*/
#include "includes.h"
-RCSID("$OpenBSD: ssh-rsa.c,v 1.4 2001/01/16 19:20:06 markus Exp $");
-
-#include "ssh.h"
-#include "xmalloc.h"
-#include "buffer.h"
-#include "bufaux.h"
+RCSID("$OpenBSD: ssh-rsa.c,v 1.21 2002/06/23 03:30:17 deraadt Exp $");
#include <openssl/evp.h>
-#include <openssl/dsa.h>
-#include <openssl/rsa.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, int *lenp,
- u_char *data, int datalen)
+ssh_rsa_sign(Key *key, u_char **sigp, u_int *lenp,
+ u_char *data, u_int datalen)
{
- EVP_MD *evp_md = EVP_sha1();
+ 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;
+ int ok, nid;
Buffer b;
if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
error("ssh_rsa_sign: no RSA key");
return -1;
}
- slen = RSA_size(key->rsa);
- sig = xmalloc(slen);
-
- dlen = evp_md->md_size;
- digest = xmalloc(dlen);
+ 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, NULL);
+ EVP_DigestFinal(&md, digest, &dlen);
+
+ slen = RSA_size(key->rsa);
+ sig = xmalloc(slen);
- ok = RSA_sign(NID_sha1, digest, dlen, sig, &len, key->rsa);
- memset(digest, 'd', dlen);
- xfree(digest);
+ 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));
+ 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;
}
*lenp = len;
if (sigp != NULL)
*sigp = ret;
- debug2("ssh_rsa_sign: done");
return 0;
}
int
-ssh_rsa_verify(
- Key *key,
- u_char *signature, int signaturelen,
- u_char *data, int datalen)
+ssh_rsa_verify(Key *key, u_char *signature, u_int signaturelen,
+ u_char *data, u_int datalen)
{
Buffer b;
- EVP_MD *evp_md = EVP_sha1();
+ const EVP_MD *evp_md;
EVP_MD_CTX md;
char *ktype;
- u_char *sigblob, *digest;
- u_int len, dlen;
- int rlen;
- int ret;
+ 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) < 768) {
- error("ssh_rsa_verify: n too small: %d bits",
- BN_num_bits(key->rsa->n));
+ 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, (char *) signature, signaturelen);
+ 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);
return -1;
}
xfree(ktype);
- sigblob = (u_char *)buffer_get_string(&b, &len);
+ 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 %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);
+ 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_sha1, digest, dlen, sigblob, len, key->rsa);
- memset(digest, 'd', dlen);
- xfree(digest);
+ 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));
+ error("ssh_rsa_verify: RSA_verify failed: %s",
+ ERR_error_string(ecode, NULL));
}
debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");
return ret;
andersk / openssh.git / blobdiff