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: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The uuid generation doesn't return error, so update the function
signature and calling code accordingly.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Message-Id: <1474432046-325-7-git-send-email-famz@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

It is very useful to know about TLS cert verification
status when debugging, so add a trace point for it.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently pbkdf is only supported with SHA1 and SHA256. Expand
this to support all algorithms known to QEMU.
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NLaurent Vivier <lvivier@redhat.com>
Message-id: 1470669081-17860-1-git-send-email-lvivier@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 1469192015-16487-2-git-send-email-berrange@redhat.com
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Call the existing qcrypto_hash_supports method from
qcrypto_hash_bytesv instead of open-coding it again.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

Cleaned up with scripts/clean-header-guards.pl.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

Header guard symbols should match their file name to make guard
collisions less likely.  Offenders found with
scripts/clean-header-guards.pl -vn.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

Tracked down with an ugly, brittle and probably buggy Perl script.

Also move includes converted to <...> up so they get included before
ours where that's obviously okay.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Tested-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NRichard Henderson <rth@twiddle.net>

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: NDaniel 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: NDaniel 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: NDaniel 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: NDaniel 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: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Move all trace-events for files in the crypto/ directory to
their own file.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-4-git-send-email-berrange@redhat.com
Signed-off-by: NStefan 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: NEric Blake <eblake@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NDaniel 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: NAlex Bligh <alex@alex.org.uk>
Signed-off-by: NDaniel 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: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NMichael 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: NPaolo 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: NWen Congyang <wency@cn.fujitsu.com>
Tested-by: NWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 57cb38b3 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: NMarkus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: NPaolo 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: NDaniel 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: NDaniel 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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel 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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel 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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel 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: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>