Commit Graph

4 Commits

Author SHA1 Message Date
Ard Biesheuvel
9ae433bc79 crypto: chacha20 - convert generic and x86 versions to skcipher
This converts the ChaCha20 code from a blkcipher to a skcipher, which
is now the preferred way to implement symmetric block and stream ciphers.

This ports the generic and x86 versions at the same time because the
latter reuses routines of the former.

Note that the skcipher_walk() API guarantees that all presented blocks
except the final one are a multiple of the chunk size, so we can simplify
the encrypt() routine somewhat.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-27 17:47:31 +08:00
Theodore Ts'o
e192be9d9a random: replace non-blocking pool with a Chacha20-based CRNG
The CRNG is faster, and we don't pretend to track entropy usage in the
CRNG any more.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-07-03 00:57:23 -04:00
Martin Willi
31d7247da5 crypto: chacha20 - Export common ChaCha20 helpers
As architecture specific drivers need a software fallback, export a
ChaCha20 en-/decryption function together with some helpers in a header
file.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-07-17 21:20:21 +08:00
Martin Willi
c08d0e6473 crypto: chacha20 - Add a generic ChaCha20 stream cipher implementation
ChaCha20 is a high speed 256-bit key size stream cipher algorithm designed by
Daniel J. Bernstein. It is further specified in RFC7539 for use in IETF
protocols as a building block for the ChaCha20-Poly1305 AEAD.

This is a portable C implementation without any architecture specific
optimizations. It uses a 16-byte IV, which includes the 12-byte ChaCha20 nonce
prepended by the initial block counter. Some algorithms require an explicit
counter value, for example the mentioned AEAD construction.

Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-04 15:04:49 +08:00