Commit Graph

116 Commits

Author SHA1 Message Date
Philippe Mathieu-Daudé 87e0331c5a docs: fix broken paths to docs/devel/tracing.txt
With the move of some docs/ to docs/devel/ on ac06724a71,
no references were updated.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-31 13:12:53 +03:00
Longpeng(Mike) 42e7e15f99 crypto: hmac: add af_alg-backend hmac support
Adds afalg-backend hmac support: introduces some private APIs
firstly, and then intergrates them into qcrypto_hmac_afalg_driver.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:05 +01:00
Longpeng(Mike) 9a05977348 crypto: hash: add afalg-backend hash support
Adds afalg-backend hash support: introduces some private APIs
firstly, and then intergrates them into qcrypto_hash_afalg_driver.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:05 +01:00
Longpeng(Mike) 25c60df32b crypto: cipher: add afalg-backend cipher support
Adds afalg-backend cipher support: introduces some private APIs
firstly, and then intergrates them into qcrypto_cipher_afalg_driver.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:05 +01:00
Longpeng(Mike) f0d92b56d8 crypto: introduce some common functions for af_alg backend
The AF_ALG socket family is the userspace interface for linux
crypto API, this patch adds af_alg family support and some common
functions for af_alg backend. It'll be used by afalg-backend crypto
latter.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>

Maintainer: modified to report an error if AF_ALG is requested
but cannot be supported

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:05 +01:00
Longpeng(Mike) 14a5a2aef4 crypto: hmac: add hmac driver framework
1) makes the public APIs in hmac-nettle/gcrypt/glib static,
   and rename them with "nettle/gcrypt/glib" prefix.

2) introduces hmac framework, including QCryptoHmacDriver
   and new public APIs.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:05 +01:00
Longpeng(Mike) d73c04e3ca crypto: hmac: introduce qcrypto_hmac_ctx_new for glib-backend
Extracts qcrypto_hmac_ctx_new() from qcrypto_hmac_new() for
glib-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) 8c2776d86c crypto: hmac: introduce qcrypto_hmac_ctx_new for nettle-backend
Extracts qcrypto_hmac_ctx_new() from qcrypto_hmac_new() for
nettle-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) 822d15ded8 crypto: hmac: introduce qcrypto_hmac_ctx_new for gcrypt-backend
1) Fix a handle-leak problem in qcrypto_hmac_new(), didn't free
   ctx->handle if gcry_mac_setkey fails.

2) Extracts qcrypto_hmac_ctx_new() from qcrypto_hmac_new() for
   gcrypt-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) 9767b75d92 crypto: hmac: move crypto/hmac.h into include/crypto/
Moves crypto/hmac.h into include/crypto/, likes cipher.h and hash.h

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) aa8efad903 crypto: hash: add hash driver framework
1) makes the public APIs in hash-nettle/gcrypt/glib static,
   and rename them with "nettle/gcrypt/glib" prefix.

2) introduces hash framework, including QCryptoHashDriver
   and new public APIs.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) 75c8007809 crypto: cipher: add cipher driver framework
1) makes the public APIs in cipher-nettle/gcrypt/builtin static,
   and rename them with "nettle/gcrypt/builtin" prefix.

2) introduces cipher framework, including QCryptoCipherDriver
   and new public APIs.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) d962c6266c crypto: cipher: introduce qcrypto_cipher_ctx_new for builtin-backend
Extracts qcrypto_cipher_ctx_new() from qcrypto_cipher_new() for
builtin-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) eabe6c58ac crypto: cipher: introduce qcrypto_cipher_ctx_new for nettle-backend
Extracts qcrypto_cipher_ctx_new() from qcrypto_cipher_new() for
nettle-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) 468fb27154 crypto: cipher: introduce qcrypto_cipher_ctx_new for gcrypt-backend
Extracts qcrypto_cipher_ctx_new() from qcrypto_cipher_new() for
gcrypt-backend impls.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Longpeng(Mike) cc5eff0186 crypto: cipher: introduce context free function
Refactors the qcrypto_cipher_free(), splits it into two parts. One
is gcrypt/nettle__cipher_free_ctx() to free the special context.

This makes code more clear, what's more, it would be used by the
later patch.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-19 10:11:04 +01:00
Daniel P. Berrange 1cd9a787a2 block: pass option prefix down to crypto layer
While the crypto layer uses a fixed option name "key-secret",
the upper block layer may have a prefix on the options. e.g.
"encrypt.key-secret", in order to avoid clashes between crypto
option names & other block option names. To ensure the crypto
layer can report accurate error messages, we must tell it what
option name prefix was used.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-19-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +02:00
Gerd Hoffmann 612fc05ad2 fix mingw build failure
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170516052439.16214-1-kraxel@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-16 15:33:25 +01:00
Geert Martin Ijewski a37278169d crypto: qcrypto_random_bytes() now works on windows w/o any other crypto libs
If no crypto library is included in the build, QEMU uses
qcrypto_random_bytes() to generate random data. That function tried to open
/dev/urandom or /dev/random and if opening both files failed it errored out.

Those files obviously do not exist on windows, so there the code uses
CryptGenRandom().

Furthermore there was some refactoring and a new function
qcrypto_random_init() was introduced. If a proper crypto library (gnutls or
libgcrypt) is included in the build, this function does nothing. If neither
is included it initializes the (platform specific) handles that are used by
qcrypto_random_bytes().
Either:
* a handle to /dev/urandom | /dev/random on unix like systems
* a handle to a cryptographic service provider on windows

Signed-off-by: Geert Martin Ijewski <gm.ijewski@web.de>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-05-09 14:41:47 +01:00
Daniel P. Berrange e4a3507e86 crypto: move 'opaque' parameter to (nearly) the end of parameter list
Previous commit moved 'opaque' to be the 2nd parameter in the list:

  commit 375092332e
  Author: Fam Zheng <famz@redhat.com>
  Date:   Fri Apr 21 20:27:02 2017 +0800

    crypto: Make errp the last parameter of functions

    Move opaque to 2nd instead of the 2nd to last, so that compilers help
    check with the conversion.

this puts it back to the 2nd to last position.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-05-09 14:41:47 +01:00
Fam Zheng 375092332e crypto: Make errp the last parameter of functions
Move opaque to 2nd instead of the 2nd to last, so that compilers help
check with the conversion.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-7-famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Commit message typo corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24 09:13:22 +02:00
Prasad J Pandit 32c813e6c2 crypto: assert cipher algorithm is always valid
Crypto routines 'qcrypto_cipher_get_block_len' and
'qcrypto_cipher_get_key_len' return non-zero cipher block and key
lengths from static arrays 'alg_block_len[]' and 'alg_key_len[]'
respectively. Returning 'zero(0)' value from either of them would
likely lead to an error condition.

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-27 13:37:14 +00:00
Li Qiang 0072d2a9fc crypto: fix leak in ivgen essiv init
On error path, the 'salt' doesn't been freed thus leading
a memory leak. This patch avoid this.

Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-27 13:37:14 +00:00
Longpeng(Mike) f4d7674722 crypto: support HMAC algorithms based on nettle
This patch add nettle-backed HMAC algorithms support

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-22 09:24:59 +00:00
Longpeng(Mike) e11680524a crypto: support HMAC algorithms based on glib
This patch add glib-backed HMAC algorithms support

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-22 09:24:59 +00:00
Longpeng(Mike) 5ce9cfe737 crypto: support HMAC algorithms based on libgcrypt
This patch add HMAC algorithms based on libgcrypt support

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-22 09:24:59 +00:00
Longpeng(Mike) 12a4f2162a crypto: add HMAC algorithms framework
This patch introduce HMAC algorithms framework.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-22 09:24:59 +00:00
Longpeng(Mike) ffb7bf452a crypto: add 3des-ede support when using libgcrypt/nettle
Libgcrypt and nettle support 3des-ede, so this patch add 3des-ede
support when using libgcrypt or nettle.

Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-21 14:26:26 +00:00
Marc-André Lureau d4c64800bb cipher: fix leak on initialization error
On error path, ctx may be leaked. Assign ctx earlier, and call
qcrypto_cipher_free() on error.

Spotted thanks to ASAN.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-12-21 14:26:26 +00:00
Daniel P. Berrange 373166636b crypto: fix initialization of gcrypt threading
The gcrypt threads implementation must be set before calling
any other gcrypt APIs, especially gcry_check_version(),
since that triggers initialization of the random pool. After
that is initialized, changes to the threads impl won't be
honoured by the random pool code. This means that gcrypt
will think thread locking is needed and so try to acquire
the random pool mutex, but this is NULL as no threads impl
was set originally. This results in a crash in the random
pool code.

For the same reasons, we must set the gcrypt threads impl
before calling gnutls_init, since that will also trigger
gcry_check_version

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-20 12:19:35 +01:00
Gonglei 77cf26cd89 crypto: add mode check in qcrypto_cipher_new() for cipher-builtin
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-19 10:09:24 +01:00
Gonglei 3c28292f39 crypto: add CTR mode support
Introduce CTR mode support for the cipher APIs.
CTR mode uses a counter rather than a traditional IV.
The counter has additional properties, including a nonce
and initial counter block. We reuse the ctx->iv as
the counter for conveniences.

Both libgcrypt and nettle are support CTR mode, the
cipher-builtin doesn't support yet.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-19 10:09:24 +01:00
Gonglei f844836ddc crypto: extend mode as a parameter in qcrypto_cipher_supports()
It can't guarantee all cipher modes are supported
if one cipher algorithm is supported by a backend.
Let's extend qcrypto_cipher_supports() to take both
the algorithm and mode as parameters.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-19 10:09:24 +01:00
Fam Zheng 2ef950f91d crypto: Switch to QEMU UUID API
The uuid generation doesn't return error, so update the function
signature and calling code accordingly.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-Id: <1474432046-325-7-git-send-email-famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-23 11:42:52 +08:00
Daniel P. Berrange b57482d7a0 crypto: add trace points for TLS cert verification
It is very useful to know about TLS cert verification
status when debugging, so add a trace point for it.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:46 +01:00
Daniel P. Berrange 533008f4f3 crypto: support more hash algorithms for pbkdf
Currently pbkdf is only supported with SHA1 and SHA256. Expand
this to support all algorithms known to QEMU.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange 2ab66cd577 crypto: increase default pbkdf2 time for luks to 2 seconds
cryptsetup recently increased the default pbkdf2 time to 2 seconds
to partially mitigate improvements in hardware performance wrt
brute-forcing the pbkdf algorithm. This updates QEMU defaults to
match.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange acd0dfd0c2 crypto: remove bogus /= 2 for pbkdf iterations
When calculating iterations for pbkdf of the key slot
data, we had a /= 2, which was copied from identical
code in cryptsetup. It was always unclear & undocumented
why cryptsetup had this division and it was recently
removed there, too.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange e74aabcffb crypto: use correct derived key size when timing pbkdf
Currently when timing the pbkdf algorithm a fixed key
size of 32 bytes is used. This results in inaccurate
timings for certain hashes depending on their digest
size. For example when using sha1 with aes-256, this
causes us to measure time for the master key digest
doing 2 sha1 operations per iteration, instead of 1.

Instead we should pass in the desired key size to the
timing routine that matches the key size that will be
used for real later.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange 8813800b7d crypto: clear out buffer after timing pbkdf algorithm
The 'out' buffer will hold a key derived from master
password, so it is best practice to clear this buffer
when no longer required.

At this time, the code isn't worrying about locking
buffers into RAM to prevent swapping sensitive data
to disk.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange 3bd18890ca crypto: make PBKDF iterations configurable for LUKS format
As protection against bruteforcing passphrases, the PBKDF
algorithm is tuned by counting the number of iterations
needed to produce 1 second of running time. If the machine
that the image will be used on is much faster than the
machine where the image is created, it can be desirable
to raise the number of iterations. This change adds a new
'iter-time' property that allows the user to choose the
iteration wallclock time.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:45 +01:00
Daniel P. Berrange 59b060be18 crypto: use uint64_t for pbkdf iteration count parameters
The qcrypto_pbkdf_count_iters method uses a 64 bit int
but then checks its value against INT32_MAX before
returning it. This bounds check is premature, because
the calling code may well scale the iteration count
by some value. It is thus better to return a 64-bit
integer and let the caller do range checking.

For consistency the qcrypto_pbkdf method is also changed
to accept a 64bit int, though this is somewhat academic
since nettle is limited to taking an 'int' while gcrypt
is limited to taking a 'long int'.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-19 16:30:42 +01:00
Daniel P. Berrange 90d6f60d07 crypto: report enum strings instead of values in errors
Several error messages print out the raw enum value, which
is less than helpful to users, as these values are not
documented, nor stable across QEMU releases. Switch to use
the enum string instead.

The nettle impl also had two typos where it mistakenly
said "algorithm" instead of "mode", and actually reported
the algorithm value too.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-12 12:00:52 +01:00
Gonglei d9269b274a crypto: fix building complaint
gnutls commit 846753877d renamed LIBGNUTLS_VERSION_NUMBER to GNUTLS_VERSION_NUMBER.
If using gnutls before that verion, we'll get the below warning:
crypto/tlscredsx509.c:618:5: warning: "GNUTLS_VERSION_NUMBER" is not defined

Because gnutls 3.x still defines LIBGNUTLS_VERSION_NUMBER for back compat, Let's
use LIBGNUTLS_VERSION_NUMBER instead of GNUTLS_VERSION_NUMBER to fix building
complaint.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-12 12:00:52 +01:00
Daniel P. Berrange a5d2f44d0d crypto: ensure XTS is only used with ciphers with 16 byte blocks
The XTS cipher mode needs to be used with a cipher which has
a block size of 16 bytes. If a mis-matching block size is used,
the code will either corrupt memory beyond the IV array, or
not fully encrypt/decrypt the IV.

This fixes a memory corruption crash when attempting to use
cast5-128 with xts, since the former has an 8 byte block size.

A test case is added to ensure the cipher creation fails with
such an invalid combination.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-12 12:00:06 +01:00
Laurent Vivier e723b87103 trace-events: fix first line comment in trace-events
Documentation is docs/tracing.txt instead of docs/trace-events.txt.

find . -name trace-events -exec \
     sed -i "s?See docs/trace-events.txt for syntax documentation.?See docs/tracing.txt for syntax documentation.?" \
     {} \;

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-id: 1470669081-17860-1-git-send-email-lvivier@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-12 10:36:01 +01:00
Daniel P. Berrange 40c8502822 crypto: add support for querying parameters for block encryption
When creating new block encryption volumes, we accept a list of
parameters to control the formatting process. It is useful to
be able to query what those parameters were for existing block
devices. Add a qcrypto_block_get_info() method which returns a
QCryptoBlockInfo instance to report this data.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1469192015-16487-2-git-send-email-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-26 17:46:37 +02:00
Daniel P. Berrange 7603289712 crypto: don't open-code qcrypto_hash_supports
Call the existing qcrypto_hash_supports method from
qcrypto_hash_bytesv instead of open-coding it again.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-07-21 10:46:27 +01:00
Daniel P. Berrange 2165477c0f crypto: use glib as fallback for hash algorithm
GLib >= 2.16 provides GChecksum API which is good enough
for md5, sha1, sha256 and sha512. Use this as a final
fallback if neither nettle or gcrypt are available. This
lets us remove the stub hash impl, and so callers can
be sure those 4 algs are always available at compile
time. They may still be disabled at runtime, so a check
for qcrypto_hash_supports() is still best practice to
report good error messages.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-07-21 10:46:27 +01:00
Daniel P. Berrange f3c8355c7a crypto: use /dev/[u]random as a final fallback random source
If neither gcrypt or gnutls are available to provide a
cryptographic random number generator, fallback to consuming
bytes directly from /dev/[u]random.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-07-21 10:46:27 +01:00