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authorHerbert Xu <herbert@gondor.apana.org.au>2006-08-22 00:07:53 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2006-09-21 11:41:52 +1000
commit5cde0af2a9825dd1edaca233bd9590566579ef21 (patch)
treee396297e3a2436d4a6ac77de63f95f2328c7a0fe /crypto
parent5c64097aa0f6dc4f27718ef47ca9a12538d62860 (diff)
downloadlinux-linaro-stable-5cde0af2a9825dd1edaca233bd9590566579ef21.tar.gz
[CRYPTO] cipher: Added block cipher type
This patch adds the new type of block ciphers. Unlike current cipher algorithms which operate on a single block at a time, block ciphers operate on an arbitrarily long linear area of data. As it is block-based, it will skip any data remaining at the end which cannot form a block. The block cipher has one major difference when compared to the existing block cipher implementation. The sg walking is now performed by the algorithm rather than the cipher mid-layer. This is needed for drivers that directly support sg lists. It also improves performance for all algorithms as it reduces the total number of indirect calls by one. In future the existing cipher algorithm will be converted to only have a single-block interface. This will be done after all existing users have switched over to the new block cipher type. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/Kconfig4
-rw-r--r--crypto/Makefile2
-rw-r--r--crypto/blkcipher.c405
3 files changed, 411 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 4ce509dba329..68790ad7308d 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 b8745f3d3595..b5051951c636 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 000000000000..034c939bf91a
--- /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");