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userauth.c
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userauth.c
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/* Copyright (c) 2004-2007, Sara Golemon <sarag@libssh2.org>
* Copyright (c) 2005 Mikhail Gusarov <dottedmag@dottedmag.net>
* 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 <ctype.h>
#include <stdio.h>
#include <assert.h>
/* Needed for struct iovec on some platforms */
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include "transport.h"
#include "session.h"
#include "userauth.h"
#define LIBSSH2_USERAUTH_MAX_BANNER 2048
/* libssh2_userauth_list
*
* List authentication methods
* Will yield successful login if "none" happens to be allowable for this user
* Not a common configuration for any SSH server though
* username should be NULL, or a null terminated string
*/
static char *userauth_list(LIBSSH2_SESSION *session, const char *username,
unsigned int username_len)
{
static const unsigned char reply_codes[4] =
{ SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE,
SSH_MSG_USERAUTH_BANNER, 0 };
/* packet_type(1) + username_len(4) + service_len(4) +
service(14)"ssh-connection" + method_len(4) = 27 */
unsigned long methods_len;
unsigned char *s;
int rc;
if(session->userauth_list_state == libssh2_NB_state_idle) {
/* Zero the whole thing out */
memset(&session->userauth_list_packet_requirev_state, 0,
sizeof(session->userauth_list_packet_requirev_state));
session->userauth_list_data_len = username_len + 27;
s = session->userauth_list_data =
LIBSSH2_ALLOC(session, session->userauth_list_data_len);
if(!session->userauth_list_data) {
_libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for userauth_list");
return NULL;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
_libssh2_store_str(&s, username, username_len);
_libssh2_store_str(&s, "ssh-connection", 14);
_libssh2_store_u32(&s, 4); /* send "none" separately */
session->userauth_list_state = libssh2_NB_state_created;
}
if(session->userauth_list_state == libssh2_NB_state_created) {
rc = _libssh2_transport_send(session, session->userauth_list_data,
session->userauth_list_data_len,
(unsigned char *)"none", 4);
if(rc == LIBSSH2_ERROR_EAGAIN) {
_libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block requesting userauth list");
return NULL;
}
/* now free the packet that was sent */
LIBSSH2_FREE(session, session->userauth_list_data);
session->userauth_list_data = NULL;
if(rc) {
_libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send userauth-none request");
session->userauth_list_state = libssh2_NB_state_idle;
return NULL;
}
session->userauth_list_state = libssh2_NB_state_sent;
}
if(session->userauth_list_state == libssh2_NB_state_sent) {
do {
rc = _libssh2_packet_requirev(session, reply_codes,
&session->userauth_list_data,
&session->userauth_list_data_len, 0,
NULL, 0,
&session->userauth_list_packet_requirev_state);
if(rc == LIBSSH2_ERROR_EAGAIN) {
_libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block requesting userauth list");
return NULL;
}
else if(rc || (session->userauth_list_data_len < 1)) {
_libssh2_error(session, rc, "Failed getting response");
session->userauth_list_state = libssh2_NB_state_idle;
return NULL;
}
if(session->userauth_list_data[0] == SSH_MSG_USERAUTH_BANNER &&
(session->userauth_list_data_len >= 5)) {
methods_len =
_libssh2_ntohu32(session->userauth_list_data + 1);
/* Cap to 512 bytes. */
if(methods_len > LIBSSH2_USERAUTH_MAX_BANNER) {
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Banner length %u exceeds max allowed (%u)",
methods_len, LIBSSH2_USERAUTH_MAX_BANNER);
methods_len = LIBSSH2_USERAUTH_MAX_BANNER - 1;
}
if (!session->userauth_banner) {
session->userauth_banner = LIBSSH2_ALLOC(session,
methods_len + 1);
}
else if(session->userauth_banner_len < methods_len) {
session->userauth_banner =
LIBSSH2_REALLOC(session, session->userauth_banner,
methods_len + 1);
}
if (!session->userauth_banner) {
_libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for userauth_banner");
continue;
}
session->userauth_banner_len = methods_len;
memmove(session->userauth_banner,
session->userauth_list_data + 5, methods_len);
session->userauth_banner[methods_len] = '\0';
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Banner: %s",
session->userauth_banner);
LIBSSH2_FREE(session, session->userauth_list_data);
}
else break;
} while(1);
if(session->userauth_list_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
/* Wow, who'dve thought... */
_libssh2_error(session, LIBSSH2_ERROR_NONE, "No error");
LIBSSH2_FREE(session, session->userauth_list_data);
session->userauth_list_data = NULL;
session->state |= LIBSSH2_STATE_AUTHENTICATED;
session->userauth_list_state = libssh2_NB_state_idle;
return NULL;
}
if(session->userauth_list_data_len < 5) {
LIBSSH2_FREE(session, session->userauth_list_data);
session->userauth_list_data = NULL;
_libssh2_error(session, LIBSSH2_ERROR_PROTO,
"Unexpected packet size");
return NULL;
}
methods_len = _libssh2_ntohu32(session->userauth_list_data + 1);
if(methods_len >= session->userauth_list_data_len - 5) {
_libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY,
"Unexpected userauth list size");
return NULL;
}
/* Do note that the memory areas overlap! */
memmove(session->userauth_list_data, session->userauth_list_data + 5,
methods_len);
session->userauth_list_data[methods_len] = '\0';
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Permitted auth methods: %s",
session->userauth_list_data);
}
session->userauth_list_state = libssh2_NB_state_idle;
return (char *) session->userauth_list_data;
}
/* libssh2_userauth_list
*
* List authentication methods
* Will yield successful login if "none" happens to be allowable for this user
* Not a common configuration for any SSH server though
* username should be NULL, or a null terminated string
*/
LIBSSH2_API char *
libssh2_userauth_list(LIBSSH2_SESSION * session, const char *user,
unsigned int user_len)
{
char *ptr;
BLOCK_ADJUST_ERRNO(ptr, session,
userauth_list(session, user, user_len));
return ptr;
}
/* libssh2_userauth_banner
*
* Retrieve banner message from server, if available.
* If no such message is sent by the server or if no authentication attempt has
* been made, this function returns NULL.
* libssh2_userauth_list makes a "none" authentication attempt and is
* sufficient to collect the pre-auth banner message.
*
* Banner ought to be UTF-8 encoded, and will be truncated to
* LIBSSH2_USERAUTH_MAX_BANNER bytes. Length will be returned in
* banner_len_out.
*/
LIBSSH2_API char *
libssh2_userauth_banner(LIBSSH2_SESSION * session,
size_t *banner_len_out)
{
char *ptr = NULL;
if(session->userauth_banner) {
ptr = session->userauth_banner;
*banner_len_out = session->userauth_banner_len;
}
return ptr;
}
/*
* libssh2_userauth_authenticated
*
* Returns: 0 if not yet authenticated
* 1 if already authenticated
*/
LIBSSH2_API int
libssh2_userauth_authenticated(LIBSSH2_SESSION * session)
{
return (session->state & LIBSSH2_STATE_AUTHENTICATED)?1:0;
}
/* userauth_password
* Plain ol' login
*/
static int
userauth_password(LIBSSH2_SESSION *session,
const char *username, unsigned int username_len,
const unsigned char *password, unsigned int password_len,
LIBSSH2_PASSWD_CHANGEREQ_FUNC((*passwd_change_cb)))
{
unsigned char *s;
static const unsigned char reply_codes[4] =
{ SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE,
SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, 0
};
int rc;
if(session->userauth_pswd_state == libssh2_NB_state_idle) {
/* Zero the whole thing out */
memset(&session->userauth_pswd_packet_requirev_state, 0,
sizeof(session->userauth_pswd_packet_requirev_state));
/*
* 40 = packet_type(1) + username_len(4) + service_len(4) +
* service(14)"ssh-connection" + method_len(4) + method(8)"password" +
* chgpwdbool(1) + password_len(4) */
session->userauth_pswd_data_len = username_len + 40;
session->userauth_pswd_data0 =
(unsigned char) ~SSH_MSG_USERAUTH_PASSWD_CHANGEREQ;
/* TODO: remove this alloc with a fixed buffer in the session
struct */
s = session->userauth_pswd_data =
LIBSSH2_ALLOC(session, session->userauth_pswd_data_len);
if(!session->userauth_pswd_data) {
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for "
"userauth-password request");
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
_libssh2_store_str(&s, username, username_len);
_libssh2_store_str(&s, "ssh-connection", sizeof("ssh-connection") - 1);
_libssh2_store_str(&s, "password", sizeof("password") - 1);
*s++ = '\0';
_libssh2_store_u32(&s, password_len);
/* 'password' is sent separately */
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Attempting to login using password authentication");
session->userauth_pswd_state = libssh2_NB_state_created;
}
if(session->userauth_pswd_state == libssh2_NB_state_created) {
rc = _libssh2_transport_send(session, session->userauth_pswd_data,
session->userauth_pswd_data_len,
password, password_len);
if(rc == LIBSSH2_ERROR_EAGAIN) {
return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
"Would block writing password request");
}
/* now free the sent packet */
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
if(rc) {
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send userauth-password request");
}
session->userauth_pswd_state = libssh2_NB_state_sent;
}
password_response:
if((session->userauth_pswd_state == libssh2_NB_state_sent)
|| (session->userauth_pswd_state == libssh2_NB_state_sent1)
|| (session->userauth_pswd_state == libssh2_NB_state_sent2)) {
if(session->userauth_pswd_state == libssh2_NB_state_sent) {
rc = _libssh2_packet_requirev(session, reply_codes,
&session->userauth_pswd_data,
&session->userauth_pswd_data_len,
0, NULL, 0,
&session->
userauth_pswd_packet_requirev_state);
if(rc) {
if(rc != LIBSSH2_ERROR_EAGAIN)
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, rc,
"Waiting for password response");
}
else if(session->userauth_pswd_data_len < 1) {
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, LIBSSH2_ERROR_PROTO,
"Unexpected packet size");
}
if(session->userauth_pswd_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Password authentication successful");
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
session->state |= LIBSSH2_STATE_AUTHENTICATED;
session->userauth_pswd_state = libssh2_NB_state_idle;
return 0;
}
else if(session->userauth_pswd_data[0] ==
SSH_MSG_USERAUTH_FAILURE) {
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Password authentication failed");
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session,
LIBSSH2_ERROR_AUTHENTICATION_FAILED,
"Authentication failed "
"(username/password)");
}
session->userauth_pswd_newpw = NULL;
session->userauth_pswd_newpw_len = 0;
session->userauth_pswd_state = libssh2_NB_state_sent1;
}
if(session->userauth_pswd_data_len < 1) {
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, LIBSSH2_ERROR_PROTO,
"Unexpected packet size");
}
if((session->userauth_pswd_data[0] ==
SSH_MSG_USERAUTH_PASSWD_CHANGEREQ)
|| (session->userauth_pswd_data0 ==
SSH_MSG_USERAUTH_PASSWD_CHANGEREQ)) {
session->userauth_pswd_data0 = SSH_MSG_USERAUTH_PASSWD_CHANGEREQ;
if((session->userauth_pswd_state == libssh2_NB_state_sent1) ||
(session->userauth_pswd_state == libssh2_NB_state_sent2)) {
if(session->userauth_pswd_state == libssh2_NB_state_sent1) {
_libssh2_debug(session, LIBSSH2_TRACE_AUTH,
"Password change required");
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
}
if(passwd_change_cb) {
if(session->userauth_pswd_state ==
libssh2_NB_state_sent1) {
passwd_change_cb(session,
&session->userauth_pswd_newpw,
&session->userauth_pswd_newpw_len,
&session->abstract);
if(!session->userauth_pswd_newpw) {
return _libssh2_error(session,
LIBSSH2_ERROR_PASSWORD_EXPIRED,
"Password expired, and "
"callback failed");
}
/* basic data_len + newpw_len(4) */
if(username_len + password_len + 44 <= UINT_MAX) {
session->userauth_pswd_data_len =
username_len + password_len + 44;
s = session->userauth_pswd_data =
LIBSSH2_ALLOC(session,
session->userauth_pswd_data_len);
}
else {
s = session->userauth_pswd_data = NULL;
session->userauth_pswd_data_len = 0;
}
if(!session->userauth_pswd_data) {
LIBSSH2_FREE(session,
session->userauth_pswd_newpw);
session->userauth_pswd_newpw = NULL;
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory "
"for userauth password "
"change request");
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
_libssh2_store_str(&s, username, username_len);
_libssh2_store_str(&s, "ssh-connection",
sizeof("ssh-connection") - 1);
_libssh2_store_str(&s, "password",
sizeof("password") - 1);
*s++ = 0x01;
_libssh2_store_str(&s, (char *)password, password_len);
_libssh2_store_u32(&s,
session->userauth_pswd_newpw_len);
/* send session->userauth_pswd_newpw separately */
session->userauth_pswd_state = libssh2_NB_state_sent2;
}
if(session->userauth_pswd_state ==
libssh2_NB_state_sent2) {
rc = _libssh2_transport_send(session,
session->userauth_pswd_data,
session->userauth_pswd_data_len,
(unsigned char *)
session->userauth_pswd_newpw,
session->userauth_pswd_newpw_len);
if(rc == LIBSSH2_ERROR_EAGAIN) {
return _libssh2_error(session,
LIBSSH2_ERROR_EAGAIN,
"Would block waiting");
}
/* free the allocated packets again */
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
LIBSSH2_FREE(session, session->userauth_pswd_newpw);
session->userauth_pswd_newpw = NULL;
if(rc) {
return _libssh2_error(session,
LIBSSH2_ERROR_SOCKET_SEND,
"Unable to send userauth "
"password-change request");
}
/*
* Ugliest use of goto ever. Blame it on the
* askN => requirev migration.
*/
session->userauth_pswd_state = libssh2_NB_state_sent;
goto password_response;
}
}
}
else {
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED,
"Password Expired, and no callback "
"specified");
}
}
}
/* FAILURE */
LIBSSH2_FREE(session, session->userauth_pswd_data);
session->userauth_pswd_data = NULL;
session->userauth_pswd_state = libssh2_NB_state_idle;
return _libssh2_error(session, LIBSSH2_ERROR_AUTHENTICATION_FAILED,
"Authentication failed");
}
/*
* libssh2_userauth_password_ex
*
* Plain ol' login
*/
LIBSSH2_API int
libssh2_userauth_password_ex(LIBSSH2_SESSION *session, const char *username,
unsigned int username_len, const char *password,
unsigned int password_len,
LIBSSH2_PASSWD_CHANGEREQ_FUNC
((*passwd_change_cb)))
{
int rc;
BLOCK_ADJUST(rc, session,
userauth_password(session, username, username_len,
(unsigned char *)password, password_len,
passwd_change_cb));
return rc;
}
static int
memory_read_publickey(LIBSSH2_SESSION * session, unsigned char **method,
size_t *method_len,
unsigned char **pubkeydata,
size_t *pubkeydata_len,
const char *pubkeyfiledata,
size_t pubkeyfiledata_len)
{
unsigned char *pubkey = NULL, *sp1, *sp2, *tmp;
size_t pubkey_len = pubkeyfiledata_len;
unsigned int tmp_len;
if(pubkeyfiledata_len <= 1) {
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid data in public key file");
}
pubkey = LIBSSH2_ALLOC(session, pubkeyfiledata_len);
if(!pubkey) {
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for public key data");
}
memcpy(pubkey, pubkeyfiledata, pubkeyfiledata_len);
/*
* Remove trailing whitespace
*/
while(pubkey_len && isspace(pubkey[pubkey_len - 1]))
pubkey_len--;
if(!pubkey_len) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Missing public key data");
}
sp1 = memchr(pubkey, ' ', pubkey_len);
if(sp1 == NULL) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid public key data");
}
sp1++;
sp2 = memchr(sp1, ' ', pubkey_len - (sp1 - pubkey));
if(sp2 == NULL) {
/* Assume that the id string is missing, but that it's okay */
sp2 = pubkey + pubkey_len;
}
if(libssh2_base64_decode(session, (char **) &tmp, &tmp_len,
(char *) sp1, sp2 - sp1)) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid key data, not base64 encoded");
}
/* Wasting some bytes here (okay, more than some), but since it's likely
* to be freed soon anyway, we'll just avoid the extra free/alloc and call
* it a wash
*/
*method = pubkey;
*method_len = sp1 - pubkey - 1;
*pubkeydata = tmp;
*pubkeydata_len = tmp_len;
return 0;
}
/*
* file_read_publickey
*
* Read a public key from an id_???.pub style file
*
* Returns an allocated string containing the decoded key in *pubkeydata
* on success.
* Returns an allocated string containing the key method (e.g. "ssh-dss")
* in method on success.
*/
static int
file_read_publickey(LIBSSH2_SESSION * session, unsigned char **method,
size_t *method_len,
unsigned char **pubkeydata,
size_t *pubkeydata_len,
const char *pubkeyfile)
{
FILE *fd;
char c;
unsigned char *pubkey = NULL, *sp1, *sp2, *tmp;
size_t pubkey_len = 0, sp_len;
unsigned int tmp_len;
_libssh2_debug(session, LIBSSH2_TRACE_AUTH, "Loading public key file: %s",
pubkeyfile);
/* Read Public Key */
fd = fopen(pubkeyfile, FOPEN_READTEXT);
if(!fd) {
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Unable to open public key file");
}
while(!feof(fd) && 1 == fread(&c, 1, 1, fd) && c != '\r' && c != '\n') {
pubkey_len++;
}
rewind(fd);
if(pubkey_len <= 1) {
fclose(fd);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid data in public key file");
}
pubkey = LIBSSH2_ALLOC(session, pubkey_len);
if(!pubkey) {
fclose(fd);
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Unable to allocate memory for public key data");
}
if(fread(pubkey, 1, pubkey_len, fd) != pubkey_len) {
LIBSSH2_FREE(session, pubkey);
fclose(fd);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Unable to read public key from file");
}
fclose(fd);
/*
* Remove trailing whitespace
*/
while(pubkey_len && isspace(pubkey[pubkey_len - 1])) {
pubkey_len--;
}
if(!pubkey_len) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Missing public key data");
}
sp1 = memchr(pubkey, ' ', pubkey_len);
if(sp1 == NULL) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid public key data");
}
sp1++;
sp_len = sp1 > pubkey ? (sp1 - pubkey) : 0;
sp2 = memchr(sp1, ' ', pubkey_len - sp_len);
if(sp2 == NULL) {
/* Assume that the id string is missing, but that it's okay */
sp2 = pubkey + pubkey_len;
}
if(libssh2_base64_decode(session, (char **) &tmp, &tmp_len,
(char *) sp1, sp2 - sp1)) {
LIBSSH2_FREE(session, pubkey);
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Invalid key data, not base64 encoded");
}
/* Wasting some bytes here (okay, more than some), but since it's likely
* to be freed soon anyway, we'll just avoid the extra free/alloc and call
* it a wash */
*method = pubkey;
*method_len = sp1 - pubkey - 1;
*pubkeydata = tmp;
*pubkeydata_len = tmp_len;
return 0;
}
static int
memory_read_privatekey(LIBSSH2_SESSION * session,
const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,
void **hostkey_abstract,
const unsigned char *method, int method_len,
const char *privkeyfiledata, size_t privkeyfiledata_len,
const char *passphrase)
{
const LIBSSH2_HOSTKEY_METHOD **hostkey_methods_avail =
libssh2_hostkey_methods();
*hostkey_method = NULL;
*hostkey_abstract = NULL;
while(*hostkey_methods_avail && (*hostkey_methods_avail)->name) {
if((*hostkey_methods_avail)->initPEMFromMemory
&& strncmp((*hostkey_methods_avail)->name, (const char *) method,
method_len) == 0) {
*hostkey_method = *hostkey_methods_avail;
break;
}
hostkey_methods_avail++;
}
if(!*hostkey_method) {
return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NONE,
"No handler for specified private key");
}
if((*hostkey_method)->
initPEMFromMemory(session, privkeyfiledata, privkeyfiledata_len,
(unsigned char *) passphrase,
hostkey_abstract)) {
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Unable to initialize private key from file");
}
return 0;
}
/* libssh2_file_read_privatekey
* Read a PEM encoded private key from an id_??? style file
*/
static int
file_read_privatekey(LIBSSH2_SESSION * session,
const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,
void **hostkey_abstract,
const unsigned char *method, int method_len,
const char *privkeyfile, const char *passphrase)
{
const LIBSSH2_HOSTKEY_METHOD **hostkey_methods_avail =
libssh2_hostkey_methods();
_libssh2_debug(session, LIBSSH2_TRACE_AUTH, "Loading private key file: %s",
privkeyfile);
*hostkey_method = NULL;
*hostkey_abstract = NULL;
while(*hostkey_methods_avail && (*hostkey_methods_avail)->name) {
if((*hostkey_methods_avail)->initPEM
&& strncmp((*hostkey_methods_avail)->name, (const char *) method,
method_len) == 0) {
*hostkey_method = *hostkey_methods_avail;
break;
}
hostkey_methods_avail++;
}
if(!*hostkey_method) {
return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NONE,
"No handler for specified private key");
}
if((*hostkey_method)->
initPEM(session, privkeyfile, (unsigned char *) passphrase,
hostkey_abstract)) {
return _libssh2_error(session, LIBSSH2_ERROR_FILE,
"Unable to initialize private key from file");
}
return 0;
}
struct privkey_file {
const char *filename;
const char *passphrase;
};
static int
sign_frommemory(LIBSSH2_SESSION *session, unsigned char **sig, size_t *sig_len,
const unsigned char *data, size_t data_len, void **abstract)
{
struct privkey_file *pk_file = (struct privkey_file *) (*abstract);
const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
void *hostkey_abstract;
struct iovec datavec;
int rc;
rc = memory_read_privatekey(session, &privkeyobj, &hostkey_abstract,
session->userauth_pblc_method,
session->userauth_pblc_method_len,
pk_file->filename,
strlen(pk_file->filename),
pk_file->passphrase);
if(rc)
return rc;
libssh2_prepare_iovec(&datavec, 1);
datavec.iov_base = (void *)data;
datavec.iov_len = data_len;
if(privkeyobj->signv(session, sig, sig_len, 1, &datavec,
&hostkey_abstract)) {
if(privkeyobj->dtor) {
privkeyobj->dtor(session, &hostkey_abstract);
}
return -1;
}
if(privkeyobj->dtor) {
privkeyobj->dtor(session, &hostkey_abstract);
}
return 0;
}
static int
sign_fromfile(LIBSSH2_SESSION *session, unsigned char **sig, size_t *sig_len,
const unsigned char *data, size_t data_len, void **abstract)
{
struct privkey_file *privkey_file = (struct privkey_file *) (*abstract);
const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
void *hostkey_abstract;
struct iovec datavec;
int rc;
rc = file_read_privatekey(session, &privkeyobj, &hostkey_abstract,
session->userauth_pblc_method,
session->userauth_pblc_method_len,
privkey_file->filename,
privkey_file->passphrase);
if(rc)
return rc;
libssh2_prepare_iovec(&datavec, 1);
datavec.iov_base = (void *)data;
datavec.iov_len = data_len;
if(privkeyobj->signv(session, sig, sig_len, 1, &datavec,
&hostkey_abstract)) {
if(privkeyobj->dtor) {
privkeyobj->dtor(session, &hostkey_abstract);
}
return -1;
}
if(privkeyobj->dtor) {
privkeyobj->dtor(session, &hostkey_abstract);
}
return 0;
}
/* userauth_hostbased_fromfile
* Authenticate using a keypair found in the named files
*/
static int
userauth_hostbased_fromfile(LIBSSH2_SESSION *session,
const char *username, size_t username_len,
const char *publickey, const char *privatekey,
const char *passphrase, const char *hostname,
size_t hostname_len,
const char *local_username,
size_t local_username_len)
{
int rc;
#if !LIBSSH2_RSA
return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED,
"RSA is not supported by crypto backend");
#endif
if(session->userauth_host_state == libssh2_NB_state_idle) {
const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
unsigned char *pubkeydata = NULL;
unsigned char *sig = NULL;
size_t pubkeydata_len = 0;
size_t sig_len = 0;
void *abstract;
unsigned char buf[5];
struct iovec datavec[4];
/* Zero the whole thing out */
memset(&session->userauth_host_packet_requirev_state, 0,
sizeof(session->userauth_host_packet_requirev_state));
if(publickey) {
rc = file_read_publickey(session, &session->userauth_host_method,
&session->userauth_host_method_len,
&pubkeydata, &pubkeydata_len, publickey);
if(rc)
/* Note: file_read_publickey() calls _libssh2_error() */
return rc;
}
else {
/* Compute public key from private key. */
rc = _libssh2_pub_priv_keyfile(session,
&session->userauth_host_method,
&session->userauth_host_method_len,
&pubkeydata, &pubkeydata_len,
privatekey, passphrase);
if(rc)
/* libssh2_pub_priv_keyfile calls _libssh2_error() */
return rc;
}
/*
* 52 = packet_type(1) + username_len(4) + servicename_len(4) +
* service_name(14)"ssh-connection" + authmethod_len(4) +
* authmethod(9)"hostbased" + method_len(4) + pubkeydata_len(4) +
* hostname_len(4) + local_username_len(4)
*/
session->userauth_host_packet_len =
username_len + session->userauth_host_method_len + hostname_len +
local_username_len + pubkeydata_len + 52;
/*
* Preallocate space for an overall length, method name again,
* and the signature, which won't be any larger than the size of
* the publickeydata itself
*/
session->userauth_host_s = session->userauth_host_packet =
LIBSSH2_ALLOC(session,
session->userauth_host_packet_len + 4 +
(4 + session->userauth_host_method_len) +
(4 + pubkeydata_len));
if(!session->userauth_host_packet) {
LIBSSH2_FREE(session, session->userauth_host_method);
session->userauth_host_method = NULL;
LIBSSH2_FREE(session, pubkeydata);
return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
"Out of memory");
}
*(session->userauth_host_s++) = SSH_MSG_USERAUTH_REQUEST;
_libssh2_store_str(&session->userauth_host_s, username, username_len);
_libssh2_store_str(&session->userauth_host_s, "ssh-connection", 14);
_libssh2_store_str(&session->userauth_host_s, "hostbased", 9);
_libssh2_store_str(&session->userauth_host_s,
(const char *)session->userauth_host_method,
session->userauth_host_method_len);
_libssh2_store_str(&session->userauth_host_s, (const char *)pubkeydata,
pubkeydata_len);
LIBSSH2_FREE(session, pubkeydata);
_libssh2_store_str(&session->userauth_host_s, hostname, hostname_len);
_libssh2_store_str(&session->userauth_host_s, local_username,
local_username_len);
rc = file_read_privatekey(session, &privkeyobj, &abstract,
session->userauth_host_method,
session->userauth_host_method_len,
privatekey, passphrase);
if(rc) {
/* Note: file_read_privatekey() calls _libssh2_error() */
LIBSSH2_FREE(session, session->userauth_host_method);
session->userauth_host_method = NULL;
LIBSSH2_FREE(session, session->userauth_host_packet);
session->userauth_host_packet = NULL;
return rc;
}
_libssh2_htonu32(buf, session->session_id_len);
libssh2_prepare_iovec(datavec, 4);
datavec[0].iov_base = (void *)buf;
datavec[0].iov_len = 4;
datavec[1].iov_base = (void *)session->session_id;
datavec[1].iov_len = session->session_id_len;
datavec[2].iov_base = (void *)session->userauth_host_packet;
datavec[2].iov_len = session->userauth_host_packet_len;