323 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			323 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * QEMU crypto TLS session support
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|  *
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|  * Copyright (c) 2015 Red Hat, Inc.
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|  *
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|  * This library is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2 of the License, or (at your option) any later version.
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|  *
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|  * This library is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
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|  *
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|  */
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| 
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| #ifndef QCRYPTO_TLSSESSION_H
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| #define QCRYPTO_TLSSESSION_H
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| 
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| #include "crypto/tlscreds.h"
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| 
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| /**
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|  * QCryptoTLSSession:
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|  *
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|  * The QCryptoTLSSession object encapsulates the
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|  * logic to integrate with a TLS providing library such
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|  * as GNUTLS, to setup and run TLS sessions.
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|  *
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|  * The API is designed such that it has no assumption about
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|  * the type of transport it is running over. It may be a
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|  * traditional TCP socket, or something else entirely. The
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|  * only requirement is a full-duplex stream of some kind.
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|  *
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|  * <example>
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|  *   <title>Using TLS session objects</title>
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|  *   <programlisting>
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|  * static ssize_t mysock_send(const char *buf, size_t len,
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|  *                            void *opaque)
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|  * {
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|  *    int fd = GPOINTER_TO_INT(opaque);
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|  *
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|  *    return write(*fd, buf, len);
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|  * }
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|  *
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|  * static ssize_t mysock_recv(const char *buf, size_t len,
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|  *                            void *opaque)
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|  * {
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|  *    int fd = GPOINTER_TO_INT(opaque);
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|  *
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|  *    return read(*fd, buf, len);
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|  * }
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|  *
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|  * static int mysock_run_tls(int sockfd,
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|  *                           QCryptoTLSCreds *creds,
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|  *                           Error *errp)
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|  * {
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|  *    QCryptoTLSSession *sess;
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|  *
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|  *    sess = qcrypto_tls_session_new(creds,
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|  *                                   "vnc.example.com",
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|  *                                   NULL,
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|  *                                   QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
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|  *                                   errp);
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|  *    if (sess == NULL) {
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|  *       return -1;
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|  *    }
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|  *
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|  *    qcrypto_tls_session_set_callbacks(sess,
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|  *                                      mysock_send,
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|  *                                      mysock_recv
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|  *                                      GINT_TO_POINTER(fd));
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|  *
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|  *    while (1) {
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|  *       if (qcrypto_tls_session_handshake(sess, errp) < 0) {
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|  *           qcrypto_tls_session_free(sess);
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|  *           return -1;
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|  *       }
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|  *
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|  *       switch(qcrypto_tls_session_get_handshake_status(sess)) {
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|  *       case QCRYPTO_TLS_HANDSHAKE_COMPLETE:
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|  *           if (qcrypto_tls_session_check_credentials(sess, errp) < )) {
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|  *               qcrypto_tls_session_free(sess);
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|  *               return -1;
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|  *           }
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|  *           goto done;
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|  *       case QCRYPTO_TLS_HANDSHAKE_RECVING:
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|  *           ...wait for GIO_IN event on fd...
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|  *           break;
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|  *       case QCRYPTO_TLS_HANDSHAKE_SENDING:
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|  *           ...wait for GIO_OUT event on fd...
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|  *           break;
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|  *       }
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|  *    }
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|  *   done:
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|  *
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|  *    ....send/recv payload data on sess...
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|  *
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|  *    qcrypto_tls_session_free(sess):
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|  * }
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|  *   </programlisting>
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|  * </example>
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|  */
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| 
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| typedef struct QCryptoTLSSession QCryptoTLSSession;
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| 
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| 
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| /**
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|  * qcrypto_tls_session_new:
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|  * @creds: pointer to a TLS credentials object
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|  * @hostname: optional hostname to validate
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|  * @aclname: optional ACL to validate peer credentials against
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|  * @endpoint: role of the TLS session, client or server
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Create a new TLS session object that will be used to
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|  * negotiate a TLS session over an arbitrary data channel.
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|  * The session object can operate as either the server or
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|  * client, according to the value of the @endpoint argument.
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|  *
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|  * For clients, the @hostname parameter should hold the full
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|  * unmodified hostname as requested by the user. This will
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|  * be used to verify the against the hostname reported in
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|  * the server's credentials (aka x509 certificate).
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|  *
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|  * The @aclname parameter (optionally) specifies the name
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|  * of an access control list that will be used to validate
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|  * the peer's credentials. For x509 credentials, the ACL
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|  * will be matched against the CommonName shown in the peer's
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|  * certificate. If the session is acting as a server, setting
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|  * an ACL will require that the client provide a validate
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|  * x509 client certificate.
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|  *
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|  * After creating the session object, the I/O callbacks
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|  * must be set using the qcrypto_tls_session_set_callbacks()
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|  * method. A TLS handshake sequence must then be completed
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|  * using qcrypto_tls_session_handshake(), before payload
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|  * data is permitted to be sent/received.
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|  *
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|  * The session object must be released by calling
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|  * qcrypto_tls_session_free() when no longer required
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|  *
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|  * Returns: a TLS session object, or NULL on error.
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|  */
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| QCryptoTLSSession *qcrypto_tls_session_new(QCryptoTLSCreds *creds,
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|                                            const char *hostname,
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|                                            const char *aclname,
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|                                            QCryptoTLSCredsEndpoint endpoint,
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|                                            Error **errp);
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| 
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| /**
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|  * qcrypto_tls_session_free:
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|  * @sess: the TLS session object
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|  *
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|  * Release all memory associated with the TLS session
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|  * object previously allocated by qcrypto_tls_session_new()
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|  */
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| void qcrypto_tls_session_free(QCryptoTLSSession *sess);
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| 
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| /**
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|  * qcrypto_tls_session_check_credentials:
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|  * @sess: the TLS session object
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Validate the peer's credentials after a successful
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|  * TLS handshake. It is an error to call this before
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|  * qcrypto_tls_session_get_handshake_status() returns
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|  * QCRYPTO_TLS_HANDSHAKE_COMPLETE
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|  *
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|  * Returns 0 if the credentials validated, -1 on error
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|  */
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| int qcrypto_tls_session_check_credentials(QCryptoTLSSession *sess,
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|                                           Error **errp);
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| 
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| typedef ssize_t (*QCryptoTLSSessionWriteFunc)(const char *buf,
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|                                               size_t len,
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|                                               void *opaque);
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| typedef ssize_t (*QCryptoTLSSessionReadFunc)(char *buf,
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|                                              size_t len,
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|                                              void *opaque);
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| 
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| /**
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|  * qcrypto_tls_session_set_callbacks:
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|  * @sess: the TLS session object
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|  * @writeFunc: callback for sending data
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|  * @readFunc: callback to receiving data
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|  * @opaque: data to pass to callbacks
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|  *
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|  * Sets the callback functions that are to be used for sending
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|  * and receiving data on the underlying data channel. Typically
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|  * the callbacks to write/read to/from a TCP socket, but there
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|  * is no assumption made about the type of channel used.
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|  *
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|  * The @writeFunc callback will be passed the encrypted
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|  * data to send to the remote peer.
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|  *
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|  * The @readFunc callback will be passed a pointer to fill
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|  * with encrypted data received from the remote peer
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|  */
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| void qcrypto_tls_session_set_callbacks(QCryptoTLSSession *sess,
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|                                        QCryptoTLSSessionWriteFunc writeFunc,
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|                                        QCryptoTLSSessionReadFunc readFunc,
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|                                        void *opaque);
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| 
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| /**
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|  * qcrypto_tls_session_write:
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|  * @sess: the TLS session object
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|  * @buf: the plain text to send
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|  * @len: the length of @buf
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|  *
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|  * Encrypt @len bytes of the data in @buf and send
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|  * it to the remote peer using the callback previously
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|  * registered with qcrypto_tls_session_set_callbacks()
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|  *
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|  * It is an error to call this before
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|  * qcrypto_tls_session_get_handshake_status() returns
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|  * QCRYPTO_TLS_HANDSHAKE_COMPLETE
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|  *
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|  * Returns: the number of bytes sent, or -1 on error
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|  */
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| ssize_t qcrypto_tls_session_write(QCryptoTLSSession *sess,
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|                                   const char *buf,
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|                                   size_t len);
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| 
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| /**
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|  * qcrypto_tls_session_read:
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|  * @sess: the TLS session object
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|  * @buf: to fill with plain text received
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|  * @len: the length of @buf
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|  *
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|  * Receive up to @len bytes of data from the remote peer
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|  * using the callback previously registered with
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|  * qcrypto_tls_session_set_callbacks(), decrypt it and
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|  * store it in @buf.
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|  *
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|  * It is an error to call this before
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|  * qcrypto_tls_session_get_handshake_status() returns
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|  * QCRYPTO_TLS_HANDSHAKE_COMPLETE
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|  *
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|  * Returns: the number of bytes received, or -1 on error
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|  */
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| ssize_t qcrypto_tls_session_read(QCryptoTLSSession *sess,
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|                                  char *buf,
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|                                  size_t len);
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| 
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| /**
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|  * qcrypto_tls_session_handshake:
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|  * @sess: the TLS session object
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Start, or continue, a TLS handshake sequence. If
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|  * the underlying data channel is non-blocking, then
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|  * this method may return control before the handshake
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|  * is complete. On non-blocking channels the
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|  * qcrypto_tls_session_get_handshake_status() method
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|  * should be used to determine whether the handshake
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|  * has completed, or is waiting to send or receive
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|  * data. In the latter cases, the caller should setup
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|  * an event loop watch and call this method again
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|  * once the underlying data channel is ready to read
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|  * or write again
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|  */
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| int qcrypto_tls_session_handshake(QCryptoTLSSession *sess,
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|                                   Error **errp);
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| 
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| typedef enum {
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|     QCRYPTO_TLS_HANDSHAKE_COMPLETE,
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|     QCRYPTO_TLS_HANDSHAKE_SENDING,
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|     QCRYPTO_TLS_HANDSHAKE_RECVING,
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| } QCryptoTLSSessionHandshakeStatus;
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| 
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| /**
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|  * qcrypto_tls_session_get_handshake_status:
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|  * @sess: the TLS session object
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|  *
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|  * Check the status of the TLS handshake. This
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|  * is used with non-blocking data channels to
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|  * determine whether the handshake is waiting
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|  * to send or receive further data to/from the
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|  * remote peer.
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|  *
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|  * Once this returns QCRYPTO_TLS_HANDSHAKE_COMPLETE
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|  * it is permitted to send/receive payload data on
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|  * the channel
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|  */
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| QCryptoTLSSessionHandshakeStatus
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| qcrypto_tls_session_get_handshake_status(QCryptoTLSSession *sess);
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| 
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| /**
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|  * qcrypto_tls_session_get_key_size:
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|  * @sess: the TLS session object
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Check the size of the data channel encryption key
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|  *
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|  * Returns: the length in bytes of the encryption key
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|  * or -1 on error
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|  */
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| int qcrypto_tls_session_get_key_size(QCryptoTLSSession *sess,
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|                                      Error **errp);
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| 
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| /**
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|  * qcrypto_tls_session_get_peer_name:
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|  * @sess: the TLS session object
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|  *
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|  * Get the identified name of the remote peer. If the
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|  * TLS session was negotiated using x509 certificate
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|  * credentials, this will return the CommonName from
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|  * the peer's certificate. If no identified name is
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|  * available it will return NULL.
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|  *
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|  * The returned data must be released with g_free()
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|  * when no longer required.
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|  *
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|  * Returns: the peer's name or NULL.
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|  */
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| char *qcrypto_tls_session_get_peer_name(QCryptoTLSSession *sess);
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| 
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| #endif /* QCRYPTO_TLSSESSION_H */
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