/* * Asynchronous block chaining cipher operations. * * This is the asynchronous version of blkcipher.c indicating completion * via a callback. * * 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 <linux/cpumask.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/rtnetlink.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/seq_file.h> #include <crypto/scatterwalk.h> #include "internal.h" static const char *skcipher_default_geniv __read_mostly; struct ablkcipher_buffer { struct list_head entry; struct scatter_walk dst; unsigned int len; void *data; }; enum { ABLKCIPHER_WALK_SLOW = 1 << 0, }; static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p) { scatterwalk_copychunks(p->data, &p->dst, p->len, 1); } void __ablkcipher_walk_complete(struct ablkcipher_walk *walk) { struct ablkcipher_buffer *p, *tmp; list_for_each_entry_safe(p, tmp, &walk->buffers, entry) { ablkcipher_buffer_write(p); list_del(&p->entry); kfree(p); } } EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete); static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk, struct ablkcipher_buffer *p) { p->dst = walk->out; list_add_tail(&p->entry, &walk->buffers); } /* Get a spot of the specified length that does not straddle a page. * The caller needs to ensure that there is enough space for this operation. */ static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len) { u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); return max(start, end_page); } static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk, unsigned int bsize) { unsigned int n = bsize; for (;;) { unsigned int len_this_page = scatterwalk_pagelen(&walk->out); if (len_this_page > n) len_this_page = n; scatterwalk_advance(&walk->out, n); if (n == len_this_page) break; n -= len_this_page; scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg)); } return bsize; } static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk, unsigned int n) { scatterwalk_advance(&walk->in, n); scatterwalk_advance(&walk->out, n); return n; } static int ablkcipher_walk_next(struct ablkcipher_request *req, struct ablkcipher_walk *walk); int ablkcipher_walk_done(struct ablkcipher_request *req, struct ablkcipher_walk *walk, int err) { struct crypto_tfm *tfm = req->base.tfm; unsigned int nbytes = 0; if (likely(err >= 0)) { unsigned int n = walk->nbytes - err; if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) n = ablkcipher_done_fast(walk, n); else if (WARN_ON(err)) { err = -EINVAL; goto err; } else n = ablkcipher_done_slow(walk, n); nbytes = walk->total - n; err = 0; } scatterwalk_done(&walk->in, 0, nbytes); scatterwalk_done(&walk->out, 1, nbytes); err: walk->total = nbytes; walk->nbytes = nbytes; if (nbytes) { crypto_yield(req->base.flags); return ablkcipher_walk_next(req, walk); } if (walk->iv != req->info) memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize); kfree(walk->iv_buffer); return err; } EXPORT_SYMBOL_GPL(ablkcipher_walk_done); static inline int ablkcipher_next_slow(struct ablkcipher_request *req, struct ablkcipher_walk *walk, unsigned int bsize, unsigned int alignmask, void **src_p, void **dst_p) { unsigned aligned_bsize = ALIGN(bsize, alignmask + 1); struct ablkcipher_buffer *p; void *src, *dst, *base; unsigned int n; n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1); n += (aligned_bsize * 3 - (alignmask + 1) + (alignmask & ~(crypto_tfm_ctx_alignment() - 1))); p = kmalloc(n, GFP_ATOMIC); if (!p) return ablkcipher_walk_done(req, walk, -ENOMEM); base = p + 1; dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1); src = dst = ablkcipher_get_spot(dst, bsize); p->len = bsize; p->data = dst; scatterwalk_copychunks(src, &walk->in, bsize, 0); ablkcipher_queue_write(walk, p); walk->nbytes = bsize; walk->flags |= ABLKCIPHER_WALK_SLOW; *src_p = src; *dst_p = dst; return 0; } static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk, struct crypto_tfm *tfm, unsigned int alignmask) { unsigned bs = walk->blocksize; unsigned int ivsize = tfm->crt_ablkcipher.ivsize; unsigned aligned_bs = ALIGN(bs, alignmask + 1); unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) - (alignmask + 1); u8 *iv; size += alignmask & ~(crypto_tfm_ctx_alignment() - 1); walk->iv_buffer = kmalloc(size, GFP_ATOMIC); if (!walk->iv_buffer) return -ENOMEM; iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1); iv = ablkcipher_get_spot(iv, bs) + aligned_bs; iv = ablkcipher_get_spot(iv, bs) + aligned_bs; iv = ablkcipher_get_spot(iv, ivsize); walk->iv = memcpy(iv, walk->iv, ivsize); return 0; } static inline int ablkcipher_next_fast(struct ablkcipher_request *req, struct ablkcipher_walk *walk) { walk->src.page = scatterwalk_page(&walk->in); walk->src.offset = offset_in_page(walk->in.offset); walk->dst.page = scatterwalk_page(&walk->out); walk->dst.offset = offset_in_page(walk->out.offset); return 0; } static int ablkcipher_walk_next(struct ablkcipher_request *req, struct ablkcipher_walk *walk) { struct crypto_tfm *tfm = req->base.tfm; unsigned int alignmask, bsize, n; void *src, *dst; int err; alignmask = crypto_tfm_alg_alignmask(tfm); n = walk->total; if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) { req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; return ablkcipher_walk_done(req, walk, -EINVAL); } walk->flags &= ~ABLKCIPHER_WALK_SLOW; src = dst = NULL; bsize = min(walk->blocksize, n); n = scatterwalk_clamp(&walk->in, n); n = scatterwalk_clamp(&walk->out, n); if (n < bsize || !scatterwalk_aligned(&walk->in, alignmask) || !scatterwalk_aligned(&walk->out, alignmask)) { err = ablkcipher_next_slow(req, walk, bsize, alignmask, &src, &dst); goto set_phys_lowmem; } walk->nbytes = n; return ablkcipher_next_fast(req, walk); set_phys_lowmem: if (err >= 0) { walk->src.page = virt_to_page(src); walk->dst.page = virt_to_page(dst); walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1)); walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1)); } return err; } static int ablkcipher_walk_first(struct ablkcipher_request *req, struct ablkcipher_walk *walk) { struct crypto_tfm *tfm = req->base.tfm; unsigned int alignmask; alignmask = crypto_tfm_alg_alignmask(tfm); if (WARN_ON_ONCE(in_irq())) return -EDEADLK; walk->nbytes = walk->total; if (unlikely(!walk->total)) return 0; walk->iv_buffer = NULL; walk->iv = req->info; if (unlikely(((unsigned long)walk->iv & alignmask))) { int err = ablkcipher_copy_iv(walk, tfm, alignmask); if (err) return err; } scatterwalk_start(&walk->in, walk->in.sg); scatterwalk_start(&walk->out, walk->out.sg); return ablkcipher_walk_next(req, walk); } int ablkcipher_walk_phys(struct ablkcipher_request *req, struct ablkcipher_walk *walk) { walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm); return ablkcipher_walk_first(req, walk); } EXPORT_SYMBOL_GPL(ablkcipher_walk_phys); static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key, unsigned int keylen) { struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm); unsigned long alignmask = crypto_ablkcipher_alignmask(tfm); int ret; u8 *buffer, *alignbuffer; unsigned long absize; absize = keylen + alignmask; buffer = kmalloc(absize, GFP_ATOMIC); if (!buffer) return -ENOMEM; alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); memcpy(alignbuffer, key, keylen); ret = cipher->setkey(tfm, alignbuffer, keylen); memset(alignbuffer, 0, keylen); kfree(buffer); return ret; } static int setkey(struct crypto_ablkcipher *tfm, const u8 *key, unsigned int keylen) { struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm); unsigned long alignmask = crypto_ablkcipher_alignmask(tfm); if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); return -EINVAL; } if ((unsigned long)key & alignmask) return setkey_unaligned(tfm, key, keylen); return cipher->setkey(tfm, key, keylen); } static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type, u32 mask) { return alg->cra_ctxsize; } int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req) { return crypto_ablkcipher_encrypt(&req->creq); } int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req) { return crypto_ablkcipher_decrypt(&req->creq); } static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask) { struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher; if (alg->ivsize > PAGE_SIZE / 8) return -EINVAL; crt->setkey = setkey; crt->encrypt = alg->encrypt; crt->decrypt = alg->decrypt; if (!alg->ivsize) { crt->givencrypt = skcipher_null_givencrypt; crt->givdecrypt = skcipher_null_givdecrypt; } crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; } static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg) __attribute__ ((unused)); static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg) { struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher; seq_printf(m, "type : ablkcipher\n"); seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize); seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize); seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize); seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>"); } const struct crypto_type crypto_ablkcipher_type = { .ctxsize = crypto_ablkcipher_ctxsize, .init = crypto_init_ablkcipher_ops, #ifdef CONFIG_PROC_FS .show = crypto_ablkcipher_show, #endif }; EXPORT_SYMBOL_GPL(crypto_ablkcipher_type); static int no_givdecrypt(struct skcipher_givcrypt_request *req) { return -ENOSYS; } static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask) { struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher; struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher; if (alg->ivsize > PAGE_SIZE / 8) return -EINVAL; crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ? alg->setkey : setkey; crt->encrypt = alg->encrypt; crt->decrypt = alg->decrypt; crt->givencrypt = alg->givencrypt; crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt; crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; } static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg) __attribute__ ((unused)); static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg) { struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher; seq_printf(m, "type : givcipher\n"); seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? "yes" : "no"); seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize); seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize); seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize); seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>"); } const struct crypto_type crypto_givcipher_type = { .ctxsize = crypto_ablkcipher_ctxsize, .init = crypto_init_givcipher_ops, #ifdef CONFIG_PROC_FS .show = crypto_givcipher_show, #endif }; EXPORT_SYMBOL_GPL(crypto_givcipher_type); const char *crypto_default_geniv(const struct crypto_alg *alg) { if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize : alg->cra_ablkcipher.ivsize) != alg->cra_blocksize) return "chainiv"; return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : skcipher_default_geniv; } static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask) { struct rtattr *tb[3]; struct { struct rtattr attr; struct crypto_attr_type data; } ptype; struct { struct rtattr attr; struct crypto_attr_alg data; } palg; struct crypto_template *tmpl; struct crypto_instance *inst; struct crypto_alg *larval; const char *geniv; int err; larval = crypto_larval_lookup(alg->cra_driver_name, (type & ~CRYPTO_ALG_TYPE_MASK) | CRYPTO_ALG_TYPE_GIVCIPHER, mask | CRYPTO_ALG_TYPE_MASK); err = PTR_ERR(larval); if (IS_ERR(larval)) goto out; err = -EAGAIN; if (!crypto_is_larval(larval)) goto drop_larval; ptype.attr.rta_len = sizeof(ptype); ptype.attr.rta_type = CRYPTOA_TYPE; ptype.data.type = type | CRYPTO_ALG_GENIV; /* GENIV tells the template that we're making a default geniv. */ ptype.data.mask = mask | CRYPTO_ALG_GENIV; tb[0] = &ptype.attr; palg.attr.rta_len = sizeof(palg); palg.attr.rta_type = CRYPTOA_ALG; /* Must use the exact name to locate ourselves. */ memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME); tb[1] = &palg.attr; tb[2] = NULL; if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_BLKCIPHER) geniv = alg->cra_blkcipher.geniv; else geniv = alg->cra_ablkcipher.geniv; if (!geniv) geniv = crypto_default_geniv(alg); tmpl = crypto_lookup_template(geniv); err = -ENOENT; if (!tmpl) goto kill_larval; inst = tmpl->alloc(tb); err = PTR_ERR(inst); if (IS_ERR(inst)) goto put_tmpl; if ((err = crypto_register_instance(tmpl, inst))) { tmpl->free(inst); goto put_tmpl; } /* Redo the lookup to use the instance we just registered. */ err = -EAGAIN; put_tmpl: crypto_tmpl_put(tmpl); kill_larval: crypto_larval_kill(larval); drop_larval: crypto_mod_put(larval); out: crypto_mod_put(alg); return err; } static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask) { struct crypto_alg *alg; alg = crypto_alg_mod_lookup(name, type, mask); if (IS_ERR(alg)) return alg; if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_GIVCIPHER) return alg; if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize : alg->cra_ablkcipher.ivsize)) return alg; crypto_mod_put(alg); alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED, mask & ~CRYPTO_ALG_TESTED); if (IS_ERR(alg)) return alg; if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_GIVCIPHER) { if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) { crypto_mod_put(alg); alg = ERR_PTR(-ENOENT); } return alg; } BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize : alg->cra_ablkcipher.ivsize)); return ERR_PTR(crypto_givcipher_default(alg, type, mask)); } int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name, u32 type, u32 mask) { struct crypto_alg *alg; int err; type = crypto_skcipher_type(type); mask = crypto_skcipher_mask(mask); alg = crypto_lookup_skcipher(name, type, mask); if (IS_ERR(alg)) return PTR_ERR(alg); err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask); crypto_mod_put(alg); return err; } EXPORT_SYMBOL_GPL(crypto_grab_skcipher); struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name, u32 type, u32 mask) { struct crypto_tfm *tfm; int err; type = crypto_skcipher_type(type); mask = crypto_skcipher_mask(mask); for (;;) { struct crypto_alg *alg; alg = crypto_lookup_skcipher(alg_name, type, mask); if (IS_ERR(alg)) { err = PTR_ERR(alg); goto err; } tfm = __crypto_alloc_tfm(alg, type, mask); if (!IS_ERR(tfm)) return __crypto_ablkcipher_cast(tfm); crypto_mod_put(alg); err = PTR_ERR(tfm); err: if (err != -EAGAIN) break; if (signal_pending(current)) { err = -EINTR; break; } } return ERR_PTR(err); } EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher); static int __init skcipher_module_init(void) { skcipher_default_geniv = num_possible_cpus() > 1 ? "eseqiv" : "chainiv"; return 0; } static void skcipher_module_exit(void) { } module_init(skcipher_module_init); module_exit(skcipher_module_exit);