===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh-rsa.c,v
retrieving revision 1.18
retrieving revision 1.18.2.1
diff -u -r1.18 -r1.18.2.1
--- src/usr.bin/ssh/ssh-rsa.c	2002/04/02 20:11:38	1.18
+++ src/usr.bin/ssh/ssh-rsa.c	2002/06/26 15:30:39	1.18.2.1
@@ -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 1.18.2.1 2002/06/26 15:30:39 jason Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -39,9 +39,7 @@
 
 /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
 int
-ssh_rsa_sign(
-    Key *key,
-    u_char **sigp, u_int *lenp,
+ssh_rsa_sign(Key *key, u_char **sigp, u_int *lenp,
     u_char *data, u_int datalen)
 {
 	const EVP_MD *evp_md;
@@ -72,17 +70,18 @@
 
 	if (ok != 1) {
 		int ecode = ERR_get_error();
-		error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL));
+		error("ssh_rsa_sign: RSA_sign failed: %s",
+		    ERR_error_string(ecode, NULL));
 		xfree(sig);
 		return -1;
 	}
 	if (len < slen) {
 		int diff = slen - len;
-		debug("slen %d > len %d", slen, len);
+		debug("slen %u > len %u", slen, len);
 		memmove(sig + diff, sig, len);
 		memset(sig, 0, diff);
 	} else if (len > slen) {
-		error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
+		error("ssh_rsa_sign: slen %u slen2 %u", slen, len);
 		xfree(sig);
 		return -1;
 	}
@@ -105,9 +104,7 @@
 }
 
 int
-ssh_rsa_verify(
-    Key *key,
-    u_char *signature, u_int signaturelen,
+ssh_rsa_verify(Key *key, u_char *signature, u_int signaturelen,
     u_char *data, u_int datalen)
 {
 	Buffer b;
@@ -115,7 +112,7 @@
 	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) {
@@ -123,8 +120,8 @@
 		return -1;
 	}
 	if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
-		error("ssh_rsa_verify: n too small: %d bits",
-		    BN_num_bits(key->rsa->n));
+		error("ssh_rsa_verify: RSA modulus too small: %d < minimum %d bits",
+		    BN_num_bits(key->rsa->n), SSH_RSA_MINIMUM_MODULUS_SIZE);
 		return -1;
 	}
 	buffer_init(&b);
@@ -145,6 +142,21 @@
 		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 %u > modlen %u", len, modlen);
+		xfree(sigblob);
+		return -1;
+	} else if (len < modlen) {
+		int diff = modlen - len;
+		debug("ssh_rsa_verify: add padding: modlen %u > len %u",
+		    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);
@@ -161,7 +173,8 @@
 	xfree(sigblob);
 	if (ret == 0) {
 		int ecode = ERR_get_error();
-		error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
+		error("ssh_rsa_verify: RSA_verify failed: %s",
+		    ERR_error_string(ecode, NULL));
 	}
 	debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");
 	return ret;