diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /crypto/lrw.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'crypto/lrw.c')
-rw-r--r-- | crypto/lrw.c | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/crypto/lrw.c b/crypto/lrw.c new file mode 100644 index 000000000..d55c9ee18 --- /dev/null +++ b/crypto/lrw.c @@ -0,0 +1,605 @@ +/* LRW: as defined by Cyril Guyot in + * http://grouper.ieee.org/groups/1619/email/pdf00017.pdf + * + * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org> + * + * Based on ecb.c + * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ +/* This implementation is checked against the test vectors in the above + * document and by a test vector provided by Ken Buchanan at + * http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html + * + * The test vectors are included in the testing module tcrypt.[ch] */ + +#include <crypto/internal/skcipher.h> +#include <crypto/scatterwalk.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> + +#include <crypto/b128ops.h> +#include <crypto/gf128mul.h> + +#define LRW_BUFFER_SIZE 128u + +#define LRW_BLOCK_SIZE 16 + +struct priv { + struct crypto_skcipher *child; + + /* + * optimizes multiplying a random (non incrementing, as at the + * start of a new sector) value with key2, we could also have + * used 4k optimization tables or no optimization at all. In the + * latter case we would have to store key2 here + */ + struct gf128mul_64k *table; + + /* + * stores: + * key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 }, + * key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 } + * key2*{ 0,0,...1,1,1,1,1 }, etc + * needed for optimized multiplication of incrementing values + * with key2 + */ + be128 mulinc[128]; +}; + +struct rctx { + be128 buf[LRW_BUFFER_SIZE / sizeof(be128)]; + + be128 t; + + be128 *ext; + + struct scatterlist srcbuf[2]; + struct scatterlist dstbuf[2]; + struct scatterlist *src; + struct scatterlist *dst; + + unsigned int left; + + struct skcipher_request subreq; +}; + +static inline void setbit128_bbe(void *b, int bit) +{ + __set_bit(bit ^ (0x80 - +#ifdef __BIG_ENDIAN + BITS_PER_LONG +#else + BITS_PER_BYTE +#endif + ), b); +} + +static int setkey(struct crypto_skcipher *parent, const u8 *key, + unsigned int keylen) +{ + struct priv *ctx = crypto_skcipher_ctx(parent); + struct crypto_skcipher *child = ctx->child; + int err, bsize = LRW_BLOCK_SIZE; + const u8 *tweak = key + keylen - bsize; + be128 tmp = { 0 }; + int i; + + crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + err = crypto_skcipher_setkey(child, key, keylen - bsize); + crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) & + CRYPTO_TFM_RES_MASK); + if (err) + return err; + + if (ctx->table) + gf128mul_free_64k(ctx->table); + + /* initialize multiplication table for Key2 */ + ctx->table = gf128mul_init_64k_bbe((be128 *)tweak); + if (!ctx->table) + return -ENOMEM; + + /* initialize optimization table */ + for (i = 0; i < 128; i++) { + setbit128_bbe(&tmp, i); + ctx->mulinc[i] = tmp; + gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table); + } + + return 0; +} + +static inline void inc(be128 *iv) +{ + be64_add_cpu(&iv->b, 1); + if (!iv->b) + be64_add_cpu(&iv->a, 1); +} + +/* this returns the number of consequative 1 bits starting + * from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */ +static inline int get_index128(be128 *block) +{ + int x; + __be32 *p = (__be32 *) block; + + for (p += 3, x = 0; x < 128; p--, x += 32) { + u32 val = be32_to_cpup(p); + + if (!~val) + continue; + + return x + ffz(val); + } + + /* + * If we get here, then x == 128 and we are incrementing the counter + * from all ones to all zeros. This means we must return index 127, i.e. + * the one corresponding to key2*{ 1,...,1 }. + */ + return 127; +} + +static int post_crypt(struct skcipher_request *req) +{ + struct rctx *rctx = skcipher_request_ctx(req); + be128 *buf = rctx->ext ?: rctx->buf; + struct skcipher_request *subreq; + const int bs = LRW_BLOCK_SIZE; + struct skcipher_walk w; + struct scatterlist *sg; + unsigned offset; + int err; + + subreq = &rctx->subreq; + err = skcipher_walk_virt(&w, subreq, false); + + while (w.nbytes) { + unsigned int avail = w.nbytes; + be128 *wdst; + + wdst = w.dst.virt.addr; + + do { + be128_xor(wdst, buf++, wdst); + wdst++; + } while ((avail -= bs) >= bs); + + err = skcipher_walk_done(&w, avail); + } + + rctx->left -= subreq->cryptlen; + + if (err || !rctx->left) + goto out; + + rctx->dst = rctx->dstbuf; + + scatterwalk_done(&w.out, 0, 1); + sg = w.out.sg; + offset = w.out.offset; + + if (rctx->dst != sg) { + rctx->dst[0] = *sg; + sg_unmark_end(rctx->dst); + scatterwalk_crypto_chain(rctx->dst, sg_next(sg), 2); + } + rctx->dst[0].length -= offset - sg->offset; + rctx->dst[0].offset = offset; + +out: + return err; +} + +static int pre_crypt(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct rctx *rctx = skcipher_request_ctx(req); + struct priv *ctx = crypto_skcipher_ctx(tfm); + be128 *buf = rctx->ext ?: rctx->buf; + struct skcipher_request *subreq; + const int bs = LRW_BLOCK_SIZE; + struct skcipher_walk w; + struct scatterlist *sg; + unsigned cryptlen; + unsigned offset; + be128 *iv; + bool more; + int err; + + subreq = &rctx->subreq; + skcipher_request_set_tfm(subreq, tfm); + + cryptlen = subreq->cryptlen; + more = rctx->left > cryptlen; + if (!more) + cryptlen = rctx->left; + + skcipher_request_set_crypt(subreq, rctx->src, rctx->dst, + cryptlen, req->iv); + + err = skcipher_walk_virt(&w, subreq, false); + iv = w.iv; + + while (w.nbytes) { + unsigned int avail = w.nbytes; + be128 *wsrc; + be128 *wdst; + + wsrc = w.src.virt.addr; + wdst = w.dst.virt.addr; + + do { + *buf++ = rctx->t; + be128_xor(wdst++, &rctx->t, wsrc++); + + /* T <- I*Key2, using the optimization + * discussed in the specification */ + be128_xor(&rctx->t, &rctx->t, + &ctx->mulinc[get_index128(iv)]); + inc(iv); + } while ((avail -= bs) >= bs); + + err = skcipher_walk_done(&w, avail); + } + + skcipher_request_set_tfm(subreq, ctx->child); + skcipher_request_set_crypt(subreq, rctx->dst, rctx->dst, + cryptlen, NULL); + + if (err || !more) + goto out; + + rctx->src = rctx->srcbuf; + + scatterwalk_done(&w.in, 0, 1); + sg = w.in.sg; + offset = w.in.offset; + + if (rctx->src != sg) { + rctx->src[0] = *sg; + sg_unmark_end(rctx->src); + scatterwalk_crypto_chain(rctx->src, sg_next(sg), 2); + } + rctx->src[0].length -= offset - sg->offset; + rctx->src[0].offset = offset; + +out: + return err; +} + +static int init_crypt(struct skcipher_request *req, crypto_completion_t done) +{ + struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); + struct rctx *rctx = skcipher_request_ctx(req); + struct skcipher_request *subreq; + gfp_t gfp; + + subreq = &rctx->subreq; + skcipher_request_set_callback(subreq, req->base.flags, done, req); + + gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : + GFP_ATOMIC; + rctx->ext = NULL; + + subreq->cryptlen = LRW_BUFFER_SIZE; + if (req->cryptlen > LRW_BUFFER_SIZE) { + unsigned int n = min(req->cryptlen, (unsigned int)PAGE_SIZE); + + rctx->ext = kmalloc(n, gfp); + if (rctx->ext) + subreq->cryptlen = n; + } + + rctx->src = req->src; + rctx->dst = req->dst; + rctx->left = req->cryptlen; + + /* calculate first value of T */ + memcpy(&rctx->t, req->iv, sizeof(rctx->t)); + + /* T <- I*Key2 */ + gf128mul_64k_bbe(&rctx->t, ctx->table); + + return 0; +} + +static void exit_crypt(struct skcipher_request *req) +{ + struct rctx *rctx = skcipher_request_ctx(req); + + rctx->left = 0; + + if (rctx->ext) + kzfree(rctx->ext); +} + +static int do_encrypt(struct skcipher_request *req, int err) +{ + struct rctx *rctx = skcipher_request_ctx(req); + struct skcipher_request *subreq; + + subreq = &rctx->subreq; + + while (!err && rctx->left) { + err = pre_crypt(req) ?: + crypto_skcipher_encrypt(subreq) ?: + post_crypt(req); + + if (err == -EINPROGRESS || err == -EBUSY) + return err; + } + + exit_crypt(req); + return err; +} + +static void encrypt_done(struct crypto_async_request *areq, int err) +{ + struct skcipher_request *req = areq->data; + struct skcipher_request *subreq; + struct rctx *rctx; + + rctx = skcipher_request_ctx(req); + + if (err == -EINPROGRESS) { + if (rctx->left != req->cryptlen) + return; + goto out; + } + + subreq = &rctx->subreq; + subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG; + + err = do_encrypt(req, err ?: post_crypt(req)); + if (rctx->left) + return; + +out: + skcipher_request_complete(req, err); +} + +static int encrypt(struct skcipher_request *req) +{ + return do_encrypt(req, init_crypt(req, encrypt_done)); +} + +static int do_decrypt(struct skcipher_request *req, int err) +{ + struct rctx *rctx = skcipher_request_ctx(req); + struct skcipher_request *subreq; + + subreq = &rctx->subreq; + + while (!err && rctx->left) { + err = pre_crypt(req) ?: + crypto_skcipher_decrypt(subreq) ?: + post_crypt(req); + + if (err == -EINPROGRESS || err == -EBUSY) + return err; + } + + exit_crypt(req); + return err; +} + +static void decrypt_done(struct crypto_async_request *areq, int err) +{ + struct skcipher_request *req = areq->data; + struct skcipher_request *subreq; + struct rctx *rctx; + + rctx = skcipher_request_ctx(req); + + if (err == -EINPROGRESS) { + if (rctx->left != req->cryptlen) + return; + goto out; + } + + subreq = &rctx->subreq; + subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG; + + err = do_decrypt(req, err ?: post_crypt(req)); + if (rctx->left) + return; + +out: + skcipher_request_complete(req, err); +} + +static int decrypt(struct skcipher_request *req) +{ + return do_decrypt(req, init_crypt(req, decrypt_done)); +} + +static int init_tfm(struct crypto_skcipher *tfm) +{ + struct skcipher_instance *inst = skcipher_alg_instance(tfm); + struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst); + struct priv *ctx = crypto_skcipher_ctx(tfm); + struct crypto_skcipher *cipher; + + cipher = crypto_spawn_skcipher(spawn); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + ctx->child = cipher; + + crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(cipher) + + sizeof(struct rctx)); + + return 0; +} + +static void exit_tfm(struct crypto_skcipher *tfm) +{ + struct priv *ctx = crypto_skcipher_ctx(tfm); + + if (ctx->table) + gf128mul_free_64k(ctx->table); + crypto_free_skcipher(ctx->child); +} + +static void free_inst(struct skcipher_instance *inst) +{ + crypto_drop_skcipher(skcipher_instance_ctx(inst)); + kfree(inst); +} + +static int create(struct crypto_template *tmpl, struct rtattr **tb) +{ + struct crypto_skcipher_spawn *spawn; + struct skcipher_instance *inst; + struct crypto_attr_type *algt; + struct skcipher_alg *alg; + const char *cipher_name; + char ecb_name[CRYPTO_MAX_ALG_NAME]; + int err; + + algt = crypto_get_attr_type(tb); + if (IS_ERR(algt)) + return PTR_ERR(algt); + + if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) + return -EINVAL; + + cipher_name = crypto_attr_alg_name(tb[1]); + if (IS_ERR(cipher_name)) + return PTR_ERR(cipher_name); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return -ENOMEM; + + spawn = skcipher_instance_ctx(inst); + + crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst)); + err = crypto_grab_skcipher(spawn, cipher_name, 0, + crypto_requires_sync(algt->type, + algt->mask)); + if (err == -ENOENT) { + err = -ENAMETOOLONG; + if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)", + cipher_name) >= CRYPTO_MAX_ALG_NAME) + goto err_free_inst; + + err = crypto_grab_skcipher(spawn, ecb_name, 0, + crypto_requires_sync(algt->type, + algt->mask)); + } + + if (err) + goto err_free_inst; + + alg = crypto_skcipher_spawn_alg(spawn); + + err = -EINVAL; + if (alg->base.cra_blocksize != LRW_BLOCK_SIZE) + goto err_drop_spawn; + + if (crypto_skcipher_alg_ivsize(alg)) + goto err_drop_spawn; + + err = crypto_inst_setname(skcipher_crypto_instance(inst), "lrw", + &alg->base); + if (err) + goto err_drop_spawn; + + err = -EINVAL; + cipher_name = alg->base.cra_name; + + /* Alas we screwed up the naming so we have to mangle the + * cipher name. + */ + if (!strncmp(cipher_name, "ecb(", 4)) { + unsigned len; + + len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name)); + if (len < 2 || len >= sizeof(ecb_name)) + goto err_drop_spawn; + + if (ecb_name[len - 1] != ')') + goto err_drop_spawn; + + 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_inst; + + 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"); |