160 lines
4.4 KiB
C
160 lines
4.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Signature verification with an asymmetric key
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*
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* See Documentation/crypto/asymmetric-keys.txt
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*
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* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#define pr_fmt(fmt) "SIG: "fmt
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#include <keys/asymmetric-subtype.h>
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#include <linux/export.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/keyctl.h>
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#include <crypto/public_key.h>
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#include <keys/user-type.h>
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#include "asymmetric_keys.h"
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/*
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* Destroy a public key signature.
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*/
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void public_key_signature_free(struct public_key_signature *sig)
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{
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int i;
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if (sig) {
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for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++)
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kfree(sig->auth_ids[i]);
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kfree(sig->s);
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kfree(sig->digest);
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kfree(sig);
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}
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}
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EXPORT_SYMBOL_GPL(public_key_signature_free);
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/**
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* query_asymmetric_key - Get information about an aymmetric key.
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* @params: Various parameters.
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* @info: Where to put the information.
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*/
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int query_asymmetric_key(const struct kernel_pkey_params *params,
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struct kernel_pkey_query *info)
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{
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const struct asymmetric_key_subtype *subtype;
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struct key *key = params->key;
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int ret;
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pr_devel("==>%s()\n", __func__);
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if (key->type != &key_type_asymmetric)
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return -EINVAL;
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subtype = asymmetric_key_subtype(key);
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if (!subtype ||
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!key->payload.data[0])
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return -EINVAL;
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if (!subtype->query)
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return -ENOTSUPP;
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ret = subtype->query(params, info);
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pr_devel("<==%s() = %d\n", __func__, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(query_asymmetric_key);
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/**
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* encrypt_blob - Encrypt data using an asymmetric key
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* @params: Various parameters
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* @data: Data blob to be encrypted, length params->data_len
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* @enc: Encrypted data buffer, length params->enc_len
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*
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* Encrypt the specified data blob using the private key specified by
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* params->key. The encrypted data is wrapped in an encoding if
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* params->encoding is specified (eg. "pkcs1").
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*
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* Returns the length of the data placed in the encrypted data buffer or an
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* error.
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*/
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int encrypt_blob(struct kernel_pkey_params *params,
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const void *data, void *enc)
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{
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params->op = kernel_pkey_encrypt;
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return asymmetric_key_eds_op(params, data, enc);
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}
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EXPORT_SYMBOL_GPL(encrypt_blob);
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/**
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* decrypt_blob - Decrypt data using an asymmetric key
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* @params: Various parameters
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* @enc: Encrypted data to be decrypted, length params->enc_len
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* @data: Decrypted data buffer, length params->data_len
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*
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* Decrypt the specified data blob using the private key specified by
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* params->key. The decrypted data is wrapped in an encoding if
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* params->encoding is specified (eg. "pkcs1").
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*
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* Returns the length of the data placed in the decrypted data buffer or an
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* error.
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*/
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int decrypt_blob(struct kernel_pkey_params *params,
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const void *enc, void *data)
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{
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params->op = kernel_pkey_decrypt;
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return asymmetric_key_eds_op(params, enc, data);
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}
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EXPORT_SYMBOL_GPL(decrypt_blob);
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/**
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* create_signature - Sign some data using an asymmetric key
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* @params: Various parameters
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* @data: Data blob to be signed, length params->data_len
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* @enc: Signature buffer, length params->enc_len
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*
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* Sign the specified data blob using the private key specified by params->key.
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* The signature is wrapped in an encoding if params->encoding is specified
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* (eg. "pkcs1"). If the encoding needs to know the digest type, this can be
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* passed through params->hash_algo (eg. "sha1").
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*
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* Returns the length of the data placed in the signature buffer or an error.
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*/
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int create_signature(struct kernel_pkey_params *params,
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const void *data, void *enc)
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{
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params->op = kernel_pkey_sign;
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return asymmetric_key_eds_op(params, data, enc);
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}
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EXPORT_SYMBOL_GPL(create_signature);
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/**
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* verify_signature - Initiate the use of an asymmetric key to verify a signature
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* @key: The asymmetric key to verify against
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* @sig: The signature to check
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*
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* Returns 0 if successful or else an error.
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*/
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int verify_signature(const struct key *key,
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const struct public_key_signature *sig)
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{
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const struct asymmetric_key_subtype *subtype;
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int ret;
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pr_devel("==>%s()\n", __func__);
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if (key->type != &key_type_asymmetric)
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return -EINVAL;
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subtype = asymmetric_key_subtype(key);
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if (!subtype ||
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!key->payload.data[0])
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return -EINVAL;
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if (!subtype->verify_signature)
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return -ENOTSUPP;
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ret = subtype->verify_signature(key, sig);
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pr_devel("<==%s() = %d\n", __func__, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(verify_signature);
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