1 /*
2 * Copyright 2012 The Android Open Source Project
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
20 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 *
24 */
25
26 #include <UniquePtr.h>
27
28 #include <sys/socket.h>
29 #include <stdarg.h>
30 #include <string.h>
31 #include <unistd.h>
32
33 #include <openssl/dsa.h>
34 #include <openssl/engine.h>
35 #include <openssl/ec.h>
36 #include <openssl/evp.h>
37 #include <openssl/objects.h>
38 #include <openssl/rsa.h>
39
40 //#define LOG_NDEBUG 0
41 #define LOG_TAG "OpenSSL-keystore"
42 #include <cutils/log.h>
43
44 #include <binder/IServiceManager.h>
45 #include <keystore/keystore.h>
46 #include <keystore/IKeystoreService.h>
47
48 #include "methods.h"
49
50 using namespace android;
51
52 #define DYNAMIC_ENGINE
53 const char* kKeystoreEngineId = "keystore";
54 static const char* kKeystoreEngineDesc = "Android keystore engine";
55
56
57 /*
58 * ex_data index for keystore's key alias.
59 */
60 int rsa_key_handle;
61 int dsa_key_handle;
62
63
64 /*
65 * Only initialize the *_key_handle once.
66 */
67 static pthread_once_t key_handle_control = PTHREAD_ONCE_INIT;
68
69 /**
70 * Many OpenSSL APIs take ownership of an argument on success but don't free the argument
71 * on failure. This means we need to tell our scoped pointers when we've transferred ownership,
72 * without triggering a warning by not using the result of release().
73 */
74 #define OWNERSHIP_TRANSFERRED(obj) \
75 typeof (obj.release()) _dummy __attribute__((unused)) = obj.release()
76
77
78 struct ENGINE_Delete {
operator ()ENGINE_Delete79 void operator()(ENGINE* p) const {
80 ENGINE_free(p);
81 }
82 };
83 typedef UniquePtr<ENGINE, ENGINE_Delete> Unique_ENGINE;
84
85 struct EVP_PKEY_Delete {
operator ()EVP_PKEY_Delete86 void operator()(EVP_PKEY* p) const {
87 EVP_PKEY_free(p);
88 }
89 };
90 typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
91
92 /**
93 * Called to initialize RSA's ex_data for the key_id handle. This should
94 * only be called when protected by a lock.
95 */
init_key_handle()96 static void init_key_handle() {
97 rsa_key_handle = RSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
98 dsa_key_handle = DSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
99 }
100
keystore_loadkey(ENGINE * e,const char * key_id,UI_METHOD * ui_method,void * callback_data)101 static EVP_PKEY* keystore_loadkey(ENGINE* e, const char* key_id, UI_METHOD* ui_method,
102 void* callback_data) {
103 #if LOG_NDEBUG
104 (void)ui_method;
105 (void)callback_data;
106 #else
107 ALOGV("keystore_loadkey(%p, \"%s\", %p, %p)", e, key_id, ui_method, callback_data);
108 #endif
109
110 sp<IServiceManager> sm = defaultServiceManager();
111 sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
112 sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
113
114 if (service == NULL) {
115 ALOGE("could not contact keystore");
116 return 0;
117 }
118
119 uint8_t *pubkey = NULL;
120 size_t pubkeyLen;
121 int32_t ret = service->get_pubkey(String16(key_id), &pubkey, &pubkeyLen);
122 if (ret < 0) {
123 ALOGW("could not contact keystore");
124 free(pubkey);
125 return NULL;
126 } else if (ret != 0) {
127 ALOGW("keystore reports error: %d", ret);
128 free(pubkey);
129 return NULL;
130 }
131
132 const unsigned char* tmp = reinterpret_cast<const unsigned char*>(pubkey);
133 Unique_EVP_PKEY pkey(d2i_PUBKEY(NULL, &tmp, pubkeyLen));
134 free(pubkey);
135 if (pkey.get() == NULL) {
136 ALOGW("Cannot convert pubkey");
137 return NULL;
138 }
139
140 switch (EVP_PKEY_type(pkey->type)) {
141 case EVP_PKEY_DSA: {
142 dsa_pkey_setup(e, pkey.get(), key_id);
143 break;
144 }
145 case EVP_PKEY_RSA: {
146 rsa_pkey_setup(e, pkey.get(), key_id);
147 break;
148 }
149 case EVP_PKEY_EC: {
150 ecdsa_pkey_setup(e, pkey.get(), key_id);
151 break;
152 }
153 default:
154 ALOGE("Unsupported key type %d", EVP_PKEY_type(pkey->type));
155 return NULL;
156 }
157
158 return pkey.release();
159 }
160
161 static const ENGINE_CMD_DEFN keystore_cmd_defns[] = {
162 {0, NULL, NULL, 0}
163 };
164
keystore_engine_setup(ENGINE * e)165 static int keystore_engine_setup(ENGINE* e) {
166 ALOGV("keystore_engine_setup");
167
168 if (!ENGINE_set_id(e, kKeystoreEngineId)
169 || !ENGINE_set_name(e, kKeystoreEngineDesc)
170 || !ENGINE_set_load_privkey_function(e, keystore_loadkey)
171 || !ENGINE_set_load_pubkey_function(e, keystore_loadkey)
172 || !ENGINE_set_flags(e, 0)
173 || !ENGINE_set_cmd_defns(e, keystore_cmd_defns)) {
174 ALOGE("Could not set up keystore engine");
175 return 0;
176 }
177
178 /* We need a handle in the keys types as well for keygen if it's not already initialized. */
179 pthread_once(&key_handle_control, init_key_handle);
180 if ((rsa_key_handle < 0) || (dsa_key_handle < 0)) {
181 ALOGE("Could not set up ex_data index");
182 return 0;
183 }
184
185 if (!dsa_register(e)) {
186 ALOGE("DSA registration failed");
187 return 0;
188 } else if (!ecdsa_register(e)) {
189 ALOGE("ECDSA registration failed");
190 return 0;
191 } else if (!rsa_register(e)) {
192 ALOGE("RSA registration failed");
193 return 0;
194 }
195
196 return 1;
197 }
198
ENGINE_keystore()199 ENGINE* ENGINE_keystore() {
200 ALOGV("ENGINE_keystore");
201
202 Unique_ENGINE engine(ENGINE_new());
203 if (engine.get() == NULL) {
204 return NULL;
205 }
206
207 if (!keystore_engine_setup(engine.get())) {
208 return NULL;
209 }
210
211 return engine.release();
212 }
213
keystore_bind_fn(ENGINE * e,const char * id)214 static int keystore_bind_fn(ENGINE *e, const char *id) {
215 ALOGV("keystore_bind_fn");
216
217 if (!id) {
218 return 0;
219 }
220
221 if (strcmp(id, kKeystoreEngineId)) {
222 return 0;
223 }
224
225 if (!keystore_engine_setup(e)) {
226 return 0;
227 }
228
229 return 1;
230 }
231
232 extern "C" {
233 #undef OPENSSL_EXPORT
234 #define OPENSSL_EXPORT extern __attribute__ ((visibility ("default")))
235
236 IMPLEMENT_DYNAMIC_CHECK_FN()
237 IMPLEMENT_DYNAMIC_BIND_FN(keystore_bind_fn)
238 };
239