/* XTS: as defined in IEEE1619/D16 * http://grouper.ieee.org/groups/1619/email/pdf00086.pdf * (sector sizes which are not a multiple of 16 bytes are, * however currently unsupported) * * Copyright (c) 2007 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. */#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/xts.h>#include <crypto/b128ops.h>#include <crypto/gf128mul.h> #define XTS_BUFFER_SIZE 128u struct priv { struct crypto_skcipher *child; struct crypto_cipher *tweak;}; struct xts_instance_ctx { struct crypto_skcipher_spawn spawn; char name[CRYPTO_MAX_ALG_NAME];}; struct rctx { le128 buf[XTS_BUFFER_SIZE / sizeof(le128)]; le128 t; le128 *ext; struct scatterlist srcbuf[2]; struct scatterlist dstbuf[2]; struct scatterlist *src; struct scatterlist *dst; unsigned int left; struct skcipher_request subreq;}; static int setkey(struct crypto_skcipher *parent, const u8 *key, unsigned int keylen){ struct priv *ctx = crypto_skcipher_ctx(parent); struct crypto_skcipher *child; struct crypto_cipher *tweak; int err; err = xts_verify_key(parent, key, keylen); if (err) return err; keylen /= 2; /* we need two cipher instances: one to compute the initial 'tweak' * by encrypting the IV (usually the 'plain' iv) and the other * one to encrypt and decrypt the data */ /* tweak cipher, uses Key2 i.e. the second half of *key */ tweak = ctx->tweak; crypto_cipher_clear_flags(tweak, CRYPTO_TFM_REQ_MASK); crypto_cipher_set_flags(tweak, crypto_skcipher_get_flags(parent) & CRYPTO_TFM_REQ_MASK); err = crypto_cipher_setkey(tweak, key + keylen, keylen); crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(tweak) & CRYPTO_TFM_RES_MASK); if (err) return err; /* data cipher, uses Key1 i.e. the first half of *key */ child = ctx->child; 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); crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) & CRYPTO_TFM_RES_MASK); return err;} static int post_crypt(struct skcipher_request *req){ struct rctx *rctx = skcipher_request_ctx(req); le128 *buf = rctx->ext ?: rctx->buf; struct skcipher_request *subreq; const int bs = XTS_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; le128 *wdst; wdst = w.dst.virt.addr; do { le128_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), 0, 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 rctx *rctx = skcipher_request_ctx(req); le128 *buf = rctx->ext ?: rctx->buf; struct skcipher_request *subreq; const int bs = XTS_BLOCK_SIZE; struct skcipher_walk w; struct scatterlist *sg; unsigned cryptlen; unsigned offset; bool more; int err; subreq = &rctx->subreq; cryptlen = subreq->cryptlen; more = rctx->left > cryptlen; if (!more) cryptlen = rctx->left; skcipher_request_set_crypt(subreq, rctx->src, rctx->dst, cryptlen, NULL); err = skcipher_walk_virt(&w, subreq, false); while (w.nbytes) { unsigned int avail = w.nbytes; le128 *wsrc; le128 *wdst; wsrc = w.src.virt.addr; wdst = w.dst.virt.addr; do { *buf++ = rctx->t; le128_xor(wdst++, &rctx->t, wsrc++); gf128mul_x_ble(&rctx->t, &rctx->t); } while ((avail -= bs) >= bs); err = skcipher_walk_done(&w, avail); } 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), 0, 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_tfm(subreq, ctx->child); 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 = XTS_BUFFER_SIZE; if (req->cryptlen > XTS_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 */ crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv); 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 && req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) 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 && req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) 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));} int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst, struct scatterlist *ssrc, unsigned int nbytes, struct xts_crypt_req *req){ const unsigned int bsize = XTS_BLOCK_SIZE; const unsigned int max_blks = req->tbuflen / bsize; struct blkcipher_walk walk; unsigned int nblocks; le128 *src, *dst, *t; le128 *t_buf = req->tbuf; int err, i; BUG_ON(max_blks < 1); blkcipher_walk_init(&walk, sdst, ssrc, nbytes); err = blkcipher_walk_virt(desc, &walk); nbytes = walk.nbytes; if (!nbytes) return err; nblocks = min(nbytes / bsize, max_blks); src = (le128 *)walk.src.virt.addr; dst = (le128 *)walk.dst.virt.addr; /* calculate first value of T */ req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv); i = 0; goto first; for (;;) { do { for (i = 0; i < nblocks; i++) { gf128mul_x_ble(&t_buf[i], t);first: t = &t_buf[i]; /* PP <- T xor P */ le128_xor(dst + i, t, src + i); } /* CC <- E(Key2,PP) */ req->crypt_fn(req->crypt_ctx, (u8 *)dst, nblocks * bsize); /* C <- T xor CC */ for (i = 0; i < nblocks; i++) le128_xor(dst + i, dst + i, &t_buf[i]); src += nblocks; dst += nblocks; nbytes -= nblocks * bsize; nblocks = min(nbytes / bsize, max_blks); } while (nblocks > 0); *(le128 *)walk.iv = *t; err = blkcipher_walk_done(desc, &walk, nbytes); nbytes = walk.nbytes; if (!nbytes) break; nblocks = min(nbytes / bsize, max_blks); src = (le128 *)walk.src.virt.addr; dst = (le128 *)walk.dst.virt.addr; } return err;}EXPORT_SYMBOL_GPL(xts_crypt); static int init_tfm(struct crypto_skcipher *tfm){ struct skcipher_instance *inst = skcipher_alg_instance(tfm); struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst); struct priv *ctx = crypto_skcipher_ctx(tfm); struct crypto_skcipher *child; struct crypto_cipher *tweak; child = crypto_spawn_skcipher(&ictx->spawn); if (IS_ERR(child)) return PTR_ERR(child); ctx->child = child; tweak = crypto_alloc_cipher(ictx->name, 0, 0); if (IS_ERR(tweak)) { crypto_free_skcipher(ctx->child); return PTR_ERR(tweak); } ctx->tweak = tweak; crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) + sizeof(struct rctx)); return 0;} static void exit_tfm(struct crypto_skcipher *tfm){ struct priv *ctx = crypto_skcipher_ctx(tfm); crypto_free_skcipher(ctx->child); crypto_free_cipher(ctx->tweak);} static void free(struct skcipher_instance *inst){ crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst);} static int create(struct crypto_template *tmpl, struct rtattr **tb){ struct skcipher_instance *inst; struct crypto_attr_type *algt; struct xts_instance_ctx *ctx; struct skcipher_alg *alg; const char *cipher_name; u32 mask; 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(*ctx), GFP_KERNEL); if (!inst)Lines 1–500 of 618. 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/* XTS: as defined in IEEE1619/D16 * http://grouper.ieee.org/groups/1619/email/pdf00086.pdf * (sector sizes which are not a multiple of 16 bytes are, * however currently unsupported) * * Copyright (c) 2007 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. */ #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/xts.h> #include <crypto/b128ops.h> #include <crypto/gf128mul.h> #define XTS_BUFFER_SIZE 128u struct priv { struct crypto_skcipher *child; struct crypto_cipher *tweak; }; struct xts_instance_ctx { struct crypto_skcipher_spawn spawn; char name[CRYPTO_MAX_ALG_NAME]; }; struct rctx { le128 buf[XTS_BUFFER_SIZE / sizeof(le128)]; le128 t; le128 *ext; struct scatterlist srcbuf[2]; struct scatterlist dstbuf[2]; struct scatterlist *src; struct scatterlist *dst; unsigned int left; struct skcipher_request subreq; }; static int setkey(struct crypto_skcipher *parent, const u8 *key, unsigned int keylen) { struct priv *ctx = crypto_skcipher_ctx(parent); struct crypto_skcipher *child; struct crypto_cipher *tweak; int err; err = xts_verify_key(parent, key, keylen); if (err) return err; keylen /= 2; /* we need two cipher instances: one to compute the initial 'tweak' * by encrypting the IV (usually the 'plain' iv) and the other * one to encrypt and decrypt the data */ /* tweak cipher, uses Key2 i.e. the second half of *key */ tweak = ctx->tweak; crypto_cipher_clear_flags(tweak, CRYPTO_TFM_REQ_MASK); crypto_cipher_set_flags(tweak, crypto_skcipher_get_flags(parent) & CRYPTO_TFM_REQ_MASK); err = crypto_cipher_setkey(tweak, key + keylen, keylen); crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(tweak) & CRYPTO_TFM_RES_MASK); if (err) return err; /* data cipher, uses Key1 i.e. the first half of *key */ child = ctx->child; 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); crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) & CRYPTO_TFM_RES_MASK); return err; } static int post_crypt(struct skcipher_request *req) { struct rctx *rctx = skcipher_request_ctx(req); le128 *buf = rctx->ext ?: rctx->buf; struct skcipher_request *subreq; const int bs = XTS_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; le128 *wdst; wdst = w.dst.virt.addr; do { le128_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), 0, 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 rctx *rctx = skcipher_request_ctx(req); le128 *buf = rctx->ext ?: rctx->buf; struct skcipher_request *subreq; const int bs = XTS_BLOCK_SIZE; struct skcipher_walk w; struct scatterlist *sg; unsigned cryptlen; unsigned offset; bool more; int err; subreq = &rctx->subreq; cryptlen = subreq->cryptlen; more = rctx->left > cryptlen; if (!more) cryptlen = rctx->left; skcipher_request_set_crypt(subreq, rctx->src, rctx->dst, cryptlen, NULL); err = skcipher_walk_virt(&w, subreq, false); while (w.nbytes) { unsigned int avail = w.nbytes; le128 *wsrc; le128 *wdst; wsrc = w.src.virt.addr; wdst = w.dst.virt.addr; do { *buf++ = rctx->t; le128_xor(wdst++, &rctx->t, wsrc++); gf128mul_x_ble(&rctx->t, &rctx->t); } while ((avail -= bs) >= bs); err = skcipher_walk_done(&w, avail); } 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), 0, 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_tfm(subreq, ctx->child); 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 = XTS_BUFFER_SIZE; if (req->cryptlen > XTS_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 */ crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv); 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 && req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) 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 && req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)) 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)); } int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst, struct scatterlist *ssrc, unsigned int nbytes, struct xts_crypt_req *req) { const unsigned int bsize = XTS_BLOCK_SIZE; const unsigned int max_blks = req->tbuflen / bsize; struct blkcipher_walk walk; unsigned int nblocks; le128 *src, *dst, *t; le128 *t_buf = req->tbuf; int err, i; BUG_ON(max_blks < 1); blkcipher_walk_init(&walk, sdst, ssrc, nbytes); err = blkcipher_walk_virt(desc, &walk); nbytes = walk.nbytes; if (!nbytes) return err; nblocks = min(nbytes / bsize, max_blks); src = (le128 *)walk.src.virt.addr; dst = (le128 *)walk.dst.virt.addr; /* calculate first value of T */ req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv); i = 0; goto first; for (;;) { do { for (i = 0; i < nblocks; i++) { gf128mul_x_ble(&t_buf[i], t); first: t = &t_buf[i]; /* PP <- T xor P */ le128_xor(dst + i, t, src + i); } /* CC <- E(Key2,PP) */ req->crypt_fn(req->crypt_ctx, (u8 *)dst, nblocks * bsize); /* C <- T xor CC */ for (i = 0; i < nblocks; i++) le128_xor(dst + i, dst + i, &t_buf[i]); src += nblocks; dst += nblocks; nbytes -= nblocks * bsize; nblocks = min(nbytes / bsize, max_blks); } while (nblocks > 0); *(le128 *)walk.iv = *t; err = blkcipher_walk_done(desc, &walk, nbytes); nbytes = walk.nbytes; if (!nbytes) break; nblocks = min(nbytes / bsize, max_blks); src = (le128 *)walk.src.virt.addr; dst = (le128 *)walk.dst.virt.addr; } return err; } EXPORT_SYMBOL_GPL(xts_crypt); static int init_tfm(struct crypto_skcipher *tfm) { struct skcipher_instance *inst = skcipher_alg_instance(tfm); struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst); struct priv *ctx = crypto_skcipher_ctx(tfm); struct crypto_skcipher *child; struct crypto_cipher *tweak; child = crypto_spawn_skcipher(&ictx->spawn); if (IS_ERR(child)) return PTR_ERR(child); ctx->child = child; tweak = crypto_alloc_cipher(ictx->name, 0, 0); if (IS_ERR(tweak)) { crypto_free_skcipher(ctx->child); return PTR_ERR(tweak); } ctx->tweak = tweak; crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) + sizeof(struct rctx)); return 0; } static void exit_tfm(struct crypto_skcipher *tfm) { struct priv *ctx = crypto_skcipher_ctx(tfm); crypto_free_skcipher(ctx->child); crypto_free_cipher(ctx->tweak); } static void free(struct skcipher_instance *inst) { crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst); } static int create(struct crypto_template *tmpl, struct rtattr **tb) { struct skcipher_instance *inst; struct crypto_attr_type *algt; struct xts_instance_ctx *ctx; struct skcipher_alg *alg; const char *cipher_name; u32 mask; 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(*ctx), GFP_KERNEL); if (!inst)