1 /*
2 * Copyright (C) 2021 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 #define LOG_TAG "RpcTlsUtils"
18 #include <log/log.h>
19
20 #include <binder/RpcTlsUtils.h>
21
22 #include "Utils.h"
23
24 #include <limits>
25
26 namespace android {
27
28 namespace {
29
30 static_assert(sizeof(unsigned char) == sizeof(uint8_t));
31
32 template <typename PemReadBioFn,
33 typename T = std::remove_pointer_t<std::invoke_result_t<
34 PemReadBioFn, BIO*, std::nullptr_t, std::nullptr_t, std::nullptr_t>>>
fromPem(const std::vector<uint8_t> & data,PemReadBioFn fn)35 bssl::UniquePtr<T> fromPem(const std::vector<uint8_t>& data, PemReadBioFn fn) {
36 if (data.size() > std::numeric_limits<int>::max()) return nullptr;
37 bssl::UniquePtr<BIO> bio(BIO_new_mem_buf(data.data(), static_cast<int>(data.size())));
38 return bssl::UniquePtr<T>(fn(bio.get(), nullptr, nullptr, nullptr));
39 }
40
41 template <typename D2iFn,
42 typename T = std::remove_pointer_t<
43 std::invoke_result_t<D2iFn, std::nullptr_t, const unsigned char**, long>>>
fromDer(const std::vector<uint8_t> & data,D2iFn fn)44 bssl::UniquePtr<T> fromDer(const std::vector<uint8_t>& data, D2iFn fn) {
45 if (data.size() > std::numeric_limits<long>::max()) return nullptr;
46 const unsigned char* dataPtr = data.data();
47 auto expectedEnd = dataPtr + data.size();
48 bssl::UniquePtr<T> ret(fn(nullptr, &dataPtr, static_cast<long>(data.size())));
49 if (dataPtr != expectedEnd) {
50 ALOGE("%s: %td bytes remaining!", __PRETTY_FUNCTION__, expectedEnd - dataPtr);
51 return nullptr;
52 }
53 return ret;
54 }
55
56 template <typename T, typename WriteBioFn = int (*)(BIO*, T*)>
serialize(T * object,WriteBioFn writeBio)57 std::vector<uint8_t> serialize(T* object, WriteBioFn writeBio) {
58 bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_mem()));
59 TEST_AND_RETURN({}, writeBio(bio.get(), object));
60 const uint8_t* data;
61 size_t len;
62 TEST_AND_RETURN({}, BIO_mem_contents(bio.get(), &data, &len));
63 return std::vector<uint8_t>(data, data + len);
64 }
65
66 } // namespace
67
deserializeCertificate(const std::vector<uint8_t> & data,RpcCertificateFormat format)68 bssl::UniquePtr<X509> deserializeCertificate(const std::vector<uint8_t>& data,
69 RpcCertificateFormat format) {
70 switch (format) {
71 case RpcCertificateFormat::PEM:
72 return fromPem(data, PEM_read_bio_X509);
73 case RpcCertificateFormat::DER:
74 return fromDer(data, d2i_X509);
75 }
76 LOG_ALWAYS_FATAL("Unsupported format %d", static_cast<int>(format));
77 }
78
serializeCertificate(X509 * x509,RpcCertificateFormat format)79 std::vector<uint8_t> serializeCertificate(X509* x509, RpcCertificateFormat format) {
80 switch (format) {
81 case RpcCertificateFormat::PEM:
82 return serialize(x509, PEM_write_bio_X509);
83 case RpcCertificateFormat::DER:
84 return serialize(x509, i2d_X509_bio);
85 }
86 LOG_ALWAYS_FATAL("Unsupported format %d", static_cast<int>(format));
87 }
88
deserializeUnencryptedPrivatekey(const std::vector<uint8_t> & data,RpcKeyFormat format)89 bssl::UniquePtr<EVP_PKEY> deserializeUnencryptedPrivatekey(const std::vector<uint8_t>& data,
90 RpcKeyFormat format) {
91 switch (format) {
92 case RpcKeyFormat::PEM:
93 return fromPem(data, PEM_read_bio_PrivateKey);
94 case RpcKeyFormat::DER:
95 return fromDer(data, d2i_AutoPrivateKey);
96 }
97 LOG_ALWAYS_FATAL("Unsupported format %d", static_cast<int>(format));
98 }
99
serializeUnencryptedPrivatekey(EVP_PKEY * pkey,RpcKeyFormat format)100 std::vector<uint8_t> serializeUnencryptedPrivatekey(EVP_PKEY* pkey, RpcKeyFormat format) {
101 switch (format) {
102 case RpcKeyFormat::PEM:
103 return serialize(pkey, [](BIO* bio, EVP_PKEY* pkey) {
104 return PEM_write_bio_PrivateKey(bio, pkey, nullptr /* enc */, nullptr /* kstr */,
105 0 /* klen */, nullptr, nullptr);
106 });
107 case RpcKeyFormat::DER:
108 return serialize(pkey, i2d_PrivateKey_bio);
109 }
110 LOG_ALWAYS_FATAL("Unsupported format %d", static_cast<int>(format));
111 }
112
113 } // namespace android
114