Modern gnutls can use a global config file to control the
crypto priority settings for TLS connections. For example
the priority string "@SYSTEM" instructs gnutls to find the
priority setting named "SYSTEM" in the global config file.
Latest gnutls GIT codebase gained the ability to reference
multiple priority strings in the config file, with the first
one that is found to existing winning. This means it is now
possible to configure QEMU out of the box with a default
priority of "@QEMU,SYSTEM", which says to look for the
settings "QEMU" first, and if not found, use the "SYSTEM"
settings.
To make use of this facility, we introduce the ability to
set the QEMU default priority at build time via a new
configure argument. It is anticipated that distro vendors
will set this when building QEMU to a suitable value for
use with distro crypto policy setup. eg current Fedora
would run
./configure --tls-priority=@SYSTEM
while future Fedora would run
./configure --tls-priority=@QEMU,SYSTEM
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The gnutls default priority is either "NORMAL" (most historical
versions of gnutls) which is a built-in label in gnutls code,
or "@SYSTEM" (latest gnutls on Fedora at least) which refers
to an admin customizable entry in a gnutls config file.
Regardless of which default is used by a distro, they are both
global defaults applying to all applications using gnutls. If
a single application on the system needs to use a weaker set
of crypto priorities, this potentially forces the weakness onto
all applications. Or conversely if a single application wants a
strong default than all others, it can't do this via the global
config file.
This adds an extra parameter to the tls credential object which
allows the mgmt app / user to explicitly provide a priority
string to QEMU when configuring TLS.
For example, to use the "NORMAL" priority, but disable SSL 3.0
one can now configure QEMU thus:
$QEMU -object tls-creds-x509,id=tls0,dir=/home/berrange/qemutls,\
priority="NORMAL:-VERS-SSL3.0" \
..other args...
If creating tls-creds-anon, whatever priority the user specifies
will always have "+ANON-DH" appended to it, since that's mandatory
to make the anonymous credentials work.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Wire up the nettle and gcrypt hash backends so that they can
support the sha224, sha384, sha512 and ripemd160 hash algorithms.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the internal hash code is using the gnutls hash APIs.
GNUTLS in turn is wrapping either nettle or gcrypt. Not only
were the GNUTLS hash APIs not added until GNUTLS 2.9.10, but
they don't expose support for all the algorithms QEMU needs
to use with LUKS.
Address this by directly wrapping nettle/gcrypt in QEMU and
avoiding GNUTLS's extra layer of indirection. This gives us
support for hash functions on a much wider range of platforms
and opens up ability to support more hash functions. It also
avoids a GNUTLS bug which would not correctly handle hashing
of large data blocks if int != size_t.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When opening an existing LUKS volume, if the iv generator is
essiv, then the iv hash algorithm is mandatory to provide. We
must report an error if it is omitted in the cipher mode spec,
not silently default to hash 0 (md5). If the iv generator is
not essiv, then we explicitly ignore any iv hash algorithm,
rather than report an error, for compatibility with dm-crypt.
When creating a new LUKS volume, if the iv generator is essiv
and no iv hsah algorithm is provided, we should default to
using the sha256 hash.
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move all trace-events for files in the crypto/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-4-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Otherwise unintended results could happen. For example,
Coverity reports a division by zero in qcrypto_afsplit_hash.
While this cannot really happen, it shows that the contract
of qcrypto_hash_digest_len can be improved.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Give slightly more information when certification loading fails.
Rather than have no information, you now get gnutls's only slightly
less unhelpful error messages.
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).
This patch is the result of coccinelle script
scripts/coccinelle/round.cocci
CC: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Move it to the actual users. There are still a few includes of
qemu/bswap.h in headers; removing them is left for future work.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Support for the PBKDF functions in nettle was not introduced
until version 2.6. Some distros QEMU targets have older
versions and thus lack PBKDF support. Address this by doing
a check in configure for the desired function and then skipping
compilation of the nettle-pbkdf.o module
Reported-by: Wen Congyang <wency@cn.fujitsu.com>
Tested-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
* Chardev fix from Marc-André
* config.status tweak from David
* Header file tweaks from Markus, myself and Veronia (Outreachy candidate)
* get_ticks_per_sec() removal from Rutuja (Outreachy candidate)
* Coverity fix from myself
* PKE implementation from myself, based on rth's XSAVE support
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging
* Log filtering from Alex and Peter
* Chardev fix from Marc-André
* config.status tweak from David
* Header file tweaks from Markus, myself and Veronia (Outreachy candidate)
* get_ticks_per_sec() removal from Rutuja (Outreachy candidate)
* Coverity fix from myself
* PKE implementation from myself, based on rth's XSAVE support
# gpg: Signature made Thu 24 Mar 2016 20:15:11 GMT using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>"
* remotes/bonzini/tags/for-upstream: (28 commits)
target-i386: implement PKE for TCG
config.status: Pass extra parameters
char: translate from QIOChannel error to errno
exec: fix error handling in file_ram_alloc
cputlb: modernise the debug support
qemu-log: support simple pid substitution for logs
target-arm: dfilter support for in_asm
qemu-log: dfilter-ise exec, out_asm, op and opt_op
qemu-log: new option -dfilter to limit output
qemu-log: Improve the "exec" TB execution logging
qemu-log: Avoid function call for disabled qemu_log_mask logging
qemu-log: correct help text for -d cpu
tcg: pass down TranslationBlock to tcg_code_gen
util: move declarations out of qemu-common.h
Replaced get_tick_per_sec() by NANOSECONDS_PER_SECOND
hw: explicitly include qemu-common.h and cpu.h
include/crypto: Include qapi-types.h or qemu/bswap.h instead of qemu-common.h
isa: Move DMA_transfer_handler from qemu-common.h to hw/isa/isa.h
Move ParallelIOArg from qemu-common.h to sysemu/char.h
Move QEMU_ALIGN_*() from qemu-common.h to qemu/osdep.h
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Conflicts:
scripts/clean-includes
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
Several include/crypto/ headers include qemu-common.h, but either need
just qapi-types.h from it, or qemu/bswap.h, or nothing at all. Replace or
drop the include accordingly. tests/test-crypto-secret.c now misses
qemu/module.h, so include it there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef. Since then, we've moved to include qemu/osdep.h
everywhere. Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h. That's in excess of
100KiB of crap most .c files don't actually need.
Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h. Include qapi/error.h in .c files that need it and don't
get it now. Include qapi-types.h in qom/object.h for uint16List.
Update scripts/clean-includes accordingly. Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h
comment quoted above similarly.
This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third. Unfortunately, the number depending on
qapi-types.h shrinks only a little. More work is needed for that one.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For versions of nettle < 3.0.0, the cipher functions took a
'void *ctx' and 'unsigned len' instad of 'const void *ctx'
and 'size_t len'. The xts functions though are builtin to
QEMU and always expect the latter signatures. Define a
second set of wrappers to use with the correct signatures
needed by XTS mode.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Prior to the nettle 3.0.0 release, the cast5_set_key function
was actually named cast128_set_key, so we must add a compatibility
definition.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Provide a block encryption implementation that follows the
LUKS/dm-crypt specification.
This supports all combinations of hash, cipher algorithm,
cipher mode and iv generator that are implemented by the
current crypto layer.
There is support for opening existing volumes formatted
by dm-crypt, and for formatting new volumes. In the latter
case it will only use key slot 0.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a generic framework for supporting different block encryption
formats. Upon instantiating a QCryptoBlock object, it will read
the encryption header and extract the encryption keys. It is
then possible to call methods to encrypt/decrypt data buffers.
There is also a mode whereby it will create/initialize a new
encryption header on a previously unformatted volume.
The initial framework comes with support for the legacy QCow
AES based encryption. This enables code in the QCow driver to
be consolidated later.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce 'XTS' as a permitted mode for the cipher APIs.
With XTS the key provided must be twice the size of the
key normally required for any given algorithm. This is
because the key will be split into two pieces for use
in XTS mode.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The built-in and nettle cipher backends for AES maintain
two separate AES contexts, one for encryption and one for
decryption. This is going to be inconvenient for the future
code dealing with XTS, so wrap them up in a single struct
so there is just one pointer to pass around for both
encryption and decryption.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The XTS (XEX with tweaked-codebook and ciphertext stealing)
cipher mode is commonly used in full disk encryption. There
is unfortunately no implementation of it in either libgcrypt
or nettle, so we need to provide our own.
The libtomcrypt project provides a repository of crypto
algorithms under a choice of either "public domain" or
the "what the fuck public license".
So this impl is taken from the libtomcrypt GIT repo and
adapted to be compatible with the way we need to call
ciphers provided by nettle/gcrypt.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
New cipher algorithms 'twofish-128', 'twofish-192' and
'twofish-256' are defined for the Twofish algorithm.
The gcrypt backend does not support 'twofish-192'.
The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
New cipher algorithms 'serpent-128', 'serpent-192' and
'serpent-256' are defined for the Serpent algorithm.
The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
A new cipher algorithm 'cast-5-128' is defined for the
Cast-5 algorithm with 128 bit key size. Smaller key sizes
are supported by Cast-5, but nothing in QEMU should use
them, so only 128 bit keys are permitted.
The nettle and gcrypt cipher backends are updated to
support the new cipher and a test vector added to the
cipher test suite. The new algorithm is enabled in the
LUKS block encryption driver.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The LUKS format specifies an anti-forensic split algorithm which
is used to artificially expand the size of the key material on
disk. This is an implementation of that algorithm.
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are a number of different algorithms that can be used
to generate initialization vectors for disk encryption. This
introduces a simple internal QCryptoBlockIV object to provide
a consistent internal API to the different algorithms. The
initially implemented algorithms are 'plain', 'plain64' and
'essiv', each matching the same named algorithm provided
by the Linux kernel dm-crypt driver.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The LUKS data format includes use of PBKDF2 (Password-Based
Key Derivation Function). The Nettle library can provide
an implementation of this, but we don't want code directly
depending on a specific crypto library backend. Introduce
a new include/crypto/pbkdf.h header which defines a QEMU
API for invoking PBKDK2. The initial implementations are
backed by nettle & gcrypt, which are commonly available
with distros shipping GNUTLS.
The test suite data is taken from the cryptsetup codebase
under the LGPLv2.1+ license. This merely aims to verify
that whatever backend we provide for this function in QEMU
will comply with the spec.
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are three backend impls provided. The preferred
is gnutls, which is backed by nettle in modern distros.
The gcrypt impl is provided for cases where QEMU build
against gnutls is disabled, but crypto is still desired.
No nettle impl is provided, since it is non-trivial to
use the nettle APIs for random numbers. Users of nettle
should ensure gnutls is enabled for QEMU.
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The qcrypto_hash_digest_len method was accidentally inside
a CONFIG_GNUTLS_HASH block, even though it doesn't depend
on gnutls. Re-arrange it to be unconditionally defined.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This converts the tlscredsx509, tlscredsanon and secret objects
to register their properties against the class rather than object.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-3-git-send-email-peter.maydell@linaro.org
Replace the uint8 softfloat-specific typedef with uint8_t.
This change was made with
find include hw fpu target-* -name '*.[ch]' | xargs sed -i -e 's/\buint8\b/uint8_t/g'
together with manual removal of the typedef definition and
manual fixing of more erroneous uses found via test compilation.
It turns out that the only code using this type is an accidental
use where uint8_t was intended anyway...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Leon Alrae <leon.alrae@imgtec.com>
Acked-by: James Hogan <james.hogan@imgtec.com>
Message-id: 1452603315-27030-7-git-send-email-peter.maydell@linaro.org
When reporting an incorrect key length for a cipher, we
mixed up the actual vs expected arguments.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QCryptoCipherAlgorithm and QCryptoCipherMode enums are
defined in the crypto/cipher.h header. In the future some
QAPI types will want to reference the hash enums, so move
the enum definition into QAPI too.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QCryptoHashAlgorithm enum is defined in the crypto/hash.h
header. In the future some QAPI types will want to reference
the hash enums, so move the enum definition into QAPI too.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add a qcrypto_hash_digest_len() method which allows querying of
the raw digest size for a given hash algorithm.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Adds new methods to allow querying the length of the cipher
key, block size and initialization vectors.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Make use of the QCryptoSecret object to support loading of
encrypted x509 keys. The optional 'passwordid' parameter
to the tls-creds-x509 object type, provides the ID of a
secret object instance that holds the decryption password
for the PEM file.
# printf "123456" > mypasswd.txt
# $QEMU \
-object secret,id=sec0,filename=mypasswd.txt \
-object tls-creds-x509,passwordid=sec0,id=creds0,\
dir=/home/berrange/.pki/qemu,endpoint=server \
-vnc :1,tls-creds=creds0
This requires QEMU to be linked to GNUTLS >= 3.1.11. If
GNUTLS is too old an error will be reported if an attempt
is made to pass a decryption password.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce a new QCryptoSecret object class which will be used
for providing passwords and keys to other objects which need
sensitive credentials.
The new object can provide secret values directly as properties,
or indirectly via a file. The latter includes support for file
descriptor passing syntax on UNIX platforms. Ordinarily passing
secret values directly as properties is insecure, since they
are visible in process listings, or in log files showing the
CLI args / QMP commands. It is possible to use AES-256-CBC to
encrypt the secret values though, in which case all that is
visible is the ciphertext. For ad hoc developer testing though,
it is fine to provide the secrets directly without encryption
so this is not explicitly forbidden.
The anticipated scenario is that libvirtd will create a random
master key per QEMU instance (eg /var/run/libvirt/qemu/$VMNAME.key)
and will use that key to encrypt all passwords it provides to
QEMU via '-object secret,....'. This avoids the need for libvirt
(or other mgmt apps) to worry about file descriptor passing.
It also makes life easier for people who are scripting the
management of QEMU, for whom FD passing is significantly more
complex.
Providing data inline (insecure, only for ad hoc dev testing)
$QEMU -object secret,id=sec0,data=letmein
Providing data indirectly in raw format
printf "letmein" > mypasswd.txt
$QEMU -object secret,id=sec0,file=mypasswd.txt
Providing data indirectly in base64 format
$QEMU -object secret,id=sec0,file=mykey.b64,format=base64
Providing data with encryption
$QEMU -object secret,id=master0,file=mykey.b64,format=base64 \
-object secret,id=sec0,data=[base64 ciphertext],\
keyid=master0,iv=[base64 IV],format=base64
Note that 'format' here refers to the format of the ciphertext
data. The decrypted data must always be in raw byte format.
More examples are shown in the updated docs.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
In qcrypto_tls_creds_get_path() coverity complains that
we are checking '*creds' for NULL, despite having
dereferenced it previously. This is harmless bug due
to fact that the trace call was too early. Moving it
after the cleanup gets the desired semantics.
In qcrypto_tls_creds_check_cert_key_purpose() coverity
complains that we're passing a pointer to a previously
free'd buffer into gnutls_x509_crt_get_key_purpose_oid()
This is harmless because we're passing a size == 0, so
gnutls won't access the buffer, but rather just report
what size it needs to be. We can avoid it though by
explicitly setting the buffer to NULL after free'ing
it.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
The qcrypto_tls_creds_x509_sanity_check() checks whether
certs exist by calling access(). It is valid for this
method to be invoked with certfile==NULL though, since
for client credentials the cert is optional. This caused
it to call access(NULL), which happens to be harmless on
current Linux, but should none the less be avoided.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The qcrypto_tls_session_check_certificate() method was setting
an Error even when the ACL check suceeded. This didn't affect
the callers detection of errors because they relied on the
function return status, but this did cause a memory leak since
the caller would not free an Error they did not expect to be
set.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The QCryptoTLSCredsX509 object was not free'ing the allocated
gnutls_dh_params_t data when unloading the credentials
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When encrypting/decrypting data, the plaintext/ciphertext
buffers are required to be a multiple of the cipher block
size. If this is not done, nettle will abort and gcrypt
will report an error. To get consistent behaviour add
explicit checks upfront for the buffer sizes.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If no IV is provided, then use a default IV of all-zeros
instead of crashing. This gives parity with gcrypt and
nettle backends.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the choice of whether to use nettle or gcrypt is
made based on what gnutls is linked to. There are times
when it is desirable to be able to force build against a
specific library. For example, if testing changes to QEMU's
crypto code all 3 possible backends need to be checked
regardless of what the local gnutls uses.
It is also desirable to be able to enable nettle/gcrypt
for cipher/hash algorithms, without enabling gnutls
for TLS support.
This gives two new configure flags, which allow the
following possibilities
Automatically determine nettle vs gcrypt from what
gnutls links to (recommended to minimize number of
crypto libraries linked to)
./configure
Automatically determine nettle vs gcrypt based on
which is installed
./configure --disable-gnutls
Force use of nettle
./configure --enable-nettle
Force use of gcrypt
./configure --enable-gcrypt
Force use of built-in AES & crippled-DES
./configure --disable-nettle --disable-gcrypt
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce a QCryptoTLSSession object that will encapsulate
all the code for setting up and using a client/sever TLS
session. This isolates the code which depends on the gnutls
library, avoiding #ifdefs in the rest of the codebase, as
well as facilitating any possible future port to other TLS
libraries, if desired. It makes use of the previously
defined QCryptoTLSCreds object to access credentials to
use with the session. It also includes further unit tests
to validate the correctness of the TLS session handshake
and certificate validation. This is functionally equivalent
to the current TLS session handling code embedded in the
VNC server, and will obsolete it.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the administrator incorrectly sets up their x509 certificates,
the errors seen at runtime during connection attempts are very
obscure and difficult to diagnose. This has been a particular
problem for people using openssl to generate their certificates
instead of the gnutls certtool, because the openssl tools don't
turn on the various x509 extensions that gnutls expects to be
present by default.
This change thus adds support in the TLS credentials object to
sanity check the certificates when QEMU first loads them. This
gives the administrator immediate feedback for the majority of
common configuration mistakes, reducing the pain involved in
setting up TLS. The code is derived from equivalent code that
has been part of libvirt's TLS support and has been seen to be
valuable in assisting admins.
It is possible to disable the sanity checking, however, via
the new 'sanity-check' property on the tls-creds object type,
with a value of 'no'.
Unit tests are included in this change to verify the correctness
of the sanity checking code in all the key scenarios it is
intended to cope with. As part of the test suite, the pkix_asn1_tab.c
from gnutls is imported. This file is intentionally copied from the
(long since obsolete) gnutls 1.6.3 source tree, since that version
was still under GPLv2+, rather than the GPLv3+ of gnutls >= 2.0.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce a QCryptoTLSCredsX509 class which is used to
manage x509 certificate TLS credentials. This will be
the preferred credential type offering strong security
characteristics
Example CLI configuration:
$QEMU -object tls-creds-x509,id=tls0,endpoint=server,\
dir=/path/to/creds/dir,verify-peer=yes
The 'id' value in the -object args will be used to associate the
credentials with the network services. For example, when the VNC
server is later converted it would use
$QEMU -object tls-creds-x509,id=tls0,.... \
-vnc 127.0.0.1:1,tls-creds=tls0
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Introduce a QCryptoTLSCredsAnon class which is used to
manage anonymous TLS credentials. Use of this class is
generally discouraged since it does not offer strong
security, but it is required for backwards compatibility
with the current VNC server implementation.
Simple example CLI configuration:
$QEMU -object tls-creds-anon,id=tls0,endpoint=server
Example using pre-created diffie-hellman parameters
$QEMU -object tls-creds-anon,id=tls0,endpoint=server,\
dir=/path/to/creds/dir
The 'id' value in the -object args will be used to associate the
credentials with the network services. For example, when the VNC
server is later converted it would use
$QEMU -object tls-creds-anon,id=tls0,.... \
-vnc 127.0.0.1:1,tls-creds=tls0
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
