diff mbox series

[v2,3/4] crypto: ecdsa - Fix enc/dec size reported by KEYCTL_PKEY_QUERY

Message ID 3d74d6134f4f87a90ebe0a37cb06c6ec144ceef7.1738521533.git.lukas@wunner.de
State New
Headers show
Series ecdsa KEYCTL_PKEY_QUERY fixes | expand

Commit Message

Lukas Wunner Feb. 2, 2025, 7 p.m. UTC 
KEYCTL_PKEY_QUERY system calls for ecdsa keys return the key size as
max_enc_size and max_dec_size, even though such keys cannot be used for
encryption/decryption.  They're exclusively for signature generation or
verification.

Only rsa keys with pkcs1 encoding can also be used for encryption or
decryption.

Return 0 instead for ecdsa keys (as well as ecrdsa keys).

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
 crypto/asymmetric_keys/public_key.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index bf165d321440..dd44a966947f 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -188,6 +188,8 @@  static int software_key_query(const struct kernel_pkey_params *params,
 	ptr = pkey_pack_u32(ptr, pkey->paramlen);
 	memcpy(ptr, pkey->params, pkey->paramlen);
 
+	memset(info, 0, sizeof(*info));
+
 	if (issig) {
 		sig = crypto_alloc_sig(alg_name, 0, 0);
 		if (IS_ERR(sig)) {
@@ -211,6 +213,9 @@  static int software_key_query(const struct kernel_pkey_params *params,
 			info->supported_ops |= KEYCTL_SUPPORTS_SIGN;
 
 		if (strcmp(params->encoding, "pkcs1") == 0) {
+			info->max_enc_size = len;
+			info->max_dec_size = len;
+
 			info->supported_ops |= KEYCTL_SUPPORTS_ENCRYPT;
 			if (pkey->key_is_private)
 				info->supported_ops |= KEYCTL_SUPPORTS_DECRYPT;
@@ -232,6 +237,8 @@  static int software_key_query(const struct kernel_pkey_params *params,
 		len = crypto_akcipher_maxsize(tfm);
 		info->max_sig_size = len;
 		info->max_data_size = len;
+		info->max_enc_size = len;
+		info->max_dec_size = len;
 
 		info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT;
 		if (pkey->key_is_private)
@@ -239,8 +246,6 @@  static int software_key_query(const struct kernel_pkey_params *params,
 	}
 
 	info->key_size = len * 8;
-	info->max_enc_size = len;
-	info->max_dec_size = len;
 
 	ret = 0;