[PATCH 0/2] drop RC4 support

[Ard Biesheuvel <ardb@kernel.org>]

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RC4 support in libell is based on the ecb(arc4) skcipher exposed by the
Linux crypto API, which is an odd beast given that it does not
distinguish between the key and the IV, and therefore does not fit the
skcipher API very well.

Now that work is underway in the linux-crypto kernel community to
implement chained requests for skciphers, we are running into problems
with this: the state that needs to be kept between skcipher requests to
implement chaining is currently kept in the TFM object (which holds the
key) in the case of ecb(arc4), and moving this into the request object
(to match the way chaining is implemented for other skcipher modes) may
enable key reuse (and thus IV reuse in the ARC4 case), which amount to
catastrophic failure for any stream cipher.

So in order to address this in a safe and robust manner, we intend to
retire the ecb(arc4) skcipher entirely on the Linux side. This obviously
requires work in the userland side as well, hence this series.

Ard Biesheuvel (2):
  tls: remove support for RC4 cipher suites
  cipher: remove obsolete arc4 support

 ell/cipher.c       |  8 +--
 ell/cipher.h       |  4 +-
 ell/tls-suites.c   | 41 ++------------
 unit/test-cipher.c | 56 --------------------
 unit/test-tls.c    |  3 +-
 5 files changed, 11 insertions(+), 101 deletions(-)

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2.20.1