d3634d0f42
All files on the filesystem, currently, are hashed using the same hash algorithm. In preparation for files from different packages being signed using different hash algorithms, this patch adds support for reading the signature hash algorithm from the 'security.ima' extended attribute and calculates the appropriate file data hash based on it. Changelog: - fix scripts Lindent and checkpatch msgs - Mimi - fix md5 support for older version, which occupied 20 bytes in the xattr, not the expected 16 bytes. Fix the comparison to compare only the first 16 bytes. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
105 lines
2.2 KiB
C
105 lines
2.2 KiB
C
/*
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* Copyright (C) 2013 Intel Corporation
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*
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* Author:
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* Dmitry Kasatkin <dmitry.kasatkin@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 2 of the License.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/err.h>
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#include <linux/key-type.h>
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#include <crypto/public_key.h>
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#include <keys/asymmetric-type.h>
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#include "integrity.h"
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/*
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* Request an asymmetric key.
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*/
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static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
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{
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struct key *key;
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char name[12];
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sprintf(name, "id:%x", keyid);
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pr_debug("key search: \"%s\"\n", name);
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if (keyring) {
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/* search in specific keyring */
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key_ref_t kref;
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kref = keyring_search(make_key_ref(keyring, 1),
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&key_type_asymmetric, name);
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if (IS_ERR(kref))
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key = ERR_CAST(kref);
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else
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key = key_ref_to_ptr(kref);
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} else {
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key = request_key(&key_type_asymmetric, name, NULL);
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}
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if (IS_ERR(key)) {
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pr_warn("Request for unknown key '%s' err %ld\n",
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name, PTR_ERR(key));
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switch (PTR_ERR(key)) {
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/* Hide some search errors */
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case -EACCES:
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case -ENOTDIR:
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case -EAGAIN:
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return ERR_PTR(-ENOKEY);
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default:
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return key;
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}
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}
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pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
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return key;
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}
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int asymmetric_verify(struct key *keyring, const char *sig,
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int siglen, const char *data, int datalen)
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{
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struct public_key_signature pks;
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struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
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struct key *key;
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int ret = -ENOMEM;
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if (siglen <= sizeof(*hdr))
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return -EBADMSG;
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siglen -= sizeof(*hdr);
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if (siglen != __be16_to_cpu(hdr->sig_size))
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return -EBADMSG;
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if (hdr->hash_algo >= PKEY_HASH__LAST)
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return -ENOPKG;
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key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
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if (IS_ERR(key))
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return PTR_ERR(key);
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memset(&pks, 0, sizeof(pks));
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pks.pkey_hash_algo = hdr->hash_algo;
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pks.digest = (u8 *)data;
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pks.digest_size = datalen;
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pks.nr_mpi = 1;
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pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
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if (pks.rsa.s)
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ret = verify_signature(key, &pks);
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mpi_free(pks.rsa.s);
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key_put(key);
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pr_debug("%s() = %d\n", __func__, ret);
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return ret;
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}
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