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authorEric Biggers <ebiggers@google.com>2023-10-18 22:53:32 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2023-10-27 18:04:24 +0800
commit21415bfe8b5543c41b64b19674e5fcc2c942623e (patch)
treeb4822090e074284ed213044701a353ced104f772 /crypto
parentd72c46f7985a22ceb39a69a3bfe05606ec891504 (diff)
crypto: cbcmac - remove unnecessary alignment logic
The cbcmac template is aligning a field in its desc context to the alignmask of its underlying 'cipher', at runtime. This is almost entirely pointless, since cbcmac is already using the cipher API functions that handle alignment themselves, and few ciphers set a nonzero alignmask anyway. Also, even without runtime alignment, an alignment of at least 4 bytes can be guaranteed. Thus, at best this code is optimizing for the rare case of ciphers that set an alignmask >= 7, at the cost of hurting the common cases. Therefore, remove the manual alignment code from cbcmac. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/ccm.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/crypto/ccm.c b/crypto/ccm.c
index 7af89a5b745c..dd7aed63efc9 100644
--- a/crypto/ccm.c
+++ b/crypto/ccm.c
@@ -56,6 +56,7 @@ struct cbcmac_tfm_ctx {
struct cbcmac_desc_ctx {
unsigned int len;
+ u8 dg[];
};
static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
@@ -785,10 +786,9 @@ static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
{
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
int bs = crypto_shash_digestsize(pdesc->tfm);
- u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
ctx->len = 0;
- memset(dg, 0, bs);
+ memset(ctx->dg, 0, bs);
return 0;
}
@@ -801,18 +801,17 @@ static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_digestsize(parent);
- u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
while (len > 0) {
unsigned int l = min(len, bs - ctx->len);
- crypto_xor(dg + ctx->len, p, l);
+ crypto_xor(&ctx->dg[ctx->len], p, l);
ctx->len +=l;
len -= l;
p += l;
if (ctx->len == bs) {
- crypto_cipher_encrypt_one(tfm, dg, dg);
+ crypto_cipher_encrypt_one(tfm, ctx->dg, ctx->dg);
ctx->len = 0;
}
}
@@ -827,12 +826,11 @@ static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_digestsize(parent);
- u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
if (ctx->len)
- crypto_cipher_encrypt_one(tfm, dg, dg);
+ crypto_cipher_encrypt_one(tfm, ctx->dg, ctx->dg);
- memcpy(out, dg, bs);
+ memcpy(out, ctx->dg, bs);
return 0;
}
@@ -889,8 +887,7 @@ static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
inst->alg.base.cra_blocksize = 1;
inst->alg.digestsize = alg->cra_blocksize;
- inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
- alg->cra_alignmask + 1) +
+ inst->alg.descsize = sizeof(struct cbcmac_desc_ctx) +
alg->cra_blocksize;
inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);