ssh token: Move SSH code to a separate utils file

This commit is contained in:
Vojtech Trefny
2021-06-22 08:26:21 +02:00
parent 73cd60b1cc
commit 3e52aa820c
5 changed files with 205 additions and 151 deletions

View File

@@ -29,13 +29,9 @@
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <json-c/json.h>
#include <libssh/libssh.h>
#include <libssh/sftp.h>
#include "libcryptsetup.h"
#define PASSWORD_LENGTH 8192
#include "ssh-utils.h"
#define TOKEN_NAME "ssh"
#define TOKEN_VERSION_MAJOR "1"
@@ -78,148 +74,6 @@ static json_object *get_token_jobj(struct crypt_device *cd, int token)
return json_tokener_parse(json_slot);
}
static int sshplugin_download_password(struct crypt_device *cd, ssh_session ssh,
const char *path, char **password, size_t *password_len)
{
char *pass = NULL;
size_t pass_len;
int r;
sftp_attributes sftp_attr = NULL;
sftp_session sftp = NULL;
sftp_file file = NULL;
sftp = sftp_new(ssh);
if (!sftp) {
crypt_log(cd, CRYPT_LOG_ERROR, "Cannot create sftp session: ");
r = SSH_FX_FAILURE;
goto out;
}
r = sftp_init(sftp);
if (r != SSH_OK) {
crypt_log(cd, CRYPT_LOG_ERROR, "Cannot init sftp session: ");
goto out;
}
file = sftp_open(sftp, path, O_RDONLY, 0);
if (!file) {
crypt_log(cd, CRYPT_LOG_ERROR, "Cannot create sftp session: ");
r = SSH_FX_FAILURE;
goto out;
}
sftp_attr = sftp_fstat(file);
if (!sftp_attr) {
crypt_log(cd, CRYPT_LOG_ERROR, "Cannot stat sftp file: ");
r = SSH_FX_FAILURE;
goto out;
}
pass_len = sftp_attr->size > PASSWORD_LENGTH ? PASSWORD_LENGTH : sftp_attr->size;
pass = malloc(pass_len);
if (!pass) {
crypt_log(cd, CRYPT_LOG_ERROR, "Not enough memory.\n");
r = SSH_FX_FAILURE;
goto out;
}
r = sftp_read(file, pass, pass_len);
if (r < 0 || (size_t)r != pass_len) {
crypt_log(cd, CRYPT_LOG_ERROR, "Cannot read remote key: ");
r = SSH_FX_FAILURE;
goto out;
}
*password = pass;
*password_len = pass_len;
r = SSH_OK;
out:
if (r != SSH_OK) {
crypt_log(cd, CRYPT_LOG_ERROR, ssh_get_error(ssh));
crypt_log(cd, CRYPT_LOG_ERROR, "\n");
free(pass);
}
if (sftp_attr)
sftp_attributes_free(sftp_attr);
if (file)
sftp_close(file);
if (sftp)
sftp_free(sftp);
return r == SSH_OK ? 0 : -EINVAL;
}
static ssh_session sshplugin_session_init(struct crypt_device *cd,
const char *host, const char *user)
{
int r, port = 22;
ssh_session ssh = ssh_new();
if (!ssh)
return NULL;
ssh_options_set(ssh, SSH_OPTIONS_HOST, host);
ssh_options_set(ssh, SSH_OPTIONS_USER, user);
ssh_options_set(ssh, SSH_OPTIONS_PORT, &port);
crypt_log(cd, CRYPT_LOG_NORMAL, "SSH token initiating ssh session.\n");
r = ssh_connect(ssh);
if (r != SSH_OK) {
crypt_log(cd, CRYPT_LOG_ERROR, "Connection failed: ");
goto out;
}
r = ssh_session_is_known_server(ssh);
if (r != SSH_SERVER_KNOWN_OK) {
crypt_log(cd, CRYPT_LOG_ERROR, "Server not known: ");
r = SSH_AUTH_ERROR;
goto out;
}
r = SSH_OK;
/* initialise list of authentication methods. yes, according to official libssh docs... */
ssh_userauth_none(ssh, NULL);
out:
if (r != SSH_OK) {
crypt_log(cd, CRYPT_LOG_ERROR, ssh_get_error(ssh));
crypt_log(cd, CRYPT_LOG_ERROR, "\n");
ssh_disconnect(ssh);
ssh_free(ssh);
ssh = NULL;
}
return ssh;
}
static int sshplugin_public_key_auth(struct crypt_device *cd, ssh_session ssh, const ssh_key pkey)
{
int r;
crypt_log(cd, CRYPT_LOG_DEBUG, "Trying public key authentication method.\n");
if (!(ssh_userauth_list(ssh, NULL) & SSH_AUTH_METHOD_PUBLICKEY)) {
crypt_log(cd, CRYPT_LOG_ERROR, "Public key auth method not allowed on host.\n");
return SSH_AUTH_ERROR;
}
r = ssh_userauth_try_publickey(ssh, NULL, pkey);
if (r == SSH_AUTH_SUCCESS) {
crypt_log(cd, CRYPT_LOG_DEBUG, "Public key method accepted.\n");
r = ssh_userauth_publickey(ssh, NULL, pkey);
}
if (r != SSH_AUTH_SUCCESS) {
crypt_log(cd, CRYPT_LOG_ERROR, "Public key authentication error: ");
crypt_log(cd, CRYPT_LOG_ERROR, ssh_get_error(ssh));
crypt_log(cd, CRYPT_LOG_ERROR, "\n");
}
return r;
}
int cryptsetup_token_open_pin(struct crypt_device *cd, int token, const char *pin,
size_t pin_size __attribute__((unused)), char **password, size_t *password_len,
void *usrptr __attribute__((unused)))