You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

110 lines
3.5 KiB

/*
* Copyright 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <keymaster/km_openssl/hmac_key.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "hmac_operation.h"
namespace keymaster {
static HmacSignOperationFactory sign_factory;
static HmacVerifyOperationFactory verify_factory;
OperationFactory* HmacKeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const {
switch (purpose) {
case KM_PURPOSE_SIGN:
return &sign_factory;
case KM_PURPOSE_VERIFY:
return &verify_factory;
default:
return nullptr;
}
}
keymaster_error_t HmacKeyFactory::LoadKey(KeymasterKeyBlob&& key_material,
const AuthorizationSet& /* additional_params */,
AuthorizationSet&& hw_enforced,
AuthorizationSet&& sw_enforced,
UniquePtr<Key>* key) const {
if (!key) return KM_ERROR_OUTPUT_PARAMETER_NULL;
uint32_t min_mac_length;
if (!hw_enforced.GetTagValue(TAG_MIN_MAC_LENGTH, &min_mac_length) &&
!sw_enforced.GetTagValue(TAG_MIN_MAC_LENGTH, &min_mac_length)) {
LOG_E("HMAC key must have KM_TAG_MIN_MAC_LENGTH", 0);
return KM_ERROR_INVALID_KEY_BLOB;
}
key->reset(new (std::nothrow)
HmacKey(move(key_material), move(hw_enforced), move(sw_enforced), this));
if (!key->get()) return KM_ERROR_MEMORY_ALLOCATION_FAILED;
return KM_ERROR_OK;
}
keymaster_error_t HmacKeyFactory::validate_algorithm_specific_new_key_params(
const AuthorizationSet& key_description) const {
uint32_t min_mac_length_bits;
if (!key_description.GetTagValue(TAG_MIN_MAC_LENGTH, &min_mac_length_bits))
return KM_ERROR_MISSING_MIN_MAC_LENGTH;
keymaster_digest_t digest;
if (!key_description.GetTagValue(TAG_DIGEST, &digest)) {
LOG_E("%d digests specified for HMAC key", key_description.GetTagCount(TAG_DIGEST));
return KM_ERROR_UNSUPPORTED_DIGEST;
}
size_t hash_size_bits = 0;
switch (digest) {
case KM_DIGEST_NONE:
return KM_ERROR_UNSUPPORTED_DIGEST;
case KM_DIGEST_MD5:
hash_size_bits = 128;
break;
case KM_DIGEST_SHA1:
hash_size_bits = 160;
break;
case KM_DIGEST_SHA_2_224:
hash_size_bits = 224;
break;
case KM_DIGEST_SHA_2_256:
hash_size_bits = 256;
break;
case KM_DIGEST_SHA_2_384:
hash_size_bits = 384;
break;
case KM_DIGEST_SHA_2_512:
hash_size_bits = 512;
break;
};
if (hash_size_bits == 0) {
// digest was not matched
return KM_ERROR_UNSUPPORTED_DIGEST;
}
if (min_mac_length_bits % 8 != 0 || min_mac_length_bits > hash_size_bits)
return KM_ERROR_UNSUPPORTED_MIN_MAC_LENGTH;
if (min_mac_length_bits < kMinHmacLengthBits) return KM_ERROR_UNSUPPORTED_MIN_MAC_LENGTH;
return KM_ERROR_OK;
}
} // namespace keymaster