// SPDX-License-Identifier: GPL-2.0-or-later /* * 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> */ #include <crypto/internal/skcipher.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/seq_file.h> #include <linux/cryptouser.h> #include <linux/compiler.h> #include <net/netlink.h> #include <crypto/scatterwalk.h> #include "internal.h" 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 void ablkcipher_done_slow(struct ablkcipher_walk *walk, unsigned int n) { 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, sg_next(walk->out.sg)); } } static inline void ablkcipher_done_fast(struct ablkcipher_walk *walk, unsigned int n) { scatterwalk_advance(&walk->in, n); scatterwalk_advance(&walk->out, 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 n; /* bytes processed */ bool more; if (unlikely(err < 0)) goto finish; n = walk->nbytes - err; walk->total -= n; more = (walk->total != 0); if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) { ablkcipher_done_fast(walk, n); } else { if (WARN_ON(err)) { /* unexpected case; didn't process all bytes */ err = -EINVAL; goto finish; } ablkcipher_done_slow(walk, n); } scatterwalk_done(&walk->in, 0, more); scatterwalk_done(&walk->out, 1, more); if (more) { crypto_yield(req->base.flags); return ablkcipher_walk_next(req, walk); } err = 0; finish: walk->nbytes = 0; 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->iv = req->info; walk->nbytes = walk->total; if (unlikely(!walk->total)) return 0; walk->iv_buffer = NULL; 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; } 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; crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; } #ifdef CONFIG_NET static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_blkcipher rblkcipher; memset(&rblkcipher, 0, sizeof(rblkcipher)); strscpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type)); strscpy(rblkcipher.geniv, "<default>", sizeof(rblkcipher.geniv)); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize; rblkcipher.ivsize = alg->cra_ablkcipher.ivsize; return nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, sizeof(rblkcipher), &rblkcipher); } #else static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) { return -ENOSYS; } #endif static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg) __maybe_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 : <default>\n"); } 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 .report = crypto_ablkcipher_report, }; EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);