- markus@cvs.openbsd.org 2002/01/25 21:42:11

     [ssh-dss.c ssh-rsa.c]
     use static EVP_MAX_MD_SIZE buffers for EVP_DigestFinal; ok stevesk@
     don't use evp_md->md_size, it's not public.

3 files changed, 19 insertions, 27 deletions

diff --git a/ChangeLog b/ChangeLog
index abcb900c8..9a79ab80c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -10,6 +10,10 @@
    - markus@cvs.openbsd.org 2002/01/25 21:00:24
      [sshconnect2.c]
      unused include
+   - markus@cvs.openbsd.org 2002/01/25 21:42:11
+     [ssh-dss.c ssh-rsa.c]
+     use static EVP_MAX_MD_SIZE buffers for EVP_DigestFinal; ok stevesk@
+     don't use evp_md->md_size, it's not public.
 
 20020130
  - (djm) Delay PRNG seeding until we need it in ssh-keygen, from markus@
@@ -7412,4 +7416,4 @@
  - Wrote replacements for strlcpy and mkdtemp
  - Released 1.0pre1
 
-$Id: ChangeLog,v 1.1801 2002/02/05 00:53:15 djm Exp $
+$Id: ChangeLog,v 1.1802 2002/02/05 00:53:43 djm Exp $
diff --git a/ssh-dss.c b/ssh-dss.c
index bd709a226..b81b8347d 100644
--- a/ssh-dss.c
+++ b/ssh-dss.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-dss.c,v 1.11 2001/12/27 18:22:16 markus Exp $");
+RCSID("$OpenBSD: ssh-dss.c,v 1.12 2002/01/25 21:42:11 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/evp.h>
@@ -48,7 +48,7 @@ ssh_dss_sign(
         DSA_SIG *sig;
         EVP_MD *evp_md = EVP_sha1();
         EVP_MD_CTX md;
-        u_char *digest, *ret, sigblob[SIGBLOB_LEN];
+        u_char *ret, digest[EVP_MAX_MD_SIZE], sigblob[SIGBLOB_LEN];
         u_int rlen, slen, len, dlen;
         Buffer b;
 
@@ -56,16 +56,13 @@ ssh_dss_sign(
                 error("ssh_dss_sign: no DSA key");
                 return -1;
         }
-        dlen = evp_md->md_size;
-        digest = xmalloc(dlen);
         EVP_DigestInit(&md, evp_md);
         EVP_DigestUpdate(&md, data, datalen);
-        EVP_DigestFinal(&md, digest, NULL);
+        EVP_DigestFinal(&md, digest, &dlen);
 
         sig = DSA_do_sign(digest, dlen, key->dsa);
+        memset(digest, 'd', sizeof(digest));
 
-        memset(digest, 0, dlen);
-        xfree(digest);
         if (sig == NULL) {
                 error("ssh_dss_sign: sign failed");
                 return -1;
@@ -115,7 +112,7 @@ ssh_dss_verify(
         DSA_SIG *sig;
         EVP_MD *evp_md = EVP_sha1();
         EVP_MD_CTX md;
-        u_char *digest, *sigblob;
+        u_char digest[EVP_MAX_MD_SIZE], *sigblob;
         u_int len, dlen;
         int rlen, ret;
         Buffer b;
@@ -173,16 +170,13 @@ ssh_dss_verify(
         }
 
         /* sha1 the data */
-        dlen = evp_md->md_size;
-        digest = xmalloc(dlen);
         EVP_DigestInit(&md, evp_md);
         EVP_DigestUpdate(&md, data, datalen);
-        EVP_DigestFinal(&md, digest, NULL);
+        EVP_DigestFinal(&md, digest, &dlen);
 
         ret = DSA_do_verify(digest, dlen, sig, key->dsa);
+        memset(digest, 'd', sizeof(digest));
 
-        memset(digest, 0, dlen);
-        xfree(digest);
         DSA_SIG_free(sig);
 
         debug("ssh_dss_verify: signature %s",
diff --git a/ssh-rsa.c b/ssh-rsa.c
index 27522ef68..c4339b95b 100644
--- a/ssh-rsa.c
+++ b/ssh-rsa.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh-rsa.c,v 1.14 2001/12/05 10:06:12 deraadt Exp $");
+RCSID("$OpenBSD: ssh-rsa.c,v 1.15 2002/01/25 21:42:11 markus Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -45,7 +45,7 @@ ssh_rsa_sign(
 {
         const EVP_MD *evp_md;
         EVP_MD_CTX md;
-        u_char *digest, *sig, *ret;
+        u_char digest[EVP_MAX_MD_SIZE], *sig, *ret;
         u_int slen, dlen, len;
         int ok, nid;
         Buffer b;
@@ -63,18 +63,15 @@ ssh_rsa_sign(
                 error("ssh_rsa_sign: EVP_get_digestbynid %d failed", nid);
                 return -1;
         }
-        dlen = evp_md->md_size;
-        digest = xmalloc(dlen);
         EVP_DigestInit(&md, evp_md);
         EVP_DigestUpdate(&md, data, datalen);
-        EVP_DigestFinal(&md, digest, NULL);
+        EVP_DigestFinal(&md, digest, &dlen);
 
         slen = RSA_size(key->rsa);
         sig = xmalloc(slen);
 
         ok = RSA_sign(nid, digest, dlen, sig, &len, key->rsa);
-        memset(digest, 'd', dlen);
-        xfree(digest);
+        memset(digest, 'd', sizeof(digest));
 
         if (ok != 1) {
                 int ecode = ERR_get_error();
@@ -120,7 +117,7 @@ ssh_rsa_verify(
         const EVP_MD *evp_md;
         EVP_MD_CTX md;
         char *ktype;
-        u_char *sigblob, *digest;
+        u_char digest[EVP_MAX_MD_SIZE], *sigblob;
         u_int len, dlen;
         int rlen, ret, nid;
 
@@ -161,15 +158,12 @@ ssh_rsa_verify(
                 xfree(sigblob);
                 return -1;
         }
-        dlen = evp_md->md_size;
-        digest = xmalloc(dlen);
         EVP_DigestInit(&md, evp_md);
         EVP_DigestUpdate(&md, data, datalen);
-        EVP_DigestFinal(&md, digest, NULL);
+        EVP_DigestFinal(&md, digest, &dlen);
 
         ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa);
-        memset(digest, 'd', dlen);
-        xfree(digest);
+        memset(digest, 'd', sizeof(digest));
         memset(sigblob, 's', len);
         xfree(sigblob);
         if (ret == 0) {