TLS relies upon the ability of ciphers to perform in-place decryption,
in order to avoid allocating additional I/O buffers for received data.
Add verification of in-place encryption and decryption to the cipher
self-tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TLS relies upon the ability to reuse a cipher by resetting only the
initialisation vector while reusing the existing key.
Add verification of resetting the initialisation vector to the cipher
self-tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The GCM cipher mode of operation (in common with other counter-based
modes of operation) has a notion of blocksize that does not neatly
fall into our current abstraction: it does operate in 16-byte blocks
but allows for an arbitrary overall data length (i.e. the final block
may be incomplete).
Model this by adding a concept of alignment size. Each call to
encrypt() or decrypt() must begin at a multiple of the alignment size
from the start of the data stream. This allows us to model GCM by
using a block size of 1 byte and an alignment size of 16 bytes.
As a side benefit, this same concept allows us to neatly model the
fact that raw AES can encrypt only a single 16-byte block, by
specifying an alignment size of zero on this cipher.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some ciphers (such as GCM) support the concept of a tag that can be
used to authenticate the encrypted data. Add a cipher method for
generating an authentication tag.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some ciphers (such as GCM) support the concept of additional
authenticated data, which does not appear in the ciphertext but may
affect the operation of the cipher.
Allow cipher_encrypt() and cipher_decrypt() to be called with a NULL
destination buffer in order to pass additional data.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Generalise the existing support for performing CBC-mode block cipher
tests, and update the code to use okx() for neater reporting of test
results.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
