/* Copyright (c) 2004-2007, Sara Golemon <sarag@libssh2.org>
* 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>
/* Needed for struct iovec on some platforms */
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
/* {{{ proto 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 *username, unsigned int username_len)
{
static const unsigned char reply_codes[3] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
unsigned long data_len = username_len + 31; /* packet_type(1) + username_len(4) + service_len(4) + service(14)"ssh-connection" +
method_len(4) + method(4)"none" */
unsigned long methods_len;
unsigned char *data, *s;
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth_list", 0);
return NULL;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
if (username) {
memcpy(s, username, username_len); s += username_len;
}
libssh2_htonu32(s, 14); s += 4;
memcpy(s, "ssh-connection", 14); s += 14;
libssh2_htonu32(s, 4); s += 4;
memcpy(s, "none", 4); s += 4;
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-none request", 0);
LIBSSH2_FREE(session, data);
return NULL;
}
LIBSSH2_FREE(session, data);
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return NULL;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
/* Wow, who'dve thought... */
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return NULL;
}
methods_len = libssh2_ntohu32(data + 1);
memcpy(data, data + 5, methods_len);
data[methods_len] = '\0';
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Permitted auth methods: %s", data);
return (char *)data;
}
/* }}} */
/* {{{ libssh2_userauth_authenticated
* 0 if not yet authenticated
* non-zero is already authenticated
*/
LIBSSH2_API int libssh2_userauth_authenticated(LIBSSH2_SESSION *session)
{
return session->state & LIBSSH2_STATE_AUTHENTICATED;
}
/* }}} */
/* {{{ libssh2_userauth_password
* 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)))
{
unsigned char *data, *s;
static const unsigned char reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, 0 };
unsigned long data_len = username_len + password_len + 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) */
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth-password request", 0);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
libssh2_htonu32(s, sizeof("password") - 1); s += 4;
memcpy(s, "password", sizeof("password") - 1); s += sizeof("password") - 1;
*s = '\0'; s++;
libssh2_htonu32(s, password_len); s += 4;
memcpy(s, password, password_len); s += password_len;
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting to login using password authentication");
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-password request", 0);
LIBSSH2_FREE(session, data);
return -1;
}
LIBSSH2_FREE(session, data);
password_response:
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Password authentication successful");
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_PASSWD_CHANGEREQ) {
char *newpw = NULL;
int newpw_len = 0;
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Password change required");
LIBSSH2_FREE(session, data);
if (passwd_change_cb) {
passwd_change_cb(session, &newpw, &newpw_len, &session->abstract);
if (!newpw) {
libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED, "Password expired, and callback failed", 0);
return -1;
}
data_len = username_len + password_len + 44 + newpw_len; /* basic data_len + newpw_len(4) */
s = data = LIBSSH2_ALLOC(session, data_len);
if (!data) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for userauth-password-change request", 0);
LIBSSH2_FREE(session, newpw);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
libssh2_htonu32(s, sizeof("password") - 1); s += 4;
memcpy(s, "password", sizeof("password") - 1); s += sizeof("password") - 1;
*s = 0xFF; s++;
libssh2_htonu32(s, password_len); s += 4;
memcpy(s, password, password_len); s += password_len;
libssh2_htonu32(s, newpw_len); s += 4;
memcpy(s, newpw, newpw_len); s += newpw_len;
if (libssh2_packet_write(session, data, data_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-password-change request", 0);
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, newpw);
return -1;
}
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, newpw);
/* Ugliest use of goto ever. Blame it on the askN => requirev migration. */
goto password_response;
} else {
libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED, "Password Expired, and no callback specified", 0);
return -1;
}
}
/* FAILURE */
LIBSSH2_FREE(session, data);
return -1;
}
/* }}} */
/* {{{ libssh2_file_read_publickey
* Read a public key from an id_???.pub style file
*/
static int libssh2_file_read_publickey(LIBSSH2_SESSION *session, unsigned char **method, unsigned long *method_len,
unsigned char **pubkeydata, unsigned long *pubkeydata_len,
const char *pubkeyfile)
{
FILE *fd;
char c;
unsigned char *pubkey = NULL, *sp1, *sp2, *tmp;
size_t pubkey_len = 0;
unsigned int tmp_len;
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Loading public key file: %s", pubkeyfile);
/* Read Public Key */
fd = fopen(pubkeyfile, "r");
if (!fd) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Unable to open public key file", 0);
return -1;
}
while (!feof(fd) && (c = fgetc(fd)) != '\r' && c != '\n') pubkey_len++;
if (feof(fd)) {
/* the last character was EOF */
pubkey_len--;
}
rewind(fd);
if (pubkey_len <= 1) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Invalid data in public key file", 0);
fclose(fd);
return -1;
}
pubkey = LIBSSH2_ALLOC(session, pubkey_len);
if (!pubkey) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for public key data", 0);
fclose(fd);
return -1;
}
if (fread(pubkey, 1, pubkey_len, fd) != pubkey_len) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Unable to read public key from file", 0);
LIBSSH2_FREE(session, pubkey);
fclose(fd);
return -1;
}
fclose(fd);
/*
* Remove trailing whitespace
*/
while (pubkey_len && isspace(pubkey[pubkey_len-1])) pubkey_len--;
if (!pubkey_len) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Missing public key data", 0);
LIBSSH2_FREE(session, pubkey);
return -1;
}
if ((sp1 = memchr(pubkey, ' ', pubkey_len)) == NULL) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Invalid public key data", 0);
LIBSSH2_FREE(session, pubkey);
return -1;
}
/* 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;
sp1++;
if ((sp2 = memchr(sp1, ' ', pubkey_len - *method_len)) == 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_error(session, LIBSSH2_ERROR_FILE, "Invalid key data, not base64 encoded", 0);
LIBSSH2_FREE(session, pubkey);
return -1;
}
*pubkeydata = tmp;
*pubkeydata_len = tmp_len;
return 0;
}
/* }}} */
/* {{{ libssh2_file_read_privatekey
* Read a PEM encoded private key from an id_??? style file
*/
static int libssh2_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_DBG_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) {
libssh2_error(session, LIBSSH2_ERROR_METHOD_NONE, "No handler for specified private key", 0);
return -1;
}
if ((*hostkey_method)->initPEM(session, privkeyfile, passphrase, hostkey_abstract)) {
libssh2_error(session, LIBSSH2_ERROR_FILE, "Unable to initialize private key from file", 0);
return -1;
}
return 0;
}
/* }}} */
/* {{{ libssh2_userauth_hostbased_fromfile_ex
* Authenticate using a keypair found in the named files
*/
LIBSSH2_API int libssh2_userauth_hostbased_fromfile_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
const char *publickey, const char *privatekey,
const char *passphrase,
const char *hostname, unsigned int hostname_len,
const char *local_username, unsigned int local_username_len)
{
const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
void *abstract;
unsigned char buf[5];
struct iovec datavec[4];
unsigned char *method, *pubkeydata, *packet, *s, *sig, *data;
static const unsigned char reply_codes[3] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
unsigned long method_len, pubkeydata_len, packet_len, sig_len, data_len;
if (libssh2_file_read_publickey(session, &method, &method_len, &pubkeydata, &pubkeydata_len, publickey)) {
return -1;
}
packet_len = username_len + method_len + hostname_len + local_username_len + pubkeydata_len + 48;
/* 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) +
* local_username_len(4)
*/
/* 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 */
s = packet = LIBSSH2_ALLOC(session, packet_len + 4 + (4 + method_len) + (4 + pubkeydata_len));
if (!packet) {
LIBSSH2_FREE(session, method);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, 14); s += 4;
memcpy(s, "ssh-connection", 14); s += 14;
libssh2_htonu32(s, 9); s += 4;
memcpy(s, "hostbased", 9); s += 9;
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
libssh2_htonu32(s, pubkeydata_len); s += 4;
memcpy(s, pubkeydata, pubkeydata_len); s += pubkeydata_len;
libssh2_htonu32(s, hostname_len); s += 4;
memcpy(s, hostname, hostname_len); s += hostname_len;
libssh2_htonu32(s, local_username_len); s += 4;
memcpy(s, local_username, local_username_len); s += local_username_len;
if (libssh2_file_read_privatekey(session, &privkeyobj, &abstract, method, method_len, privatekey, passphrase)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
return -1;
}
libssh2_htonu32(buf, session->session_id_len);
datavec[0].iov_base = buf;
datavec[0].iov_len = 4;
datavec[1].iov_base = session->session_id;
datavec[1].iov_len = session->session_id_len;
datavec[2].iov_base = packet;
datavec[2].iov_len = packet_len;
if (privkeyobj->signv(session, &sig, &sig_len, 3, datavec, &abstract)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
return -1;
}
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
if (sig_len > pubkeydata_len) {
unsigned char *newpacket;
/* Should *NEVER* happen, but...well.. better safe than sorry */
newpacket = LIBSSH2_REALLOC(session, packet, packet_len + 4 + (4 + method_len) + (4 + sig_len)); /* PK sigblob */
if (!newpacket) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Failed allocating additional space for userauth-hostbased packet", 0);
LIBSSH2_FREE(session, sig);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
return -1;
}
packet = newpacket;
}
s = packet + packet_len;
libssh2_htonu32(s, 4 + method_len + 4 + sig_len); s += 4;
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
LIBSSH2_FREE(session, method);
libssh2_htonu32(s, sig_len); s += 4;
memcpy(s, sig, sig_len); s += sig_len;
LIBSSH2_FREE(session, sig);
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting hostbased authentication");
if (libssh2_packet_write(session, packet, s - packet)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-hostbased request", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
LIBSSH2_FREE(session, packet);
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_DBG_AUTH,
"Hostbased authentication successful");
/* We are us and we've proved it. */
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
/* This public key is not allowed for this user on this server */
LIBSSH2_FREE(session, data);
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED, "Invalid signature for supplied public key, or bad username/public key combination", 0);
return -1;
}
/* }}} */
/* {{{ libssh2_userauth_publickey_fromfile_ex
* Authenticate using a keypair found in the named files
*/
LIBSSH2_API int libssh2_userauth_publickey_fromfile_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
const char *publickey, const char *privatekey,
const char *passphrase)
{
const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
void *abstract;
unsigned char buf[5];
struct iovec datavec[4];
unsigned char *method, *pubkeydata, *packet, *s, *b, *sig, *data;
unsigned char reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_PK_OK, 0 };
unsigned long method_len, pubkeydata_len, packet_len, sig_len, data_len;
if (libssh2_file_read_publickey(session, &method, &method_len, &pubkeydata, &pubkeydata_len, publickey)) {
return -1;
}
packet_len = username_len + method_len + pubkeydata_len + 45; /* packet_type(1) + username_len(4) + servicename_len(4) +
service_name(14)"ssh-connection" + authmethod_len(4) +
authmethod(9)"publickey" + sig_included(1)'\0' +
algmethod_len(4) + publickey_len(4) */
/* 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 */
s = packet = LIBSSH2_ALLOC(session, packet_len + 4 + (4 + method_len) + (4 + pubkeydata_len));
if (!packet) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, pubkeydata);
return -1;
}
*(s++) = SSH_MSG_USERAUTH_REQUEST;
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
libssh2_htonu32(s, 14); s += 4;
memcpy(s, "ssh-connection", 14); s += 14;
libssh2_htonu32(s, 9); s += 4;
memcpy(s, "publickey", 9); s += 9;
b = s;
*(s++) = 0; /* Not sending signature with *this* packet */
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
libssh2_htonu32(s, pubkeydata_len); s += 4;
memcpy(s, pubkeydata, pubkeydata_len); s += pubkeydata_len;
LIBSSH2_FREE(session, pubkeydata);
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting publickey authentication");
if (libssh2_packet_write(session, packet, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-publickey request", 0);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
return -1;
}
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Pubkey authentication prematurely successful");
/* God help any SSH server that allows an UNVERIFIED public key to validate the user */
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_FAILURE) {
/* This public key is not allowed for this user on this server */
LIBSSH2_FREE(session, data);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED, "Username/PublicKey combination invalid", 0);
return -1;
}
/* Semi-Success! */
LIBSSH2_FREE(session, data);
if (libssh2_file_read_privatekey(session, &privkeyobj, &abstract, method, method_len, privatekey, passphrase)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
return -1;
}
*b = 0xFF;
libssh2_htonu32(buf, session->session_id_len);
datavec[0].iov_base = buf;
datavec[0].iov_len = 4;
datavec[1].iov_base = session->session_id;
datavec[1].iov_len = session->session_id_len;
datavec[2].iov_base = packet;
datavec[2].iov_len = packet_len;
if (privkeyobj->signv(session, &sig, &sig_len, 3, datavec, &abstract)) {
LIBSSH2_FREE(session, method);
LIBSSH2_FREE(session, packet);
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
return -1;
}
if (privkeyobj->dtor) {
privkeyobj->dtor(session, &abstract);
}
if (sig_len > pubkeydata_len) {
unsigned char *newpacket;
/* Should *NEVER* happen, but...well.. better safe than sorry */
newpacket = LIBSSH2_REALLOC(session, packet, packet_len + 4 + (4 + method_len) + (4 + sig_len)); /* PK sigblob */
if (!newpacket) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Failed allocating additional space for userauth-publickey packet", 0);
LIBSSH2_FREE(session, sig);
LIBSSH2_FREE(session, packet);
LIBSSH2_FREE(session, method);
return -1;
}
packet = newpacket;
}
s = packet + packet_len;
libssh2_htonu32(s, 4 + method_len + 4 + sig_len); s += 4;
libssh2_htonu32(s, method_len); s += 4;
memcpy(s, method, method_len); s += method_len;
LIBSSH2_FREE(session, method);
libssh2_htonu32(s, sig_len); s += 4;
memcpy(s, sig, sig_len); s += sig_len;
LIBSSH2_FREE(session, sig);
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting publickey authentication -- phase 2");
if (libssh2_packet_write(session, packet, s - packet)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-publickey request", 0);
LIBSSH2_FREE(session, packet);
return -1;
}
LIBSSH2_FREE(session, packet);
/* PK_OK is no longer valid */
reply_codes[2] = 0;
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Publickey authentication successful");
/* We are us and we've proved it. */
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
/* This public key is not allowed for this user on this server */
LIBSSH2_FREE(session, data);
libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED, "Invalid signature for supplied public key, or bad username/public key combination", 0);
return -1;
}
/* }}} */
/* {{{ libssh2_userauth_keyboard_interactive
* Authenticate using a challenge-response authentication
*/
LIBSSH2_API int libssh2_userauth_keyboard_interactive_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC((*response_callback)))
{
unsigned char *s, *data; /* packet */
unsigned long packet_len;
packet_len = 1 /* byte SSH_MSG_USERAUTH_REQUEST */
+ 4 + username_len /* string user name (ISO-10646 UTF-8, as defined in [RFC-3629]) */
+ 4 + 14 /* string service name (US-ASCII) */
+ 4 + 20 /* string "keyboard-interactive" (US-ASCII) */
+ 4 + 0 /* string language tag (as defined in [RFC-3066]) */
+ 4 + 0 /* string submethods (ISO-10646 UTF-8) */
;
if (!(data = s = LIBSSH2_ALLOC(session, packet_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive authentication", 0);
return -1;
}
*s++ = SSH_MSG_USERAUTH_REQUEST;
/* user name */
libssh2_htonu32(s, username_len); s += 4;
memcpy(s, username, username_len); s += username_len;
/* service name */
libssh2_htonu32(s, sizeof("ssh-connection") - 1); s += 4;
memcpy(s, "ssh-connection", sizeof("ssh-connection") - 1); s += sizeof("ssh-connection") - 1;
/* "keyboard-interactive" */
libssh2_htonu32(s, sizeof("keyboard-interactive") - 1); s += 4;
memcpy(s, "keyboard-interactive", sizeof("keyboard-interactive") - 1); s += sizeof("keyboard-interactive") - 1;
/* language tag */
libssh2_htonu32(s, 0); s += 4;
/* submethods */
libssh2_htonu32(s, 0); s += 4;
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Attempting keyboard-interactive authentication");
if (libssh2_packet_write(session, data, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send keyboard-interactive request", 0);
LIBSSH2_FREE(session, data);
return -1;
}
LIBSSH2_FREE(session, data);
for (;;) {
static const unsigned char reply_codes[4] = { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_INFO_REQUEST, 0 };
unsigned int auth_name_len;
char* auth_name = NULL;
unsigned auth_instruction_len;
char* auth_instruction = NULL;
unsigned int language_tag_len;
unsigned long data_len;
unsigned int num_prompts = 0;
unsigned int i;
int auth_failure = 1;
LIBSSH2_USERAUTH_KBDINT_PROMPT* prompts = NULL;
LIBSSH2_USERAUTH_KBDINT_RESPONSE* responses = NULL;
if (libssh2_packet_requirev(session, reply_codes, &data, &data_len)) {
return -1;
}
if (data[0] == SSH_MSG_USERAUTH_SUCCESS) {
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Keyboard-interactive authentication successful");
LIBSSH2_FREE(session, data);
session->state |= LIBSSH2_STATE_AUTHENTICATED;
return 0;
}
if (data[0] == SSH_MSG_USERAUTH_FAILURE) {
LIBSSH2_FREE(session, data);
return -1;
}
/* server requested PAM-like conversation */
s = data + 1;
/* string name (ISO-10646 UTF-8) */
auth_name_len = libssh2_ntohu32(s); s += 4;
if (!(auth_name = LIBSSH2_ALLOC(session, auth_name_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive 'name' request field", 0);
goto cleanup;
}
memcpy(auth_name, s, auth_name_len); s += auth_name_len;
/* string instruction (ISO-10646 UTF-8) */
auth_instruction_len = libssh2_ntohu32(s); s += 4;
if (!(auth_instruction = LIBSSH2_ALLOC(session, auth_instruction_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive 'instruction' request field", 0);
goto cleanup;
}
memcpy(auth_instruction, s, auth_instruction_len); s += auth_instruction_len;
/* string language tag (as defined in [RFC-3066]) */
language_tag_len = libssh2_ntohu32(s); s += 4;
/* ignoring this field as deprecated */ s += language_tag_len;
/* int num-prompts */
num_prompts = libssh2_ntohu32(s); s += 4;
prompts = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) * num_prompts);
if (!prompts) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive prompts array", 0);
goto cleanup;
}
memset(prompts, 0, sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) * num_prompts);
responses = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) * num_prompts);
if (!responses) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive responses array", 0);
goto cleanup;
}
memset(responses, 0, sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) * num_prompts);
for(i = 0; i != num_prompts; ++i) {
/* string prompt[1] (ISO-10646 UTF-8) */
prompts[i].length = libssh2_ntohu32(s); s += 4;
if (!(prompts[i].text = LIBSSH2_ALLOC(session, prompts[i].length))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive prompt message", 0);
goto cleanup;
}
memcpy(prompts[i].text, s, prompts[i].length); s += prompts[i].length;
/* boolean echo[1] */
prompts[i].echo = *s++;
}
response_callback(auth_name, auth_name_len, auth_instruction, auth_instruction_len, num_prompts, prompts, responses, &session->abstract);
_libssh2_debug(session, LIBSSH2_DBG_AUTH, "Keyboard-interactive response callback function invoked");
packet_len = 1 /* byte SSH_MSG_USERAUTH_INFO_RESPONSE */
+ 4 /* int num-responses */
;
for (i = 0; i != num_prompts; ++i) {
packet_len += 4 + responses[i].length; /* string response[1] (ISO-10646 UTF-8) */
}
if (!(data = s = LIBSSH2_ALLOC(session, packet_len))) {
libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for keyboard-interactive response packet", 0);
goto cleanup;
}
*s = SSH_MSG_USERAUTH_INFO_RESPONSE; s++;
libssh2_htonu32(s, num_prompts); s += 4;
for (i = 0; i != num_prompts; ++i) {
libssh2_htonu32(s, responses[i].length); s += 4;
memcpy(s, responses[i].text, responses[i].length); s += responses[i].length;
}
if (libssh2_packet_write(session, data, packet_len)) {
libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send userauth-keyboard-interactive request", 0);
goto cleanup;
}
auth_failure = 0;
cleanup:
/* It's safe to clean all the data here, because unallocated pointers
* are filled by zeroes
*/
LIBSSH2_FREE(session, data);
if (prompts) {
for (i = 0; i != num_prompts; ++i) {
LIBSSH2_FREE(session, prompts[i].text);
}
}
if (responses) {
for (i = 0; i != num_prompts; ++i) {
LIBSSH2_FREE(session, responses[i].text);
}
}
LIBSSH2_FREE(session, prompts);
LIBSSH2_FREE(session, responses);
if (auth_failure) {
return -1;
}
}
}
/* }}} */