libsecret/library/gsecret-session.c

664 lines
18 KiB
C

/* GSecret - GLib wrapper for Secret Service
*
* Copyright 2011 Collabora Ltd.
* Copyright 2012 Red Hat Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2 of the licence or (at
* your option) any later version.
*
* See the included COPYING file for more information.
*/
#include "config.h"
#include "gsecret-private.h"
#ifdef WITH_GCRYPT
#include "egg/egg-dh.h"
#include "egg/egg-hkdf.h"
#include "egg/egg-libgcrypt.h"
#endif
#include "egg/egg-hex.h"
#include "egg/egg-secure-memory.h"
#include <glib/gi18n-lib.h>
EGG_SECURE_DECLARE (secret_session);
#define ALGORITHMS_AES "dh-ietf1024-sha256-aes128-cbc-pkcs7"
#define ALGORITHMS_PLAIN "plain"
struct _GSecretSession {
gchar *path;
const gchar *algorithms;
#ifdef WITH_GCRYPT
gcry_mpi_t prime;
gcry_mpi_t privat;
gcry_mpi_t publi;
#endif
gpointer key;
gsize n_key;
};
void
_gsecret_session_free (gpointer data)
{
GSecretSession *session = data;
if (session == NULL)
return;
g_free (session->path);
#ifdef WITH_GCRYPT
gcry_mpi_release (session->publi);
gcry_mpi_release (session->privat);
gcry_mpi_release (session->prime);
#endif
egg_secure_free (session->key);
g_free (session);
}
#ifdef WITH_GCRYPT
static GVariant *
request_open_session_aes (GSecretSession *session)
{
gcry_error_t gcry;
gcry_mpi_t base;
unsigned char *buffer;
size_t n_buffer;
GVariant *argument;
g_assert (session->prime == NULL);
g_assert (session->privat == NULL);
g_assert (session->publi == NULL);
/* Initialize our local parameters and values */
if (!egg_dh_default_params ("ietf-ike-grp-modp-1024",
&session->prime, &base))
g_return_val_if_reached (NULL);
#if 0
g_printerr ("\n lib prime: ");
gcry_mpi_dump (session->prime);
g_printerr ("\n lib base: ");
gcry_mpi_dump (base);
g_printerr ("\n");
#endif
if (!egg_dh_gen_pair (session->prime, base, 0,
&session->publi, &session->privat))
g_return_val_if_reached (NULL);
gcry_mpi_release (base);
gcry = gcry_mpi_aprint (GCRYMPI_FMT_USG, &buffer, &n_buffer, session->publi);
g_return_val_if_fail (gcry == 0, NULL);
argument = g_variant_new_from_data (G_VARIANT_TYPE ("ay"),
buffer, n_buffer, TRUE,
gcry_free, buffer);
return g_variant_new ("(sv)", ALGORITHMS_AES, argument);
}
static gboolean
response_open_session_aes (GSecretSession *session,
GVariant *response)
{
gconstpointer buffer;
GVariant *argument;
const gchar *sig;
gsize n_buffer;
gcry_mpi_t peer;
gcry_error_t gcry;
gpointer ikm;
gsize n_ikm;
sig = g_variant_get_type_string (response);
g_return_val_if_fail (sig != NULL, FALSE);
if (!g_str_equal (sig, "(vo)")) {
g_warning ("invalid OpenSession() response from daemon with signature: %s", sig);
return FALSE;
}
g_assert (session->path == NULL);
g_variant_get (response, "(vo)", &argument, &session->path);
buffer = g_variant_get_fixed_array (argument, &n_buffer, sizeof (guchar));
gcry = gcry_mpi_scan (&peer, GCRYMPI_FMT_USG, buffer, n_buffer, NULL);
g_return_val_if_fail (gcry == 0, FALSE);
g_variant_unref (argument);
#if 0
g_printerr (" lib publi: ");
gcry_mpi_dump (session->publi);
g_printerr ("\n lib peer: ");
gcry_mpi_dump (peer);
g_printerr ("\n");
#endif
ikm = egg_dh_gen_secret (peer, session->privat, session->prime, &n_ikm);
gcry_mpi_release (peer);
#if 0
g_printerr (" lib ikm: %s\n", egg_hex_encode (ikm, n_ikm));
#endif
if (ikm == NULL) {
g_warning ("couldn't negotiate a valid AES session key");
g_free (session->path);
session->path = NULL;
return FALSE;
}
session->n_key = 16;
session->key = egg_secure_alloc (session->n_key);
if (!egg_hkdf_perform ("sha256", ikm, n_ikm, NULL, 0, NULL, 0,
session->key, session->n_key))
g_return_val_if_reached (FALSE);
egg_secure_free (ikm);
session->algorithms = ALGORITHMS_AES;
return TRUE;
}
#endif /* WITH_GCRYPT */
static GVariant *
request_open_session_plain (GSecretSession *session)
{
GVariant *argument = g_variant_new_string ("");
return g_variant_new ("(sv)", "plain", argument);
}
static gboolean
response_open_session_plain (GSecretSession *session,
GVariant *response)
{
GVariant *argument;
const gchar *sig;
sig = g_variant_get_type_string (response);
g_return_val_if_fail (sig != NULL, FALSE);
if (!g_str_equal (sig, "(vo)")) {
g_warning ("invalid OpenSession() response from daemon with signature: %s",
g_variant_get_type_string (response));
return FALSE;
}
g_assert (session->path == NULL);
g_variant_get (response, "(vo)", &argument, &session->path);
g_variant_unref (argument);
g_assert (session->key == NULL);
g_assert (session->n_key == 0);
session->algorithms = ALGORITHMS_PLAIN;
return TRUE;
}
typedef struct {
GCancellable *cancellable;
GSecretSession *session;
} OpenSessionClosure;
static void
open_session_closure_free (gpointer data)
{
OpenSessionClosure *closure = data;
g_assert (closure);
g_clear_object (&closure->cancellable);
_gsecret_session_free (closure->session);
g_free (closure);
}
static void
on_service_open_session_plain (GObject *source,
GAsyncResult *result,
gpointer user_data)
{
GSimpleAsyncResult *res = G_SIMPLE_ASYNC_RESULT (user_data);
OpenSessionClosure *closure = g_simple_async_result_get_op_res_gpointer (res);
GSecretService *service = GSECRET_SERVICE (source);
GError *error = NULL;
GVariant *response;
response = g_dbus_proxy_call_finish (G_DBUS_PROXY (service), result, &error);
/* A successful response, decode it */
if (response != NULL) {
if (response_open_session_plain (closure->session, response)) {
_gsecret_service_take_session (service, closure->session);
closure->session = NULL;
} else {
g_simple_async_result_set_error (res, GSECRET_ERROR, GSECRET_ERROR_PROTOCOL,
_("Couldn't communicate with the secret storage"));
}
g_simple_async_result_complete (res);
g_variant_unref (response);
} else {
g_simple_async_result_take_error (res, error);
g_simple_async_result_complete (res);
}
g_object_unref (res);
}
#ifdef WITH_GCRYPT
static void
on_service_open_session_aes (GObject *source,
GAsyncResult *result,
gpointer user_data)
{
GSimpleAsyncResult *res = G_SIMPLE_ASYNC_RESULT (user_data);
OpenSessionClosure * closure = g_simple_async_result_get_op_res_gpointer (res);
GSecretService *service = GSECRET_SERVICE (source);
GError *error = NULL;
GVariant *response;
response = g_dbus_proxy_call_finish (G_DBUS_PROXY (service), result, &error);
/* A successful response, decode it */
if (response != NULL) {
if (response_open_session_aes (closure->session, response)) {
_gsecret_service_take_session (service, closure->session);
closure->session = NULL;
} else {
g_simple_async_result_set_error (res, GSECRET_ERROR, GSECRET_ERROR_PROTOCOL,
_("Couldn't communicate with the secret storage"));
}
g_simple_async_result_complete (res);
g_variant_unref (response);
} else {
/* AES session not supported, request a plain session */
if (g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_NOT_SUPPORTED)) {
g_dbus_proxy_call (G_DBUS_PROXY (source), "OpenSession",
request_open_session_plain (closure->session),
G_DBUS_CALL_FLAGS_NONE, -1,
closure->cancellable, on_service_open_session_plain,
g_object_ref (res));
g_error_free (error);
/* Other errors result in a failure */
} else {
g_simple_async_result_take_error (res, error);
g_simple_async_result_complete (res);
}
}
g_object_unref (res);
}
#endif /* WITH_GCRYPT */
void
_gsecret_session_open (GSecretService *service,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSimpleAsyncResult *res;
OpenSessionClosure *closure;
res = g_simple_async_result_new (G_OBJECT (service), callback, user_data,
_gsecret_session_open);
closure = g_new (OpenSessionClosure, 1);
closure->cancellable = cancellable ? g_object_ref (cancellable) : cancellable;
closure->session = g_new0 (GSecretSession, 1);
g_simple_async_result_set_op_res_gpointer (res, closure, open_session_closure_free);
g_dbus_proxy_call (G_DBUS_PROXY (service), "OpenSession",
#ifdef WITH_GCRYPT
request_open_session_aes (closure->session),
G_DBUS_CALL_FLAGS_NONE, -1,
cancellable, on_service_open_session_aes,
#else
request_open_session_plain (closure->session),
G_DBUS_CALL_FLAGS_NONE, -1,
cancellable, on_service_open_session_plain,
#endif
g_object_ref (res));
g_object_unref (res);
}
gboolean
_gsecret_session_open_finish (GAsyncResult *result,
GError **error)
{
if (g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (result), error))
return FALSE;
return TRUE;
}
#ifdef WITH_GCRYPT
static gboolean
pkcs7_unpad_bytes_in_place (guchar *padded,
gsize *n_padded)
{
gsize n_pad, i;
if (*n_padded == 0)
return FALSE;
n_pad = padded[*n_padded - 1];
/* Validate the padding */
if (n_pad == 0 || n_pad > 16)
return FALSE;
if (n_pad > *n_padded)
return FALSE;
for (i = *n_padded - n_pad; i < *n_padded; ++i) {
if (padded[i] != n_pad)
return FALSE;
}
/* The last bit of data */
*n_padded -= n_pad;
/* Null teriminate as a courtesy */
padded[*n_padded] = 0;
return TRUE;
}
static GSecretValue *
service_decode_aes_secret (GSecretSession *session,
gconstpointer param,
gsize n_param,
gconstpointer value,
gsize n_value,
const gchar *content_type)
{
gcry_cipher_hd_t cih;
gsize n_padded;
gcry_error_t gcry;
guchar *padded;
gsize pos;
if (n_param != 16) {
g_message ("received an encrypted secret structure with invalid parameter");
return NULL;
}
if (n_value == 0 || n_value % 16 != 0) {
g_message ("received an encrypted secret structure with bad secret length");
return NULL;
}
gcry = gcry_cipher_open (&cih, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CBC, 0);
if (gcry != 0) {
g_warning ("couldn't create AES cipher: %s", gcry_strerror (gcry));
return NULL;
}
#if 0
g_printerr (" lib iv: %s\n", egg_hex_encode (param, n_param));
#endif
gcry = gcry_cipher_setiv (cih, param, n_param);
g_return_val_if_fail (gcry == 0, NULL);
#if 0
g_printerr (" lib key: %s\n", egg_hex_encode (session->key, session->n_key));
#endif
gcry = gcry_cipher_setkey (cih, session->key, session->n_key);
g_return_val_if_fail (gcry == 0, NULL);
/* Copy the memory buffer */
n_padded = n_value;
padded = egg_secure_alloc (n_padded);
memcpy (padded, value, n_padded);
/* Perform the decryption */
for (pos = 0; pos < n_padded; pos += 16) {
gcry = gcry_cipher_decrypt (cih, (guchar*)padded + pos, 16, NULL, 0);
g_return_val_if_fail (gcry == 0, FALSE);
}
gcry_cipher_close (cih);
/* Unpad the resulting value */
if (!pkcs7_unpad_bytes_in_place (padded, &n_padded)) {
egg_secure_clear (padded, n_padded);
egg_secure_free (padded);
g_message ("received an invalid or unencryptable secret");
return FALSE;
}
return gsecret_value_new_full ((gchar *)padded, n_padded, content_type, egg_secure_free);
}
#endif /* WITH_GCRYPT */
static GSecretValue *
service_decode_plain_secret (GSecretSession *session,
gconstpointer param,
gsize n_param,
gconstpointer value,
gsize n_value,
const gchar *content_type)
{
if (n_param != 0) {
g_message ("received a plain secret structure with invalid parameter");
return NULL;
}
return gsecret_value_new (value, n_value, content_type);
}
GSecretValue *
_gsecret_session_decode_secret (GSecretSession *session,
GVariant *encoded)
{
GSecretValue *result;
gconstpointer param;
gconstpointer value;
gchar *session_path;
gchar *content_type;
gsize n_param;
gsize n_value;
GVariant *vparam;
GVariant *vvalue;
g_return_val_if_fail (session != NULL, NULL);
g_return_val_if_fail (encoded != NULL, NULL);
/* Parsing (oayays) */
g_variant_get_child (encoded, 0, "o", &session_path);
if (session_path == NULL || !g_str_equal (session_path, session->path)) {
g_message ("received a secret encoded with wrong session: %s != %s",
session_path, session->path);
g_free (session_path);
return NULL;
}
vparam = g_variant_get_child_value (encoded, 1);
param = g_variant_get_fixed_array (vparam, &n_param, sizeof (guchar));
vvalue = g_variant_get_child_value (encoded, 2);
value = g_variant_get_fixed_array (vvalue, &n_value, sizeof (guchar));
g_variant_get_child (encoded, 3, "s", &content_type);
#ifdef WITH_GCRYPT
if (session->key != NULL)
result = service_decode_aes_secret (session, param, n_param,
value, n_value, content_type);
else
#endif
result = service_decode_plain_secret (session, param, n_param,
value, n_value, content_type);
g_variant_unref (vparam);
g_variant_unref (vvalue);
g_free (content_type);
g_free (session_path);
return result;
}
#ifdef WITH_GCRYPT
static guchar*
pkcs7_pad_bytes_in_secure_memory (gconstpointer secret,
gsize length,
gsize *n_padded)
{
gsize n_pad;
guchar *padded;
/* Pad the secret */
*n_padded = ((length + 16) / 16) * 16;
g_assert (length < *n_padded);
g_assert (*n_padded > 0);
n_pad = *n_padded - length;
g_assert (n_pad > 0 && n_pad <= 16);
padded = egg_secure_alloc (*n_padded);
memcpy (padded, secret, length);
memset (padded + length, n_pad, n_pad);
return padded;
}
static gboolean
service_encode_aes_secret (GSecretSession *session,
GSecretValue *value,
GVariantBuilder *builder)
{
gcry_cipher_hd_t cih;
guchar *padded;
gsize n_padded, pos;
gcry_error_t gcry;
gpointer iv;
gconstpointer secret;
gsize n_secret;
GVariant *child;
g_variant_builder_add (builder, "o", session->path);
/* Create the cipher */
gcry = gcry_cipher_open (&cih, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CBC, 0);
if (gcry != 0) {
g_warning ("couldn't create AES cipher: %s", gcry_strerror (gcry));
return FALSE;
}
secret = gsecret_value_get (value, &n_secret);
/* Perform the encoding here */
padded = pkcs7_pad_bytes_in_secure_memory (secret, n_secret, &n_padded);
g_assert (padded != NULL);
/* Setup the IV */
iv = g_malloc0 (16);
gcry_create_nonce (iv, 16);
gcry = gcry_cipher_setiv (cih, iv, 16);
g_return_val_if_fail (gcry == 0, FALSE);
/* Setup the key */
gcry = gcry_cipher_setkey (cih, session->key, session->n_key);
g_return_val_if_fail (gcry == 0, FALSE);
/* Perform the encryption */
for (pos = 0; pos < n_padded; pos += 16) {
gcry = gcry_cipher_encrypt (cih, (guchar*)padded + pos, 16, NULL, 0);
g_return_val_if_fail (gcry == 0, FALSE);
}
gcry_cipher_close (cih);
child = g_variant_new_from_data (G_VARIANT_TYPE ("ay"), iv, 16, TRUE, g_free, iv);
g_variant_builder_add_value (builder, child);
child = g_variant_new_from_data (G_VARIANT_TYPE ("ay"), padded, n_padded, TRUE, egg_secure_free, padded);
g_variant_builder_add_value (builder, child);
g_variant_builder_add (builder, "s", gsecret_value_get_content_type (value));
return TRUE;
}
#endif /* WITH_GCRYPT */
static gboolean
service_encode_plain_secret (GSecretSession *session,
GSecretValue *value,
GVariantBuilder *builder)
{
gconstpointer secret;
gsize n_secret;
GVariant *child;
g_variant_builder_add (builder, "o", session->path);
secret = gsecret_value_get (value, &n_secret);
child = g_variant_new_from_data (G_VARIANT_TYPE ("ay"), "", 0, TRUE, NULL, NULL);
g_variant_builder_add_value (builder, child);
g_variant_unref (child);
child = g_variant_new_from_data (G_VARIANT_TYPE ("ay"), secret, n_secret, TRUE,
gsecret_value_unref, gsecret_value_ref (value));
g_variant_builder_add_value (builder, child);
g_variant_unref (child);
g_variant_builder_add (builder, "s", gsecret_value_get_content_type (value));
return TRUE;
}
GVariant *
_gsecret_session_encode_secret (GSecretSession *session,
GSecretValue *value)
{
GVariantBuilder *builder;
GVariant *result = NULL;
GVariantType *type;
gboolean ret;
g_return_val_if_fail (session != NULL, NULL);
g_return_val_if_fail (value != NULL, NULL);
type = g_variant_type_new ("(oayays)");
builder = g_variant_builder_new (type);
#ifdef WITH_GCRYPT
if (session->key)
ret = service_encode_aes_secret (session, value, builder);
else
#endif
ret = service_encode_plain_secret (session, value, builder);
if (ret)
result = g_variant_builder_end (builder);
g_variant_builder_unref (builder);
g_variant_type_free (type);
return result;
}
const gchar *
_gsecret_session_get_algorithms (GSecretSession *session)
{
g_return_val_if_fail (session != NULL, NULL);
return session->algorithms;
}
const gchar *
_gsecret_session_get_path (GSecretSession *session)
{
g_return_val_if_fail (session != NULL, NULL);
return session->path;
}