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![Herbert Xu](/assets/img/avatar_default.png)
The buffer rctx->ext contains potentially sensitive data and should
be freed with kzfree.
Cc: <stable@vger.kernel.org>
Fixes: 700cb3f5fe
("crypto: lrw - Convert to skcipher")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
600 lines
13 KiB
C
600 lines
13 KiB
C
/* LRW: as defined by Cyril Guyot in
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* http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
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*
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* Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
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*
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* Based on ecb.c
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* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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/* This implementation is checked against the test vectors in the above
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* document and by a test vector provided by Ken Buchanan at
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* http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
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*
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* The test vectors are included in the testing module tcrypt.[ch] */
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#include <crypto/internal/skcipher.h>
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#include <crypto/scatterwalk.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#include <crypto/b128ops.h>
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#include <crypto/gf128mul.h>
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#define LRW_BUFFER_SIZE 128u
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#define LRW_BLOCK_SIZE 16
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struct priv {
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struct crypto_skcipher *child;
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/*
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* optimizes multiplying a random (non incrementing, as at the
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* start of a new sector) value with key2, we could also have
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* used 4k optimization tables or no optimization at all. In the
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* latter case we would have to store key2 here
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*/
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struct gf128mul_64k *table;
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/*
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* stores:
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* key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
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* key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
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* key2*{ 0,0,...1,1,1,1,1 }, etc
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* needed for optimized multiplication of incrementing values
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* with key2
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*/
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be128 mulinc[128];
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};
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struct rctx {
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be128 buf[LRW_BUFFER_SIZE / sizeof(be128)];
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be128 t;
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be128 *ext;
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struct scatterlist srcbuf[2];
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struct scatterlist dstbuf[2];
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struct scatterlist *src;
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struct scatterlist *dst;
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unsigned int left;
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struct skcipher_request subreq;
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};
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static inline void setbit128_bbe(void *b, int bit)
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{
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__set_bit(bit ^ (0x80 -
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#ifdef __BIG_ENDIAN
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BITS_PER_LONG
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#else
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BITS_PER_BYTE
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#endif
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), b);
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}
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static int setkey(struct crypto_skcipher *parent, const u8 *key,
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unsigned int keylen)
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{
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struct priv *ctx = crypto_skcipher_ctx(parent);
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struct crypto_skcipher *child = ctx->child;
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int err, bsize = LRW_BLOCK_SIZE;
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const u8 *tweak = key + keylen - bsize;
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be128 tmp = { 0 };
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int i;
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crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
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crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_skcipher_setkey(child, key, keylen - bsize);
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crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
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CRYPTO_TFM_RES_MASK);
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if (err)
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return err;
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if (ctx->table)
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gf128mul_free_64k(ctx->table);
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/* initialize multiplication table for Key2 */
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ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
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if (!ctx->table)
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return -ENOMEM;
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/* initialize optimization table */
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for (i = 0; i < 128; i++) {
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setbit128_bbe(&tmp, i);
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ctx->mulinc[i] = tmp;
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gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
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}
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return 0;
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}
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static inline void inc(be128 *iv)
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{
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be64_add_cpu(&iv->b, 1);
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if (!iv->b)
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be64_add_cpu(&iv->a, 1);
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}
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/* this returns the number of consequative 1 bits starting
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* from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */
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static inline int get_index128(be128 *block)
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{
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int x;
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__be32 *p = (__be32 *) block;
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for (p += 3, x = 0; x < 128; p--, x += 32) {
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u32 val = be32_to_cpup(p);
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if (!~val)
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continue;
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return x + ffz(val);
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}
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return x;
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}
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static int post_crypt(struct skcipher_request *req)
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{
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struct rctx *rctx = skcipher_request_ctx(req);
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be128 *buf = rctx->ext ?: rctx->buf;
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struct skcipher_request *subreq;
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const int bs = LRW_BLOCK_SIZE;
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struct skcipher_walk w;
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struct scatterlist *sg;
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unsigned offset;
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int err;
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subreq = &rctx->subreq;
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err = skcipher_walk_virt(&w, subreq, false);
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while (w.nbytes) {
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unsigned int avail = w.nbytes;
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be128 *wdst;
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wdst = w.dst.virt.addr;
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do {
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be128_xor(wdst, buf++, wdst);
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wdst++;
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} while ((avail -= bs) >= bs);
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err = skcipher_walk_done(&w, avail);
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}
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rctx->left -= subreq->cryptlen;
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if (err || !rctx->left)
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goto out;
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rctx->dst = rctx->dstbuf;
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scatterwalk_done(&w.out, 0, 1);
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sg = w.out.sg;
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offset = w.out.offset;
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if (rctx->dst != sg) {
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rctx->dst[0] = *sg;
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sg_unmark_end(rctx->dst);
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scatterwalk_crypto_chain(rctx->dst, sg_next(sg), 0, 2);
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}
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rctx->dst[0].length -= offset - sg->offset;
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rctx->dst[0].offset = offset;
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out:
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return err;
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}
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static int pre_crypt(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct rctx *rctx = skcipher_request_ctx(req);
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struct priv *ctx = crypto_skcipher_ctx(tfm);
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be128 *buf = rctx->ext ?: rctx->buf;
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struct skcipher_request *subreq;
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const int bs = LRW_BLOCK_SIZE;
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struct skcipher_walk w;
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struct scatterlist *sg;
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unsigned cryptlen;
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unsigned offset;
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be128 *iv;
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bool more;
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int err;
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subreq = &rctx->subreq;
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skcipher_request_set_tfm(subreq, tfm);
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cryptlen = subreq->cryptlen;
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more = rctx->left > cryptlen;
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if (!more)
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cryptlen = rctx->left;
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skcipher_request_set_crypt(subreq, rctx->src, rctx->dst,
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cryptlen, req->iv);
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err = skcipher_walk_virt(&w, subreq, false);
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iv = w.iv;
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while (w.nbytes) {
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unsigned int avail = w.nbytes;
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be128 *wsrc;
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be128 *wdst;
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wsrc = w.src.virt.addr;
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wdst = w.dst.virt.addr;
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do {
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*buf++ = rctx->t;
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be128_xor(wdst++, &rctx->t, wsrc++);
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/* T <- I*Key2, using the optimization
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* discussed in the specification */
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be128_xor(&rctx->t, &rctx->t,
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&ctx->mulinc[get_index128(iv)]);
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inc(iv);
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} while ((avail -= bs) >= bs);
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err = skcipher_walk_done(&w, avail);
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}
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skcipher_request_set_tfm(subreq, ctx->child);
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skcipher_request_set_crypt(subreq, rctx->dst, rctx->dst,
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cryptlen, NULL);
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if (err || !more)
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goto out;
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rctx->src = rctx->srcbuf;
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scatterwalk_done(&w.in, 0, 1);
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sg = w.in.sg;
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offset = w.in.offset;
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if (rctx->src != sg) {
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rctx->src[0] = *sg;
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sg_unmark_end(rctx->src);
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scatterwalk_crypto_chain(rctx->src, sg_next(sg), 0, 2);
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}
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rctx->src[0].length -= offset - sg->offset;
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rctx->src[0].offset = offset;
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out:
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return err;
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}
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static int init_crypt(struct skcipher_request *req, crypto_completion_t done)
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{
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struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
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struct rctx *rctx = skcipher_request_ctx(req);
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struct skcipher_request *subreq;
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gfp_t gfp;
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subreq = &rctx->subreq;
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skcipher_request_set_callback(subreq, req->base.flags, done, req);
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gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
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GFP_ATOMIC;
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rctx->ext = NULL;
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subreq->cryptlen = LRW_BUFFER_SIZE;
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if (req->cryptlen > LRW_BUFFER_SIZE) {
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unsigned int n = min(req->cryptlen, (unsigned int)PAGE_SIZE);
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rctx->ext = kmalloc(n, gfp);
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if (rctx->ext)
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subreq->cryptlen = n;
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}
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rctx->src = req->src;
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rctx->dst = req->dst;
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rctx->left = req->cryptlen;
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/* calculate first value of T */
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memcpy(&rctx->t, req->iv, sizeof(rctx->t));
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/* T <- I*Key2 */
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gf128mul_64k_bbe(&rctx->t, ctx->table);
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return 0;
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}
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static void exit_crypt(struct skcipher_request *req)
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{
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struct rctx *rctx = skcipher_request_ctx(req);
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rctx->left = 0;
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if (rctx->ext)
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kzfree(rctx->ext);
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}
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static int do_encrypt(struct skcipher_request *req, int err)
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{
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struct rctx *rctx = skcipher_request_ctx(req);
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struct skcipher_request *subreq;
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subreq = &rctx->subreq;
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while (!err && rctx->left) {
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err = pre_crypt(req) ?:
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crypto_skcipher_encrypt(subreq) ?:
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post_crypt(req);
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if (err == -EINPROGRESS || err == -EBUSY)
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return err;
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}
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exit_crypt(req);
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return err;
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}
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static void encrypt_done(struct crypto_async_request *areq, int err)
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{
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struct skcipher_request *req = areq->data;
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struct skcipher_request *subreq;
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struct rctx *rctx;
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rctx = skcipher_request_ctx(req);
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if (err == -EINPROGRESS) {
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if (rctx->left != req->cryptlen)
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return;
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goto out;
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}
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subreq = &rctx->subreq;
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subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
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err = do_encrypt(req, err ?: post_crypt(req));
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if (rctx->left)
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return;
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out:
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skcipher_request_complete(req, err);
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}
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static int encrypt(struct skcipher_request *req)
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{
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return do_encrypt(req, init_crypt(req, encrypt_done));
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}
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static int do_decrypt(struct skcipher_request *req, int err)
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{
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struct rctx *rctx = skcipher_request_ctx(req);
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struct skcipher_request *subreq;
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subreq = &rctx->subreq;
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while (!err && rctx->left) {
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err = pre_crypt(req) ?:
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crypto_skcipher_decrypt(subreq) ?:
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post_crypt(req);
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if (err == -EINPROGRESS || err == -EBUSY)
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return err;
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}
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exit_crypt(req);
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return err;
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}
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static void decrypt_done(struct crypto_async_request *areq, int err)
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{
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struct skcipher_request *req = areq->data;
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struct skcipher_request *subreq;
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struct rctx *rctx;
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rctx = skcipher_request_ctx(req);
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if (err == -EINPROGRESS) {
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if (rctx->left != req->cryptlen)
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return;
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goto out;
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}
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subreq = &rctx->subreq;
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subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
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err = do_decrypt(req, err ?: post_crypt(req));
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if (rctx->left)
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return;
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out:
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skcipher_request_complete(req, err);
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}
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static int decrypt(struct skcipher_request *req)
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{
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return do_decrypt(req, init_crypt(req, decrypt_done));
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}
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static int init_tfm(struct crypto_skcipher *tfm)
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{
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struct skcipher_instance *inst = skcipher_alg_instance(tfm);
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struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
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struct priv *ctx = crypto_skcipher_ctx(tfm);
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struct crypto_skcipher *cipher;
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cipher = crypto_spawn_skcipher(spawn);
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if (IS_ERR(cipher))
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return PTR_ERR(cipher);
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ctx->child = cipher;
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crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(cipher) +
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sizeof(struct rctx));
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return 0;
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}
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static void exit_tfm(struct crypto_skcipher *tfm)
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{
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struct priv *ctx = crypto_skcipher_ctx(tfm);
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if (ctx->table)
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gf128mul_free_64k(ctx->table);
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crypto_free_skcipher(ctx->child);
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}
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static void free(struct skcipher_instance *inst)
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{
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crypto_drop_skcipher(skcipher_instance_ctx(inst));
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kfree(inst);
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}
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static int create(struct crypto_template *tmpl, struct rtattr **tb)
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{
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struct crypto_skcipher_spawn *spawn;
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struct skcipher_instance *inst;
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struct crypto_attr_type *algt;
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struct skcipher_alg *alg;
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const char *cipher_name;
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char ecb_name[CRYPTO_MAX_ALG_NAME];
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int err;
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algt = crypto_get_attr_type(tb);
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if (IS_ERR(algt))
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return PTR_ERR(algt);
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if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
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return -EINVAL;
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cipher_name = crypto_attr_alg_name(tb[1]);
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if (IS_ERR(cipher_name))
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return PTR_ERR(cipher_name);
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inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
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if (!inst)
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return -ENOMEM;
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spawn = skcipher_instance_ctx(inst);
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crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
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err = crypto_grab_skcipher(spawn, cipher_name, 0,
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crypto_requires_sync(algt->type,
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algt->mask));
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if (err == -ENOENT) {
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err = -ENAMETOOLONG;
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if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
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cipher_name) >= CRYPTO_MAX_ALG_NAME)
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goto err_free_inst;
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err = crypto_grab_skcipher(spawn, ecb_name, 0,
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crypto_requires_sync(algt->type,
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algt->mask));
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}
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if (err)
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goto err_free_inst;
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alg = crypto_skcipher_spawn_alg(spawn);
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err = -EINVAL;
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if (alg->base.cra_blocksize != LRW_BLOCK_SIZE)
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goto err_drop_spawn;
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if (crypto_skcipher_alg_ivsize(alg))
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goto err_drop_spawn;
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err = crypto_inst_setname(skcipher_crypto_instance(inst), "lrw",
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&alg->base);
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if (err)
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goto err_drop_spawn;
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err = -EINVAL;
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cipher_name = alg->base.cra_name;
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/* Alas we screwed up the naming so we have to mangle the
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* cipher name.
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*/
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if (!strncmp(cipher_name, "ecb(", 4)) {
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unsigned len;
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len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
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if (len < 2 || len >= sizeof(ecb_name))
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goto err_drop_spawn;
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if (ecb_name[len - 1] != ')')
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goto err_drop_spawn;
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|
|
ecb_name[len - 1] = 0;
|
|
|
|
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
|
|
"lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) {
|
|
err = -ENAMETOOLONG;
|
|
goto err_drop_spawn;
|
|
}
|
|
} else
|
|
goto err_drop_spawn;
|
|
|
|
inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
|
|
inst->alg.base.cra_priority = alg->base.cra_priority;
|
|
inst->alg.base.cra_blocksize = LRW_BLOCK_SIZE;
|
|
inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
|
|
(__alignof__(u64) - 1);
|
|
|
|
inst->alg.ivsize = LRW_BLOCK_SIZE;
|
|
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
|
|
LRW_BLOCK_SIZE;
|
|
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
|
|
LRW_BLOCK_SIZE;
|
|
|
|
inst->alg.base.cra_ctxsize = sizeof(struct priv);
|
|
|
|
inst->alg.init = init_tfm;
|
|
inst->alg.exit = exit_tfm;
|
|
|
|
inst->alg.setkey = setkey;
|
|
inst->alg.encrypt = encrypt;
|
|
inst->alg.decrypt = decrypt;
|
|
|
|
inst->free = free;
|
|
|
|
err = skcipher_register_instance(tmpl, inst);
|
|
if (err)
|
|
goto err_drop_spawn;
|
|
|
|
out:
|
|
return err;
|
|
|
|
err_drop_spawn:
|
|
crypto_drop_skcipher(spawn);
|
|
err_free_inst:
|
|
kfree(inst);
|
|
goto out;
|
|
}
|
|
|
|
static struct crypto_template crypto_tmpl = {
|
|
.name = "lrw",
|
|
.create = create,
|
|
.module = THIS_MODULE,
|
|
};
|
|
|
|
static int __init crypto_module_init(void)
|
|
{
|
|
return crypto_register_template(&crypto_tmpl);
|
|
}
|
|
|
|
static void __exit crypto_module_exit(void)
|
|
{
|
|
crypto_unregister_template(&crypto_tmpl);
|
|
}
|
|
|
|
module_init(crypto_module_init);
|
|
module_exit(crypto_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("LRW block cipher mode");
|
|
MODULE_ALIAS_CRYPTO("lrw");
|