In preparation for support of NIST P521, adjust the basic tests on the length of the provided key parameter to only ensure that the length of the x plus y coordinates parameter array is not an odd number and that each coordinate fits into an array of 'ndigits' digits. Mathematical tests on the key's parameters are then done in ecc_is_pubkey_valid_full eliminating invalid keys. The change is necessary since NIST P521 keys do not have keys with coordinates that each fully require 'full' digits (= u64), unlike NIST P192/256/384 that all require multiple 'full' digits. Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx> --- crypto/ecdsa.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index c3748ddc9964..228f675ac2ed 100644 --- a/crypto/ecdsa.c +++ b/crypto/ecdsa.c @@ -230,7 +230,7 @@ static int ecdsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsig if (ret < 0) return ret; - if (keylen < 1 || (((keylen - 1) >> 1) % sizeof(u64)) != 0) + if (keylen < 1 || ((keylen - 1) & 1) != 0) return -EINVAL; /* we only accept uncompressed format indicated by '4' */ if (d[0] != 4) @@ -239,7 +239,7 @@ static int ecdsa_set_pub_key(struct crypto_akcipher *tfm, const void *key, unsig keylen--; digitlen = keylen >> 1; - ndigits = digitlen / sizeof(u64); + ndigits = DIV_ROUND_UP(digitlen, sizeof(u64)); if (ndigits != ctx->curve->g.ndigits) return -EINVAL; -- 2.43.0
