crypto: ecdsa - Rename keylen to bufsize where necessary

In cases where 'keylen' was referring to the size of the buffer used by
a curve's digits, it does not reflect the purpose of the variable anymore
once NIST P521 is used. What it refers to then is the size of the buffer,
which may be a few bytes larger than the size a coordinate of a key.
Therefore, rename keylen to bufsize where appropriate.

Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index 75d3eea885dbb28b43f4aaec15c5f127c02dee75..c7923f30661b8b35e2779d96292b9f26b6cb7d0d 100644 (file)
--- a/crypto/ecdsa.c
+++ b/crypto/ecdsa.c
@@ -35,8 +35,8 @@ struct ecdsa_signature_ctx {
 static int ecdsa_get_signature_rs(u64 *dest, size_t hdrlen, unsigned char tag,
                                  const void *value, size_t vlen, unsigned int ndigits)
 {
-       size_t keylen = ndigits * sizeof(u64);
-       ssize_t diff = vlen - keylen;
+       size_t bufsize = ndigits * sizeof(u64);
+       ssize_t diff = vlen - bufsize;
        const char *d = value;
        u8 rs[ECC_MAX_BYTES];
 
@@ -58,7 +58,7 @@ static int ecdsa_get_signature_rs(u64 *dest, size_t hdrlen, unsigned char tag,
                if (diff)
                        return -EINVAL;
        }
-       if (-diff >= keylen)
+       if (-diff >= bufsize)
                return -EINVAL;
 
        if (diff) {
@@ -138,7 +138,7 @@ static int ecdsa_verify(struct akcipher_request *req)
 {
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct ecc_ctx *ctx = akcipher_tfm_ctx(tfm);
-       size_t keylen = ctx->curve->g.ndigits * sizeof(u64);
+       size_t bufsize = ctx->curve->g.ndigits * sizeof(u64);
        struct ecdsa_signature_ctx sig_ctx = {
                .curve = ctx->curve,
        };
@@ -165,14 +165,14 @@ static int ecdsa_verify(struct akcipher_request *req)
                goto error;
 
        /* if the hash is shorter then we will add leading zeros to fit to ndigits */
-       diff = keylen - req->dst_len;
+       diff = bufsize - req->dst_len;
        if (diff >= 0) {
                if (diff)
                        memset(rawhash, 0, diff);
                memcpy(&rawhash[diff], buffer + req->src_len, req->dst_len);
        } else if (diff < 0) {
                /* given hash is longer, we take the left-most bytes */
-               memcpy(&rawhash, buffer + req->src_len, keylen);
+               memcpy(&rawhash, buffer + req->src_len, bufsize);
        }
 
        ecc_swap_digits((u64 *)rawhash, hash, ctx->curve->g.ndigits);