adbd: use libadbd_auth for authentication.

Bug: http://b/137798163
Test: for i in `seq 1 100000`; do echo $i; adb wait-for-device shell "su 0 stop; su 0 start; sleep 10"; adb disconnect; done
Change-Id: Ie481e79a48c4aabf18ef797317ba18f207808c63
diff --git a/daemon/auth.cpp b/daemon/auth.cpp
index 7a3a4f5..2e84ce6 100644
--- a/daemon/auth.cpp
+++ b/daemon/auth.cpp
@@ -31,6 +31,7 @@
 #include <algorithm>
 #include <memory>
 
+#include <adbd_auth.h>
 #include <android-base/file.h>
 #include <android-base/strings.h>
 #include <crypto_utils/android_pubkey.h>
@@ -38,85 +39,57 @@
 #include <openssl/rsa.h>
 #include <openssl/sha.h>
 
-static fdevent* listener_fde = nullptr;
-static fdevent* framework_fde = nullptr;
-static auto& framework_mutex = *new std::mutex();
-static int framework_fd GUARDED_BY(framework_mutex) = -1;
-static auto& connected_keys GUARDED_BY(framework_mutex) = *new std::vector<std::string>;
+static AdbdAuthContext* auth_ctx;
 
 static void adb_disconnected(void* unused, atransport* t);
 static struct adisconnect adb_disconnect = {adb_disconnected, nullptr};
-static atransport* adb_transport;
-static bool needs_retry = false;
 
 bool auth_required = true;
 
-bool adbd_auth_verify(const char* token, size_t token_size, const std::string& sig,
-                      std::string* auth_key) {
-    static constexpr const char* key_paths[] = { "/adb_keys", "/data/misc/adb/adb_keys", nullptr };
-
-    for (const auto& path : key_paths) {
-        if (access(path, R_OK) == 0) {
-            LOG(INFO) << "Loading keys from " << path;
-            std::string content;
-            if (!android::base::ReadFileToString(path, &content)) {
-                PLOG(ERROR) << "Couldn't read " << path;
-                continue;
-            }
-
-            for (const auto& line : android::base::Split(content, "\n")) {
-                if (line.empty()) continue;
-                *auth_key = line;
-                // TODO: do we really have to support both ' ' and '\t'?
-                char* sep = strpbrk(const_cast<char*>(line.c_str()), " \t");
-                if (sep) *sep = '\0';
-
-                // b64_pton requires one additional byte in the target buffer for
-                // decoding to succeed. See http://b/28035006 for details.
-                uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1];
-                if (b64_pton(line.c_str(), keybuf, sizeof(keybuf)) != ANDROID_PUBKEY_ENCODED_SIZE) {
-                    LOG(ERROR) << "Invalid base64 key " << line.c_str() << " in " << path;
-                    continue;
-                }
-
-                RSA* key = nullptr;
-                if (!android_pubkey_decode(keybuf, ANDROID_PUBKEY_ENCODED_SIZE, &key)) {
-                    LOG(ERROR) << "Failed to parse key " << line.c_str() << " in " << path;
-                    continue;
-                }
-
-                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) return true;
-            }
-        }
-    }
-    auth_key->clear();
-    return false;
+static void IteratePublicKeys(std::function<bool(std::string_view public_key)> f) {
+    adbd_auth_get_public_keys(
+            auth_ctx,
+            [](const char* public_key, size_t len, void* arg) {
+                return (*static_cast<decltype(f)*>(arg))(std::string_view(public_key, len));
+            },
+            &f);
 }
 
-static bool adbd_send_key_message_locked(std::string_view msg_type, std::string_view key)
-        REQUIRES(framework_mutex) {
-    if (framework_fd < 0) {
-        LOG(ERROR) << "Client not connected to send msg_type " << msg_type;
-        return false;
-    }
-    std::string msg = std::string(msg_type) + std::string(key);
-    int msg_len = msg.length();
-    if (msg_len >= static_cast<int>(MAX_FRAMEWORK_PAYLOAD)) {
-        LOG(ERROR) << "Key too long (" << msg_len << ")";
-        return false;
-    }
+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();
 
-    LOG(DEBUG) << "Sending '" << msg << "'";
-    if (!WriteFdExactly(framework_fd, msg.c_str(), msg_len)) {
-        PLOG(ERROR) << "Failed to write " << msg_type;
-        return false;
-    }
-    return true;
+    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) {
@@ -127,113 +100,6 @@
     return okay;
 }
 
-static void adb_disconnected(void* unused, atransport* t) {
-    LOG(INFO) << "ADB disconnect";
-    adb_transport = nullptr;
-    needs_retry = false;
-    {
-        std::lock_guard<std::mutex> lock(framework_mutex);
-        if (framework_fd >= 0) {
-            adbd_send_key_message_locked("DC", t->auth_key);
-        }
-        connected_keys.erase(std::remove(connected_keys.begin(), connected_keys.end(), t->auth_key),
-                             connected_keys.end());
-    }
-}
-
-static void framework_disconnected() {
-    LOG(INFO) << "Framework disconnect";
-    if (framework_fde) {
-        fdevent_destroy(framework_fde);
-        {
-            std::lock_guard<std::mutex> lock(framework_mutex);
-            framework_fd = -1;
-        }
-    }
-}
-
-static void adbd_auth_event(int fd, unsigned events, void*) {
-    if (events & FDE_READ) {
-        char response[2];
-        int ret = unix_read(fd, response, sizeof(response));
-        if (ret <= 0) {
-            framework_disconnected();
-        } else if (ret == 2 && response[0] == 'O' && response[1] == 'K') {
-            if (adb_transport) {
-                adbd_auth_verified(adb_transport);
-            }
-        }
-    }
-}
-
-void adbd_auth_confirm_key(atransport* t) {
-    if (!adb_transport) {
-        adb_transport = t;
-        t->AddDisconnect(&adb_disconnect);
-    }
-
-    {
-        std::lock_guard<std::mutex> lock(framework_mutex);
-        if (framework_fd < 0) {
-            LOG(ERROR) << "Client not connected";
-            needs_retry = true;
-            return;
-        }
-
-        adbd_send_key_message_locked("PK", t->auth_key);
-    }
-}
-
-static void adbd_auth_listener(int fd, unsigned events, void* data) {
-    int s = adb_socket_accept(fd, nullptr, nullptr);
-    if (s < 0) {
-        PLOG(ERROR) << "Failed to accept";
-        return;
-    }
-
-    {
-        std::lock_guard<std::mutex> lock(framework_mutex);
-        if (framework_fd >= 0) {
-            LOG(WARNING) << "adb received framework auth socket connection again";
-            framework_disconnected();
-        }
-
-        framework_fd = s;
-        framework_fde = fdevent_create(framework_fd, adbd_auth_event, nullptr);
-        fdevent_add(framework_fde, FDE_READ);
-
-        if (needs_retry) {
-            needs_retry = false;
-            send_auth_request(adb_transport);
-        }
-
-        // if a client connected before the framework was available notify the framework of the
-        // connected key now.
-        if (!connected_keys.empty()) {
-            for (const auto& key : connected_keys) {
-                adbd_send_key_message_locked("CK", key);
-            }
-        }
-    }
-}
-
-void adbd_notify_framework_connected_key(atransport* t) {
-    if (!adb_transport) {
-        adb_transport = t;
-        t->AddDisconnect(&adb_disconnect);
-    }
-    {
-        std::lock_guard<std::mutex> lock(framework_mutex);
-        if (std::find(connected_keys.begin(), connected_keys.end(), t->auth_key) ==
-            connected_keys.end()) {
-            connected_keys.push_back(t->auth_key);
-        }
-        if (framework_fd >= 0) {
-            adbd_send_key_message_locked("CK", t->auth_key);
-        }
-    }
-}
-
 void adbd_cloexec_auth_socket() {
     int fd = android_get_control_socket("adbd");
     if (fd == -1) {
@@ -243,20 +109,23 @@
     fcntl(fd, F_SETFD, FD_CLOEXEC);
 }
 
+static void adbd_auth_key_authorized(void* arg, uint64_t id) {
+    LOG(INFO) << "adb client authorized";
+    auto* transport = static_cast<atransport*>(arg);
+    transport->auth_id = id;
+    adbd_auth_verified(transport);
+}
+
 void adbd_auth_init(void) {
-    int fd = android_get_control_socket("adbd");
-    if (fd == -1) {
-        PLOG(ERROR) << "Failed to get adbd socket";
-        return;
-    }
-
-    if (listen(fd, 4) == -1) {
-        PLOG(ERROR) << "Failed to listen on '" << fd << "'";
-        return;
-    }
-
-    listener_fde = fdevent_create(fd, adbd_auth_listener, nullptr);
-    fdevent_add(listener_fde, FDE_READ);
+    AdbdAuthCallbacks cb;
+    cb.version = 1;
+    cb.callbacks.v1.key_authorized = adbd_auth_key_authorized;
+    auth_ctx = adbd_auth_new(&cb);
+    std::thread([]() {
+        adb_thread_setname("adbd auth");
+        adbd_auth_run(auth_ctx);
+        LOG(FATAL) << "auth thread terminated";
+    }).detach();
 }
 
 void send_auth_request(atransport* t) {
@@ -280,3 +149,18 @@
     handle_online(t);
     send_connect(t);
 }
+
+static void adb_disconnected(void* unused, atransport* t) {
+    LOG(INFO) << "ADB disconnect";
+    adbd_auth_notify_disconnect(auth_ctx, t->auth_id);
+}
+
+void adbd_auth_confirm_key(atransport* t) {
+    LOG(INFO) << "prompting user to authorize key";
+    t->AddDisconnect(&adb_disconnect);
+    adbd_auth_prompt_user(auth_ctx, t->auth_key.data(), t->auth_key.size(), t);
+}
+
+void adbd_notify_framework_connected_key(atransport* t) {
+    adbd_auth_notify_auth(auth_ctx, t->auth_key.data(), t->auth_key.size());
+}