diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/Kconfig | 4 | ||||
| -rw-r--r-- | crypto/Makefile | 2 | ||||
| -rw-r--r-- | crypto/blkcipher.c | 405 |
3 files changed, 411 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 4ce509dba32..68790ad7308 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -16,6 +16,10 @@ config CRYPTO_ALGAPI help This option provides the API for cryptographic algorithms. +config CRYPTO_BLKCIPHER + tristate + select CRYPTO_ALGAPI + config CRYPTO_MANAGER tristate "Cryptographic algorithm manager" select CRYPTO_ALGAPI diff --git a/crypto/Makefile b/crypto/Makefile index b8745f3d359..b5051951c63 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -8,6 +8,8 @@ crypto_algapi-$(CONFIG_PROC_FS) += proc.o crypto_algapi-objs := algapi.o $(crypto_algapi-y) obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o +obj-$(CONFIG_CRYPTO_BLKCIPHER) += blkcipher.o + obj-$(CONFIG_CRYPTO_MANAGER) += cryptomgr.o obj-$(CONFIG_CRYPTO_HMAC) += hmac.o obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c new file mode 100644 index 00000000000..034c939bf91 --- /dev/null +++ b/crypto/blkcipher.c @@ -0,0 +1,405 @@ +/* + * 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/kernel.h> +#include <linux/io.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); +} + +static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len) +{ + if (offset_in_page(start + len) < len) + return (u8 *)((unsigned long)(start + len) & PAGE_MASK); + return start; +} + +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 * 2 + (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); + + 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(struct crypto_tfm *tfm, const u8 *key, + unsigned int keylen) +{ + struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; + + if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + return cipher->setkey(tfm, key, keylen); +} + +static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg) +{ + struct blkcipher_alg *cipher = &alg->cra_blkcipher; + unsigned int len = alg->cra_ctxsize; + + if (cipher->ivsize) { + len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1); + len += cipher->ivsize; + } + + return len; +} + +static int crypto_init_blkcipher_ops(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; + + if (alg->ivsize > PAGE_SIZE / 8) + return -EINVAL; + + 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 void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg) + __attribute_used__; +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"); |