From c5ae0c2aa71a0950c6cf99c35146a3b4684fb167 Mon Sep 17 00:00:00 2001 From: Alexander Golubev Date: Tue, 23 Jan 2024 18:13:43 +0300 Subject: [PATCH] tdeioslave/sftp: even bigger authentication overhaul - Move authentication methods into separate functions so it would be easier to correctly handle error after those and select which should be called in which order. - A lot of minor improvements along the way Signed-off-by: Alexander Golubev (cherry picked from commit 2756ae762fefc3fe86463174866674a987856d89) --- tdeioslave/sftp/tdeio_sftp.cpp | 439 +++++++++++++++++++++------------ tdeioslave/sftp/tdeio_sftp.h | 49 +++- 2 files changed, 326 insertions(+), 162 deletions(-) diff --git a/tdeioslave/sftp/tdeio_sftp.cpp b/tdeioslave/sftp/tdeio_sftp.cpp index 040d57778..71c69f76d 100644 --- a/tdeioslave/sftp/tdeio_sftp.cpp +++ b/tdeioslave/sftp/tdeio_sftp.cpp @@ -33,6 +33,7 @@ #include #include +#include #include #include @@ -170,6 +171,46 @@ void log_callback(ssh_session session, int priority, const char *message, slave->log_callback(session, priority, message, userdata); } +class PublicKeyAuth: public SSHAuthMethod { +public: + int flag() override {return SSH_AUTH_METHOD_PUBLICKEY;}; + TQString name() override { return i18n("public key"); }; + int authenticate(sftpProtocol *ioslave) const override { + return ioslave->authenticatePublicKey(); + } + SSHAuthMethod* clone() override {return new PublicKeyAuth; } +}; + +class KeyboardInteractiveAuth: public SSHAuthMethod { +public: + KeyboardInteractiveAuth(bool noPaswordQuery = false): mNoPaswordQuery(noPaswordQuery) {} + + int flag() override {return SSH_AUTH_METHOD_INTERACTIVE;}; + TQString name() override { return i18n("keyboard interactive"); }; + int authenticate(sftpProtocol *ioslave) const override { + return ioslave->authenticateKeyboardInteractive(mNoPaswordQuery); + } + SSHAuthMethod* clone() override {return new KeyboardInteractiveAuth(mNoPaswordQuery); } + +private: + const bool mNoPaswordQuery; +}; + +class PasswordAuth: public SSHAuthMethod { +public: + PasswordAuth(bool noPaswordQuery = false): mNoPaswordQuery(noPaswordQuery) {} + + int flag() override {return SSH_AUTH_METHOD_PASSWORD;}; + TQString name() override { return i18n("password"); }; + int authenticate(sftpProtocol *ioslave) const override { + return ioslave->authenticatePassword(mNoPaswordQuery); + } + SSHAuthMethod* clone() override {return new PasswordAuth(mNoPaswordQuery); } + +private: + const bool mNoPaswordQuery; +}; + // Public key authentication int sftpProtocol::auth_callback(const char *prompt, char *buf, size_t len, int echo, int verify, void *userdata) @@ -209,7 +250,7 @@ int sftpProtocol::auth_callback(const char *prompt, char *buf, size_t len, bool firstTry = !mPubKeyAuthData.attemptedKeys.contains(keyFile); if (!firstTry) { - errMsg = i18n("Incorrect or invalid passphrase."); + errMsg = i18n("Incorrect or invalid passphrase.").append('\n'); } // libssh prompt is trash and we know we use this function only for publickey auth, so we'll give @@ -255,9 +296,45 @@ void sftpProtocol::log_callback(ssh_session session, int priority, kdDebug(TDEIO_SFTP_DB) << "[" << priority << "] " << message << endl; } -int sftpProtocol::authenticateKeyboardInteractive() { - TQString name, instruction, prompt; - int err = SSH_AUTH_ERROR; +int sftpProtocol::authenticatePublicKey(){ + // First let's do some cleanup + mPubKeyAuthData.wasCalled = 0; + mPubKeyAuthData.wasCanceled = 0; + mPubKeyAuthData.attemptedKeys.clear(); + + kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with public key" << endl; + int rc; + + while (1) { + mPubKeyAuthData.wasCalled = 0; + rc = ssh_userauth_publickey_auto(mSession, nullptr, nullptr); + + kdDebug(TDEIO_SFTP_DB) << "ssh_userauth_publickey_auto returned rc=" << rc + << " ssh_err=" << ssh_get_error_code(mSession) + << " (" << ssh_get_error(mSession) << ")" << endl; + if (rc == SSH_AUTH_DENIED) { + if (!mPubKeyAuthData.wasCalled) { + kdDebug(TDEIO_SFTP_DB) << "Passkey auth denied because it has no matching key" << endl; + break; /* rc == SSH_AUTH_DENIED */ + } else if (mPubKeyAuthData.wasCanceled) { + kdDebug(TDEIO_SFTP_DB) << "Passkey auth denied because user canceled" << endl; + rc = sftpProtocol::SSH_AUTH_CANCELED; + break; + } else { + kdDebug(TDEIO_SFTP_DB) << "User entered wrong passphrase for the key" << endl; + // Try it again + } + } else { + // every other rc is either error or success + break; + } + } + + return rc; +} + +int sftpProtocol::authenticateKeyboardInteractive(bool noPaswordQuery) { + int rc = SSH_AUTH_ERROR; kdDebug(TDEIO_SFTP_DB) << "Entering keyboard interactive function" << endl; @@ -265,27 +342,30 @@ int sftpProtocol::authenticateKeyboardInteractive() { int n = 0; int i = 0; - err = ssh_userauth_kbdint(mSession, NULL, NULL); + rc = ssh_userauth_kbdint(mSession, NULL, NULL); - if (err != SSH_AUTH_INFO) { - kdDebug(TDEIO_SFTP_DB) << "Finishing kbdint auth err=" << err + if (rc == SSH_AUTH_DENIED) { // do nothing + kdDebug(TDEIO_SFTP_DB) << "kb-interactive auth was denied; retrying again" << endl; + } else if (rc != SSH_AUTH_INFO) { + kdDebug(TDEIO_SFTP_DB) << "Finishing kb-interactive auth rc=" << rc << " ssh_err=" << ssh_get_error_code(mSession) << " (" << ssh_get_error(mSession) << ")" << endl; - break; } - // See RFC4256 Section 3.3 User Interface for meaning of the values + // See "RFC4256 Section 3.3 User Interface" for meaning of the values + TQString name, instruction, prompt; name = TQString::fromUtf8(ssh_userauth_kbdint_getname(mSession)); instruction = TQString::fromUtf8(ssh_userauth_kbdint_getinstruction(mSession)); n = ssh_userauth_kbdint_getnprompts(mSession); kdDebug(TDEIO_SFTP_DB) << "name=" << name << " instruction=" << instruction - << " prompts" << n << endl; + << " prompts:" << n << endl; for (i = 0; i < n; ++i) { char echo; TQString answer; + TQString errMsg; prompt = TQString::fromUtf8(ssh_userauth_kbdint_getprompt(mSession, i, &echo)); kdDebug(TDEIO_SFTP_DB) << "prompt=" << prompt << " echo=" << TQString::number(echo) << endl; @@ -309,18 +389,23 @@ int sftpProtocol::authenticateKeyboardInteractive() { if (prompt.lower().startsWith("password")) { // We can assume that the ssh server asks for a password and we will handle that case // with more care since it's what most users will see - infoKbdInt.prompt = i18n("Please enter your password."); - infoKbdInt.realmValue = TQString::null; // passwords use generic realm - infoKbdInt.keepPassword = true; - - if (!mPassword.isEmpty()) { // if we have a cached password we might use it + if (noPaswordQuery) { // if we have a cached password we might use it kdDebug(TDEIO_SFTP_DB) << "Using cached password" << endl; answer = mPassword; purgeString(mPassword); // if we used up password purge it + } else { + infoKbdInt.prompt = i18n("Please enter your password."); + infoKbdInt.realmValue = TQString(); // passwords use generic realm + infoKbdInt.keepPassword = true; + + if (mPasswordWasPrompted) { + errMsg = i18n("Login failed: incorrect password or username.").append('\n'); + } + mPasswordWasPrompted = true; } } else { // If the server's request doesn't look like a password, keep the servers prompt but - // don't prompt saving it + // don't prompt for saving the answer infoKbdInt.prompt = i18n("Please enter answer for the next request:"); if (!instruction.isEmpty()) { infoKbdInt.prompt.append("\n\n").append(instruction); @@ -332,34 +417,37 @@ int sftpProtocol::authenticateKeyboardInteractive() { /* FIXME: We can query a new user name but we will have to reinitialize the connection if * it changes <2024-01-10 Fat-Zer> */ if (answer.isNull()) { - if (openPassDlg(infoKbdInt)) { - kdDebug(TDEIO_SFTP_DB) << "Got the answer from the password dialog" << endl; + if (openPassDlg(infoKbdInt, errMsg)) { answer = infoKbdInt.password; + kdDebug(TDEIO_SFTP_DB) << "Got the answer from the password dialog" << endl; } else { - /* FIXME: Some reasonable action upon cancellation? <2024-01-10 Fat-Zer> */ + return sftpProtocol::SSH_AUTH_CANCELED; } } } else { // ssh server asks for some clear-text information from a user (e.g. a one-time // identification code) which should be echoed while user enters it. As for now tdeio has - // no means of handle that correctly, so we will have to be creative with the password + // no means to handle that correctly, so we will have to be creative with the password // dialog. TQString newPrompt; if (!instruction.isEmpty()) { newPrompt = instruction + "\n\n"; } - newPrompt.append(prompt + "\n\n"); + newPrompt.append(prompt).append("\n\n"); newPrompt.append(i18n("Use the username input field to answer this question.")); infoKbdInt.prompt = newPrompt; + infoKbdInt.url.setUser(infoKbdInt.username); + infoKbdInt.username = TQString::null; + infoKbdInt.readOnly = false; if (openPassDlg(infoKbdInt)) { answer = infoKbdInt.username; kdDebug(TDEIO_SFTP_DB) << "Got the answer from the password dialog: " << answer << endl; } else { - /* FIXME: Some reasonable action upon cancellation? <2024-01-10 Fat-Zer> */ + return sftpProtocol::SSH_AUTH_CANCELED; } } @@ -372,9 +460,76 @@ int sftpProtocol::authenticateKeyboardInteractive() { } // for each ssh_userauth_kbdint_getprompt() } // while (1) - return err; + return rc; +} + +int sftpProtocol::authenticatePassword(bool noPaswordQuery) { + kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with password" << endl; + + AuthInfo info = authInfo(); + info.readOnly = false; + info.keepPassword = true; + info.prompt = i18n("Please enter your username and password."); + + int rc; + do { + TQString errMsg; + TQString password; + + PasswordPurger pPurger(password); + + if(noPaswordQuery) { // on the first try use cached password + password = mPassword; + purgeString(mPassword); + } else { + if (mPasswordWasPrompted) { + errMsg = i18n("Login failed: incorrect password or username.").append('\n'); + } + + mPasswordWasPrompted = true; + + // Handle user canceled or dialog failed to open... + if (!openPassDlg(info, errMsg)) { + kdDebug(TDEIO_SFTP_DB) << "User canceled password dialog" << endl; + return sftpProtocol::SSH_AUTH_CANCELED; + } + + password = info.password; + + if (info.username != sshUsername()) { + kdDebug(TDEIO_SFTP_DB) << "Username changed from " << mUsername + << " to " << info.username << endl; + mUsername = info.username; + mPassword = info.password; + // libssh doc says that most servers don't permit changing the username during + // authentication, so we should reinitialize the session here + return sftpProtocol::SSH_AUTH_NEED_RECONNECT; + } + } + + rc = ssh_userauth_password(mSession, info.username.utf8().data(), + password.utf8().data()); + + } while (rc == SSH_AUTH_DENIED && !noPaswordQuery); + return rc; } + +TQString sftpProtocol::sshUsername() { + int rc; + TQString rv; + + char *ssh_username = NULL; + rc = ssh_options_get(mSession, SSH_OPTIONS_USER, &ssh_username); + if (rc == 0 && ssh_username && ssh_username[0]) { + rv = TQString::fromUtf8(ssh_username); + } + ssh_string_free_char(ssh_username); + + return rv; +} + + TDEIO::AuthInfo sftpProtocol::authInfo() { TDEIO::AuthInfo rv; @@ -639,8 +794,6 @@ void sftpProtocol::setHost(const TQString& h, int port, const TQString& user, co int sftpProtocol::initializeConnection() { - TQString msg; // msg for dialog box - TQString caption; // dialog box caption unsigned char *hash = NULL; // the server hash char *hexa; char *verbosity; @@ -686,7 +839,7 @@ int sftpProtocol::initializeConnection() { if (mPort > 0) { rc = ssh_options_set(mSession, SSH_OPTIONS_PORT, &mPort); if (rc < 0) { - error(TDEIO::ERR_OUT_OF_MEMORY, i18n("Could not set port.")); + error(TDEIO::ERR_OUT_OF_MEMORY, i18n("Could not set port.")); return SSH_ERROR; } } @@ -786,7 +939,9 @@ int sftpProtocol::initializeConnection() { delete hexa; return SSH_ERROR; case TDEIO_SSH_KNOWN_HOSTS_NOT_FOUND: - case TDEIO_SSH_KNOWN_HOSTS_UNKNOWN: + case TDEIO_SSH_KNOWN_HOSTS_UNKNOWN: { + TQString msg; // msg for dialog box + TQString caption; // dialog box caption hexa = ssh_get_hexa(hash, hlen); delete hash; caption = i18n("Warning: Cannot verify host's identity."); @@ -811,6 +966,7 @@ int sftpProtocol::initializeConnection() { return SSH_ERROR; } break; + } case TDEIO_SSH_KNOWN_HOSTS_ERROR: delete hash; error(TDEIO::ERR_COULD_NOT_CONNECT, TQString::fromUtf8(ssh_get_error(mSession))); @@ -819,17 +975,6 @@ int sftpProtocol::initializeConnection() { kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with the server" << endl; - // If no username was set upon connection, get the name from connection - // (probably it'd be the current user's name) - if (mUsername.isEmpty()) { - char *ssh_username = NULL; - rc = ssh_options_get(mSession, SSH_OPTIONS_USER, &ssh_username); - if (rc == 0 && ssh_username && ssh_username[0]) { - mUsername = ssh_username; - } - ssh_string_free_char(ssh_username); - } - connectionCloser.abort(); return SSH_OK; @@ -852,16 +997,10 @@ void sftpProtocol::openConnection() { return; } - // Setup AuthInfo for use with password caching and the - // password dialog box. - AuthInfo info = authInfo(); - info.keepPassword = true; // make the "keep Password" check box visible to the user. - - PasswordPurger pwPurger{mPassword}; - PasswordPurger infoPurger{info.password}; - // Check for cached authentication info if no password is specified... if (mPassword.isEmpty()) { + AuthInfo info = authInfo(); + kdDebug(TDEIO_SFTP_DB) << "checking cache: info.username = " << info.username << ", info.url = " << info.url.prettyURL() << endl; @@ -869,19 +1008,24 @@ void sftpProtocol::openConnection() { kdDebug() << "using cached" << endl; mUsername = info.username; mPassword = info.password; + + purgeString(info.password); //< not really necessary because of Qt's implicit data sharing } } + mPasswordWasPrompted = false; + PasswordPurger pwPurger{mPassword}; + int rc; +connection_restart: // Start the ssh connection. if (initializeConnection() < 0) { return; } - ExitGuard connectionCloser([this](){ closeConnection(); }); - // Try to authenticate + // Try to authenticate (this required before calling ssh_auth_list()) rc = ssh_userauth_none(mSession, NULL); if (rc == SSH_AUTH_ERROR) { error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed (method: %1).") @@ -889,123 +1033,112 @@ void sftpProtocol::openConnection() { return; } - int method = ssh_auth_list(mSession); - if (!method && rc != SSH_AUTH_SUCCESS) { - error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed." - " The server did not send any authentication methods!")); - return; - } - bool firstTime = true; - bool dlgResult; + // Preinit the list of supported auth methods + static const auto authMethodsNormal= [](){ + std::vector> rv; + rv.emplace_back(std::make_unique()); + rv.emplace_back(std::make_unique()); + rv.emplace_back(std::make_unique()); + return rv; + }(); + + const static int supportedMethods = std::accumulate( + authMethodsNormal.begin(), authMethodsNormal.end(), + SSH_AUTH_METHOD_NONE | SSH_AUTH_METHOD_HOSTBASED, //< methods supported automagically + [](int acc, const auto &m){ return acc |= m->flag(); }); + + int attemptedMethods = 0; + while (rc != SSH_AUTH_SUCCESS) { - /* FIXME: if there are problems with auth we are likely to stuck in this loop <2024-01-20 Fat-Zer> */ - - // Try to authenticate with public key first - if (rc != SSH_AUTH_SUCCESS && (method & SSH_AUTH_METHOD_PUBLICKEY) && !mPassword) { - // might mess up next login attempt if we won't clean it up - ExitGuard pubKeyInfoCleanser([this]() { - mPubKeyAuthData.wasCalled = 0; - mPubKeyAuthData.wasCanceled = 0; - mPubKeyAuthData.attemptedKeys.clear(); - }); - - kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with public key" << endl; - bool keepTryingPasskey=true; - while (keepTryingPasskey) { - mPubKeyAuthData.wasCalled = 0; - rc = ssh_userauth_publickey_auto(mSession, nullptr, nullptr); - - kdDebug(TDEIO_SFTP_DB) << "ssh_userauth_publickey_auto returned rc=" << rc - << " ssh_err=" << ssh_get_error_code(mSession) - << " (" << ssh_get_error(mSession) << ")" << endl; - - switch (rc) { - case SSH_AUTH_SUCCESS: - case SSH_AUTH_PARTIAL: - keepTryingPasskey=false; - break; - case SSH_AUTH_AGAIN: - // Returned in case of some errors like if server hangs up or there were too many auth attempts - case SSH_AUTH_ERROR: - error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed (method: %1).") - .arg(i18n("public key"))); - /* FIXME: add some additional info from ssh_get_error() if available <2024-01-20 Fat-Zer> */ - return; - - case SSH_AUTH_DENIED: - if (!mPubKeyAuthData.wasCalled) { - kdDebug(TDEIO_SFTP_DB) << "Passkey auth denied because it has no matching key" << endl; - keepTryingPasskey = false; - } else if (mPubKeyAuthData.wasCanceled) { - kdDebug(TDEIO_SFTP_DB) << "Passkey auth denied because user canceled" << endl; - keepTryingPasskey = false; - } else { - kdDebug(TDEIO_SFTP_DB) << "User entered wrong passphrase for the key" << endl; - } - break; - } - } + // Note this loop can rerun in case of multistage ssh authentication e.g. "password,publickey" + // which will require user to provide a valid password at first and then a valid public key. + // see AuthenticationMethods in man 5 sshd_config for more info + bool wasCanceled = false; + int availableMethodes = ssh_auth_list(mSession); + + if (!availableMethodes) { + // Technically libssh docs suggest that the server merely MAY send auth methods, but it's + // highly unclear what we should do in such case and it looks like openssh doesn't have an + // option for that, so let's just consider this server a jerk and don't talk to him anymore. + error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed." + " The server did not send any authentication methods!")); + return; + } else if (!(availableMethodes & supportedMethods)) { + error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed." + " The server sent only unsupported authentication methods!")); + return; } - // Try to authenticate with keyboard interactive - if (rc != SSH_AUTH_SUCCESS && (method & SSH_AUTH_METHOD_INTERACTIVE)) - { - kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with keyboard interactive" << endl; - rc = authenticateKeyboardInteractive(); + const auto *authMethods = &authMethodsNormal; - if (rc == SSH_AUTH_ERROR) - { + // If we have cached password we want try to use it before public key + if(!mPassword.isEmpty()) { + static const auto authMethodsWithPassword = []() { + std::vector> rv; + rv.emplace_back(std::make_unique(/* noPasswordQuery = */true)); + rv.emplace_back(std::make_unique(/* noPasswordQuery = */true)); + for (const auto &m: authMethodsNormal) { rv.emplace_back(m->clone()); } + return rv; + }(); + + authMethods = &authMethodsWithPassword; + } + + // Actually iterate over the list of methods and try them out + for (const auto &method: *authMethods) { + if (!(availableMethodes & method->flag())) { continue; } + + rc = method->authenticate( this ); + attemptedMethods |= method->flag(); + if (rc == SSH_AUTH_SUCCESS || rc == SSH_AUTH_PARTIAL) { + kdDebug(TDEIO_SFTP_DB) << "method=" << method->name() << ": auth " + << (rc == SSH_AUTH_SUCCESS ? "success" : "partial") << endl; + break; // either next auth method or continue on with the connect + } else if (rc == SSH_AUTH_AGAIN || rc == SSH_AUTH_ERROR ) { + // SSH_AUTH_AGAIN returned in case of some errors like if server hangs up or there were too many auth attempts error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed (method: %1).") - .arg(i18n("keyboard interactive"))); + .arg(method->name())); + /* FIXME: add some additional info from ssh_get_error() if available <2024-01-20 Fat-Zer> */ + return; + } else if (rc == SSH_AUTH_CANCELED) { + kdDebug(TDEIO_SFTP_DB) << "method=" << method->name() << " was canceled by user" << endl; + // don't quit immediately due to that the user might have canceled one method to use another + wasCanceled = true; + } else if (rc == SSH_AUTH_NEED_RECONNECT) { + kdDebug(TDEIO_SFTP_DB) << "method=" << method->name() << " requested reconnection" << endl; + goto connection_restart; + } else if (rc == SSH_AUTH_DENIED) { + kdDebug(TDEIO_SFTP_DB) << "Auth for method=" << method->name() << " was denied" << endl; + // do nothing, just proceed with next auth method + } else { + // Shouldn't happen, but to be on the safe side better handle it + error(TDEIO::ERR_UNKNOWN, i18n("Authentication failed unexpectedly")); return; } } - // Try to authenticate with password - if (rc != SSH_AUTH_SUCCESS && (method & SSH_AUTH_METHOD_PASSWORD)) - { - kdDebug(TDEIO_SFTP_DB) << "Trying to authenticate with password" << endl; - - info.keepPassword = true; - for(;;) - { - if(!firstTime || mPassword.isEmpty()) - { - if (firstTime) { - info.prompt = i18n("Please enter your username and password."); - } else { - info.prompt = i18n("Login failed.\nPlease confirm your username and password, and enter them again."); - } - dlgResult = openPassDlg(info); - - // Handle user canceled or dialog failed to open... - if (!dlgResult) { - kdDebug(TDEIO_SFTP_DB) << "User canceled, dlgResult = " << dlgResult << endl; - error(TDEIO::ERR_USER_CANCELED, TQString()); - return; - } - - firstTime = false; - } + // At this point rc values should be one of: + // SSH_AUTH_SUCCESS, SSH_AUTH_PARTIAL, SSH_AUTH_DENIED or SSH_AUTH_CANCELED + if (wasCanceled && (rc == SSH_AUTH_CANCELED || rc == SSH_AUTH_DENIED)) { + error(TDEIO::ERR_USER_CANCELED, TQString::null); + return; + } else if (rc != SSH_AUTH_SUCCESS && rc != SSH_AUTH_PARTIAL) { + TQStringList attemptedMethodsLst; + for (auto &method: authMethodsNormal) { + if (attemptedMethods & method->flag()) { attemptedMethodsLst << method->name(); } + } - if (mUsername != info.username) { - kdDebug(TDEIO_SFTP_DB) << "Username changed from " << mUsername - << " to " << info.username << endl; - } - mUsername = info.username; - /* FIXME: libssh doc says that most servers won't allow user switching in-session - * <2024-01-21 Fat-Zer> */ - rc = ssh_userauth_password(mSession, mUsername.utf8().data(), - info.password.utf8().data()); - if (rc == SSH_AUTH_ERROR) { - error(TDEIO::ERR_COULD_NOT_LOGIN, i18n("Authentication failed (method: %1).") - .arg(i18n("password"))); - return; - } else if (rc == SSH_AUTH_SUCCESS) { - break; - } + TQString errMsg = i18n("Authentication denied (attempted method was: %1).", + "Authentication denied (attempted methods were: %1).", + attemptedMethodsLst.size()) + .arg(attemptedMethodsLst.join(", ")); + if (availableMethodes & ~supportedMethods) { + errMsg.append("\n") + .append(i18n("Note: server also declares some other unsupported authentication methods")); } + error(TDEIO::ERR_COULD_NOT_LOGIN, errMsg); + return; } } diff --git a/tdeioslave/sftp/tdeio_sftp.h b/tdeioslave/sftp/tdeio_sftp.h index 065ef7cda..66a348e68 100644 --- a/tdeioslave/sftp/tdeio_sftp.h +++ b/tdeioslave/sftp/tdeio_sftp.h @@ -96,10 +96,18 @@ public: void log_callback(ssh_session session, int priority, const char *message, void *userdata); + // Callbacks for SSHAuthMethod-derived strategies + int authenticatePublicKey(); + int authenticateKeyboardInteractive(bool noPaswordQuery = false); + int authenticatePassword(bool noPaswordQuery = false); + + /** Some extra authentication failure reasons intended to use alongside was declared in libssh */ + enum extra_ssh_auth_e { + SSH_AUTH_CANCELED=128, //< user canceled password entry dialog + SSH_AUTH_NEED_RECONNECT //< it is required to reinitialize connection from scratch + }; private: // Private variables - void statMime(const KURL &url); - void closeFile(); /** True if ioslave is connected to sftp server. */ bool mConnected; @@ -118,8 +126,9 @@ private: // Private variables /** Username to use when connecting */ TQString mUsername; - /** User's password. Note: the password would be set only if it was passed to - * setHost() or received from cache */ + /** User's password. Note: the password would be set only if it was somehow cached: passed to + * setHost(), received from passwdserver's cache or was entered by user before reconnection + */ TQString mPassword; /** The open file */ @@ -142,19 +151,26 @@ private: // Private variables /** Some data needed to interact with auth_callback() */ struct { - /** true if callback was called */ - bool wasCalled; - /** true if user canceled password entry dialog */ - bool wasCanceled; /** List of keys user was already prompted to enter the passphrase for. * Note: Under most sane circumstances the list shouldn't go beyond size=2, * so no fancy containers here */ TQStringList attemptedKeys; + /** true if callback was called */ + bool wasCalled; + /** true if user canceled password entry dialog */ + bool wasCanceled; } mPubKeyAuthData; + /** true if the password dialog was prompted to the user at leas once */ + bool mPasswordWasPrompted = false; + private: // private methods - int authenticateKeyboardInteractive(); + void statMime(const KURL &url); + void closeFile(); + + /** @returns username used by libssh during the connection */ + TQString sshUsername(); /** A small helper function to construct auth info skeleton for the protocol */ TDEIO::AuthInfo authInfo(); @@ -170,4 +186,19 @@ private: // private methods TQString canonicalizePath(const TQString &path); }; +/** A base class for ssh authentication methods. */ +class SSHAuthMethod { +public: + /** libssh's flag for he method */ + virtual int flag() = 0; + /** The user-friendly (probably translated) name of the method */ + virtual TQString name() = 0; + /** Actually do perform the auth process */ + virtual int authenticate(sftpProtocol *ioslave) const = 0; + /** Creates a copy of derived class */ + virtual SSHAuthMethod* clone() = 0; + + virtual ~SSHAuthMethod() {}; +}; + #endif