1 /*
2 * Copyright 2014 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 #pragma once
18
19 #include <openssl/bn.h>
20 #include <openssl/ec.h>
21 #include <openssl/engine.h>
22 #include <openssl/evp.h>
23 #include <openssl/rsa.h>
24 #include <openssl/x509.h>
25
26 #include <keymaster/UniquePtr.h>
27 #include <keymaster/authorization_set.h>
28
29 #include <hardware/keymaster_defs.h>
30
31 namespace keymaster {
32
33 template <typename BlobType> struct TKeymasterBlob;
34 typedef TKeymasterBlob<keymaster_key_blob_t> KeymasterKeyBlob;
35
36 class EvpMdCtxCleaner {
37 public:
EvpMdCtxCleaner(EVP_MD_CTX * ctx)38 explicit EvpMdCtxCleaner(EVP_MD_CTX* ctx) : ctx_(ctx) {}
~EvpMdCtxCleaner()39 ~EvpMdCtxCleaner() { EVP_MD_CTX_cleanup(ctx_); }
40
41 private:
42 EVP_MD_CTX* ctx_;
43 };
44
45 template <typename T, typename FreeFuncRet, FreeFuncRet (*FreeFunc)(T*)>
46 struct OpenSslObjectDeleter {
operatorOpenSslObjectDeleter47 void operator()(T* p) { FreeFunc(p); }
48 };
49
50 #define DEFINE_OPENSSL_OBJECT_POINTER(name) \
51 typedef OpenSslObjectDeleter<name, decltype(name##_free(nullptr)), name##_free> name##_Delete; \
52 typedef UniquePtr<name, name##_Delete> name##_Ptr;
53
54 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_BIT_STRING)
55 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_INTEGER)
56 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_OBJECT)
57 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_OCTET_STRING)
58 DEFINE_OPENSSL_OBJECT_POINTER(ASN1_TIME)
59 DEFINE_OPENSSL_OBJECT_POINTER(BN_CTX)
60 DEFINE_OPENSSL_OBJECT_POINTER(EC_GROUP)
61 DEFINE_OPENSSL_OBJECT_POINTER(EC_KEY)
62 DEFINE_OPENSSL_OBJECT_POINTER(EC_POINT)
63 DEFINE_OPENSSL_OBJECT_POINTER(ENGINE)
64 DEFINE_OPENSSL_OBJECT_POINTER(EVP_PKEY)
65 DEFINE_OPENSSL_OBJECT_POINTER(EVP_PKEY_CTX)
66 DEFINE_OPENSSL_OBJECT_POINTER(PKCS8_PRIV_KEY_INFO)
67 DEFINE_OPENSSL_OBJECT_POINTER(RSA)
68 DEFINE_OPENSSL_OBJECT_POINTER(X509)
69 DEFINE_OPENSSL_OBJECT_POINTER(X509_ALGOR)
70 DEFINE_OPENSSL_OBJECT_POINTER(X509_EXTENSION)
71 DEFINE_OPENSSL_OBJECT_POINTER(X509_NAME)
72
73 typedef OpenSslObjectDeleter<BIGNUM, void, BN_free> BIGNUM_Delete;
74 typedef UniquePtr<BIGNUM, BIGNUM_Delete> BIGNUM_Ptr;
75
76 keymaster_error_t ec_get_group_size(const EC_GROUP* group, size_t* key_size_bits);
77 EC_GROUP* ec_get_group(keymaster_ec_curve_t curve);
78
79 /**
80 * Many OpenSSL APIs take ownership of an argument on success but don't free the argument on
81 * failure. This means we need to tell our scoped pointers when we've transferred ownership, without
82 * triggering a warning by not using the result of release().
83 */
84 template <typename T, typename Delete_T>
release_because_ownership_transferred(UniquePtr<T,Delete_T> & p)85 inline void release_because_ownership_transferred(UniquePtr<T, Delete_T>& p) {
86 T* val __attribute__((unused)) = p.release();
87 }
88
89 keymaster_error_t convert_pkcs8_blob_to_evp(const uint8_t* key_data, size_t key_length,
90 keymaster_algorithm_t expected_algorithm,
91 UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* pkey);
92
93 keymaster_error_t KeyMaterialToEvpKey(keymaster_key_format_t key_format,
94 const KeymasterKeyBlob& key_material,
95 keymaster_algorithm_t expected_algorithm,
96 UniquePtr<EVP_PKEY, EVP_PKEY_Delete>* evp_pkey);
97
98 keymaster_error_t EvpKeyToKeyMaterial(const EVP_PKEY* evp_pkey, KeymasterKeyBlob* key_blob);
99
100 keymaster_error_t GetEcdsa256KeyFromCert(const keymaster_blob_t* km_cert, uint8_t* x_coord,
101 size_t x_length, uint8_t* y_coord, size_t y_length);
102
103 size_t ec_group_size_bits(EC_KEY* ec_key);
104
105 keymaster_error_t GenerateRandom(uint8_t* buf, size_t length);
106
IsCertSigningKey(const AuthorizationSet & key_description)107 inline bool IsCertSigningKey(const AuthorizationSet& key_description) {
108 return key_description.Contains(TAG_PURPOSE, KM_PURPOSE_SIGN) ||
109 key_description.Contains(TAG_PURPOSE, KM_PURPOSE_ATTEST_KEY);
110 }
111
KmDigestToEvpDigest(keymaster_digest_t digest)112 inline const EVP_MD* KmDigestToEvpDigest(keymaster_digest_t digest) {
113 switch (digest) {
114 case KM_DIGEST_MD5:
115 return EVP_md5();
116 case KM_DIGEST_SHA1:
117 return EVP_sha1();
118 case KM_DIGEST_SHA_2_224:
119 return EVP_sha224();
120 case KM_DIGEST_SHA_2_256:
121 return EVP_sha256();
122 case KM_DIGEST_SHA_2_384:
123 return EVP_sha384();
124 case KM_DIGEST_SHA_2_512:
125 return EVP_sha512();
126 default:
127 return nullptr;
128 }
129 }
130
131 } // namespace keymaster
132