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/legacy_support/rsa_keymaster1_key.h>
18
19 #include <utility>
20
21 #include <keymaster/contexts/soft_keymaster_context.h>
22 #include <keymaster/km_openssl/openssl_utils.h>
23 #include <keymaster/logger.h>
24
25 #include "rsa_keymaster1_operation.h"
26
27 namespace keymaster {
28
RsaKeymaster1KeyFactory(const SoftwareKeyBlobMaker & blob_maker,const KeymasterContext & context,const Keymaster1Engine * engine)29 RsaKeymaster1KeyFactory::RsaKeymaster1KeyFactory(const SoftwareKeyBlobMaker& blob_maker,
30 const KeymasterContext& context,
31 const Keymaster1Engine* engine)
32 : RsaKeyFactory(blob_maker, context), engine_(engine),
33 sign_factory_(new (std::nothrow) RsaKeymaster1OperationFactory(KM_PURPOSE_SIGN, engine)),
34 decrypt_factory_(new (std::nothrow)
35 RsaKeymaster1OperationFactory(KM_PURPOSE_DECRYPT, engine)),
36 // For pubkey ops we can use the normal operation factories.
37 verify_factory_(new (std::nothrow) RsaVerificationOperationFactory),
38 encrypt_factory_(new (std::nothrow) RsaEncryptionOperationFactory) {}
39
is_supported(uint32_t digest)40 static bool is_supported(uint32_t digest) {
41 return digest == KM_DIGEST_NONE || digest == KM_DIGEST_SHA_2_256;
42 }
43
UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet & key_description,AuthorizationSet * new_description)44 static void UpdateToWorkAroundUnsupportedDigests(const AuthorizationSet& key_description,
45 AuthorizationSet* new_description) {
46 bool have_unsupported_digests = false;
47 bool have_digest_none = false;
48 bool have_pad_none = false;
49 bool have_padding_requiring_digest = false;
50 for (const keymaster_key_param_t& entry : key_description) {
51 new_description->push_back(entry);
52
53 if (entry.tag == TAG_DIGEST) {
54 if (entry.enumerated == KM_DIGEST_NONE) {
55 have_digest_none = true;
56 } else if (!is_supported(entry.enumerated)) {
57 LOG_D("Found request for unsupported digest %u", entry.enumerated);
58 have_unsupported_digests = true;
59 }
60 }
61
62 if (entry.tag == TAG_PADDING) {
63 switch (entry.enumerated) {
64 case KM_PAD_RSA_PSS:
65 case KM_PAD_RSA_OAEP:
66 have_padding_requiring_digest = true;
67 break;
68 case KM_PAD_NONE:
69 have_pad_none = true;
70 break;
71 }
72 }
73 }
74
75 if (have_unsupported_digests && !have_digest_none) {
76 LOG_I("Adding KM_DIGEST_NONE to key authorization, to enable software digesting", 0);
77 new_description->push_back(TAG_DIGEST, KM_DIGEST_NONE);
78 }
79
80 if (have_unsupported_digests && have_padding_requiring_digest && !have_pad_none) {
81 LOG_I("Adding KM_PAD_NONE to key authorization, to enable PSS or OAEP software padding", 0);
82 new_description->push_back(TAG_PADDING, KM_PAD_NONE);
83 }
84 }
85
GenerateKey(const AuthorizationSet & key_description,UniquePtr<Key>,const KeymasterBlob &,KeymasterKeyBlob * key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced,CertificateChain *) const86 keymaster_error_t RsaKeymaster1KeyFactory::GenerateKey(const AuthorizationSet& key_description,
87 UniquePtr<Key> /* attest_key */,
88 const KeymasterBlob& /* issuer_subject */,
89 KeymasterKeyBlob* key_blob,
90 AuthorizationSet* hw_enforced,
91 AuthorizationSet* sw_enforced,
92 CertificateChain* /* cert_chain */) const {
93 AuthorizationSet key_params_copy;
94 UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
95 return engine_->GenerateKey(key_params_copy, key_blob, hw_enforced, sw_enforced);
96 }
97
98 keymaster_error_t //
ImportKey(const AuthorizationSet & key_description,keymaster_key_format_t input_key_material_format,const KeymasterKeyBlob & input_key_material,UniquePtr<Key>,const KeymasterBlob &,KeymasterKeyBlob * output_key_blob,AuthorizationSet * hw_enforced,AuthorizationSet * sw_enforced,CertificateChain *) const99 RsaKeymaster1KeyFactory::ImportKey(const AuthorizationSet& key_description,
100 keymaster_key_format_t input_key_material_format,
101 const KeymasterKeyBlob& input_key_material,
102 UniquePtr<Key> /* attest_key */,
103 const KeymasterBlob& /* issuer_subject */,
104 KeymasterKeyBlob* output_key_blob, //
105 AuthorizationSet* hw_enforced, //
106 AuthorizationSet* sw_enforced,
107 CertificateChain* /* cert_chain */) const {
108 AuthorizationSet key_params_copy;
109 UpdateToWorkAroundUnsupportedDigests(key_description, &key_params_copy);
110 return engine_->ImportKey(key_params_copy, input_key_material_format, input_key_material,
111 output_key_blob, hw_enforced, sw_enforced);
112 }
113
LoadKey(KeymasterKeyBlob && key_material,const AuthorizationSet & additional_params,AuthorizationSet && hw_enforced,AuthorizationSet && sw_enforced,UniquePtr<Key> * key) const114 keymaster_error_t RsaKeymaster1KeyFactory::LoadKey(KeymasterKeyBlob&& key_material,
115 const AuthorizationSet& additional_params,
116 AuthorizationSet&& hw_enforced,
117 AuthorizationSet&& sw_enforced,
118 UniquePtr<Key>* key) const {
119 if (!key) return KM_ERROR_OUTPUT_PARAMETER_NULL;
120
121 keymaster_error_t error;
122 RSA_Ptr rsa(engine_->BuildRsaKey(key_material, additional_params, &error));
123 if (!rsa.get()) return error;
124
125 key->reset(new (std::nothrow)
126 RsaKeymaster1Key(rsa.release(), std::move(hw_enforced), std::move(sw_enforced),
127 this));
128 if (!(*key)) return KM_ERROR_MEMORY_ALLOCATION_FAILED;
129
130 (*key)->key_material() = std::move(key_material);
131 return KM_ERROR_OK;
132 }
133
GetOperationFactory(keymaster_purpose_t purpose) const134 OperationFactory* RsaKeymaster1KeyFactory::GetOperationFactory(keymaster_purpose_t purpose) const {
135 switch (purpose) {
136 case KM_PURPOSE_SIGN:
137 return sign_factory_.get();
138 case KM_PURPOSE_VERIFY:
139 return verify_factory_.get();
140 case KM_PURPOSE_ENCRYPT:
141 return encrypt_factory_.get();
142 case KM_PURPOSE_DECRYPT:
143 return decrypt_factory_.get();
144 case KM_PURPOSE_DERIVE_KEY:
145 case KM_PURPOSE_WRAP:
146 case KM_PURPOSE_AGREE_KEY:
147 case KM_PURPOSE_ATTEST_KEY:
148 break;
149 }
150 return nullptr;
151 }
152
153 } // namespace keymaster
154