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![Lubomir Rintel](/assets/img/avatar_default.png)
This changes UAPI, breaking iwd and libell: ell/key.c: In function 'kernel_dh_compute': ell/key.c:205:38: error: 'struct keyctl_dh_params' has no member named 'private'; did you mean 'dh_private'? struct keyctl_dh_params params = { .private = private, ^~~~~~~ dh_private This reverts commit8a2336e549
. Fixes:8a2336e549
("uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name") Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: David Howells <dhowells@redhat.com> cc: Randy Dunlap <rdunlap@infradead.org> cc: Mat Martineau <mathew.j.martineau@linux.intel.com> cc: Stephan Mueller <smueller@chronox.de> cc: James Morris <jmorris@namei.org> cc: "Serge E. Hallyn" <serge@hallyn.com> cc: Mat Martineau <mathew.j.martineau@linux.intel.com> cc: Andrew Morton <akpm@linux-foundation.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: <stable@vger.kernel.org> Signed-off-by: James Morris <james.morris@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
428 lines
8.7 KiB
C
428 lines
8.7 KiB
C
/* Crypto operations using stored keys
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*
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* Copyright (c) 2016, Intel Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/scatterlist.h>
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#include <linux/crypto.h>
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#include <crypto/hash.h>
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#include <crypto/kpp.h>
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#include <crypto/dh.h>
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#include <keys/user-type.h>
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#include "internal.h"
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static ssize_t dh_data_from_key(key_serial_t keyid, void **data)
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{
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struct key *key;
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key_ref_t key_ref;
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long status;
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ssize_t ret;
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key_ref = lookup_user_key(keyid, 0, KEY_NEED_READ);
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if (IS_ERR(key_ref)) {
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ret = -ENOKEY;
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goto error;
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}
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key = key_ref_to_ptr(key_ref);
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ret = -EOPNOTSUPP;
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if (key->type == &key_type_user) {
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down_read(&key->sem);
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status = key_validate(key);
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if (status == 0) {
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const struct user_key_payload *payload;
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uint8_t *duplicate;
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payload = user_key_payload_locked(key);
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duplicate = kmemdup(payload->data, payload->datalen,
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GFP_KERNEL);
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if (duplicate) {
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*data = duplicate;
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ret = payload->datalen;
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} else {
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ret = -ENOMEM;
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}
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}
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up_read(&key->sem);
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}
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key_put(key);
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error:
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return ret;
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}
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static void dh_free_data(struct dh *dh)
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{
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kzfree(dh->key);
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kzfree(dh->p);
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kzfree(dh->g);
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}
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struct dh_completion {
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struct completion completion;
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int err;
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};
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static void dh_crypto_done(struct crypto_async_request *req, int err)
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{
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struct dh_completion *compl = req->data;
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if (err == -EINPROGRESS)
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return;
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compl->err = err;
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complete(&compl->completion);
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}
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struct kdf_sdesc {
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struct shash_desc shash;
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char ctx[];
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};
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static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
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{
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struct crypto_shash *tfm;
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struct kdf_sdesc *sdesc;
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int size;
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int err;
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/* allocate synchronous hash */
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tfm = crypto_alloc_shash(hashname, 0, 0);
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if (IS_ERR(tfm)) {
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pr_info("could not allocate digest TFM handle %s\n", hashname);
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return PTR_ERR(tfm);
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}
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err = -EINVAL;
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if (crypto_shash_digestsize(tfm) == 0)
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goto out_free_tfm;
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err = -ENOMEM;
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size = sizeof(struct shash_desc) + crypto_shash_descsize(tfm);
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sdesc = kmalloc(size, GFP_KERNEL);
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if (!sdesc)
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goto out_free_tfm;
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sdesc->shash.tfm = tfm;
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sdesc->shash.flags = 0x0;
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*sdesc_ret = sdesc;
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return 0;
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out_free_tfm:
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crypto_free_shash(tfm);
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return err;
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}
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static void kdf_dealloc(struct kdf_sdesc *sdesc)
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{
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if (!sdesc)
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return;
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if (sdesc->shash.tfm)
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crypto_free_shash(sdesc->shash.tfm);
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kzfree(sdesc);
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}
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/*
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* Implementation of the KDF in counter mode according to SP800-108 section 5.1
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* as well as SP800-56A section 5.8.1 (Single-step KDF).
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*
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* SP800-56A:
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* The src pointer is defined as Z || other info where Z is the shared secret
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* from DH and other info is an arbitrary string (see SP800-56A section
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* 5.8.1.2).
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*
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* 'dlen' must be a multiple of the digest size.
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*/
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static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
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u8 *dst, unsigned int dlen, unsigned int zlen)
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{
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struct shash_desc *desc = &sdesc->shash;
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unsigned int h = crypto_shash_digestsize(desc->tfm);
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int err = 0;
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u8 *dst_orig = dst;
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__be32 counter = cpu_to_be32(1);
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while (dlen) {
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err = crypto_shash_init(desc);
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if (err)
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goto err;
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err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32));
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if (err)
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goto err;
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if (zlen && h) {
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u8 tmpbuffer[32];
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size_t chunk = min_t(size_t, zlen, sizeof(tmpbuffer));
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memset(tmpbuffer, 0, chunk);
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do {
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err = crypto_shash_update(desc, tmpbuffer,
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chunk);
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if (err)
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goto err;
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zlen -= chunk;
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chunk = min_t(size_t, zlen, sizeof(tmpbuffer));
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} while (zlen);
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}
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if (src && slen) {
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err = crypto_shash_update(desc, src, slen);
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if (err)
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goto err;
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}
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err = crypto_shash_final(desc, dst);
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if (err)
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goto err;
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dlen -= h;
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dst += h;
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counter = cpu_to_be32(be32_to_cpu(counter) + 1);
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}
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return 0;
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err:
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memzero_explicit(dst_orig, dlen);
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return err;
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}
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static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
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char __user *buffer, size_t buflen,
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uint8_t *kbuf, size_t kbuflen, size_t lzero)
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{
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uint8_t *outbuf = NULL;
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int ret;
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size_t outbuf_len = roundup(buflen,
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crypto_shash_digestsize(sdesc->shash.tfm));
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outbuf = kmalloc(outbuf_len, GFP_KERNEL);
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if (!outbuf) {
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ret = -ENOMEM;
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goto err;
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}
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ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, outbuf_len, lzero);
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if (ret)
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goto err;
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ret = buflen;
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if (copy_to_user(buffer, outbuf, buflen) != 0)
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ret = -EFAULT;
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err:
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kzfree(outbuf);
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return ret;
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}
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long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
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char __user *buffer, size_t buflen,
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struct keyctl_kdf_params *kdfcopy)
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{
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long ret;
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ssize_t dlen;
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int secretlen;
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int outlen;
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struct keyctl_dh_params pcopy;
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struct dh dh_inputs;
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struct scatterlist outsg;
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struct dh_completion compl;
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struct crypto_kpp *tfm;
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struct kpp_request *req;
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uint8_t *secret;
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uint8_t *outbuf;
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struct kdf_sdesc *sdesc = NULL;
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if (!params || (!buffer && buflen)) {
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ret = -EINVAL;
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goto out1;
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}
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if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
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ret = -EFAULT;
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goto out1;
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}
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if (kdfcopy) {
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char *hashname;
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if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) {
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ret = -EINVAL;
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goto out1;
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}
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if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN ||
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kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) {
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ret = -EMSGSIZE;
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goto out1;
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}
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/* get KDF name string */
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hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME);
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if (IS_ERR(hashname)) {
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ret = PTR_ERR(hashname);
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goto out1;
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}
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/* allocate KDF from the kernel crypto API */
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ret = kdf_alloc(&sdesc, hashname);
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kfree(hashname);
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if (ret)
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goto out1;
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}
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memset(&dh_inputs, 0, sizeof(dh_inputs));
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dlen = dh_data_from_key(pcopy.prime, &dh_inputs.p);
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if (dlen < 0) {
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ret = dlen;
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goto out1;
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}
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dh_inputs.p_size = dlen;
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dlen = dh_data_from_key(pcopy.base, &dh_inputs.g);
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if (dlen < 0) {
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ret = dlen;
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goto out2;
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}
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dh_inputs.g_size = dlen;
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dlen = dh_data_from_key(pcopy.private, &dh_inputs.key);
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if (dlen < 0) {
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ret = dlen;
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goto out2;
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}
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dh_inputs.key_size = dlen;
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secretlen = crypto_dh_key_len(&dh_inputs);
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secret = kmalloc(secretlen, GFP_KERNEL);
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if (!secret) {
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ret = -ENOMEM;
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goto out2;
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}
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ret = crypto_dh_encode_key(secret, secretlen, &dh_inputs);
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if (ret)
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goto out3;
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tfm = crypto_alloc_kpp("dh", 0, 0);
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if (IS_ERR(tfm)) {
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ret = PTR_ERR(tfm);
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goto out3;
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}
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ret = crypto_kpp_set_secret(tfm, secret, secretlen);
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if (ret)
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goto out4;
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outlen = crypto_kpp_maxsize(tfm);
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if (!kdfcopy) {
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/*
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* When not using a KDF, buflen 0 is used to read the
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* required buffer length
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*/
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if (buflen == 0) {
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ret = outlen;
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goto out4;
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} else if (outlen > buflen) {
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ret = -EOVERFLOW;
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goto out4;
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}
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}
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outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen,
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GFP_KERNEL);
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if (!outbuf) {
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ret = -ENOMEM;
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goto out4;
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}
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sg_init_one(&outsg, outbuf, outlen);
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req = kpp_request_alloc(tfm, GFP_KERNEL);
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if (!req) {
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ret = -ENOMEM;
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goto out5;
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}
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kpp_request_set_input(req, NULL, 0);
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kpp_request_set_output(req, &outsg, outlen);
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init_completion(&compl.completion);
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kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
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CRYPTO_TFM_REQ_MAY_SLEEP,
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dh_crypto_done, &compl);
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/*
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* For DH, generate_public_key and generate_shared_secret are
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* the same calculation
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*/
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ret = crypto_kpp_generate_public_key(req);
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if (ret == -EINPROGRESS) {
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wait_for_completion(&compl.completion);
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ret = compl.err;
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if (ret)
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goto out6;
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}
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if (kdfcopy) {
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/*
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* Concatenate SP800-56A otherinfo past DH shared secret -- the
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* input to the KDF is (DH shared secret || otherinfo)
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*/
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if (copy_from_user(outbuf + req->dst_len, kdfcopy->otherinfo,
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kdfcopy->otherinfolen) != 0) {
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ret = -EFAULT;
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goto out6;
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}
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ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, outbuf,
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req->dst_len + kdfcopy->otherinfolen,
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outlen - req->dst_len);
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} else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) {
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ret = req->dst_len;
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} else {
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ret = -EFAULT;
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}
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out6:
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kpp_request_free(req);
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out5:
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kzfree(outbuf);
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out4:
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crypto_free_kpp(tfm);
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out3:
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kzfree(secret);
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out2:
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dh_free_data(&dh_inputs);
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out1:
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kdf_dealloc(sdesc);
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return ret;
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}
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long keyctl_dh_compute(struct keyctl_dh_params __user *params,
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char __user *buffer, size_t buflen,
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struct keyctl_kdf_params __user *kdf)
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{
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struct keyctl_kdf_params kdfcopy;
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if (!kdf)
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return __keyctl_dh_compute(params, buffer, buflen, NULL);
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if (copy_from_user(&kdfcopy, kdf, sizeof(kdfcopy)) != 0)
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return -EFAULT;
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return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
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}
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