| /* |
| * Block chaining cipher operations. |
| * |
| * Generic encrypt/decrypt wrapper for ciphers, handles operations across |
| * multiple page boundaries by using temporary blocks. In user context, |
| * the kernel is given a chance to schedule us once per page. |
| * |
| * 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 <linux/crypto.h> |
| #include <linux/errno.h> |
| #include <linux/hardirq.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/scatterlist.h> |
| #include <linux/seq_file.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| |
| #include "internal.h" |
| #include "scatterwalk.h" |
| |
| enum { |
| BLKCIPHER_WALK_PHYS = 1 << 0, |
| BLKCIPHER_WALK_SLOW = 1 << 1, |
| BLKCIPHER_WALK_COPY = 1 << 2, |
| BLKCIPHER_WALK_DIFF = 1 << 3, |
| }; |
| |
| static int blkcipher_walk_next(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk); |
| static int blkcipher_walk_first(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk); |
| |
| static inline void blkcipher_map_src(struct blkcipher_walk *walk) |
| { |
| walk->src.virt.addr = scatterwalk_map(&walk->in, 0); |
| } |
| |
| static inline void blkcipher_map_dst(struct blkcipher_walk *walk) |
| { |
| walk->dst.virt.addr = scatterwalk_map(&walk->out, 1); |
| } |
| |
| static inline void blkcipher_unmap_src(struct blkcipher_walk *walk) |
| { |
| scatterwalk_unmap(walk->src.virt.addr, 0); |
| } |
| |
| static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk) |
| { |
| scatterwalk_unmap(walk->dst.virt.addr, 1); |
| } |
| |
| /* 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 *blkcipher_get_spot(u8 *start, unsigned int len) |
| { |
| u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); |
| return start > end_page ? start : end_page; |
| } |
| |
| static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm, |
| struct blkcipher_walk *walk, |
| unsigned int bsize) |
| { |
| u8 *addr; |
| unsigned int alignmask = crypto_blkcipher_alignmask(tfm); |
| |
| addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1); |
| addr = blkcipher_get_spot(addr, bsize); |
| scatterwalk_copychunks(addr, &walk->out, bsize, 1); |
| return bsize; |
| } |
| |
| static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk, |
| unsigned int n) |
| { |
| n = walk->nbytes - n; |
| |
| if (walk->flags & BLKCIPHER_WALK_COPY) { |
| blkcipher_map_dst(walk); |
| memcpy(walk->dst.virt.addr, walk->page, n); |
| blkcipher_unmap_dst(walk); |
| } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) { |
| blkcipher_unmap_src(walk); |
| if (walk->flags & BLKCIPHER_WALK_DIFF) |
| blkcipher_unmap_dst(walk); |
| } |
| |
| scatterwalk_advance(&walk->in, n); |
| scatterwalk_advance(&walk->out, n); |
| |
| return n; |
| } |
| |
| int blkcipher_walk_done(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk, int err) |
| { |
| struct crypto_blkcipher *tfm = desc->tfm; |
| unsigned int nbytes = 0; |
| |
| if (likely(err >= 0)) { |
| unsigned int bsize = crypto_blkcipher_blocksize(tfm); |
| unsigned int n; |
| |
| if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW))) |
| n = blkcipher_done_fast(walk, err); |
| else |
| n = blkcipher_done_slow(tfm, walk, bsize); |
| |
| nbytes = walk->total - n; |
| err = 0; |
| } |
| |
| scatterwalk_done(&walk->in, 0, nbytes); |
| scatterwalk_done(&walk->out, 1, nbytes); |
| |
| walk->total = nbytes; |
| walk->nbytes = nbytes; |
| |
| if (nbytes) { |
| crypto_yield(desc->flags); |
| return blkcipher_walk_next(desc, walk); |
| } |
| |
| if (walk->iv != desc->info) |
| memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm)); |
| if (walk->buffer != walk->page) |
| kfree(walk->buffer); |
| if (walk->page) |
| free_page((unsigned long)walk->page); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(blkcipher_walk_done); |
| |
| static inline int blkcipher_next_slow(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk, |
| unsigned int bsize, |
| unsigned int alignmask) |
| { |
| unsigned int n; |
| |
| if (walk->buffer) |
| goto ok; |
| |
| walk->buffer = walk->page; |
| if (walk->buffer) |
| goto ok; |
| |
| n = bsize * 3 - (alignmask + 1) + |
| (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); |
| walk->buffer = kmalloc(n, GFP_ATOMIC); |
| if (!walk->buffer) |
| return blkcipher_walk_done(desc, walk, -ENOMEM); |
| |
| ok: |
| walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer, |
| alignmask + 1); |
| walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize); |
| walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize, |
| bsize); |
| |
| scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); |
| |
| walk->nbytes = bsize; |
| walk->flags |= BLKCIPHER_WALK_SLOW; |
| |
| return 0; |
| } |
| |
| static inline int blkcipher_next_copy(struct blkcipher_walk *walk) |
| { |
| u8 *tmp = walk->page; |
| |
| blkcipher_map_src(walk); |
| memcpy(tmp, walk->src.virt.addr, walk->nbytes); |
| blkcipher_unmap_src(walk); |
| |
| walk->src.virt.addr = tmp; |
| walk->dst.virt.addr = tmp; |
| |
| return 0; |
| } |
| |
| static inline int blkcipher_next_fast(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk) |
| { |
| unsigned long diff; |
| |
| walk->src.phys.page = scatterwalk_page(&walk->in); |
| walk->src.phys.offset = offset_in_page(walk->in.offset); |
| walk->dst.phys.page = scatterwalk_page(&walk->out); |
| walk->dst.phys.offset = offset_in_page(walk->out.offset); |
| |
| if (walk->flags & BLKCIPHER_WALK_PHYS) |
| return 0; |
| |
| diff = walk->src.phys.offset - walk->dst.phys.offset; |
| diff |= walk->src.virt.page - walk->dst.virt.page; |
| |
| blkcipher_map_src(walk); |
| walk->dst.virt.addr = walk->src.virt.addr; |
| |
| if (diff) { |
| walk->flags |= BLKCIPHER_WALK_DIFF; |
| blkcipher_map_dst(walk); |
| } |
| |
| return 0; |
| } |
| |
| static int blkcipher_walk_next(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk) |
| { |
| struct crypto_blkcipher *tfm = desc->tfm; |
| unsigned int alignmask = crypto_blkcipher_alignmask(tfm); |
| unsigned int bsize = crypto_blkcipher_blocksize(tfm); |
| unsigned int n; |
| int err; |
| |
| n = walk->total; |
| if (unlikely(n < bsize)) { |
| desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; |
| return blkcipher_walk_done(desc, walk, -EINVAL); |
| } |
| |
| walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY | |
| BLKCIPHER_WALK_DIFF); |
| if (!scatterwalk_aligned(&walk->in, alignmask) || |
| !scatterwalk_aligned(&walk->out, alignmask)) { |
| walk->flags |= BLKCIPHER_WALK_COPY; |
| if (!walk->page) { |
| walk->page = (void *)__get_free_page(GFP_ATOMIC); |
| if (!walk->page) |
| n = 0; |
| } |
| } |
| |
| n = scatterwalk_clamp(&walk->in, n); |
| n = scatterwalk_clamp(&walk->out, n); |
| |
| if (unlikely(n < bsize)) { |
| err = blkcipher_next_slow(desc, walk, bsize, alignmask); |
| goto set_phys_lowmem; |
| } |
| |
| walk->nbytes = n; |
| if (walk->flags & BLKCIPHER_WALK_COPY) { |
| err = blkcipher_next_copy(walk); |
| goto set_phys_lowmem; |
| } |
| |
| return blkcipher_next_fast(desc, walk); |
| |
| set_phys_lowmem: |
| if (walk->flags & BLKCIPHER_WALK_PHYS) { |
| walk->src.phys.page = virt_to_page(walk->src.virt.addr); |
| walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); |
| walk->src.phys.offset &= PAGE_SIZE - 1; |
| walk->dst.phys.offset &= PAGE_SIZE - 1; |
| } |
| return err; |
| } |
| |
| static inline int blkcipher_copy_iv(struct blkcipher_walk *walk, |
| struct crypto_blkcipher *tfm, |
| unsigned int alignmask) |
| { |
| unsigned bs = crypto_blkcipher_blocksize(tfm); |
| unsigned int ivsize = crypto_blkcipher_ivsize(tfm); |
| unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1); |
| u8 *iv; |
| |
| size += alignmask & ~(crypto_tfm_ctx_alignment() - 1); |
| walk->buffer = kmalloc(size, GFP_ATOMIC); |
| if (!walk->buffer) |
| return -ENOMEM; |
| |
| iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1); |
| iv = blkcipher_get_spot(iv, bs) + bs; |
| iv = blkcipher_get_spot(iv, bs) + bs; |
| iv = blkcipher_get_spot(iv, ivsize); |
| |
| walk->iv = memcpy(iv, walk->iv, ivsize); |
| return 0; |
| } |
| |
| int blkcipher_walk_virt(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk) |
| { |
| walk->flags &= ~BLKCIPHER_WALK_PHYS; |
| return blkcipher_walk_first(desc, walk); |
| } |
| EXPORT_SYMBOL_GPL(blkcipher_walk_virt); |
| |
| int blkcipher_walk_phys(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk) |
| { |
| walk->flags |= BLKCIPHER_WALK_PHYS; |
| return blkcipher_walk_first(desc, walk); |
| } |
| EXPORT_SYMBOL_GPL(blkcipher_walk_phys); |
| |
| static int blkcipher_walk_first(struct blkcipher_desc *desc, |
| struct blkcipher_walk *walk) |
| { |
| struct crypto_blkcipher *tfm = desc->tfm; |
| unsigned int alignmask = crypto_blkcipher_alignmask(tfm); |
| |
| if (WARN_ON_ONCE(in_irq())) |
| return -EDEADLK; |
| |
| walk->nbytes = walk->total; |
| if (unlikely(!walk->total)) |
| return 0; |
| |
| walk->buffer = NULL; |
| walk->iv = desc->info; |
| if (unlikely(((unsigned long)walk->iv & alignmask))) { |
| int err = blkcipher_copy_iv(walk, tfm, alignmask); |
| if (err) |
| return err; |
| } |
| |
| scatterwalk_start(&walk->in, walk->in.sg); |
| scatterwalk_start(&walk->out, walk->out.sg); |
| walk->page = NULL; |
| |
| return blkcipher_walk_next(desc, walk); |
| } |
| |
| static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, |
| unsigned int keylen) |
| { |
| struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; |
| unsigned long alignmask = crypto_tfm_alg_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_tfm *tfm, const u8 *key, unsigned int keylen) |
| { |
| struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; |
| unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); |
| |
| if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { |
| tfm->crt_flags |= 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 int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key, |
| unsigned int keylen) |
| { |
| return setkey(crypto_ablkcipher_tfm(tfm), key, keylen); |
| } |
| |
| static int async_encrypt(struct ablkcipher_request *req) |
| { |
| struct crypto_tfm *tfm = req->base.tfm; |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| struct blkcipher_desc desc = { |
| .tfm = __crypto_blkcipher_cast(tfm), |
| .info = req->info, |
| .flags = req->base.flags, |
| }; |
| |
| |
| return alg->encrypt(&desc, req->dst, req->src, req->nbytes); |
| } |
| |
| static int async_decrypt(struct ablkcipher_request *req) |
| { |
| struct crypto_tfm *tfm = req->base.tfm; |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| struct blkcipher_desc desc = { |
| .tfm = __crypto_blkcipher_cast(tfm), |
| .info = req->info, |
| .flags = req->base.flags, |
| }; |
| |
| return alg->decrypt(&desc, req->dst, req->src, req->nbytes); |
| } |
| |
| static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type, |
| u32 mask) |
| { |
| struct blkcipher_alg *cipher = &alg->cra_blkcipher; |
| unsigned int len = alg->cra_ctxsize; |
| |
| type ^= CRYPTO_ALG_ASYNC; |
| mask &= CRYPTO_ALG_ASYNC; |
| if ((type & mask) && cipher->ivsize) { |
| len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1); |
| len += cipher->ivsize; |
| } |
| |
| return len; |
| } |
| |
| static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm) |
| { |
| struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher; |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| |
| crt->setkey = async_setkey; |
| crt->encrypt = async_encrypt; |
| crt->decrypt = async_decrypt; |
| crt->ivsize = alg->ivsize; |
| |
| return 0; |
| } |
| |
| static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm) |
| { |
| struct blkcipher_tfm *crt = &tfm->crt_blkcipher; |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1; |
| unsigned long addr; |
| |
| crt->setkey = setkey; |
| crt->encrypt = alg->encrypt; |
| crt->decrypt = alg->decrypt; |
| |
| addr = (unsigned long)crypto_tfm_ctx(tfm); |
| addr = ALIGN(addr, align); |
| addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align); |
| crt->iv = (void *)addr; |
| |
| return 0; |
| } |
| |
| static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask) |
| { |
| struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; |
| |
| if (alg->ivsize > PAGE_SIZE / 8) |
| return -EINVAL; |
| |
| type ^= CRYPTO_ALG_ASYNC; |
| mask &= CRYPTO_ALG_ASYNC; |
| if (type & mask) |
| return crypto_init_blkcipher_ops_sync(tfm); |
| else |
| return crypto_init_blkcipher_ops_async(tfm); |
| } |
| |
| static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg) |
| __attribute__ ((unused)); |
| static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg) |
| { |
| seq_printf(m, "type : blkcipher\n"); |
| seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); |
| seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize); |
| seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize); |
| seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize); |
| } |
| |
| const struct crypto_type crypto_blkcipher_type = { |
| .ctxsize = crypto_blkcipher_ctxsize, |
| .init = crypto_init_blkcipher_ops, |
| #ifdef CONFIG_PROC_FS |
| .show = crypto_blkcipher_show, |
| #endif |
| }; |
| EXPORT_SYMBOL_GPL(crypto_blkcipher_type); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Generic block chaining cipher type"); |