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
26 using std::unique_ptr;
27
28 namespace keymaster {
29
EcdsaKeymaster1KeyFactory(const SoftKeymasterContext * context,const Keymaster1Engine * engine)30 EcdsaKeymaster1KeyFactory::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
is_supported(uint32_t digest)37 static bool is_supported(uint32_t digest) {
38 return digest == KM_DIGEST_NONE || digest == KM_DIGEST_SHA_2_256;
39 }
40
UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet & key_description,AuthorizationSet * new_description)41 static 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
GenerateKey(const AuthorizationSet & key_description,KeymasterKeyBlob * key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced) const64 keymaster_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
71 keymaster_ec_curve_t ec_curve;
72 uint32_t key_size;
73 keymaster_error_t error = GetCurveAndSize(key_description, &ec_curve, &key_size);
74 if (error != KM_ERROR_OK) {
75 return error;
76 } else if (!key_description.Contains(TAG_KEY_SIZE, key_size)) {
77 key_params_copy.push_back(TAG_KEY_SIZE, key_size);
78 }
79 return engine_->GenerateKey(key_params_copy, key_blob, hw_enforced, sw_enforced);
80 }
81
ImportKey(const AuthorizationSet & key_description,keymaster_key_format_t input_key_material_format,const KeymasterKeyBlob & input_key_material,KeymasterKeyBlob * output_key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced) const82 keymaster_error_t EcdsaKeymaster1KeyFactory::ImportKey(
83 const AuthorizationSet& key_description, keymaster_key_format_t input_key_material_format,
84 const KeymasterKeyBlob& input_key_material, KeymasterKeyBlob* output_key_blob,
85 AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) const {
86 AuthorizationSet key_params_copy;
87 UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
88 return engine_->ImportKey(key_params_copy, input_key_material_format, input_key_material,
89 output_key_blob, hw_enforced, sw_enforced);
90 }
91
LoadKey(const KeymasterKeyBlob & key_material,const AuthorizationSet & additional_params,const AuthorizationSet & hw_enforced,const AuthorizationSet & sw_enforced,UniquePtr<Key> * key) const92 keymaster_error_t EcdsaKeymaster1KeyFactory::LoadKey(const KeymasterKeyBlob& key_material,
93 const AuthorizationSet& additional_params,
94 const AuthorizationSet& hw_enforced,
95 const AuthorizationSet& sw_enforced,
96 UniquePtr<Key>* key) const {
97 if (!key)
98 return KM_ERROR_OUTPUT_PARAMETER_NULL;
99
100 keymaster_error_t error;
101 unique_ptr<EC_KEY, EC_KEY_Delete> ecdsa(
102 engine_->BuildEcKey(key_material, additional_params, &error));
103 if (!ecdsa)
104 return error;
105
106 key->reset(new (std::nothrow)
107 EcdsaKeymaster1Key(ecdsa.release(), hw_enforced, sw_enforced, &error));
108 if (!key->get())
109 error = KM_ERROR_MEMORY_ALLOCATION_FAILED;
110
111 if (error != KM_ERROR_OK)
112 return error;
113
114 return KM_ERROR_OK;
115 }
116
117 OperationFactory*
GetOperationFactory(keymaster_purpose_t purpose) const118 EcdsaKeymaster1KeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const {
119 switch (purpose) {
120 case KM_PURPOSE_SIGN:
121 return sign_factory_.get();
122 case KM_PURPOSE_VERIFY:
123 return verify_factory_.get();
124 default:
125 return nullptr;
126 }
127 }
128
129 } // namespace keymaster
130