From 0086557046b018c7fe7ffa52680c0c7ea7af32d7 Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Thu, 4 Apr 2024 10:18:46 -0400 Subject: crypto: ecdsa - Adjust tests on length of key parameters In preparation for support of NIST P521, adjust the basic tests on the length of the provided key parameters 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 rejecting invalid keys. The change is necessary since NIST P521 keys do not have keys with coordinates that each require 'full' digits (= all bits in u64 used). NIST P521 only requires 2 bytes (9 bits) in the most significant digit unlike NIST P192/256/384 that each require multiple 'full' digits. Tested-by: Lukas Wunner Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Stefan Berger Signed-off-by: Herbert Xu --- crypto/ecdsa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'crypto/ecdsa.c') diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index e819d098..9462a4d6 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) -- cgit v1.2.3