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ba59e59b8b
The lmk IV mode, which dm-crypt supports for Loop-AES compatibility, involves an MD5 computation. Update its implementation to use the MD5 library API instead of crypto_shash. This has many benefits, such as: - Simpler code. Notably, much of the error-handling code is no longer needed, since the library functions can't fail. - Reduced stack usage. crypt_iv_lmk_one() now allocates only 112 bytes on the stack instead of 520 bytes. - The library functions are strongly typed, preventing bugs like https://lore.kernel.org/r/f1625ddc-e82e-4b77-80c2-dc8e45b54848@gmail.com - Slightly improved performance, as the library provides direct access to the MD5 code without unnecessary overhead such as indirect calls. To preserve the existing behavior of lmk support being disabled when the kernel is booted with "fips=1", make crypt_iv_lmk_ctr() check fips_enabled itself. Previously it relied on crypto_alloc_shash("md5") failing. (I don't know for sure that lmk *actually* needs to be disallowed in FIPS mode; this just preserves the existing behavior.) Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>
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.