qemu/include/crypto/tls-cipher-suites.h
Philippe Mathieu-Daudé 993aec27aa crypto: Add tls-cipher-suites object
On the host OS, various aspects of TLS operation are configurable.
In particular it is possible for the sysadmin to control the TLS
cipher/protocol algorithms that applications are permitted to use.

* Any given crypto library has a built-in default priority list
  defined by the distro maintainer of the library package (or by
  upstream).

* The "crypto-policies" RPM (or equivalent host OS package)
  provides a config file such as "/etc/crypto-policies/config",
  where the sysadmin can set a high level (library-independent)
  policy.

  The "update-crypto-policies --set" command (or equivalent) is
  used to translate the global policy to individual library
  representations, producing files such as
  "/etc/crypto-policies/back-ends/*.config". The generated files,
  if present, are loaded by the various crypto libraries to
  override their own built-in defaults.

  For example, the GNUTLS library may read
  "/etc/crypto-policies/back-ends/gnutls.config".

* A management application (or the QEMU user) may overide the
  system-wide crypto-policies config via their own config, if
  they need to diverge from the former.

Thus the priority order is "QEMU user config" > "crypto-policies
system config" > "library built-in config".

Introduce the "tls-cipher-suites" object for exposing the ordered
list of permitted TLS cipher suites from the host side to the
guest firmware, via fw_cfg. The list is represented as an array
of bytes.

The priority at which the host-side policy is retrieved is given
by the "priority" property of the new object type. For example,
"priority=@SYSTEM" may be used to refer to
"/etc/crypto-policies/back-ends/gnutls.config" (given that QEMU
uses GNUTLS).

The firmware uses the IANA_TLS_CIPHER array for configuring
guest-side TLS, for example in UEFI HTTPS Boot.

[Description from Daniel P. Berrangé, edited by Laszlo Ersek.]

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200623172726.21040-2-philmd@redhat.com>
2020-07-03 18:16:01 +02:00

40 lines
1.1 KiB
C

/*
* QEMU TLS Cipher Suites Registry (RFC8447)
*
* Copyright (c) 2018-2020 Red Hat, Inc.
*
* Author: Philippe Mathieu-Daudé <philmd@redhat.com>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef QCRYPTO_TLSCIPHERSUITES_H
#define QCRYPTO_TLSCIPHERSUITES_H
#include "qom/object.h"
#include "crypto/tlscreds.h"
#define TYPE_QCRYPTO_TLS_CIPHER_SUITES "tls-cipher-suites"
#define QCRYPTO_TLS_CIPHER_SUITES(obj) \
OBJECT_CHECK(QCryptoTLSCipherSuites, (obj), TYPE_QCRYPTO_TLS_CIPHER_SUITES)
typedef struct QCryptoTLSCipherSuites {
/* <private> */
QCryptoTLSCreds parent_obj;
/* <public> */
} QCryptoTLSCipherSuites;
/**
* qcrypto_tls_cipher_suites_get_data:
* @obj: pointer to a TLS cipher suites object
* @errp: pointer to a NULL-initialized error object
*
* Returns: reference to a byte array containing the data.
* The caller should release the reference when no longer
* required.
*/
GByteArray *qcrypto_tls_cipher_suites_get_data(QCryptoTLSCipherSuites *obj,
Error **errp);
#endif /* QCRYPTO_TLSCIPHERSUITES_H */