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/* Copyright (c) 2004-2006, Sara Golemon <sarag@libssh2.org>
* Copyright (c) 2009-2014 by Daniel Stenberg
* All rights reserved.
*
* Redistribution and use in source and binary forms,
* with or without modification, are permitted provided
* that the following conditions are met:
*
* Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
*
* 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.
*
* Neither the name of the copyright holder nor the names
* of any other contributors may be used to endorse or
* promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "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 COPYRIGHT OWNER OR
* CONTRIBUTORS 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 "libssh2_priv.h"
#include "misc.h"
/* Needed for struct iovec on some platforms */
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#if LIBSSH2_RSA
/* ***********
* ssh-rsa *
*********** */
static int hostkey_method_ssh_rsa_dtor(LIBSSH2_SESSION * session,
void **abstract);
/*
* hostkey_method_ssh_rsa_init
*
* Initialize the server hostkey working area with e/n pair
*/
static int
hostkey_method_ssh_rsa_init(LIBSSH2_SESSION * session,
const unsigned char *hostkey_data,
size_t hostkey_data_len,
void **abstract)
{
libssh2_rsa_ctx *rsactx;
const unsigned char *s, *e, *n;
unsigned long len, e_len, n_len;
(void) hostkey_data_len;
if (*abstract) {
hostkey_method_ssh_rsa_dtor(session, abstract);
*abstract = NULL;
}
s = hostkey_data;
len = _libssh2_ntohu32(s);
s += 4;
if (len != 7 || strncmp((char *) s, "ssh-rsa", 7) != 0) {
return -1;
}
s += 7;
e_len = _libssh2_ntohu32(s);
s += 4;
e = s;
s += e_len;
n_len = _libssh2_ntohu32(s);
s += 4;
n = s;
if (_libssh2_rsa_new(&rsactx, e, e_len, n, n_len, NULL, 0,
NULL, 0, NULL, 0, NULL, 0, NULL, 0, NULL, 0))
return -1;
*abstract = rsactx;
return 0;
}
/*
* hostkey_method_ssh_rsa_initPEM
*
* Load a Private Key from a PEM file
*/
static int
hostkey_method_ssh_rsa_initPEM(LIBSSH2_SESSION * session,
const char *privkeyfile,
unsigned const char *passphrase,
void **abstract)
{
libssh2_rsa_ctx *rsactx;
int ret;
if (*abstract) {
hostkey_method_ssh_rsa_dtor(session, abstract);
*abstract = NULL;
}
ret = _libssh2_rsa_new_private(&rsactx, session, privkeyfile, passphrase);
if (ret) {
return -1;
}
*abstract = rsactx;
return 0;
}
/*
* hostkey_method_ssh_rsa_initPEMFromMemory
*
* Load a Private Key from a memory
*/
static int
hostkey_method_ssh_rsa_initPEMFromMemory(LIBSSH2_SESSION * session,
const char *privkeyfiledata,
size_t privkeyfiledata_len,
unsigned const char *passphrase,
void **abstract)
{
libssh2_rsa_ctx *rsactx;
int ret;
if (*abstract) {
hostkey_method_ssh_rsa_dtor(session, abstract);
*abstract = NULL;
}
ret = _libssh2_rsa_new_private_frommemory(&rsactx, session,
privkeyfiledata,
privkeyfiledata_len, passphrase);
if (ret) {
return -1;
}
*abstract = rsactx;
return 0;
}
/*
* hostkey_method_ssh_rsa_sign
*
* Verify signature created by remote
*/
static int
hostkey_method_ssh_rsa_sig_verify(LIBSSH2_SESSION * session,
const unsigned char *sig,
size_t sig_len,
const unsigned char *m,
size_t m_len, void **abstract)
{
libssh2_rsa_ctx *rsactx = (libssh2_rsa_ctx *) (*abstract);
(void) session;
/* Skip past keyname_len(4) + keyname(7){"ssh-rsa"} + signature_len(4) */
sig += 15;
sig_len -= 15;
return _libssh2_rsa_sha1_verify(rsactx, sig, sig_len, m, m_len);
}
/*
* hostkey_method_ssh_rsa_signv
*
* Construct a signature from an array of vectors
*/
static int
hostkey_method_ssh_rsa_signv(LIBSSH2_SESSION * session,
unsigned char **signature,
size_t *signature_len,
int veccount,
const struct iovec datavec[],
void **abstract)
{
libssh2_rsa_ctx *rsactx = (libssh2_rsa_ctx *) (*abstract);
int ret;
int i;
unsigned char hash[SHA_DIGEST_LENGTH];
libssh2_sha1_ctx ctx;
libssh2_sha1_init(&ctx);
for(i = 0; i < veccount; i++) {
libssh2_sha1_update(ctx, datavec[i].iov_base, datavec[i].iov_len);
}
libssh2_sha1_final(ctx, hash);
ret = _libssh2_rsa_sha1_sign(session, rsactx, hash, SHA_DIGEST_LENGTH,
signature, signature_len);
if (ret) {
return -1;
}
return 0;
}
/*
* hostkey_method_ssh_rsa_dtor
*
* Shutdown the hostkey
*/
static int
hostkey_method_ssh_rsa_dtor(LIBSSH2_SESSION * session, void **abstract)
{
libssh2_rsa_ctx *rsactx = (libssh2_rsa_ctx *) (*abstract);
(void) session;
_libssh2_rsa_free(rsactx);
*abstract = NULL;
return 0;
}
static const LIBSSH2_HOSTKEY_METHOD hostkey_method_ssh_rsa = {
"ssh-rsa",
MD5_DIGEST_LENGTH,
hostkey_method_ssh_rsa_init,
hostkey_method_ssh_rsa_initPEM,
hostkey_method_ssh_rsa_initPEMFromMemory,
hostkey_method_ssh_rsa_sig_verify,
hostkey_method_ssh_rsa_signv,
NULL, /* encrypt */
hostkey_method_ssh_rsa_dtor,
};
#endif /* LIBSSH2_RSA */
#if LIBSSH2_DSA
/* ***********
* ssh-dss *
*********** */
static int hostkey_method_ssh_dss_dtor(LIBSSH2_SESSION * session,
void **abstract);
/*
* hostkey_method_ssh_dss_init
*
* Initialize the server hostkey working area with p/q/g/y set
*/
static int
hostkey_method_ssh_dss_init(LIBSSH2_SESSION * session,
const unsigned char *hostkey_data,
size_t hostkey_data_len,
void **abstract)
{
libssh2_dsa_ctx *dsactx;
const unsigned char *p, *q, *g, *y, *s;
unsigned long p_len, q_len, g_len, y_len, len;
(void) hostkey_data_len;
if (*abstract) {
hostkey_method_ssh_dss_dtor(session, abstract);
*abstract = NULL;
}
s = hostkey_data;
len = _libssh2_ntohu32(s);
s += 4;
if (len != 7 || strncmp((char *) s, "ssh-dss", 7) != 0) {
return -1;
}
s += 7;
p_len = _libssh2_ntohu32(s);
s += 4;
p = s;
s += p_len;
q_len = _libssh2_ntohu32(s);
s += 4;
q = s;
s += q_len;
g_len = _libssh2_ntohu32(s);
s += 4;
g = s;
s += g_len;
y_len = _libssh2_ntohu32(s);
s += 4;
y = s;
/* s += y_len; */
_libssh2_dsa_new(&dsactx, p, p_len, q, q_len, g, g_len, y, y_len, NULL, 0);
*abstract = dsactx;
return 0;
}
/*
* hostkey_method_ssh_dss_initPEM
*
* Load a Private Key from a PEM file
*/
static int
hostkey_method_ssh_dss_initPEM(LIBSSH2_SESSION * session,
const char *privkeyfile,
unsigned const char *passphrase,
void **abstract)
{
libssh2_dsa_ctx *dsactx;
int ret;
if (*abstract) {
hostkey_method_ssh_dss_dtor(session, abstract);
*abstract = NULL;
}
ret = _libssh2_dsa_new_private(&dsactx, session, privkeyfile, passphrase);
if (ret) {
return -1;
}
*abstract = dsactx;
return 0;
}
/*
* hostkey_method_ssh_dss_initPEMFromMemory
*
* Load a Private Key from memory
*/
static int
hostkey_method_ssh_dss_initPEMFromMemory(LIBSSH2_SESSION * session,
const char *privkeyfiledata,
size_t privkeyfiledata_len,
unsigned const char *passphrase,
void **abstract)
{
libssh2_dsa_ctx *dsactx;
int ret;
if (*abstract) {
hostkey_method_ssh_dss_dtor(session, abstract);
*abstract = NULL;
}
ret = _libssh2_dsa_new_private_frommemory(&dsactx, session,
privkeyfiledata,
privkeyfiledata_len, passphrase);
if (ret) {
return -1;
}
*abstract = dsactx;
return 0;
}
/*
* libssh2_hostkey_method_ssh_dss_sign
*
* Verify signature created by remote
*/
static int
hostkey_method_ssh_dss_sig_verify(LIBSSH2_SESSION * session,
const unsigned char *sig,
size_t sig_len,
const unsigned char *m,
size_t m_len, void **abstract)
{
libssh2_dsa_ctx *dsactx = (libssh2_dsa_ctx *) (*abstract);
/* Skip past keyname_len(4) + keyname(7){"ssh-dss"} + signature_len(4) */
sig += 15;
sig_len -= 15;
if (sig_len != 40) {
return _libssh2_error(session, LIBSSH2_ERROR_PROTO,
"Invalid DSS signature length");
}
return _libssh2_dsa_sha1_verify(dsactx, sig, m, m_len);
}
/*
* hostkey_method_ssh_dss_signv
*
* Construct a signature from an array of vectors
*/
static int
hostkey_method_ssh_dss_signv(LIBSSH2_SESSION * session,
unsigned char **signature,
size_t *signature_len,
int veccount,
const struct iovec datavec[],
void **abstract)
{
libssh2_dsa_ctx *dsactx = (libssh2_dsa_ctx *) (*abstract);
unsigned char hash[SHA_DIGEST_LENGTH];
libssh2_sha1_ctx ctx;
int i;
*signature = LIBSSH2_CALLOC(session, 2 * SHA_DIGEST_LENGTH);
if (!*signature) {
return -1;
}
*signature_len = 2 * SHA_DIGEST_LENGTH;
libssh2_sha1_init(&ctx);
for(i = 0; i < veccount; i++) {
libssh2_sha1_update(ctx, datavec[i].iov_base, datavec[i].iov_len);
}
libssh2_sha1_final(ctx, hash);
if (_libssh2_dsa_sha1_sign(dsactx, hash, SHA_DIGEST_LENGTH, *signature)) {
LIBSSH2_FREE(session, *signature);
return -1;
}
return 0;
}
/*
* libssh2_hostkey_method_ssh_dss_dtor
*
* Shutdown the hostkey method
*/
static int
hostkey_method_ssh_dss_dtor(LIBSSH2_SESSION * session, void **abstract)
{
libssh2_dsa_ctx *dsactx = (libssh2_dsa_ctx *) (*abstract);
(void) session;
_libssh2_dsa_free(dsactx);
*abstract = NULL;
return 0;
}
static const LIBSSH2_HOSTKEY_METHOD hostkey_method_ssh_dss = {
"ssh-dss",
MD5_DIGEST_LENGTH,
hostkey_method_ssh_dss_init,
hostkey_method_ssh_dss_initPEM,
hostkey_method_ssh_dss_initPEMFromMemory,
hostkey_method_ssh_dss_sig_verify,
hostkey_method_ssh_dss_signv,
NULL, /* encrypt */
hostkey_method_ssh_dss_dtor,
};
#endif /* LIBSSH2_DSA */
static const LIBSSH2_HOSTKEY_METHOD *hostkey_methods[] = {
#if LIBSSH2_RSA
&hostkey_method_ssh_rsa,
#endif /* LIBSSH2_RSA */
#if LIBSSH2_DSA
&hostkey_method_ssh_dss,
#endif /* LIBSSH2_DSA */
NULL
};
const LIBSSH2_HOSTKEY_METHOD **
libssh2_hostkey_methods(void)
{
return hostkey_methods;
}
/*
* libssh2_hostkey_hash
*
* Returns hash signature
* Returned buffer should NOT be freed
* Length of buffer is determined by hash type
* i.e. MD5 == 16, SHA1 == 20
*/
LIBSSH2_API const char *
libssh2_hostkey_hash(LIBSSH2_SESSION * session, int hash_type)
{
switch (hash_type) {
#if LIBSSH2_MD5
case LIBSSH2_HOSTKEY_HASH_MD5:
return (session->server_hostkey_md5_valid)
? (char *) session->server_hostkey_md5
: NULL;
break;
#endif /* LIBSSH2_MD5 */
case LIBSSH2_HOSTKEY_HASH_SHA1:
return (session->server_hostkey_sha1_valid)
? (char *) session->server_hostkey_sha1
: NULL;
break;
default:
return NULL;
}
}
static int hostkey_type(const unsigned char *hostkey, size_t len)
{
const unsigned char rsa[] = {
0, 0, 0, 0x07, 's', 's', 'h', '-', 'r', 's', 'a'
};
const unsigned char dss[] = {
0, 0, 0, 0x07, 's', 's', 'h', '-', 'd', 's', 's'
};
if (len < 11)
return LIBSSH2_HOSTKEY_TYPE_UNKNOWN;
if (!memcmp(rsa, hostkey, 11))
return LIBSSH2_HOSTKEY_TYPE_RSA;
if (!memcmp(dss, hostkey, 11))
return LIBSSH2_HOSTKEY_TYPE_DSS;
return LIBSSH2_HOSTKEY_TYPE_UNKNOWN;
}
/*
* libssh2_session_hostkey()
*
* Returns the server key and length.
*
*/
LIBSSH2_API const char *
libssh2_session_hostkey(LIBSSH2_SESSION *session, size_t *len, int *type)
{
if(session->server_hostkey_len) {
if(len)
*len = session->server_hostkey_len;
if (type)
*type = hostkey_type(session->server_hostkey,
session->server_hostkey_len);
return (char *) session->server_hostkey;
}
if(len)
*len = 0;
return NULL;
}