[PATCH] crypto: ecdsa - explicitly zeroize pub_key

[Vladis Dronov <vdronov@redhat.com>]

The FIPS standard, as a part of the Sensitive Security Parameter area,
requires the FIPS module to provide methods to zeroise all the unprotected
SSP (Security Sensitive Parameters), i.e. both the CSP (Critical Security
Parameters), and the PSP (Public Security Parameters):

    A module shall provide methods to zeroise all unprotected SSPs and key
    components within the module.

This requirement is mentioned in the section AS09.28 "Sensitive security
parameter zeroisation – Levels 1, 2, 3, and 4" of FIPS 140-3 / ISO 19790.
This is required for the FIPS certification. Thus, add a public key
zeroization to ecdsa_ecc_ctx_deinit().

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
 crypto/ecdsa.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index 117526d15dde..e7f58ad5ac76 100644
--- a/crypto/ecdsa.c
+++ b/crypto/ecdsa.c
@@ -96,10 +96,12 @@ static int ecdsa_ecc_ctx_init(struct ecc_ctx *ctx, unsigned int curve_id)
 	return 0;
 }
 
-
 static void ecdsa_ecc_ctx_deinit(struct ecc_ctx *ctx)
 {
 	ctx->pub_key_set = false;
+
+	memzero_explicit(ctx->x, sizeof(ctx->x));
+	memzero_explicit(ctx->y, sizeof(ctx->y));
 }
 
 static int ecdsa_ecc_ctx_reset(struct ecc_ctx *ctx)
-- 
2.49.0