1/*
2 * Copyright 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "ec_keymaster1_key.h"
18
19#include <memory>
20
21#include <keymaster/logger.h>
22
23#include "ecdsa_keymaster1_operation.h"
24#include "ecdsa_operation.h"
25
26using std::unique_ptr;
27
28namespace keymaster {
29
30EcdsaKeymaster1KeyFactory::EcdsaKeymaster1KeyFactory(const SoftKeymasterContext* context,
31                                                     const Keymaster1Engine* engine)
32    : EcKeyFactory(context), engine_(engine),
33      sign_factory_(new EcdsaKeymaster1OperationFactory(KM_PURPOSE_SIGN, engine)),
34      // For pubkey ops we can use the normal operation factories.
35      verify_factory_(new EcdsaVerifyOperationFactory) {}
36
37static bool is_supported(uint32_t digest) {
38    return digest == KM_DIGEST_NONE || digest == KM_DIGEST_SHA_2_256;
39}
40
41static void UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet& key_description,
42                                                 AuthorizationSet* new_description) {
43    bool have_unsupported_digests = false;
44    bool have_digest_none = false;
45    for (const keymaster_key_param_t& entry : key_description) {
46        new_description->push_back(entry);
47
48        if (entry.tag == TAG_DIGEST) {
49            if (entry.enumerated == KM_DIGEST_NONE) {
50                have_digest_none = true;
51            } else if (!is_supported(entry.enumerated)) {
52                LOG_D("Found request for unsupported digest %u", entry.enumerated);
53                have_unsupported_digests = true;
54            }
55        }
56    }
57
58    if (have_unsupported_digests && !have_digest_none) {
59        LOG_I("Adding KM_DIGEST_NONE to key authorization, to enable software digesting", 0);
60        new_description->push_back(TAG_DIGEST, KM_DIGEST_NONE);
61    }
62}
63
64keymaster_error_t EcdsaKeymaster1KeyFactory::GenerateKey(const AuthorizationSet& key_description,
65                                                         KeymasterKeyBlob* key_blob,
66                                                         AuthorizationSet* hw_enforced,
67                                                         AuthorizationSet* sw_enforced) const {
68    AuthorizationSet key_params_copy;
69    UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
70    return engine_->GenerateKey(key_params_copy, key_blob, hw_enforced, sw_enforced);
71}
72
73keymaster_error_t EcdsaKeymaster1KeyFactory::ImportKey(
74    const AuthorizationSet& key_description, keymaster_key_format_t input_key_material_format,
75    const KeymasterKeyBlob& input_key_material, KeymasterKeyBlob* output_key_blob,
76    AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) const {
77    AuthorizationSet key_params_copy;
78    UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
79    return engine_->ImportKey(key_params_copy, input_key_material_format, input_key_material,
80                              output_key_blob, hw_enforced, sw_enforced);
81}
82
83keymaster_error_t EcdsaKeymaster1KeyFactory::LoadKey(const KeymasterKeyBlob& key_material,
84                                                     const AuthorizationSet& additional_params,
85                                                     const AuthorizationSet& hw_enforced,
86                                                     const AuthorizationSet& sw_enforced,
87                                                     UniquePtr<Key>* key) const {
88    if (!key)
89        return KM_ERROR_OUTPUT_PARAMETER_NULL;
90
91    keymaster_error_t error;
92    unique_ptr<EC_KEY, EC_KEY_Delete> ecdsa(
93        engine_->BuildEcKey(key_material, additional_params, &error));
94    if (!ecdsa)
95        return error;
96
97    key->reset(new (std::nothrow)
98                   EcdsaKeymaster1Key(ecdsa.release(), hw_enforced, sw_enforced, &error));
99    if (!key->get())
100        error = KM_ERROR_MEMORY_ALLOCATION_FAILED;
101
102    if (error != KM_ERROR_OK)
103        return error;
104
105    return KM_ERROR_OK;
106}
107
108OperationFactory*
109EcdsaKeymaster1KeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const {
110    switch (purpose) {
111    case KM_PURPOSE_SIGN:
112        return sign_factory_.get();
113    case KM_PURPOSE_VERIFY:
114        return verify_factory_.get();
115    default:
116        return nullptr;
117    }
118}
119
120}  // namespace keymaster
121