diff options
Diffstat (limited to 'usr.bin/ssh/ssh-rsa.c')
| -rw-r--r-- | usr.bin/ssh/ssh-rsa.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/usr.bin/ssh/ssh-rsa.c b/usr.bin/ssh/ssh-rsa.c new file mode 100644 index 00000000000..cc31154d969 --- /dev/null +++ b/usr.bin/ssh/ssh-rsa.c @@ -0,0 +1,163 @@ +/* + * 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 1.1 2000/11/12 19:50:38 markus Exp $"); + +#include "ssh.h" +#include "xmalloc.h" +#include "buffer.h" +#include "bufaux.h" + +#include <openssl/evp.h> +#include <openssl/dsa.h> +#include <openssl/rsa.h> +#include <openssl/err.h> + +#include "key.h" + +#define INTBLOB_LEN 20 +#define SIGBLOB_LEN (2*INTBLOB_LEN) + +/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ +int +ssh_rsa_sign( + Key *key, + unsigned char **sigp, int *lenp, + unsigned char *data, int datalen) +{ + EVP_MD *evp_md = EVP_sha1(); + EVP_MD_CTX md; + unsigned char *digest, *sig, *ret; + unsigned int slen, dlen, len; + int ok; + 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); + EVP_DigestInit(&md, evp_md); + EVP_DigestUpdate(&md, data, datalen); + EVP_DigestFinal(&md, digest, NULL); + + ok = RSA_sign(NID_sha1, digest, dlen, sig, &len, key->rsa); + memset(digest, 'd', dlen); + xfree(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; + debug2("ssh_rsa_sign: done"); + return 0; +} + +int +ssh_rsa_verify( + Key *key, + unsigned char *signature, int signaturelen, + unsigned char *data, int datalen) +{ + Buffer b; + EVP_MD *evp_md = EVP_sha1(); + EVP_MD_CTX md; + char *ktype; + unsigned char *sigblob, *digest; + unsigned int len, dlen; + int rlen; + int ret; + + if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) { + error("ssh_rsa_verify: no RSA key"); + return -1; + } + buffer_init(&b); + buffer_append(&b, (char *) 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 = (unsigned char *)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); + 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); + + ret = RSA_verify(NID_sha1, digest, dlen, sigblob, len, key->rsa); + memset(digest, 'd', dlen); + xfree(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; +} |