From patchwork Mon Jul 22 13:16:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 13738839 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0301BC3DA64 for ; Mon, 22 Jul 2024 13:18:07 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sVsuX-0000GQ-7j; Mon, 22 Jul 2024 09:17:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sVsuJ-0008VP-J0 for qemu-devel@nongnu.org; Mon, 22 Jul 2024 09:16:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sVsuG-0007cD-6p for qemu-devel@nongnu.org; Mon, 22 Jul 2024 09:16:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721654205; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iz7gdYSSGyBra3y/0Srn+q7HWefemtlpPT4z6ITk7Z8=; b=IJ7ky6ZmDHNG7qkQLXuZ+XJ5LPe+upHFdjBshZXHuPHqqp+vsYf1/PMbqDovX3eg0jz5+2 2/m36I21VWAXNUmkaKkXTC9yIog570VwKhlDDj5/esDOLQVFmossNLIP7TwSeJaWk1vByD 8xHLuzfmRtdVHt/ZOfBhPVJflCnuWQI= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-282-Z9V9Gd5yM5mAu8_T8xB7-A-1; Mon, 22 Jul 2024 09:16:43 -0400 X-MC-Unique: Z9V9Gd5yM5mAu8_T8xB7-A-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 706B41955D4C; Mon, 22 Jul 2024 13:16:42 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.102]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 657061944F2E; Mon, 22 Jul 2024 13:16:35 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: Michael Roth , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , =?utf-8?q?Marc?= =?utf-8?q?-Andr=C3=A9_Lureau?= , Markus Armbruster , Paolo Bonzini Subject: [PATCH 5/5] crypto: propagate errors from TLS session I/O callbacks Date: Mon, 22 Jul 2024 14:16:11 +0100 Message-ID: <20240722131611.2820041-6-berrange@redhat.com> In-Reply-To: <20240722131611.2820041-1-berrange@redhat.com> References: <20240722131611.2820041-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.133, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org GNUTLS doesn't know how to perform I/O on anything other than plain FDs, so the TLS session provides it with some I/O callbacks. The GNUTLS API design requires these callbacks to return a unix errno value, which means we're currently loosing the useful QEMU "Error" object. This changes the I/O callbacks in QEMU to stash the "Error" object in the QCryptoTLSSession class, and fetch it when seeing an I/O error returned from GNUTLS, thus preserving useful error messages. Signed-off-by: Daniel P. Berrangé Reviewed-by: Philippe Mathieu-Daudé --- crypto/tlssession.c | 71 +++++++++++++++++++++++++---- include/crypto/tlssession.h | 10 +++- io/channel-tls.c | 18 ++++---- tests/unit/test-crypto-tlssession.c | 28 ++++++++++-- 4 files changed, 103 insertions(+), 24 deletions(-) diff --git a/crypto/tlssession.c b/crypto/tlssession.c index f0076a4add..e5cbe86bf0 100644 --- a/crypto/tlssession.c +++ b/crypto/tlssession.c @@ -44,6 +44,13 @@ struct QCryptoTLSSession { QCryptoTLSSessionReadFunc readFunc; void *opaque; char *peername; + + /* + * Allow concurrent reads and writes, so track + * errors separately + */ + Error *rerr; + Error *werr; }; @@ -54,6 +61,9 @@ qcrypto_tls_session_free(QCryptoTLSSession *session) return; } + error_free(session->rerr); + error_free(session->werr); + gnutls_deinit(session->handle); g_free(session->hostname); g_free(session->peername); @@ -67,13 +77,26 @@ static ssize_t qcrypto_tls_session_push(void *opaque, const void *buf, size_t len) { QCryptoTLSSession *session = opaque; + ssize_t ret; if (!session->writeFunc) { errno = EIO; return -1; }; - return session->writeFunc(buf, len, session->opaque); + error_free(session->werr); + session->werr = NULL; + + ret = session->writeFunc(buf, len, session->opaque, &session->werr); + if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) { + errno = EAGAIN; + return -1; + } else if (ret < 0) { + errno = EIO; + return -1; + } else { + return ret; + } } @@ -81,13 +104,26 @@ static ssize_t qcrypto_tls_session_pull(void *opaque, void *buf, size_t len) { QCryptoTLSSession *session = opaque; + ssize_t ret; if (!session->readFunc) { errno = EIO; return -1; }; - return session->readFunc(buf, len, session->opaque); + error_free(session->rerr); + session->rerr = NULL; + + ret = session->readFunc(buf, len, session->opaque, &session->rerr); + if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) { + errno = EAGAIN; + return -1; + } else if (ret < 0) { + errno = EIO; + return -1; + } else { + return ret; + } } #define TLS_PRIORITY_ADDITIONAL_ANON "+ANON-DH" @@ -450,8 +486,13 @@ qcrypto_tls_session_write(QCryptoTLSSession *session, if (ret == GNUTLS_E_AGAIN) { return QCRYPTO_TLS_SESSION_ERR_BLOCK; } else { - error_setg(errp, - "Cannot write to TLS channel: %s", gnutls_strerror(ret)); + if (session->werr) { + error_propagate(errp, session->werr); + session->werr = NULL; + } else { + error_setg(errp, + "Cannot write to TLS channel: %s", gnutls_strerror(ret)); + } return -1; } } @@ -476,8 +517,13 @@ qcrypto_tls_session_read(QCryptoTLSSession *session, gracefulTermination){ return 0; } else { - error_setg(errp, - "Cannot read from TLS channel: %s", gnutls_strerror(ret)); + if (session->rerr) { + error_propagate(errp, session->rerr); + session->rerr = NULL; + } else { + error_setg(errp, + "Cannot read from TLS channel: %s", gnutls_strerror(ret)); + } return -1; } } @@ -505,11 +551,20 @@ qcrypto_tls_session_handshake(QCryptoTLSSession *session, ret == GNUTLS_E_AGAIN) { ret = 1; } else { - error_setg(errp, "TLS handshake failed: %s", - gnutls_strerror(ret)); + if (session->rerr || session->werr) { + error_setg(errp, "TLS handshake failed: %s: %s", + gnutls_strerror(ret), + error_get_pretty(session->rerr ? session->rerr : session->werr)); + } else { + error_setg(errp, "TLS handshake failed: %s", + gnutls_strerror(ret)); + } ret = -1; } } + error_free(session->rerr); + error_free(session->werr); + session->rerr = session->werr = NULL; return ret; } diff --git a/include/crypto/tlssession.h b/include/crypto/tlssession.h index 291e602540..f694a5c3c5 100644 --- a/include/crypto/tlssession.h +++ b/include/crypto/tlssession.h @@ -178,12 +178,18 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(QCryptoTLSSession, qcrypto_tls_session_free) int qcrypto_tls_session_check_credentials(QCryptoTLSSession *sess, Error **errp); +/* + * These must return QCRYPTO_TLS_SESSION_ERR_BLOCK if the I/O + * would block, but on other errors, must fill 'errp' + */ typedef ssize_t (*QCryptoTLSSessionWriteFunc)(const char *buf, size_t len, - void *opaque); + void *opaque, + Error **errp); typedef ssize_t (*QCryptoTLSSessionReadFunc)(char *buf, size_t len, - void *opaque); + void *opaque, + Error **errp); /** * qcrypto_tls_session_set_callbacks: diff --git a/io/channel-tls.c b/io/channel-tls.c index eab64b0706..980dc5b89f 100644 --- a/io/channel-tls.c +++ b/io/channel-tls.c @@ -28,17 +28,16 @@ static ssize_t qio_channel_tls_write_handler(const char *buf, size_t len, - void *opaque) + void *opaque, + Error **errp) { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque); ssize_t ret; - ret = qio_channel_write(tioc->master, buf, len, NULL); + ret = qio_channel_write(tioc->master, buf, len, errp); if (ret == QIO_CHANNEL_ERR_BLOCK) { - errno = EAGAIN; - return -1; + return QCRYPTO_TLS_SESSION_ERR_BLOCK; } else if (ret < 0) { - errno = EIO; return -1; } return ret; @@ -46,17 +45,16 @@ static ssize_t qio_channel_tls_write_handler(const char *buf, static ssize_t qio_channel_tls_read_handler(char *buf, size_t len, - void *opaque) + void *opaque, + Error **errp) { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque); ssize_t ret; - ret = qio_channel_read(tioc->master, buf, len, NULL); + ret = qio_channel_read(tioc->master, buf, len, errp); if (ret == QIO_CHANNEL_ERR_BLOCK) { - errno = EAGAIN; - return -1; + return QCRYPTO_TLS_SESSION_ERR_BLOCK; } else if (ret < 0) { - errno = EIO; return -1; } return ret; diff --git a/tests/unit/test-crypto-tlssession.c b/tests/unit/test-crypto-tlssession.c index b12e7b6879..34f1f4e1a4 100644 --- a/tests/unit/test-crypto-tlssession.c +++ b/tests/unit/test-crypto-tlssession.c @@ -35,18 +35,38 @@ #define PSKFILE WORKDIR "keys.psk" #define KEYFILE WORKDIR "key-ctx.pem" -static ssize_t testWrite(const char *buf, size_t len, void *opaque) +static ssize_t testWrite(const char *buf, size_t len, void *opaque, Error **errp) { int *fd = opaque; + int ret; - return write(*fd, buf, len); + ret = write(*fd, buf, len); + if (ret < 0) { + if (errno == EAGAIN) { + return QCRYPTO_TLS_SESSION_ERR_BLOCK; + } else { + error_setg_errno(errp, errno, "unable to write"); + return -1; + } + } + return ret; } -static ssize_t testRead(char *buf, size_t len, void *opaque) +static ssize_t testRead(char *buf, size_t len, void *opaque, Error **errp) { int *fd = opaque; + int ret; - return read(*fd, buf, len); + ret = read(*fd, buf, len); + if (ret < 0) { + if (errno == EAGAIN) { + return QCRYPTO_TLS_SESSION_ERR_BLOCK; + } else { + error_setg_errno(errp, errno, "unable to read"); + return -1; + } + } + return ret; } static QCryptoTLSCreds *test_tls_creds_psk_create(