123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116 |
- /*
- * Glue code for optimized assembly version of Salsa20.
- *
- * Copyright (c) 2007 Tan Swee Heng <thesweeheng@gmail.com>
- *
- * The assembly codes are public domain assembly codes written by Daniel. J.
- * Bernstein <djb@cr.yp.to>. The codes are modified to include indentation
- * and to remove extraneous comments and functions that are not needed.
- * - i586 version, renamed as salsa20-i586-asm_32.S
- * available from <http://cr.yp.to/snuffle/salsa20/x86-pm/salsa20.s>
- * - x86-64 version, renamed as salsa20-x86_64-asm_64.S
- * available from <http://cr.yp.to/snuffle/salsa20/amd64-3/salsa20.s>
- *
- * 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/module.h>
- #include <linux/crypto.h>
- #define SALSA20_IV_SIZE 8U
- #define SALSA20_MIN_KEY_SIZE 16U
- #define SALSA20_MAX_KEY_SIZE 32U
- struct salsa20_ctx
- {
- u32 input[16];
- };
- asmlinkage void salsa20_keysetup(struct salsa20_ctx *ctx, const u8 *k,
- u32 keysize, u32 ivsize);
- asmlinkage void salsa20_ivsetup(struct salsa20_ctx *ctx, const u8 *iv);
- asmlinkage void salsa20_encrypt_bytes(struct salsa20_ctx *ctx,
- const u8 *src, u8 *dst, u32 bytes);
- static int setkey(struct crypto_tfm *tfm, const u8 *key,
- unsigned int keysize)
- {
- struct salsa20_ctx *ctx = crypto_tfm_ctx(tfm);
- salsa20_keysetup(ctx, key, keysize*8, SALSA20_IV_SIZE*8);
- return 0;
- }
- static int 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 salsa20_ctx *ctx = crypto_blkcipher_ctx(tfm);
- int err;
- blkcipher_walk_init(&walk, dst, src, nbytes);
- err = blkcipher_walk_virt_block(desc, &walk, 64);
- salsa20_ivsetup(ctx, walk.iv);
- while (walk.nbytes >= 64) {
- salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
- walk.dst.virt.addr,
- walk.nbytes - (walk.nbytes % 64));
- err = blkcipher_walk_done(desc, &walk, walk.nbytes % 64);
- }
- if (walk.nbytes) {
- salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
- walk.dst.virt.addr, walk.nbytes);
- err = blkcipher_walk_done(desc, &walk, 0);
- }
- return err;
- }
- static struct crypto_alg alg = {
- .cra_name = "salsa20",
- .cra_driver_name = "salsa20-asm",
- .cra_priority = 200,
- .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
- .cra_type = &crypto_blkcipher_type,
- .cra_blocksize = 1,
- .cra_ctxsize = sizeof(struct salsa20_ctx),
- .cra_alignmask = 3,
- .cra_module = THIS_MODULE,
- .cra_u = {
- .blkcipher = {
- .setkey = setkey,
- .encrypt = encrypt,
- .decrypt = encrypt,
- .min_keysize = SALSA20_MIN_KEY_SIZE,
- .max_keysize = SALSA20_MAX_KEY_SIZE,
- .ivsize = SALSA20_IV_SIZE,
- }
- }
- };
- static int __init init(void)
- {
- return crypto_register_alg(&alg);
- }
- static void __exit fini(void)
- {
- crypto_unregister_alg(&alg);
- }
- module_init(init);
- module_exit(fini);
- MODULE_LICENSE("GPL");
- MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm (optimized assembly version)");
- MODULE_ALIAS_CRYPTO("salsa20");
- MODULE_ALIAS_CRYPTO("salsa20-asm");
|