diff options
| -rw-r--r-- | crypto/Kconfig | 9 | ||||
| -rw-r--r-- | crypto/Makefile | 1 | ||||
| -rw-r--r-- | crypto/pcbc.c | 348 |
3 files changed, 358 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 92ba249..9d3a44c 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -168,6 +168,15 @@ config CRYPTO_CBC CBC: Cipher Block Chaining mode This block cipher algorithm is required for IPSec. +config CRYPTO_PCBC + tristate "PCBC support" + select CRYPTO_BLKCIPHER + select CRYPTO_MANAGER + default m + help + PCBC: Propagating Cipher Block Chaining mode + This block cipher algorithm is required for RxRPC. + config CRYPTO_LRW tristate "LRW support (EXPERIMENTAL)" depends on EXPERIMENTAL diff --git a/crypto/Makefile b/crypto/Makefile index 60e3d24f..9ef048d 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_CRYPTO_TGR192) += tgr192.o obj-$(CONFIG_CRYPTO_GF128MUL) += gf128mul.o obj-$(CONFIG_CRYPTO_ECB) += ecb.o obj-$(CONFIG_CRYPTO_CBC) += cbc.o +obj-$(CONFIG_CRYPTO_PCBC) += pcbc.o obj-$(CONFIG_CRYPTO_LRW) += lrw.o obj-$(CONFIG_CRYPTO_DES) += des.o obj-$(CONFIG_CRYPTO_BLOWFISH) += blowfish.o diff --git a/crypto/pcbc.c b/crypto/pcbc.c new file mode 100644 index 0000000..0ffb46e --- /dev/null +++ b/crypto/pcbc.c @@ -0,0 +1,348 @@ +/* + * PCBC: Propagating Cipher Block Chaining mode + * + * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * Derived from cbc.c + * - 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/algapi.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> + +struct crypto_pcbc_ctx { + struct crypto_cipher *child; + void (*xor)(u8 *dst, const u8 *src, unsigned int bs); +}; + +static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key, + unsigned int keylen) +{ + struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(parent); + struct crypto_cipher *child = ctx->child; + int err; + + crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); + crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) & + CRYPTO_TFM_REQ_MASK); + err = crypto_cipher_setkey(child, key, keylen); + crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) & + CRYPTO_TFM_RES_MASK); + return err; +} + +static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc, + struct blkcipher_walk *walk, + struct crypto_cipher *tfm, + void (*xor)(u8 *, const u8 *, + unsigned int)) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_encrypt; + int bsize = crypto_cipher_blocksize(tfm); + unsigned int nbytes = walk->nbytes; + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + u8 *iv = walk->iv; + + do { + xor(iv, src, bsize); + fn(crypto_cipher_tfm(tfm), dst, iv); + memcpy(iv, dst, bsize); + xor(iv, src, bsize); + + src += bsize; + dst += bsize; + } while ((nbytes -= bsize) >= bsize); + + return nbytes; +} + +static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc, + struct blkcipher_walk *walk, + struct crypto_cipher *tfm, + void (*xor)(u8 *, const u8 *, + unsigned int)) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_encrypt; + int bsize = crypto_cipher_blocksize(tfm); + unsigned int nbytes = walk->nbytes; + u8 *src = walk->src.virt.addr; + u8 *iv = walk->iv; + u8 tmpbuf[bsize]; + + do { + memcpy(tmpbuf, src, bsize); + xor(iv, tmpbuf, bsize); + fn(crypto_cipher_tfm(tfm), src, iv); + memcpy(iv, src, bsize); + xor(iv, tmpbuf, bsize); + + src += bsize; + } while ((nbytes -= bsize) >= bsize); + + memcpy(walk->iv, iv, bsize); + + return nbytes; +} + +static int crypto_pcbc_encrypt(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + struct blkcipher_walk walk; + struct crypto_blkcipher *tfm = desc->tfm; + struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm); + struct crypto_cipher *child = ctx->child; + void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor; + int err; + + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + if (walk.src.virt.addr == walk.dst.virt.addr) + nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child, + xor); + else + nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child, + xor); + err = blkcipher_walk_done(desc, &walk, nbytes); + } + + return err; +} + +static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc, + struct blkcipher_walk *walk, + struct crypto_cipher *tfm, + void (*xor)(u8 *, const u8 *, + unsigned int)) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_decrypt; + int bsize = crypto_cipher_blocksize(tfm); + unsigned int nbytes = walk->nbytes; + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + u8 *iv = walk->iv; + + do { + fn(crypto_cipher_tfm(tfm), dst, src); + xor(dst, iv, bsize); + memcpy(iv, src, bsize); + xor(iv, dst, bsize); + + src += bsize; + dst += bsize; + } while ((nbytes -= bsize) >= bsize); + + memcpy(walk->iv, iv, bsize); + + return nbytes; +} + +static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc, + struct blkcipher_walk *walk, + struct crypto_cipher *tfm, + void (*xor)(u8 *, const u8 *, + unsigned int)) +{ + void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = + crypto_cipher_alg(tfm)->cia_decrypt; + int bsize = crypto_cipher_blocksize(tfm); + unsigned int nbytes = walk->nbytes; + u8 *src = walk->src.virt.addr; + u8 *iv = walk->iv; + u8 tmpbuf[bsize]; + + do { + memcpy(tmpbuf, src, bsize); + fn(crypto_cipher_tfm(tfm), src, src); + xor(src, iv, bsize); + memcpy(iv, tmpbuf, bsize); + xor(iv, src, bsize); + + src += bsize; + } while ((nbytes -= bsize) >= bsize); + + memcpy(walk->iv, iv, bsize); + + return nbytes; +} + +static int crypto_pcbc_decrypt(struct blkcipher_desc *desc, + struct scatterlist *dst, struct scatterlist *src, + unsigned int nbytes) +{ + struct blkcipher_walk walk; + struct crypto_blkcipher *tfm = desc->tfm; + struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm); + struct crypto_cipher *child = ctx->child; + void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor; + int err; + + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + if (walk.src.virt.addr == walk.dst.virt.addr) + nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child, + xor); + else + nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child, + xor); + err = blkcipher_walk_done(desc, &walk, nbytes); + } + + return err; +} + +static void xor_byte(u8 *a, const u8 *b, unsigned int bs) +{ + do { + *a++ ^= *b++; + } while (--bs); +} + +static void xor_quad(u8 *dst, const u8 *src, unsigned int bs) +{ + u32 *a = (u32 *)dst; + u32 *b = (u32 *)src; + + do { + *a++ ^= *b++; + } while ((bs -= 4)); +} + +static void xor_64(u8 *a, const u8 *b, unsigned int bs) +{ + ((u32 *)a)[0] ^= ((u32 *)b)[0]; + ((u32 *)a)[1] ^= ((u32 *)b)[1]; +} + +static void xor_128(u8 *a, const u8 *b, unsigned int bs) +{ + ((u32 *)a)[0] ^= ((u32 *)b)[0]; + ((u32 *)a)[1] ^= ((u32 *)b)[1]; + ((u32 *)a)[2] ^= ((u32 *)b)[2]; + ((u32 *)a)[3] ^= ((u32 *)b)[3]; +} + +static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_spawn *spawn = crypto_instance_ctx(inst); + struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm); + + switch (crypto_tfm_alg_blocksize(tfm)) { + case 8: + ctx->xor = xor_64; + break; + + case 16: + ctx->xor = xor_128; + break; + + default: + if (crypto_tfm_alg_blocksize(tfm) % 4) + ctx->xor = xor_byte; + else + ctx->xor = xor_quad; + } + + tfm = crypto_spawn_tfm(spawn); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + ctx->child = crypto_cipher_cast(tfm); + return 0; +} + +static void crypto_pcbc_exit_tfm(struct crypto_tfm *tfm) +{ + struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm); + crypto_free_cipher(ctx->child); +} + +static struct crypto_instance *crypto_pcbc_alloc(void *param, unsigned int len) +{ + struct crypto_instance *inst; + struct crypto_alg *alg; + + alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER, + CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC); + if (IS_ERR(alg)) + return ERR_PTR(PTR_ERR(alg)); + + inst = crypto_alloc_instance("pcbc", alg); + if (IS_ERR(inst)) + goto out_put_alg; + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = alg->cra_blocksize; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_blkcipher_type; + + if (!(alg->cra_blocksize % 4)) + inst->alg.cra_alignmask |= 3; + inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize; + inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize; + inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize; + + inst->alg.cra_ctxsize = sizeof(struct crypto_pcbc_ctx); + + inst->alg.cra_init = crypto_pcbc_init_tfm; + inst->alg.cra_exit = crypto_pcbc_exit_tfm; + + inst->alg.cra_blkcipher.setkey = crypto_pcbc_setkey; + inst->alg.cra_blkcipher.encrypt = crypto_pcbc_encrypt; + inst->alg.cra_blkcipher.decrypt = crypto_pcbc_decrypt; + +out_put_alg: + crypto_mod_put(alg); + return inst; +} + +static void crypto_pcbc_free(struct crypto_instance *inst) +{ + crypto_drop_spawn(crypto_instance_ctx(inst)); + kfree(inst); +} + +static struct crypto_template crypto_pcbc_tmpl = { + .name = "pcbc", + .alloc = crypto_pcbc_alloc, + .free = crypto_pcbc_free, + .module = THIS_MODULE, +}; + +static int __init crypto_pcbc_module_init(void) +{ + return crypto_register_template(&crypto_pcbc_tmpl); +} + +static void __exit crypto_pcbc_module_exit(void) +{ + crypto_unregister_template(&crypto_pcbc_tmpl); +} + +module_init(crypto_pcbc_module_init); +module_exit(crypto_pcbc_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("PCBC block cipher algorithm"); |
