL_R_UNKNOWN_PKEY_TYPE);
                                goto f_err;
                        }
+
+                       /* Send signature algorithm. */
+                       if (SSL_USE_SIGALGS(s)) {
+                               if (!tls12_get_sigandhash(p, pkey, md)) {
+                                       /* Should never happen */
+                                       al = SSL_AD_INTERNAL_ERROR;
+                                       SSLerror(s, ERR_R_INTERNAL_ERROR);
+                                       goto f_err;
+                               }
+                               p += 2;
+                       }
+                       EVP_SignInit_ex(&md_ctx, md, NULL);
+                       EVP_SignUpdate(&md_ctx, s->s3->client_random,
+                           SSL3_RANDOM_SIZE);
+                       EVP_SignUpdate(&md_ctx, s->s3->server_random,
+                           SSL3_RANDOM_SIZE);
+                       EVP_SignUpdate(&md_ctx, d, n);
+                       if (!EVP_SignFinal(&md_ctx, &p[2], (unsigned int *)&i,
+                           pkey)) {
+                               SSLerror(s, ERR_R_EVP_LIB);
+                               goto err;
+                       }
+                       s2n(i, p);
+                       n += i + 2;
+                       if (SSL_USE_SIGALGS(s))
+                               n += 2;
                }
 
                ssl3_handshake_msg_finish(s, n);