static gboolean
gcr_secret_exchange_default_decrypt_transport_data (GcrSecretExchange *exchange,
GckAllocator allocator,
const guchar *cipher_text,
gsize n_cipher_text,
const guchar *iv,
gsize n_iv,
guchar **plain_text,
gsize *n_plain_text)
{
GcrSecretExchangeDefault *data = exchange->pv->default_exchange;
guchar* padded;
guchar* result;
gsize n_result;
gsize pos;
gcry_cipher_hd_t cih;
gcry_error_t gcry;
g_return_val_if_fail (data != NULL, FALSE);
g_return_val_if_fail (data->key != NULL, FALSE);
if (iv == NULL || n_iv != EXCHANGE_1_IV_LENGTH) {
g_message ("secret-exchange: invalid or missing iv");
return FALSE;
}
if (n_cipher_text % 16 != 0) {
g_message ("secret-message: invalid length for cipher text");
return FALSE;
}
gcry = gcry_cipher_open (&cih, EXCHANGE_1_CIPHER_ALGO, EXCHANGE_1_CIPHER_MODE, 0);
if (gcry != 0) {
g_warning ("couldn't create aes cipher context: %s", gcry_strerror (gcry));
return FALSE;
}
/* 16 = 128 bits */
gcry = gcry_cipher_setkey (cih, data->key, EXCHANGE_1_KEY_LENGTH);
g_return_val_if_fail (gcry == 0, FALSE);
/* 16 = 128 bits */
gcry = gcry_cipher_setiv (cih, iv, n_iv);
g_return_val_if_fail (gcry == 0, FALSE);
/* Allocate memory for the result */
padded = (allocator) (NULL, n_cipher_text);
g_return_val_if_fail (padded != NULL, FALSE);
for (pos = 0; pos < n_cipher_text; pos += 16) {
gcry = gcry_cipher_decrypt (cih, padded + pos, 16, (guchar *)cipher_text + pos, 16);
g_return_val_if_fail (gcry == 0, FALSE);
}
gcry_cipher_close (cih);
if (!egg_padding_pkcs7_unpad (allocator, 16, padded, n_cipher_text,
(gpointer*)&result, &n_result))
result = NULL;
/* Free the padded text */
(allocator) (padded, 0);
*plain_text = result;
*n_plain_text = n_result;
return TRUE;
}
CK_RV
gkm_aes_mechanism_unwrap (GkmSession *session, CK_MECHANISM_PTR mech,
GkmObject *wrapper, CK_VOID_PTR input, CK_ULONG n_input,
CK_ATTRIBUTE_PTR attrs, CK_ULONG n_attrs,
GkmObject **unwrapped)
{
gcry_cipher_hd_t cih;
gcry_error_t gcry;
CK_ATTRIBUTE attr;
GArray *array;
GkmAesKey *key;
gpointer padded, value;
gsize n_padded, n_value;
GkmTransaction *transaction;
gsize block, pos;
gboolean ret;
g_return_val_if_fail (GKM_IS_SESSION (session), CKR_GENERAL_ERROR);
g_return_val_if_fail (mech, CKR_GENERAL_ERROR);
g_return_val_if_fail (mech->mechanism == CKM_AES_CBC_PAD, CKR_GENERAL_ERROR);
g_return_val_if_fail (GKM_IS_OBJECT (wrapper), CKR_GENERAL_ERROR);
if (!GKM_IS_AES_KEY (wrapper))
return CKR_WRAPPING_KEY_TYPE_INCONSISTENT;
key = GKM_AES_KEY (wrapper);
block = gkm_aes_key_get_block_size (key);
g_return_val_if_fail (block != 0, CKR_GENERAL_ERROR);
if (n_input == 0 || n_input % block != 0)
return CKR_WRAPPED_KEY_LEN_RANGE;
cih = gkm_aes_key_get_cipher (key, GCRY_CIPHER_MODE_CBC);
if (cih == NULL)
return CKR_FUNCTION_FAILED;
if (!mech->pParameter || gcry_cipher_setiv (cih, mech->pParameter, mech->ulParameterLen) != 0) {
gcry_cipher_close (cih);
return CKR_MECHANISM_PARAM_INVALID;
}
padded = egg_secure_alloc (n_input);
memcpy (padded, input, n_input);
n_padded = n_input;
/* In place decryption */
for (pos = 0; pos < n_padded; pos += block) {
gcry = gcry_cipher_decrypt (cih, (guchar*)padded + pos, block, NULL, 0);
g_return_val_if_fail (gcry == 0, CKR_GENERAL_ERROR);
}
gcry_cipher_close (cih);
/* Unpad the resulting value */
ret = egg_padding_pkcs7_unpad (egg_secure_realloc, block, padded, n_padded, &value, &n_value);
egg_secure_free (padded);
/* TODO: This is dubious, there doesn't seem to be an rv for 'bad decrypt' */
if (ret == FALSE)
return CKR_WRAPPED_KEY_INVALID;
/* Now setup the attributes with our new value */
array = g_array_new (FALSE, FALSE, sizeof (CK_ATTRIBUTE));
/* Prepend the value */
attr.type = CKA_VALUE;
attr.pValue = value;
attr.ulValueLen = n_value;
g_array_append_val (array, attr);
/* Add the remainder of the attributes */
g_array_append_vals (array, attrs, n_attrs);
transaction = gkm_transaction_new ();
/* Now create an object with these attributes */
*unwrapped = gkm_session_create_object_for_attributes (session, transaction,
(CK_ATTRIBUTE_PTR)array->data, array->len);
egg_secure_free (value);
g_array_free (array, TRUE);
return gkm_transaction_complete_and_unref (transaction);
}
