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: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
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>
OpenSSL's libcrypto always defines AES symbols with the same names as
qemu's local aes code. This is problematic when enabling at least curl
as that frequently also uses libcrypto. It might not be noticed when
running, but if you try to statically link, everything falls down.
An example snippet:
LINK qemu-nbd
.../libcrypto.a(aes-x86_64.o): In function 'AES_encrypt':
(.text+0x460): multiple definition of 'AES_encrypt'
crypto/aes.o:aes.c:(.text+0x670): first defined here
.../libcrypto.a(aes-x86_64.o): In function 'AES_decrypt':
(.text+0x9f0): multiple definition of 'AES_decrypt'
crypto/aes.o:aes.c:(.text+0xb30): first defined here
.../libcrypto.a(aes-x86_64.o): In function 'AES_cbc_encrypt':
(.text+0xf90): multiple definition of 'AES_cbc_encrypt'
crypto/aes.o:aes.c:(.text+0xff0): first defined here
collect2: error: ld returned 1 exit status
.../qemu-2.6.0/rules.mak:105: recipe for target 'qemu-nbd' failed
make: *** [qemu-nbd] Error 1
The aes.h header has redefines already for FreeBSD, but go ahead and
enable that for everyone since there's no real good reason to not use
a namespace all the time.
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Signed-off-by: Daniel 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: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@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>
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>
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>
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.
NB: If this commit breaks compilation for your out-of-tree
patchseries or fork, then you need to make sure you add
#include "qemu/osdep.h" to any new .c files that you have.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
The example code wouldn't even compile, since it did not use
a consistent spelling for the Error ** parameter.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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>
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>
Introduce a QCryptoTLSCreds class to act as the base class for
storing TLS credentials. This will be later subclassed to provide
handling of anonymous and x509 credential types. The subclasses
will be user creatable objects, so instances can be created &
deleted via 'object-add' and 'object-del' QMP commands respectively,
or via the -object command line arg.
If the credentials cannot be initialized an error will be reported
as a QMP reply, or on stderr respectively.
The idea is to make it possible to represent and manage TLS
credentials independently of the network service that is using
them. This will enable multiple services to use the same set of
credentials and minimize code duplication. A later patch will
convert the current VNC server TLS code over to use this object.
The representation of credentials will be functionally equivalent
to that currently implemented in the VNC server with one exception.
The new code has the ability to (optionally) load a pre-generated
set of diffie-hellman parameters, if the file dh-params.pem exists,
whereas the current VNC server will always generate them on startup.
This is beneficial for admins who wish to avoid the (small) time
sink of generating DH parameters at startup and/or avoid depleting
entropy.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce a generic cipher API and an implementation of it that
supports only the built-in AES and DES-RFB algorithms.
The test suite checks the supported algorithms + modes to
validate that every backend implementation is actually correctly
complying with the specs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-5-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To prepare for a generic internal cipher API, move the
built-in D3DES implementation into the crypto/ directory.
This is not in fact a normal D3DES implementation, it is
D3DES with double & triple length modes removed, and the
key bytes in reversed bit order. IOW it is crippled
specifically for the "benefit" of RFB, so call the new
files desrfb.c instead of d3des.c to make it clear that
it isn't a generally useful impl.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-4-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To prepare for a generic internal cipher API, move the
built-in AES implementation into the crypto/ directory
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a new crypto/ directory that will (eventually) contain
all the cryptographic related code. This initially defines a
wrapper for initializing gnutls and for computing hashes with
gnutls. The former ensures that gnutls is guaranteed to be
initialized exactly once in QEMU regardless of CLI args. The
block quorum code currently fails to initialize gnutls so it
only works by luck, if VNC server TLS is not requested. The
hash APIs avoids the need to litter the rest of the code with
preprocessor checks and simplifies callers by allocating the
correct amount of memory for the requested hash.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-2-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
