mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-15 10:17:20 +00:00
184 lines
5.3 KiB
C
184 lines
5.3 KiB
C
/*
|
|
* Copyright (c) 2000 Markus Friedl. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
RCSID("$OpenBSD: ssh-rsa.c,v 1.20 2002/06/10 16:53:06 stevesk Exp $");
|
|
|
|
#include <openssl/evp.h>
|
|
#include <openssl/err.h>
|
|
|
|
#include "xmalloc.h"
|
|
#include "log.h"
|
|
#include "buffer.h"
|
|
#include "bufaux.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, u_int *lenp,
|
|
u_char *data, u_int datalen)
|
|
{
|
|
const EVP_MD *evp_md;
|
|
EVP_MD_CTX md;
|
|
u_char digest[EVP_MAX_MD_SIZE], *sig, *ret;
|
|
u_int slen, dlen, len;
|
|
int ok, nid;
|
|
Buffer b;
|
|
|
|
if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
|
|
error("ssh_rsa_sign: no RSA key");
|
|
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;
|
|
}
|
|
EVP_DigestInit(&md, evp_md);
|
|
EVP_DigestUpdate(&md, data, datalen);
|
|
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', sizeof(digest));
|
|
|
|
if (ok != 1) {
|
|
int ecode = ERR_get_error();
|
|
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);
|
|
memmove(sig + diff, sig, len);
|
|
memset(sig, 0, diff);
|
|
} else if (len > slen) {
|
|
error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
|
|
xfree(sig);
|
|
return -1;
|
|
}
|
|
/* encode signature */
|
|
buffer_init(&b);
|
|
buffer_put_cstring(&b, "ssh-rsa");
|
|
buffer_put_string(&b, sig, slen);
|
|
len = buffer_len(&b);
|
|
ret = xmalloc(len);
|
|
memcpy(ret, buffer_ptr(&b), len);
|
|
buffer_free(&b);
|
|
memset(sig, 's', slen);
|
|
xfree(sig);
|
|
|
|
if (lenp != NULL)
|
|
*lenp = len;
|
|
if (sigp != NULL)
|
|
*sigp = ret;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ssh_rsa_verify(
|
|
Key *key,
|
|
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 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 (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
|
|
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);
|
|
buffer_append(&b, signature, signaturelen);
|
|
ktype = buffer_get_string(&b, NULL);
|
|
if (strcmp("ssh-rsa", ktype) != 0) {
|
|
error("ssh_rsa_verify: cannot handle type %s", ktype);
|
|
buffer_free(&b);
|
|
xfree(ktype);
|
|
return -1;
|
|
}
|
|
xfree(ktype);
|
|
sigblob = buffer_get_string(&b, &len);
|
|
rlen = buffer_len(&b);
|
|
buffer_free(&b);
|
|
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;
|
|
}
|
|
EVP_DigestInit(&md, evp_md);
|
|
EVP_DigestUpdate(&md, data, datalen);
|
|
EVP_DigestFinal(&md, digest, &dlen);
|
|
|
|
ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa);
|
|
memset(digest, 'd', sizeof(digest));
|
|
memset(sigblob, 's', len);
|
|
xfree(sigblob);
|
|
if (ret == 0) {
|
|
int ecode = ERR_get_error();
|
|
error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
|
|
}
|
|
debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");
|
|
return ret;
|
|
}
|