diff options
| author | Lukas Wunner <lukas@wunner.de> | 2025-04-07 21:32:42 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2025-04-16 15:16:21 +0800 |
| commit | 6b7f9397c98c72902f9364056413c73fe6dee1d8 (patch) | |
| tree | f2b0c7b7989bb46cec0a8f242a3b7b8ba0ba8d3e /crypto/sig.c | |
| parent | 3828485e1c7b111290122ab6e083c2a37132b5c2 (diff) | |
crypto: ecdsa - Fix NIST P521 key size reported by KEYCTL_PKEY_QUERY
When user space issues a KEYCTL_PKEY_QUERY system call for a NIST P521
key, the key_size is incorrectly reported as 528 bits instead of 521.
That's because the key size obtained through crypto_sig_keysize() is in
bytes and software_key_query() multiplies by 8 to yield the size in bits.
The underlying assumption is that the key size is always a multiple of 8.
With the recent addition of NIST P521, that's no longer the case.
Fix by returning the key_size in bits from crypto_sig_keysize() and
adjusting the calculations in software_key_query().
The ->key_size() callbacks of sig_alg algorithms now return the size in
bits, whereas the ->digest_size() and ->max_size() callbacks return the
size in bytes. This matches with the units in struct keyctl_pkey_query.
Fixes: a7d45ba77d3d ("crypto: ecdsa - Register NIST P521 and extend test suite")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/sig.c')
| -rw-r--r-- | crypto/sig.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/crypto/sig.c b/crypto/sig.c index dfc7cae90802..53a3dd6fbe3f 100644 --- a/crypto/sig.c +++ b/crypto/sig.c @@ -102,6 +102,11 @@ static int sig_default_set_key(struct crypto_sig *tfm, return -ENOSYS; } +static unsigned int sig_default_size(struct crypto_sig *tfm) +{ + return DIV_ROUND_UP_POW2(crypto_sig_keysize(tfm), BITS_PER_BYTE); +} + static int sig_prepare_alg(struct sig_alg *alg) { struct crypto_alg *base = &alg->base; @@ -117,9 +122,9 @@ static int sig_prepare_alg(struct sig_alg *alg) if (!alg->key_size) return -EINVAL; if (!alg->max_size) - alg->max_size = alg->key_size; + alg->max_size = sig_default_size; if (!alg->digest_size) - alg->digest_size = alg->key_size; + alg->digest_size = sig_default_size; base->cra_type = &crypto_sig_type; base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; |