| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <keystore.h> |
| |
| #include <utils/UniquePtr.h> |
| |
| #include <sys/socket.h> |
| #include <stdarg.h> |
| #include <string.h> |
| |
| #include <openssl/objects.h> |
| #include <openssl/engine.h> |
| #include <openssl/evp.h> |
| |
| #define LOG_NDEBUG 0 |
| #define LOG_TAG "OpenSSL-keystore" |
| #include <cutils/log.h> |
| |
| #include <keystore_client.h> |
| |
| |
| #define DYNAMIC_ENGINE |
| #define KEYSTORE_ENGINE_ID "keystore" |
| #define KEYSTORE_ENGINE_NAME "Android keystore engine" |
| |
| /** |
| * Many OpenSSL APIs take ownership of an argument on success but don't free the argument |
| * on failure. This means we need to tell our scoped pointers when we've transferred ownership, |
| * without triggering a warning by not using the result of release(). |
| */ |
| #define OWNERSHIP_TRANSFERRED(obj) \ |
| typeof (obj.release()) _dummy __attribute__((unused)) = obj.release() |
| |
| struct ENGINE_Delete { |
| void operator()(ENGINE* p) const { |
| ENGINE_free(p); |
| } |
| }; |
| typedef UniquePtr<ENGINE, ENGINE_Delete> Unique_ENGINE; |
| |
| struct EVP_PKEY_Delete { |
| void operator()(EVP_PKEY* p) const { |
| EVP_PKEY_free(p); |
| } |
| }; |
| typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY; |
| |
| struct RSA_Delete { |
| void operator()(RSA* p) const { |
| RSA_free(p); |
| } |
| }; |
| typedef UniquePtr<RSA, RSA_Delete> Unique_RSA; |
| |
| |
| /* |
| * RSA ex_data index for keystore's key handle. |
| */ |
| static int rsa_key_handle; |
| |
| |
| /** |
| * Execute a keystore command. The number of arguments should be passed in |
| * "numArgs" and be preceeded by the length as a size_t. |
| * |
| * If a reply is expected, the "reply" field must be of size |
| * KEYSTORE_MESSAGE_SIZE. |
| * |
| * Example for numArgs == 2: |
| * keystore_cmd(cmd, reply, 2, size_t, char*, size_t, char*); |
| * |
| * The return value will be the length of the reply stored in "reply." |
| * If an error occurs, the return value will be -1. |
| */ |
| |
| /** |
| * Makes sure the ex_data for the keyhandle is initially set to NULL. |
| */ |
| int keyhandle_new(void*, void*, CRYPTO_EX_DATA* ad, int idx, long, void*) { |
| return CRYPTO_set_ex_data(ad, idx, NULL); |
| } |
| |
| /** |
| * Frees a previously allocated keyhandle stored in ex_data. |
| */ |
| void keyhandle_free(void *, void *ptr, CRYPTO_EX_DATA*, int, long, void*) { |
| char* keyhandle = reinterpret_cast<char*>(ptr); |
| if (keyhandle != NULL) { |
| free(keyhandle); |
| } |
| } |
| |
| /** |
| * Duplicates a keyhandle stored in ex_data in case we copy a key. |
| */ |
| int keyhandle_dup(CRYPTO_EX_DATA* to, CRYPTO_EX_DATA*, void *ptrRef, int idx, long, void *) { |
| // This appears to be a bug in OpenSSL. |
| void** ptr = reinterpret_cast<void**>(ptrRef); |
| char* keyhandle = reinterpret_cast<char*>(*ptr); |
| if (keyhandle != NULL) { |
| char* keyhandle_copy = strdup(keyhandle); |
| *ptr = keyhandle_copy; |
| |
| // Call this in case OpenSSL is fixed in the future. |
| (void) CRYPTO_set_ex_data(to, idx, keyhandle_copy); |
| } |
| return 1; |
| } |
| |
| int keystore_rsa_priv_enc(int flen, const unsigned char* from, unsigned char* to, RSA* rsa, |
| int padding) { |
| ALOGV("keystore_rsa_sign(%d, %p, %p, %p, %d)", flen, from, to, rsa, padding); |
| |
| int num = RSA_size(rsa); |
| UniquePtr<uint8_t> padded(new uint8_t[num]); |
| if (padded.get() == NULL) { |
| ALOGE("could not allocate padded signature"); |
| return 0; |
| } |
| |
| switch (padding) { |
| case RSA_PKCS1_PADDING: |
| if (!RSA_padding_add_PKCS1_type_1(padded.get(), num, from, flen)) { |
| return 0; |
| } |
| break; |
| case RSA_X931_PADDING: |
| if (!RSA_padding_add_X931(padded.get(), num, from, flen)) { |
| return 0; |
| } |
| break; |
| case RSA_NO_PADDING: |
| if (!RSA_padding_add_none(padded.get(), num, from, flen)) { |
| return 0; |
| } |
| break; |
| default: |
| ALOGE("Unknown padding type: %d", padding); |
| return 0; |
| } |
| |
| uint8_t* key_id = reinterpret_cast<uint8_t*>(RSA_get_ex_data(rsa, rsa_key_handle)); |
| if (key_id == NULL) { |
| ALOGE("key had no key_id!"); |
| return 0; |
| } |
| |
| Keystore_Reply reply; |
| if (keystore_cmd(CommandCodes[SIGN], &reply, 2, strlen(reinterpret_cast<const char*>(key_id)), |
| key_id, static_cast<size_t>(num), reinterpret_cast<const uint8_t*>(padded.get())) |
| != NO_ERROR) { |
| ALOGE("There was an error during rsa_mod_exp"); |
| return 0; |
| } |
| |
| const size_t replyLen = reply.length(); |
| if (replyLen <= 0) { |
| ALOGW("No valid signature returned"); |
| return 0; |
| } |
| |
| memcpy(to, reply.get(), replyLen); |
| |
| ALOGV("rsa=%p keystore_rsa_sign => returning %p len %llu", rsa, to, |
| (unsigned long long) replyLen); |
| return static_cast<int>(replyLen); |
| } |
| |
| static RSA_METHOD keystore_rsa_meth = { |
| KEYSTORE_ENGINE_NAME, |
| NULL, /* rsa_pub_enc */ |
| NULL, /* rsa_pub_dec (verification) */ |
| keystore_rsa_priv_enc, /* rsa_priv_enc (signing) */ |
| NULL, /* rsa_priv_dec */ |
| NULL, /* rsa_mod_exp */ |
| NULL, /* bn_mod_exp */ |
| NULL, /* init */ |
| NULL, /* finish */ |
| RSA_FLAG_EXT_PKEY | RSA_FLAG_NO_BLINDING, /* flags */ |
| NULL, /* app_data */ |
| NULL, /* rsa_sign */ |
| NULL, /* rsa_verify */ |
| NULL, /* rsa_keygen */ |
| }; |
| |
| static int register_rsa_methods() { |
| const RSA_METHOD* rsa_meth = RSA_PKCS1_SSLeay(); |
| |
| keystore_rsa_meth.rsa_pub_enc = rsa_meth->rsa_pub_enc; |
| keystore_rsa_meth.rsa_pub_dec = rsa_meth->rsa_pub_dec; |
| keystore_rsa_meth.rsa_priv_dec = rsa_meth->rsa_priv_dec; |
| keystore_rsa_meth.rsa_mod_exp = rsa_meth->rsa_mod_exp; |
| keystore_rsa_meth.bn_mod_exp = rsa_meth->bn_mod_exp; |
| |
| return 1; |
| } |
| |
| static EVP_PKEY* keystore_loadkey(ENGINE* e, const char* key_id, UI_METHOD *ui_method, |
| void *callback_data) { |
| ALOGV("keystore_loadkey(%p, \"%s\", %p, %p)", e, key_id, ui_method, callback_data); |
| |
| Keystore_Reply reply; |
| if (keystore_cmd(CommandCodes[GET_PUBKEY], &reply, 1, strlen(key_id), key_id) != NO_ERROR) { |
| ALOGV("Cannot get public key for %s", key_id); |
| return NULL; |
| } |
| |
| const unsigned char* tmp = reinterpret_cast<const unsigned char*>(reply.get()); |
| Unique_EVP_PKEY pkey(d2i_PUBKEY(NULL, &tmp, reply.length())); |
| if (pkey.get() == NULL) { |
| ALOGW("Cannot convert pubkey"); |
| return NULL; |
| } |
| |
| switch (EVP_PKEY_type(pkey->type)) { |
| case EVP_PKEY_RSA: { |
| Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get())); |
| if (!RSA_set_ex_data(rsa.get(), rsa_key_handle, reinterpret_cast<void*>(strdup(key_id)))) { |
| ALOGW("Could not set ex_data for loaded RSA key"); |
| return NULL; |
| } |
| |
| RSA_set_method(rsa.get(), &keystore_rsa_meth); |
| RSA_blinding_off(rsa.get()); |
| |
| /* |
| * This should probably be an OpenSSL API, but EVP_PKEY_free calls |
| * ENGINE_finish(), so we need to call ENGINE_init() here. |
| */ |
| ENGINE_init(e); |
| rsa->engine = e; |
| rsa->flags |= RSA_FLAG_EXT_PKEY; |
| |
| break; |
| } |
| default: |
| ALOGE("Unsupported key type %d", EVP_PKEY_type(pkey->type)); |
| return NULL; |
| } |
| |
| return pkey.release(); |
| } |
| |
| static const ENGINE_CMD_DEFN keystore_cmd_defns[] = { |
| {0, NULL, NULL, 0} |
| }; |
| |
| static int keystore_engine_setup(ENGINE* e) { |
| ALOGV("keystore_engine_setup"); |
| |
| if (!ENGINE_set_id(e, KEYSTORE_ENGINE_ID) |
| || !ENGINE_set_name(e, KEYSTORE_ENGINE_NAME) |
| || !ENGINE_set_load_privkey_function(e, keystore_loadkey) |
| || !ENGINE_set_load_pubkey_function(e, keystore_loadkey) |
| || !ENGINE_set_cmd_defns(e, keystore_cmd_defns)) { |
| ALOGE("Could not set up keystore engine"); |
| return 0; |
| } |
| |
| if (!ENGINE_set_RSA(e, &keystore_rsa_meth) |
| || !register_rsa_methods()) { |
| ALOGE("Could not set up keystore RSA methods"); |
| return 0; |
| } |
| |
| /* We need a handle in the RSA keys as well for keygen. */ |
| rsa_key_handle = RSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free); |
| if (rsa_key_handle < 0) { |
| ALOGE("Could not set up RSA ex_data index"); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| ENGINE* ENGINE_keystore() { |
| ALOGV("ENGINE_keystore"); |
| |
| Unique_ENGINE engine(ENGINE_new()); |
| if (engine.get() == NULL) { |
| return NULL; |
| } |
| |
| if (!keystore_engine_setup(engine.get())) { |
| return NULL; |
| } |
| |
| return engine.release(); |
| } |
| |
| static int keystore_bind_fn(ENGINE *e, const char *id) { |
| ALOGV("keystore_bind_fn"); |
| |
| if (!id) { |
| return 0; |
| } |
| |
| if (strcmp(id, KEYSTORE_ENGINE_ID)) { |
| return 0; |
| } |
| |
| if (!keystore_engine_setup(e)) { |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| extern "C" { |
| #undef OPENSSL_EXPORT |
| #define OPENSSL_EXPORT extern __attribute__ ((visibility ("default"))) |
| |
| IMPLEMENT_DYNAMIC_CHECK_FN() |
| IMPLEMENT_DYNAMIC_BIND_FN(keystore_bind_fn) |
| }; |