UPSTREAM: crypto: poly1305 - expose init/update/final library interface

Expose the existing generic Poly1305 code via a init/update/final
library interface so that callers are not required to go through
the crypto API's shash abstraction to access it. At the same time,
make some preparations so that the library implementation can be
superseded by an accelerated arch-specific version in the future.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit a1d93064094cc5e24d64e35cf093e7191d0c9344)
Bug: 152722841
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Change-Id: Ic30a6cfc6c2b4c83da14f499f1178509197a62ad
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Ard Biesheuvel 2019-11-08 13:22:21 +01:00 • committed by Alexander Martinz
commit 5f380b61d1
No known key found for this signature in database
GPG key ID: CF15BDD9A321A9B2
4 changed files with 138 additions and 22 deletions

View file

@ -85,31 +85,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_update);
int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
{
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
__le32 digest[4];
u64 f = 0;
if (unlikely(!dctx->sset))
return -ENOKEY;
if (unlikely(dctx->buflen)) {
dctx->buf[dctx->buflen++] = 1;
memset(dctx->buf + dctx->buflen, 0,
POLY1305_BLOCK_SIZE - dctx->buflen);
poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0);
}
poly1305_core_emit(&dctx->h, digest);
/* mac = (h + s) % (2^128) */
f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0];
put_unaligned_le32(f, dst + 0);
f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1];
put_unaligned_le32(f, dst + 4);
f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2];
put_unaligned_le32(f, dst + 8);
f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3];
put_unaligned_le32(f, dst + 12);
poly1305_final_generic(dctx, dst);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_poly1305_final);