summaryrefslogtreecommitdiff
path: root/crypto/salsa20_generic.c
diff options
context:
space:
mode:
Diffstat (limited to 'crypto/salsa20_generic.c')
-rw-r--r--crypto/salsa20_generic.c251
1 files changed, 0 insertions, 251 deletions
diff --git a/crypto/salsa20_generic.c b/crypto/salsa20_generic.c
deleted file mode 100644
index 9a4770c02284..000000000000
--- a/crypto/salsa20_generic.c
+++ /dev/null
@@ -1,251 +0,0 @@
-/*
- * Salsa20: Salsa20 stream cipher algorithm
- *
- * Copyright (c) 2007 Tan Swee Heng <thesweeheng@gmail.com>
- *
- * Derived from:
- * - salsa20.c: Public domain C code by Daniel J. Bernstein <djb@cr.yp.to>
- *
- * Salsa20 is a stream cipher candidate in eSTREAM, the ECRYPT Stream
- * Cipher Project. It is designed by Daniel J. Bernstein <djb@cr.yp.to>.
- * More information about eSTREAM and Salsa20 can be found here:
- * http://www.ecrypt.eu.org/stream/
- * http://cr.yp.to/snuffle.html
- *
- * 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/init.h>
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/crypto.h>
-#include <linux/types.h>
-#include <linux/bitops.h>
-#include <crypto/algapi.h>
-#include <asm/byteorder.h>
-
-#define SALSA20_IV_SIZE 8U
-#define SALSA20_MIN_KEY_SIZE 16U
-#define SALSA20_MAX_KEY_SIZE 32U
-
-/*
- * Start of code taken from D. J. Bernstein's reference implementation.
- * With some modifications and optimizations made to suit our needs.
- */
-
-/*
-salsa20-ref.c version 20051118
-D. J. Bernstein
-Public domain.
-*/
-
-#define U32TO8_LITTLE(p, v) \
- { (p)[0] = (v >> 0) & 0xff; (p)[1] = (v >> 8) & 0xff; \
- (p)[2] = (v >> 16) & 0xff; (p)[3] = (v >> 24) & 0xff; }
-#define U8TO32_LITTLE(p) \
- (((u32)((p)[0]) ) | ((u32)((p)[1]) << 8) | \
- ((u32)((p)[2]) << 16) | ((u32)((p)[3]) << 24) )
-
-struct salsa20_ctx
-{
- u32 input[16];
-};
-
-static void salsa20_wordtobyte(u8 output[64], const u32 input[16])
-{
- u32 x[16];
- int i;
-
- memcpy(x, input, sizeof(x));
- for (i = 20; i > 0; i -= 2) {
- x[ 4] ^= rol32((x[ 0] + x[12]), 7);
- x[ 8] ^= rol32((x[ 4] + x[ 0]), 9);
- x[12] ^= rol32((x[ 8] + x[ 4]), 13);
- x[ 0] ^= rol32((x[12] + x[ 8]), 18);
- x[ 9] ^= rol32((x[ 5] + x[ 1]), 7);
- x[13] ^= rol32((x[ 9] + x[ 5]), 9);
- x[ 1] ^= rol32((x[13] + x[ 9]), 13);
- x[ 5] ^= rol32((x[ 1] + x[13]), 18);
- x[14] ^= rol32((x[10] + x[ 6]), 7);
- x[ 2] ^= rol32((x[14] + x[10]), 9);
- x[ 6] ^= rol32((x[ 2] + x[14]), 13);
- x[10] ^= rol32((x[ 6] + x[ 2]), 18);
- x[ 3] ^= rol32((x[15] + x[11]), 7);
- x[ 7] ^= rol32((x[ 3] + x[15]), 9);
- x[11] ^= rol32((x[ 7] + x[ 3]), 13);
- x[15] ^= rol32((x[11] + x[ 7]), 18);
- x[ 1] ^= rol32((x[ 0] + x[ 3]), 7);
- x[ 2] ^= rol32((x[ 1] + x[ 0]), 9);
- x[ 3] ^= rol32((x[ 2] + x[ 1]), 13);
- x[ 0] ^= rol32((x[ 3] + x[ 2]), 18);
- x[ 6] ^= rol32((x[ 5] + x[ 4]), 7);
- x[ 7] ^= rol32((x[ 6] + x[ 5]), 9);
- x[ 4] ^= rol32((x[ 7] + x[ 6]), 13);
- x[ 5] ^= rol32((x[ 4] + x[ 7]), 18);
- x[11] ^= rol32((x[10] + x[ 9]), 7);
- x[ 8] ^= rol32((x[11] + x[10]), 9);
- x[ 9] ^= rol32((x[ 8] + x[11]), 13);
- x[10] ^= rol32((x[ 9] + x[ 8]), 18);
- x[12] ^= rol32((x[15] + x[14]), 7);
- x[13] ^= rol32((x[12] + x[15]), 9);
- x[14] ^= rol32((x[13] + x[12]), 13);
- x[15] ^= rol32((x[14] + x[13]), 18);
- }
- for (i = 0; i < 16; ++i)
- x[i] += input[i];
- for (i = 0; i < 16; ++i)
- U32TO8_LITTLE(output + 4 * i,x[i]);
-}
-
-static const char sigma[16] = "expand 32-byte k";
-static const char tau[16] = "expand 16-byte k";
-
-static void salsa20_keysetup(struct salsa20_ctx *ctx, const u8 *k, u32 kbytes)
-{
- const char *constants;
-
- ctx->input[1] = U8TO32_LITTLE(k + 0);
- ctx->input[2] = U8TO32_LITTLE(k + 4);
- ctx->input[3] = U8TO32_LITTLE(k + 8);
- ctx->input[4] = U8TO32_LITTLE(k + 12);
- if (kbytes == 32) { /* recommended */
- k += 16;
- constants = sigma;
- } else { /* kbytes == 16 */
- constants = tau;
- }
- ctx->input[11] = U8TO32_LITTLE(k + 0);
- ctx->input[12] = U8TO32_LITTLE(k + 4);
- ctx->input[13] = U8TO32_LITTLE(k + 8);
- ctx->input[14] = U8TO32_LITTLE(k + 12);
- ctx->input[0] = U8TO32_LITTLE(constants + 0);
- ctx->input[5] = U8TO32_LITTLE(constants + 4);
- ctx->input[10] = U8TO32_LITTLE(constants + 8);
- ctx->input[15] = U8TO32_LITTLE(constants + 12);
-}
-
-static void salsa20_ivsetup(struct salsa20_ctx *ctx, const u8 *iv)
-{
- ctx->input[6] = U8TO32_LITTLE(iv + 0);
- ctx->input[7] = U8TO32_LITTLE(iv + 4);
- ctx->input[8] = 0;
- ctx->input[9] = 0;
-}
-
-static void salsa20_encrypt_bytes(struct salsa20_ctx *ctx, u8 *dst,
- const u8 *src, unsigned int bytes)
-{
- u8 buf[64];
-
- if (dst != src)
- memcpy(dst, src, bytes);
-
- while (bytes) {
- salsa20_wordtobyte(buf, ctx->input);
-
- ctx->input[8]++;
- if (!ctx->input[8])
- ctx->input[9]++;
-
- if (bytes <= 64) {
- crypto_xor(dst, buf, bytes);
- return;
- }
-
- crypto_xor(dst, buf, 64);
- bytes -= 64;
- dst += 64;
- }
-}
-
-/*
- * End of code taken from D. J. Bernstein's reference implementation.
- */
-
-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);
- 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);
-
- if (likely(walk.nbytes == nbytes))
- {
- salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
- walk.src.virt.addr, nbytes);
- return blkcipher_walk_done(desc, &walk, 0);
- }
-
- while (walk.nbytes >= 64) {
- salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
- walk.src.virt.addr,
- walk.nbytes - (walk.nbytes % 64));
- err = blkcipher_walk_done(desc, &walk, walk.nbytes % 64);
- }
-
- if (walk.nbytes) {
- salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
- walk.src.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-generic",
- .cra_priority = 100,
- .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 salsa20_generic_mod_init(void)
-{
- return crypto_register_alg(&alg);
-}
-
-static void __exit salsa20_generic_mod_fini(void)
-{
- crypto_unregister_alg(&alg);
-}
-
-module_init(salsa20_generic_mod_init);
-module_exit(salsa20_generic_mod_fini);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm");
-MODULE_ALIAS("salsa20");
generated by cgit (git 2.34.1) at 2025-12-25 03:02:57 +0000