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| author | Eric Biggers <ebiggers@kernel.org> | 2026-04-19 23:34:22 -0700 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2026-05-07 16:10:01 +0800 |
| commit | 58d0b2b90796d603b01afb8eeaeb14c58131ad57 (patch) | |
| tree | e2191a0a2d589139b577e1a7334bc15505662ded /crypto | |
| parent | 7cca456c3e6a0fefc752e9e93634aa63545d6a68 (diff) | |
| download | linux-next-history-58d0b2b90796d603b01afb8eeaeb14c58131ad57.tar.gz | |
crypto: drbg - Clean up loop in drbg_hmac_update()
This loop is a bit hard to read, with the loop counter that's used in
the HMAC being separate from the actual loop counter, which counts
backwards for some reason. Just replace it with a regular loop.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/drbg.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c index b54c807930af8..ad7b9577479e0 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -137,11 +137,6 @@ struct drbg_state { size_t test_entropylen; }; -enum drbg_prefixes { - DRBG_PREFIX0 = 0x00, - DRBG_PREFIX1, -}; - /****************************************************************** * HMAC DRBG functions ******************************************************************/ @@ -151,19 +146,14 @@ static void drbg_hmac_update(struct drbg_state *drbg, const u8 *data1, size_t data1_len, const u8 *data2, size_t data2_len) { - int i = 0; struct hmac_sha512_ctx hmac_ctx; u8 new_key[DRBG_STATE_LEN]; - for (i = 2; 0 < i; i--) { - /* first round uses 0x0, second 0x1 */ - unsigned char prefix = DRBG_PREFIX0; - if (1 == i) - prefix = DRBG_PREFIX1; + for (u8 i = 0; i < 2; i++) { /* 10.1.2.2 step 1 and 4 -- concatenation and HMAC for key */ hmac_sha512_init(&hmac_ctx, &drbg->key); hmac_sha512_update(&hmac_ctx, drbg->V, DRBG_STATE_LEN); - hmac_sha512_update(&hmac_ctx, &prefix, 1); + hmac_sha512_update(&hmac_ctx, &i, 1); hmac_sha512_update(&hmac_ctx, data1, data1_len); hmac_sha512_update(&hmac_ctx, data2, data2_len); hmac_sha512_final(&hmac_ctx, new_key); |