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2016-09-19crypto: use correct derived key size when timing pbkdfDaniel P. Berrange1-3/+7
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>
2016-09-19crypto: clear out buffer after timing pbkdf algorithmDaniel P. Berrange1-4/+9
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>
2016-09-19crypto: use uint64_t for pbkdf iteration count parametersDaniel P. Berrange1-11/+5
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>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster1-0/+1
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>
2016-03-17crypto: add support for PBKDF2 algorithmDaniel P. Berrange1-0/+109
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>