Eric Biggers ac667f9f18 crypto: crypto4xx - Remove insecure and unused rng_alg
commit 7811ec9e97 upstream.

Remove crypto4xx_rng, as it is insecure and unused:

- It has only a 64-bit security strength, which is highly inadequate.
  This can be seen by the fact that crypto4xx_hw_init() seeds it with
  only 64 bits of entropy, and the fact that the original commit
  mentions that it implements ANSI X9.17 Annex C.

  Another issue was that this driver didn't implement the crypto_rng API
  correctly, as crypto4xx_prng_generate() didn't return 0 on success.

- No user of this code is known.  It's usable only theoretically via the
  "rng" algorithm type of AF_ALG.  But userspace actually just uses the
  actual Linux RNG (/dev/random etc) instead.  And rng_algs don't
  contribute entropy to the actual Linux RNG either.  (This may have
  been confused with hwrng, which does contribute entropy.)

Fixes: d072bfa488 ("crypto: crypto4xx - add prng crypto support")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18 16:53:27 +02:00
…
…
…

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%