treewide: update LLVM Bugzilla links

LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues. While all of the links are still valid, they may not necessarily
show the most up to date information around the issues, as all updates
will occur on GitHub, not Bugzilla.

Another complication is that the Bugzilla issue number is not always the
same as the GitHub issue number. Thankfully, LLVM maintains this mapping
through two shortlinks:

https://llvm.org/bz<num> -> https://bugs.llvm.org/show_bug.cgi?id=<num>
https://llvm.org/pr<num> -> https://github.com/llvm/llvm-project/issues/<mapped_num>

Switch all "https://bugs.llvm.org/show_bug.cgi?id=<num>" links to the
"https://llvm.org/pr<num>" shortlink so that the links show the most up to
date information. Each migrated issue links back to the Bugzilla entry,
so there should be no loss of fidelity of information here.

Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Fangrui Song <maskray@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

crypto: blake2b - update file comment

The file comment for blake2b_generic.c makes it sound like it's the
reference implementation of BLAKE2b with only minor changes. But it's
actually been changed a lot. Update the comment to make this clearer.

Reviewed-by: David Sterba <dsterba@suse.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - sync with blake2s implementation

Sync the BLAKE2b code with the BLAKE2s code as much as possible:

- Move a lot of code into new headers <crypto/blake2b.h> and
<crypto/internal/blake2b.h>, and adjust it to be like the
corresponding BLAKE2s code, i.e. like <crypto/blake2s.h> and
<crypto/internal/blake2s.h>.

- Rename constants, e.g. BLAKE2B_*_DIGEST_SIZE => BLAKE2B_*_HASH_SIZE.

- Use a macro BLAKE2B_ALG() to define the shash_alg structs.

- Export blake2b_compress_generic() for use as a fallback.

This makes it much easier to add optimized implementations of BLAKE2b,
as optimized implementations can use the helper functions
crypto_blake2b_{setkey,init,update,final}() and
blake2b_compress_generic(). The ARM implementation will use these.

But this change is also helpful because it eliminates unnecessary
differences between the BLAKE2b and BLAKE2s code, so that the same
improvements can easily be made to both. (The two algorithms are
basically identical, except for the word size and constants.) It also
makes it straightforward to add a library API for BLAKE2b in the future
if/when it's needed.

This change does make the BLAKE2b code slightly more complicated than it
needs to be, as it doesn't actually provide a library API yet. For
example, __blake2b_update() doesn't really need to exist yet; it could
just be inlined into crypto_blake2b_update(). But I believe this is
outweighed by the benefits of keeping the code in sync.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - Fix clang optimization for ARMv7-M

When building for ARMv7-M, clang-9 or higher tries to unroll some loops,
which ends up confusing the register allocator to the point of generating
rather bad code and using more than the warning limit for stack frames:

warning: stack frame size of 1200 bytes in function 'blake2b_compress' [-Wframe-larger-than=]

Forcing it to not unroll the final loop avoids this problem.

Fixes: 91d689337fe8 ("crypto: blake2b - add blake2b generic implementation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN

The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to
make the ->setkey() functions provide more information about errors.

However, no one actually checks for this flag, which makes it pointless.

Also, many algorithms fail to set this flag when given a bad length key.
Reviewing just the generic implementations, this is the case for
aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309,
rfc7539, rfc7539esp, salsa20, seqiv, and xcbc. But there are probably
many more in arch/*/crypto/ and drivers/crypto/.

Some algorithms can even set this flag when the key is the correct
length. For example, authenc and authencesn set it when the key payload
is malformed in any way (not just a bad length), the atmel-sha and ccree
drivers can set it if a memory allocation fails, and the chelsio driver
sets it for bad auth tag lengths, not just bad key lengths.

So even if someone actually wanted to start checking this flag (which
seems unlikely, since it's been unused for a long time), there would be
a lot of work needed to get it working correctly. But it would probably
be much better to go back to the drawing board and just define different
return values, like -EINVAL if the key is invalid for the algorithm vs.
-EKEYREJECTED if the key was rejected by a policy like "no weak keys".
That would be much simpler, less error-prone, and easier to test.

So just remove this flag.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - rename tfm context and _setkey callback

The TFM context can be renamed to a more appropriate name and the local
varaibles as well, using 'tctx' which seems to be more common than
'mctx'.

The _setkey callback was the last one without the blake2b_ prefix,
rename that too.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - merge _update to api callback

Now that there's only one call to blake2b_update, we can merge it to the
callback and simplify. The empty input check is split and the rest of
code un-indented.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - open code set last block helper

The helper is trival and called once, inlining makes things simpler.
There's a comment to tie it back to the idea behind the code.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - delete unused structs or members

All the code for param block has been inlined, last_node and outlen from
the state are not used or have become redundant due to other code.
Remove it.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - simplify key init

The keyed init writes the key bytes to the input buffer and does an
update. We can do that in two ways: fill the buffer and update
immediatelly. This is what current blake2b_init_key does. Any other
following _update or _final will continue from the updated state.

The other way is to write the key and set the number of bytes to process
at the next _update or _final, lazy evaluation. Which leads to the the
simplified code in this patch.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - merge blake2 init to api callback

The call chain from blake2b_init can be simplified because the param
block is effectively zeros, besides the key.

- blake2b_init0 zeroes state and sets IV
- blake2b_init sets up param block with defaults (key and some 1s)
- init with key, write it to the input buffer and recalculate state

So the compact way is to zero out the state and initialize index 0 of
the state directly with the non-zero values and the key.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - merge _final implementation to callback

blake2b_final is called only once, merge it to the crypto API callback
and simplify. This avoids the temporary buffer and swaps the bytes of
internal buffer.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: blake2b - add blake2b generic implementation

The patch brings support of several BLAKE2 variants (2b with various
digest lengths). The keyed digest is supported, using tfm->setkey call.
The in-tree user will be btrfs (for checksumming), we're going to use
the BLAKE2b-256 variant.

The code is reference implementation taken from the official sources and
modified in terms of kernel coding style (whitespace, comments, uintXX_t
-> uXX types, removed unused prototypes and #ifdefs, removed testing
code, changed secure_zero_memory -> memzero_explicit, used own helpers
for unaligned reads/writes and rotations).

Further changes removed sanity checks of key length or output size,
these values are verified in the crypto API callbacks or hardcoded in
shash_alg and not exposed to users.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>