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authorBen Lindstrom <mouring@eviladmin.org>2002-06-06 20:55:04 +0000
committerBen Lindstrom <mouring@eviladmin.org>2002-06-06 20:55:04 +0000
commitceae9d1c333c24894cccddc861c1b9b6d208a8bc (patch)
treeb6c428a9f721579f0379cc1aa5f6768aaedcf3cc /ssh-rsa.c
parent01fff0c9d4f64d13e02ea6d516b5a335a35d00dd (diff)
- markus@cvs.openbsd.org 2002/05/31 13:20:50
[ssh-rsa.c] pad received signature with leading zeros, because RSA_verify expects a signature of RSA_size. the drafts says the signature is transmitted unpadded (e.g. putty does not pad), reported by anakin@pobox.com
Diffstat (limited to 'ssh-rsa.c')
-rw-r--r--ssh-rsa.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/ssh-rsa.c b/ssh-rsa.c
index fe4dc1f8..458c9c84 100644
--- a/ssh-rsa.c
+++ b/ssh-rsa.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: ssh-rsa.c,v 1.18 2002/04/02 20:11:38 markus Exp $");
+RCSID("$OpenBSD: ssh-rsa.c,v 1.19 2002/05/31 13:20:50 markus Exp $");
#include <openssl/evp.h>
#include <openssl/err.h>
@@ -115,7 +115,7 @@ ssh_rsa_verify(
EVP_MD_CTX md;
char *ktype;
u_char digest[EVP_MAX_MD_SIZE], *sigblob;
- u_int len, dlen;
+ u_int len, dlen, modlen;
int rlen, ret, nid;
if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
@@ -145,6 +145,21 @@ ssh_rsa_verify(
xfree(sigblob);
return -1;
}
+ /* RSA_verify expects a signature of RSA_size */
+ modlen = RSA_size(key->rsa);
+ if (len > modlen) {
+ error("ssh_rsa_verify: len %d > modlen %d", len, modlen);
+ xfree(sigblob);
+ return -1;
+ } else if (len < modlen) {
+ int diff = modlen - len;
+ debug("ssh_rsa_verify: add padding: modlen %d > len %d",
+ modlen, len);
+ sigblob = xrealloc(sigblob, modlen);
+ memmove(sigblob + diff, sigblob, len);
+ memset(sigblob, 0, diff);
+ len = modlen;
+ }
nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
error("ssh_rsa_verify: EVP_get_digestbynid %d failed", nid);