version 1.31, 2014/02/02 03:44:31 |
version 1.32, 2014/06/24 01:13:21 |
|
|
|
|
#include <string.h> |
#include <string.h> |
|
|
#include "xmalloc.h" |
#include "sshbuf.h" |
#include "buffer.h" |
|
#include "compat.h" |
#include "compat.h" |
#include "log.h" |
#include "ssherr.h" |
#include "key.h" |
|
#include "digest.h" |
#include "digest.h" |
|
#define SSHKEY_INTERNAL |
|
#include "sshkey.h" |
|
|
#define INTBLOB_LEN 20 |
#define INTBLOB_LEN 20 |
#define SIGBLOB_LEN (2*INTBLOB_LEN) |
#define SIGBLOB_LEN (2*INTBLOB_LEN) |
|
|
int |
int |
ssh_dss_sign(const Key *key, u_char **sigp, u_int *lenp, |
ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, |
const u_char *data, u_int datalen) |
const u_char *data, size_t datalen, u_int compat) |
{ |
{ |
DSA_SIG *sig; |
DSA_SIG *sig = NULL; |
u_char digest[SSH_DIGEST_MAX_LENGTH], sigblob[SIGBLOB_LEN]; |
u_char digest[SSH_DIGEST_MAX_LENGTH], sigblob[SIGBLOB_LEN]; |
u_int rlen, slen, len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); |
size_t rlen, slen, len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); |
Buffer b; |
struct sshbuf *b = NULL; |
|
int ret = SSH_ERR_INVALID_ARGUMENT; |
|
|
if (key == NULL || key_type_plain(key->type) != KEY_DSA || |
if (lenp != NULL) |
key->dsa == NULL) { |
*lenp = 0; |
error("%s: no DSA key", __func__); |
if (sigp != NULL) |
return -1; |
*sigp = NULL; |
} |
|
|
|
if (ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, |
if (key == NULL || key->dsa == NULL || |
digest, sizeof(digest)) != 0) { |
sshkey_type_plain(key->type) != KEY_DSA) |
error("%s: ssh_digest_memory failed", __func__); |
return SSH_ERR_INVALID_ARGUMENT; |
return -1; |
if (dlen == 0) |
} |
return SSH_ERR_INTERNAL_ERROR; |
|
|
sig = DSA_do_sign(digest, dlen, key->dsa); |
if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, |
explicit_bzero(digest, sizeof(digest)); |
digest, sizeof(digest))) != 0) |
|
goto out; |
|
|
if (sig == NULL) { |
if ((sig = DSA_do_sign(digest, dlen, key->dsa)) == NULL) { |
error("ssh_dss_sign: sign failed"); |
ret = SSH_ERR_LIBCRYPTO_ERROR; |
return -1; |
goto out; |
} |
} |
|
|
rlen = BN_num_bytes(sig->r); |
rlen = BN_num_bytes(sig->r); |
slen = BN_num_bytes(sig->s); |
slen = BN_num_bytes(sig->s); |
if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) { |
if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) { |
error("bad sig size %u %u", rlen, slen); |
ret = SSH_ERR_INTERNAL_ERROR; |
DSA_SIG_free(sig); |
goto out; |
return -1; |
|
} |
} |
explicit_bzero(sigblob, SIGBLOB_LEN); |
explicit_bzero(sigblob, SIGBLOB_LEN); |
BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen); |
BN_bn2bin(sig->r, sigblob + SIGBLOB_LEN - INTBLOB_LEN - rlen); |
BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen); |
BN_bn2bin(sig->s, sigblob + SIGBLOB_LEN - slen); |
DSA_SIG_free(sig); |
|
|
|
if (datafellows & SSH_BUG_SIGBLOB) { |
if (compat & SSH_BUG_SIGBLOB) { |
if (lenp != NULL) |
|
*lenp = SIGBLOB_LEN; |
|
if (sigp != NULL) { |
if (sigp != NULL) { |
*sigp = xmalloc(SIGBLOB_LEN); |
if ((*sigp = malloc(SIGBLOB_LEN)) == NULL) { |
|
ret = SSH_ERR_ALLOC_FAIL; |
|
goto out; |
|
} |
memcpy(*sigp, sigblob, SIGBLOB_LEN); |
memcpy(*sigp, sigblob, SIGBLOB_LEN); |
} |
} |
|
if (lenp != NULL) |
|
*lenp = SIGBLOB_LEN; |
|
ret = 0; |
} else { |
} else { |
/* ietf-drafts */ |
/* ietf-drafts */ |
buffer_init(&b); |
if ((b = sshbuf_new()) == NULL) { |
buffer_put_cstring(&b, "ssh-dss"); |
ret = SSH_ERR_ALLOC_FAIL; |
buffer_put_string(&b, sigblob, SIGBLOB_LEN); |
goto out; |
len = buffer_len(&b); |
} |
if (lenp != NULL) |
if ((ret = sshbuf_put_cstring(b, "ssh-dss")) != 0 || |
*lenp = len; |
(ret = sshbuf_put_string(b, sigblob, SIGBLOB_LEN)) != 0) |
|
goto out; |
|
len = sshbuf_len(b); |
if (sigp != NULL) { |
if (sigp != NULL) { |
*sigp = xmalloc(len); |
if ((*sigp = malloc(len)) == NULL) { |
memcpy(*sigp, buffer_ptr(&b), len); |
ret = SSH_ERR_ALLOC_FAIL; |
|
goto out; |
|
} |
|
memcpy(*sigp, sshbuf_ptr(b), len); |
} |
} |
buffer_free(&b); |
if (lenp != NULL) |
|
*lenp = len; |
|
ret = 0; |
} |
} |
return 0; |
out: |
|
explicit_bzero(digest, sizeof(digest)); |
|
if (sig != NULL) |
|
DSA_SIG_free(sig); |
|
if (b != NULL) |
|
sshbuf_free(b); |
|
return ret; |
} |
} |
|
|
int |
int |
ssh_dss_verify(const Key *key, const u_char *signature, u_int signaturelen, |
ssh_dss_verify(const struct sshkey *key, |
const u_char *data, u_int datalen) |
const u_char *signature, size_t signaturelen, |
|
const u_char *data, size_t datalen, u_int compat) |
{ |
{ |
DSA_SIG *sig; |
DSA_SIG *sig = NULL; |
u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob; |
u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob = NULL; |
u_int len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); |
size_t len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); |
int rlen, ret; |
int ret = SSH_ERR_INTERNAL_ERROR; |
Buffer b; |
struct sshbuf *b = NULL; |
|
char *ktype = NULL; |
|
|
if (key == NULL || key_type_plain(key->type) != KEY_DSA || |
if (key == NULL || key->dsa == NULL || |
key->dsa == NULL) { |
sshkey_type_plain(key->type) != KEY_DSA) |
error("%s: no DSA key", __func__); |
return SSH_ERR_INVALID_ARGUMENT; |
return -1; |
if (dlen == 0) |
} |
return SSH_ERR_INTERNAL_ERROR; |
|
|
/* fetch signature */ |
/* fetch signature */ |
if (datafellows & SSH_BUG_SIGBLOB) { |
if (compat & SSH_BUG_SIGBLOB) { |
sigblob = xmalloc(signaturelen); |
if ((sigblob = malloc(signaturelen)) == NULL) |
|
return SSH_ERR_ALLOC_FAIL; |
memcpy(sigblob, signature, signaturelen); |
memcpy(sigblob, signature, signaturelen); |
len = signaturelen; |
len = signaturelen; |
} else { |
} else { |
/* ietf-drafts */ |
/* ietf-drafts */ |
char *ktype; |
if ((b = sshbuf_from(signature, signaturelen)) == NULL) |
buffer_init(&b); |
return SSH_ERR_ALLOC_FAIL; |
buffer_append(&b, signature, signaturelen); |
if (sshbuf_get_cstring(b, &ktype, NULL) != 0 || |
ktype = buffer_get_cstring(&b, NULL); |
sshbuf_get_string(b, &sigblob, &len) != 0) { |
|
ret = SSH_ERR_INVALID_FORMAT; |
|
goto out; |
|
} |
if (strcmp("ssh-dss", ktype) != 0) { |
if (strcmp("ssh-dss", ktype) != 0) { |
error("%s: cannot handle type %s", __func__, ktype); |
ret = SSH_ERR_KEY_TYPE_MISMATCH; |
buffer_free(&b); |
goto out; |
free(ktype); |
|
return -1; |
|
} |
} |
free(ktype); |
if (sshbuf_len(b) != 0) { |
sigblob = buffer_get_string(&b, &len); |
ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; |
rlen = buffer_len(&b); |
goto out; |
buffer_free(&b); |
|
if (rlen != 0) { |
|
error("%s: remaining bytes in signature %d", |
|
__func__, rlen); |
|
free(sigblob); |
|
return -1; |
|
} |
} |
} |
} |
|
|
if (len != SIGBLOB_LEN) { |
if (len != SIGBLOB_LEN) { |
fatal("bad sigbloblen %u != SIGBLOB_LEN", len); |
ret = SSH_ERR_INVALID_FORMAT; |
|
goto out; |
} |
} |
|
|
/* parse signature */ |
/* parse signature */ |
if ((sig = DSA_SIG_new()) == NULL) |
if ((sig = DSA_SIG_new()) == NULL || |
fatal("%s: DSA_SIG_new failed", __func__); |
(sig->r = BN_new()) == NULL || |
if ((sig->r = BN_new()) == NULL) |
(sig->s = BN_new()) == NULL) { |
fatal("%s: BN_new failed", __func__); |
ret = SSH_ERR_ALLOC_FAIL; |
if ((sig->s = BN_new()) == NULL) |
goto out; |
fatal("ssh_dss_verify: BN_new failed"); |
} |
if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) || |
if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) || |
(BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL)) |
(BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL)) { |
fatal("%s: BN_bin2bn failed", __func__); |
ret = SSH_ERR_LIBCRYPTO_ERROR; |
|
goto out; |
|
} |
|
|
/* clean up */ |
|
explicit_bzero(sigblob, len); |
|
free(sigblob); |
|
|
|
/* sha1 the data */ |
/* sha1 the data */ |
if (ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, |
if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, |
digest, sizeof(digest)) != 0) { |
digest, sizeof(digest))) != 0) |
error("%s: digest_memory failed", __func__); |
goto out; |
return -1; |
|
|
switch (DSA_do_verify(digest, dlen, sig, key->dsa)) { |
|
case 1: |
|
ret = 0; |
|
break; |
|
case 0: |
|
ret = SSH_ERR_SIGNATURE_INVALID; |
|
goto out; |
|
default: |
|
ret = SSH_ERR_LIBCRYPTO_ERROR; |
|
goto out; |
} |
} |
|
|
ret = DSA_do_verify(digest, dlen, sig, key->dsa); |
out: |
explicit_bzero(digest, sizeof(digest)); |
explicit_bzero(digest, sizeof(digest)); |
|
if (sig != NULL) |
DSA_SIG_free(sig); |
DSA_SIG_free(sig); |
|
if (b != NULL) |
debug("%s: signature %s", __func__, |
sshbuf_free(b); |
ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error"); |
if (ktype != NULL) |
|
free(ktype); |
|
if (sigblob != NULL) { |
|
explicit_bzero(sigblob, len); |
|
free(sigblob); |
|
} |
return ret; |
return ret; |
} |
} |