nrf_security: CRACEN: Fix hardfault when using sxsymcrypt API

Using the following sequence of calls led to the hardfault:
        sx_mac_create_hmac_sha2_256(ctx, key)
        sx_mac_feed(ctx, 'chunk 1')
        sx_mac_feed(ctx, 'chunk 2')
        sx_mac_generate(ctx)
        sx_mac_wait(ctx)

Reason: attempt to dereference a pointer that has not been set.

Ref: NCSDK-36712

Signed-off-by: Anton Zyma <[email protected]>

Author: AntonZma

subsys/nrf_security/src/drivers/cracen/sxsymcrypt/src/hmac.c

@@ -58,6 +58,7 @@ static int sx_hash_create_hmac_ba413(struct sxmac *mac_ctx, const struct sxhasha
 		return SX_ERR_INCOMPATIBLE_HW;
 	}
 
+	mac_ctx->key = keyref;
 	sx_hw_reserve(&mac_ctx->dma);
 
 	mac_ctx->cfg = &ba413cfg;
@@ -119,6 +120,7 @@ static int sx_hash_create_hmac_ba418(struct sxmac *mac_ctx, const struct sxhasha
 		return SX_ERR_INVALID_KEYREF;
 	}
 
+	mac_ctx->key = keyref;
 	sx_hw_reserve(&mac_ctx->dma);
 
 	mac_ctx->cfg = &ba418cfg;