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 <keymaster/contexts/soft_keymaster_context.h>
18 #include <keymaster/legacy_support/rsa_keymaster1_key.h>
19
20 #include <keymaster/km_openssl/openssl_utils.h>
21 #include <keymaster/logger.h>
22
23 #include "rsa_keymaster1_operation.h"
24
25 namespace keymaster {
26
RsaKeymaster1KeyFactory(const SoftwareKeyBlobMaker * blob_maker,const Keymaster1Engine * engine)27 RsaKeymaster1KeyFactory::RsaKeymaster1KeyFactory(const SoftwareKeyBlobMaker* blob_maker,
28 const Keymaster1Engine* engine)
29 : RsaKeyFactory(blob_maker), engine_(engine),
30 sign_factory_(new RsaKeymaster1OperationFactory(KM_PURPOSE_SIGN, engine)),
31 decrypt_factory_(new RsaKeymaster1OperationFactory(KM_PURPOSE_DECRYPT, engine)),
32 // For pubkey ops we can use the normal operation factories.
33 verify_factory_(new RsaVerificationOperationFactory),
34 encrypt_factory_(new RsaEncryptionOperationFactory) {}
35
is_supported(uint32_t digest)36 static bool is_supported(uint32_t digest) {
37 return digest == KM_DIGEST_NONE || digest == KM_DIGEST_SHA_2_256;
38 }
39
UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet & key_description,AuthorizationSet * new_description)40 static void UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet& key_description,
41 AuthorizationSet* new_description) {
42 bool have_unsupported_digests = false;
43 bool have_digest_none = false;
44 bool have_pad_none = false;
45 bool have_padding_requiring_digest = false;
46 for (const keymaster_key_param_t& entry : key_description) {
47 new_description->push_back(entry);
48
49 if (entry.tag == TAG_DIGEST) {
50 if (entry.enumerated == KM_DIGEST_NONE) {
51 have_digest_none = true;
52 } else if (!is_supported(entry.enumerated)) {
53 LOG_D("Found request for unsupported digest %u", entry.enumerated);
54 have_unsupported_digests = true;
55 }
56 }
57
58 if (entry.tag == TAG_PADDING) {
59 switch (entry.enumerated) {
60 case KM_PAD_RSA_PSS:
61 case KM_PAD_RSA_OAEP:
62 have_padding_requiring_digest = true;
63 break;
64 case KM_PAD_NONE:
65 have_pad_none = true;
66 break;
67 }
68 }
69 }
70
71 if (have_unsupported_digests && !have_digest_none) {
72 LOG_I("Adding KM_DIGEST_NONE to key authorization, to enable software digesting", 0);
73 new_description->push_back(TAG_DIGEST, KM_DIGEST_NONE);
74 }
75
76 if (have_unsupported_digests && have_padding_requiring_digest && !have_pad_none) {
77 LOG_I("Adding KM_PAD_NONE to key authorization, to enable PSS or OAEP software padding", 0);
78 new_description->push_back(TAG_PADDING, KM_PAD_NONE);
79 }
80 }
81
GenerateKey(const AuthorizationSet & key_description,KeymasterKeyBlob * key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced) const82 keymaster_error_t RsaKeymaster1KeyFactory::GenerateKey(const AuthorizationSet& key_description,
83 KeymasterKeyBlob* key_blob,
84 AuthorizationSet* hw_enforced,
85 AuthorizationSet* sw_enforced) const {
86 AuthorizationSet key_params_copy;
87 UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
88 return engine_->GenerateKey(key_params_copy, key_blob, hw_enforced, sw_enforced);
89 }
90
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) const91 keymaster_error_t RsaKeymaster1KeyFactory::ImportKey(
92 const AuthorizationSet& key_description, keymaster_key_format_t input_key_material_format,
93 const KeymasterKeyBlob& input_key_material, KeymasterKeyBlob* output_key_blob,
94 AuthorizationSet* hw_enforced, AuthorizationSet* sw_enforced) const {
95 AuthorizationSet key_params_copy;
96 UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
97 return engine_->ImportKey(key_params_copy, input_key_material_format, input_key_material,
98 output_key_blob, hw_enforced, sw_enforced);
99 }
100
LoadKey(KeymasterKeyBlob && key_material,const AuthorizationSet & additional_params,AuthorizationSet && hw_enforced,AuthorizationSet && sw_enforced,UniquePtr<Key> * key) const101 keymaster_error_t RsaKeymaster1KeyFactory::LoadKey(KeymasterKeyBlob&& key_material,
102 const AuthorizationSet& additional_params,
103 AuthorizationSet&& hw_enforced,
104 AuthorizationSet&& sw_enforced,
105 UniquePtr<Key>* key) const {
106 if (!key)
107 return KM_ERROR_OUTPUT_PARAMETER_NULL;
108
109 keymaster_error_t error;
110 RSA_Ptr rsa(engine_->BuildRsaKey(key_material, additional_params, &error));
111 if (!rsa.get())
112 return error;
113
114 key->reset(new (std::nothrow)
115 RsaKeymaster1Key(rsa.release(), move(hw_enforced), move(sw_enforced), this));
116 if (!(*key))
117 return KM_ERROR_MEMORY_ALLOCATION_FAILED;
118
119 (*key)->key_material() = move(key_material);
120 return KM_ERROR_OK;
121 }
122
GetOperationFactory(keymaster_purpose_t purpose) const123 OperationFactory* RsaKeymaster1KeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const {
124 switch (purpose) {
125 case KM_PURPOSE_SIGN:
126 return sign_factory_.get();
127 case KM_PURPOSE_VERIFY:
128 return verify_factory_.get();
129 case KM_PURPOSE_ENCRYPT:
130 return encrypt_factory_.get();
131 case KM_PURPOSE_DECRYPT:
132 return decrypt_factory_.get();
133 case KM_PURPOSE_DERIVE_KEY:
134 case KM_PURPOSE_WRAP:
135 break;
136 }
137 return nullptr;
138 }
139
140 } // namespace keymaster
141