/* Signature verification with an asymmetric key * * See Documentation/crypto/asymmetric-keys.txt * * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #define pr_fmt(fmt) "SIG: "fmt #include <keys/asymmetric-subtype.h> #include <linux/export.h> #include <linux/err.h> #include <linux/slab.h> #include <crypto/public_key.h> #include "asymmetric_keys.h" /* * Destroy a public key signature. */ void public_key_signature_free(struct public_key_signature *sig) { int i; if (sig) { for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++) kfree(sig->auth_ids[i]); kfree(sig->s); kfree(sig->digest); kfree(sig); } } EXPORT_SYMBOL_GPL(public_key_signature_free); /** * verify_signature - Initiate the use of an asymmetric key to verify a signature * @key: The asymmetric key to verify against * @sig: The signature to check * * Returns 0 if successful or else an error. */ int verify_signature(const struct key *key, const struct public_key_signature *sig) { const struct asymmetric_key_subtype *subtype; int ret; pr_devel("==>%s()\n", __func__); if (key->type != &key_type_asymmetric) return -EINVAL; subtype = asymmetric_key_subtype(key); if (!subtype || !key->payload.data[0]) return -EINVAL; if (!subtype->verify_signature) return -ENOTSUPP; ret = subtype->verify_signature(key, sig); pr_devel("<==%s() = %d\n", __func__, ret); return ret; } EXPORT_SYMBOL_GPL(verify_signature);