| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define TRACE_TAG AUTH |
| |
| #include "sysdeps.h" |
| |
| #include <resolv.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <algorithm> |
| #include <chrono> |
| #include <iomanip> |
| #include <map> |
| #include <memory> |
| #include <thread> |
| |
| #include <adb/crypto/rsa_2048_key.h> |
| #include <adb/tls/adb_ca_list.h> |
| #include <adbd_auth.h> |
| #include <android-base/file.h> |
| #include <android-base/no_destructor.h> |
| #include <android-base/strings.h> |
| #include <crypto_utils/android_pubkey.h> |
| #include <openssl/obj_mac.h> |
| #include <openssl/rsa.h> |
| #include <openssl/sha.h> |
| #include <openssl/ssl.h> |
| |
| #include "adb.h" |
| #include "adb_auth.h" |
| #include "adb_io.h" |
| #include "adb_wifi.h" |
| #include "fdevent/fdevent.h" |
| #include "transport.h" |
| #include "types.h" |
| |
| using namespace adb::crypto; |
| using namespace adb::tls; |
| using namespace std::chrono_literals; |
| |
| static AdbdAuthContext* auth_ctx; |
| |
| static RSA* rsa_pkey = nullptr; |
| |
| static void adb_disconnected(void* unused, atransport* t); |
| static struct adisconnect adb_disconnect = {adb_disconnected, nullptr}; |
| |
| static android::base::NoDestructor<std::map<uint32_t, weak_ptr<atransport>>> transports; |
| static uint32_t transport_auth_id = 0; |
| |
| bool auth_required = true; |
| bool socket_access_allowed = true; |
| |
| static void* transport_to_callback_arg(atransport* transport) { |
| uint32_t id = transport_auth_id++; |
| (*transports)[id] = transport->weak(); |
| return reinterpret_cast<void*>(id); |
| } |
| |
| static atransport* transport_from_callback_arg(void* id) { |
| uint64_t id_u64 = reinterpret_cast<uint64_t>(id); |
| if (id_u64 > std::numeric_limits<uint32_t>::max()) { |
| LOG(FATAL) << "transport_from_callback_arg called on out of range value: " << id_u64; |
| } |
| |
| uint32_t id_u32 = static_cast<uint32_t>(id_u64); |
| auto it = transports->find(id_u32); |
| if (it == transports->end()) { |
| LOG(ERROR) << "transport_from_callback_arg failed to find transport for id " << id_u32; |
| return nullptr; |
| } |
| |
| atransport* t = it->second.get(); |
| if (!t) { |
| LOG(WARNING) << "transport_from_callback_arg found already destructed transport"; |
| return nullptr; |
| } |
| |
| transports->erase(it); |
| return t; |
| } |
| |
| static void IteratePublicKeys(std::function<bool(std::string_view public_key)> f) { |
| adbd_auth_get_public_keys( |
| auth_ctx, |
| [](void* opaque, const char* public_key, size_t len) { |
| return (*static_cast<decltype(f)*>(opaque))(std::string_view(public_key, len)); |
| }, |
| &f); |
| } |
| |
| bssl::UniquePtr<STACK_OF(X509_NAME)> adbd_tls_client_ca_list() { |
| if (!auth_required) { |
| return nullptr; |
| } |
| |
| bssl::UniquePtr<STACK_OF(X509_NAME)> ca_list(sk_X509_NAME_new_null()); |
| |
| IteratePublicKeys([&](std::string_view public_key) { |
| // TODO: do we really have to support both ' ' and '\t'? |
| std::vector<std::string> split = android::base::Split(std::string(public_key), " \t"); |
| uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1]; |
| const std::string& pubkey = split[0]; |
| if (b64_pton(pubkey.c_str(), keybuf, sizeof(keybuf)) != ANDROID_PUBKEY_ENCODED_SIZE) { |
| LOG(ERROR) << "Invalid base64 key " << pubkey; |
| return true; |
| } |
| |
| RSA* key = nullptr; |
| if (!android_pubkey_decode(keybuf, ANDROID_PUBKEY_ENCODED_SIZE, &key)) { |
| LOG(ERROR) << "Failed to parse key " << pubkey; |
| return true; |
| } |
| bssl::UniquePtr<RSA> rsa_key(key); |
| |
| unsigned char* dkey = nullptr; |
| int len = i2d_RSA_PUBKEY(rsa_key.get(), &dkey); |
| if (len <= 0 || dkey == nullptr) { |
| LOG(ERROR) << "Failed to encode RSA public key"; |
| return true; |
| } |
| |
| uint8_t digest[SHA256_DIGEST_LENGTH]; |
| // Put the encoded key in the commonName attribute of the issuer name. |
| // Note that the commonName has a max length of 64 bytes, which is less |
| // than the SHA256_DIGEST_LENGTH. |
| SHA256(dkey, len, digest); |
| OPENSSL_free(dkey); |
| |
| auto digest_str = SHA256BitsToHexString( |
| std::string_view(reinterpret_cast<const char*>(&digest[0]), sizeof(digest))); |
| LOG(INFO) << "fingerprint=[" << digest_str << "]"; |
| auto issuer = CreateCAIssuerFromEncodedKey(digest_str); |
| CHECK(bssl::PushToStack(ca_list.get(), std::move(issuer))); |
| return true; |
| }); |
| |
| return ca_list; |
| } |
| |
| bool adbd_auth_verify(const char* token, size_t token_size, const std::string& sig, |
| std::string* auth_key) { |
| bool authorized = false; |
| auth_key->clear(); |
| |
| IteratePublicKeys([&](std::string_view public_key) { |
| // TODO: do we really have to support both ' ' and '\t'? |
| std::vector<std::string> split = android::base::Split(std::string(public_key), " \t"); |
| uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1]; |
| const std::string& pubkey = split[0]; |
| if (b64_pton(pubkey.c_str(), keybuf, sizeof(keybuf)) != ANDROID_PUBKEY_ENCODED_SIZE) { |
| LOG(ERROR) << "Invalid base64 key " << pubkey; |
| return true; |
| } |
| |
| RSA* key = nullptr; |
| if (!android_pubkey_decode(keybuf, ANDROID_PUBKEY_ENCODED_SIZE, &key)) { |
| LOG(ERROR) << "Failed to parse key " << pubkey; |
| return true; |
| } |
| |
| bool verified = |
| (RSA_verify(NID_sha1, reinterpret_cast<const uint8_t*>(token), token_size, |
| reinterpret_cast<const uint8_t*>(sig.c_str()), sig.size(), key) == 1); |
| RSA_free(key); |
| if (verified) { |
| *auth_key = public_key; |
| authorized = true; |
| return false; |
| } |
| |
| return true; |
| }); |
| |
| return authorized; |
| } |
| |
| static bool adbd_auth_generate_token(void* token, size_t token_size) { |
| FILE* fp = fopen("/dev/urandom", "re"); |
| if (!fp) return false; |
| bool okay = (fread(token, token_size, 1, fp) == 1); |
| fclose(fp); |
| return okay; |
| } |
| |
| void adbd_cloexec_auth_socket() { |
| int fd = android_get_control_socket("adbd"); |
| if (fd == -1) { |
| PLOG(ERROR) << "Failed to get adbd socket"; |
| return; |
| } |
| fcntl(fd, F_SETFD, FD_CLOEXEC); |
| } |
| |
| static void adbd_auth_key_authorized(void* arg, uint64_t id) { |
| LOG(INFO) << "adb client " << id << " authorized"; |
| fdevent_run_on_looper([=]() { |
| auto* transport = transport_from_callback_arg(arg); |
| if (!transport) { |
| LOG(ERROR) << "authorization received for deleted transport (" << id << "), ignoring"; |
| return; |
| } |
| |
| if (transport->auth_id.has_value()) { |
| if (transport->auth_id.value() != id) { |
| LOG(ERROR) |
| << "authorization received, but auth id doesn't match, ignoring (expected " |
| << transport->auth_id.value() << ", got " << id << ")"; |
| return; |
| } |
| } else { |
| // Older versions (i.e. dogfood/beta builds) of libadbd_auth didn't pass the initial |
| // auth id to us, so we'll just have to trust it until R ships and we can retcon this. |
| transport->auth_id = id; |
| } |
| |
| adbd_auth_verified(transport); |
| }); |
| } |
| |
| static void adbd_key_removed(const char* public_key, size_t len) { |
| // The framework removed the key from its keystore. We need to disconnect all |
| // devices using that key. Search by t->auth_key |
| std::string_view auth_key(public_key, len); |
| kick_all_transports_by_auth_key(auth_key); |
| } |
| |
| void adbd_auth_init(void) { |
| AdbdAuthCallbacksV1 cb; |
| cb.version = 1; |
| cb.key_authorized = adbd_auth_key_authorized; |
| cb.key_removed = adbd_key_removed; |
| auth_ctx = adbd_auth_new(&cb); |
| adbd_wifi_init(auth_ctx); |
| std::thread([]() { |
| adb_thread_setname("adbd auth"); |
| adbd_auth_run(auth_ctx); |
| LOG(FATAL) << "auth thread terminated"; |
| }).detach(); |
| } |
| |
| void send_auth_request(atransport* t) { |
| LOG(INFO) << "Calling send_auth_request..."; |
| |
| if (!adbd_auth_generate_token(t->token, sizeof(t->token))) { |
| PLOG(ERROR) << "Error generating token"; |
| return; |
| } |
| |
| apacket* p = get_apacket(); |
| p->msg.command = A_AUTH; |
| p->msg.arg0 = ADB_AUTH_TOKEN; |
| p->msg.data_length = sizeof(t->token); |
| p->payload.assign(t->token, t->token + sizeof(t->token)); |
| send_packet(p, t); |
| } |
| |
| void adbd_auth_verified(atransport* t) { |
| LOG(INFO) << "adb client authorized"; |
| handle_online(t); |
| send_connect(t); |
| } |
| |
| static void adb_disconnected(void* unused, atransport* t) { |
| LOG(INFO) << "ADB disconnect"; |
| CHECK(t->auth_id.has_value()); |
| adbd_auth_notify_disconnect(auth_ctx, t->auth_id.value()); |
| } |
| |
| void adbd_auth_confirm_key(atransport* t) { |
| LOG(INFO) << "prompting user to authorize key"; |
| t->AddDisconnect(&adb_disconnect); |
| if (adbd_auth_prompt_user_with_id) { |
| t->auth_id = adbd_auth_prompt_user_with_id(auth_ctx, t->auth_key.data(), t->auth_key.size(), |
| transport_to_callback_arg(t)); |
| } else { |
| adbd_auth_prompt_user(auth_ctx, t->auth_key.data(), t->auth_key.size(), |
| transport_to_callback_arg(t)); |
| } |
| } |
| |
| void adbd_notify_framework_connected_key(atransport* t) { |
| t->auth_id = adbd_auth_notify_auth(auth_ctx, t->auth_key.data(), t->auth_key.size()); |
| } |
| |
| int adbd_tls_verify_cert(X509_STORE_CTX* ctx, std::string* auth_key) { |
| if (!auth_required) { |
| // Any key will do. |
| LOG(INFO) << __func__ << ": auth not required"; |
| return 1; |
| } |
| |
| bool authorized = false; |
| X509* cert = X509_STORE_CTX_get0_cert(ctx); |
| if (cert == nullptr) { |
| LOG(INFO) << "got null x509 certificate"; |
| return 0; |
| } |
| bssl::UniquePtr<EVP_PKEY> evp_pkey(X509_get_pubkey(cert)); |
| if (evp_pkey == nullptr) { |
| LOG(INFO) << "got null evp_pkey from x509 certificate"; |
| return 0; |
| } |
| |
| IteratePublicKeys([&](std::string_view public_key) { |
| // TODO: do we really have to support both ' ' and '\t'? |
| std::vector<std::string> split = android::base::Split(std::string(public_key), " \t"); |
| uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1]; |
| const std::string& pubkey = split[0]; |
| if (b64_pton(pubkey.c_str(), keybuf, sizeof(keybuf)) != ANDROID_PUBKEY_ENCODED_SIZE) { |
| LOG(ERROR) << "Invalid base64 key " << pubkey; |
| return true; |
| } |
| |
| RSA* key = nullptr; |
| if (!android_pubkey_decode(keybuf, ANDROID_PUBKEY_ENCODED_SIZE, &key)) { |
| LOG(ERROR) << "Failed to parse key " << pubkey; |
| return true; |
| } |
| |
| bool verified = false; |
| bssl::UniquePtr<EVP_PKEY> known_evp(EVP_PKEY_new()); |
| EVP_PKEY_set1_RSA(known_evp.get(), key); |
| if (EVP_PKEY_cmp(known_evp.get(), evp_pkey.get())) { |
| LOG(INFO) << "Matched auth_key=" << public_key; |
| verified = true; |
| } else { |
| LOG(INFO) << "auth_key doesn't match [" << public_key << "]"; |
| } |
| RSA_free(key); |
| if (verified) { |
| *auth_key = public_key; |
| authorized = true; |
| return false; |
| } |
| |
| return true; |
| }); |
| |
| return authorized ? 1 : 0; |
| } |
| |
| void adbd_auth_tls_handshake(atransport* t) { |
| if (rsa_pkey == nullptr) { |
| // Generate a random RSA key to feed into the X509 certificate |
| auto rsa_2048 = CreateRSA2048Key(); |
| CHECK(rsa_2048.has_value()); |
| rsa_pkey = EVP_PKEY_get1_RSA(rsa_2048->GetEvpPkey()); |
| CHECK(rsa_pkey); |
| } |
| |
| std::thread([t]() { |
| std::string auth_key; |
| if (t->connection()->DoTlsHandshake(rsa_pkey, &auth_key)) { |
| LOG(INFO) << "auth_key=" << auth_key; |
| if (t->IsTcpDevice()) { |
| t->auth_key = auth_key; |
| adbd_wifi_secure_connect(t); |
| } else { |
| adbd_auth_verified(t); |
| adbd_notify_framework_connected_key(t); |
| } |
| } else { |
| // Only allow one attempt at the handshake. |
| t->Kick(); |
| } |
| }).detach(); |
| } |