Prepare the buffer for encryption only after initializing the cipher, so
that there's just one failure point. This allows to remove the 'error'
label.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
The initialization vector is not optional thus we also don't need to
check whether the caller passed it in. Additionally we can use c99
initializers for the gnutls_datum_t structs.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
'gnutls_datum_t' simply holds pointers to the encryption key and its
length. There's absolutely no point in securely erasing that.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It always returns true. Make the logic a bit simpler to see through.
This completely removes 'virCryptoHaveCipher' as it's pointless in the
current form.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Clear the key and IV structs using virSecureErase.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Clear out the value using virSecureErase and free it with g_free so
that VIR_DISPOSE_N can be phased out.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
G_STATIC_ASSERT() is a drop-in functional equivalent of
the GNULIB verify() macro.
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Now that GnuTLS is a requirement, we can drop a lot of
conditionally built code. However, not all ifdef-s can go because
we still want libvirt_setuid to build without gnutls.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Now that virCryptoGenerateRandom() is plain wrapper over
virRandomBytes() we can drop it in favour of the latter.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
While /dev/urandom is not terrible source of random data
gnutls_rnd is better. Prefer that one.
Also, since nearly every platform we build on already has gnutls
(if not all of them) this is going to be used by default.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Instead of having each caller report error move it into the
function. This way we can produce more accurate error messages
too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
To unify our vir*Random() functions we need to make
virCryptoGenerateRandom NOT allocate return buffer. It should
just fill given buffer with random data.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When generating random stream using gnults fails an error is
reported. However, the error is not helpful as it contains only
an integer error code (a negative number). Use gnutls_strerror()
to turn the error code into a string explaining what went wrong.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This function allocates a buffer, fills it in with random bytes
and then returns it. However, the buffer is held in @buf
variable, therefore having @ret variable which does not hold
return value of the function is misleading.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
In libvirt when a function wants to return an error code it
should be a negative value. Returning a positive value (or zero)
means success. But virRandomBytes() does not follow this rule.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
virCryptoHashString also needs to know the size of the returned hash.
Return it if the hash conversion succeeded so the caller does not need
to access the hashinfo array.
This should make virCryptoHashString build without gnutls.
Also fixes the missing return value for the virCryptoHashBuf stub.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Suggested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Ditch the use of gnulib's digest functions in favor of GnuTLS,
which might be more likely to get FIPS-certified.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
A function that keeps the hash in binary form instead of converting
it to human-readable hexadecimal form.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
If we are encoding a block of data that is 16 bytes in length,
we cannot leave it as 16 bytes, we must pad it out to the next
block boundary, 32 bytes. Without this padding, the decoder will
incorrectly treat the last byte of plain text as the padding
length, as it can't distinguish padded from non-padded data.
The problem exhibited itself when using a 16 byte passphrase
for a LUKS volume
$ virsh secret-set-value 55806c7d-8e93-456f-829b-607d8c198367 \
$(echo -n 1234567812345678 | base64)
Secret value set
$ virsh start demo
error: Failed to start domain demo
error: internal error: process exited while connecting to monitor: >>>>>>>>>>Len 16
2017-05-02T10:35:40.016390Z qemu-system-x86_64: -object \
secret,id=virtio-disk1-luks-secret0,data=SEtNi5vDUeyseMKHwc1c1Q==,\
keyid=masterKey0,iv=zm7apUB1A6dPcH53VW960Q==,format=base64: \
Incorrect number of padding bytes (56) found on decrypted data
Notice how the padding '56' corresponds to the ordinal value of
the character '8'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the logic from qemuDomainGenerateRandomKey into this new
function, altering the comments, variable names, and error messages
to keep things more generic.
NB: Although perhaps more reasonable to add soemthing to virrandom.c.
The virrandom.c was included in the setuid_rpc_client, so I chose
placement in vircrypto.
Introduce virCryptoHaveCipher and virCryptoEncryptData to handle
performing encryption.
virCryptoHaveCipher:
Boolean function to determine whether the requested cipher algorithm
is available. It's expected this API will be called prior to
virCryptoEncryptdata. It will return true/false.
virCryptoEncryptData:
Based on the requested cipher type, call the specific encryption
API to encrypt the data.
Currently the only algorithm support is the AES 256 CBC encryption.
Adjust tests for the API's
While running vircryptotest, it was found that valgrind pointed out the
following error:
==27453== Invalid write of size 1
==27453== at 0x4C7D7C9: virCryptoHashString (vircrypto.c:76)
==27453== by 0x401C4E: testCryptoHash (vircryptotest.c:41)
==27453== by 0x402A11: virtTestRun (testutils.c:199)
==27453== by 0x401AD5: mymain (vircryptotest.c:76)
==27453== by 0x40318D: virtTestMain (testutils.c:782)
==27453== by 0x3E6CE1ED1C: (below main) (libc-start.c:226)
==27453== Address 0x51f0541 is 0 bytes after a block of size 65 alloc'd
==27453== at 0x4A0577B: calloc (vg_replace_malloc.c:593)
==27453== by 0x4C69F2E: virAllocN (viralloc.c:189)
==27453== by 0x4C7D76B: virCryptoHashString (vircrypto.c:69)
==27453== by 0x401C4E: testCryptoHash (vircryptotest.c:41)
==27453== by 0x402A11: virtTestRun (testutils.c:199)
==27453== by 0x401AD5: mymain (vircryptotest.c:76)
==27453== by 0x40318D: virtTestMain (testutils.c:782)
==27453== by 0x3E6CE1ED1C: (below main) (libc-start.c:226)
==27453==
...and many more. Two observations: hashstrlen was already set
to include the trailing NUL byte (so writing to hashstrlen as
the array offset was indeed writing one byte beyond bounds), and
VIR_ALLOC_N already guarantees zero-initialization (so we already
have a trailing NUL without needing to explicitly write one).
Signed-off-by: Eric Blake <eblake@redhat.com>
GNULIB provides APIs for calculating md5 and sha256 hashes,
but these APIs only return you raw byte arrays. Most users
in libvirt want the hash in printable string format. Add
some helper APIs in util/vircrypto.{c,h} for doing this.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
