*/
#include "includes.h"
-RCSID("$OpenBSD: ssh-rsa.c,v 1.12 2001/11/07 22:10:28 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>
#include "key.h"
#include "ssh-rsa.h"
#include "compat.h"
+#include "ssh.h"
/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
int
ssh_rsa_sign(
Key *key,
- u_char **sigp, int *lenp,
- u_char *data, int datalen)
+ u_char **sigp, u_int *lenp,
+ u_char *data, u_int datalen)
{
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;
error("ssh_rsa_sign: no RSA key");
return -1;
}
- if (datafellows & SSH_BUG_SIGBLOB) {
- error("ssh_rsa_sign: SSH_BUG_SIGBLOB not supported");
- return -1;
- }
nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
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();
int
ssh_rsa_verify(
Key *key,
- u_char *signature, int signaturelen,
- u_char *data, int datalen)
+ u_char *signature, u_int signaturelen,
+ u_char *data, u_int datalen)
{
Buffer b;
const EVP_MD *evp_md;
EVP_MD_CTX md;
char *ktype;
- u_char *sigblob, *digest;
- u_int len, dlen;
+ u_char digest[EVP_MAX_MD_SIZE], *sigblob;
+ u_int len, dlen, modlen;
int rlen, ret, nid;
if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
error("ssh_rsa_verify: no RSA key");
return -1;
}
- if (datafellows & SSH_BUG_SIGBLOB) {
- error("ssh_rsa_verify: SSH_BUG_SIGBLOB not supported");
- return -1;
- }
- if (BN_num_bits(key->rsa->n) < 768) {
+ 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));
return -1;
sigblob = buffer_get_string(&b, &len);
rlen = buffer_len(&b);
buffer_free(&b);
- if(rlen != 0) {
+ if (rlen != 0) {
error("ssh_rsa_verify: remaining bytes in signature %d", rlen);
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);
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) {