| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Speck: a lightweight block cipher |
| * |
| * Copyright (c) 2018 Google, Inc |
| * |
| * Speck has 10 variants, including 5 block sizes. For now we only implement |
| * the variants Speck128/128, Speck128/192, Speck128/256, Speck64/96, and |
| * Speck64/128. Speck${B}/${K} denotes the variant with a block size of B bits |
| * and a key size of K bits. The Speck128 variants are believed to be the most |
| * secure variants, and they use the same block size and key sizes as AES. The |
| * Speck64 variants are less secure, but on 32-bit processors are usually |
| * faster. The remaining variants (Speck32, Speck48, and Speck96) are even less |
| * secure and/or not as well suited for implementation on either 32-bit or |
| * 64-bit processors, so are omitted. |
| * |
| * Reference: "The Simon and Speck Families of Lightweight Block Ciphers" |
| * https://eprint.iacr.org/2013/404.pdf |
| * |
| * In a correspondence, the Speck designers have also clarified that the words |
| * should be interpreted in little-endian format, and the words should be |
| * ordered such that the first word of each block is 'y' rather than 'x', and |
| * the first key word (rather than the last) becomes the first round key. |
| */ |
| |
| #include <asm/unaligned.h> |
| #include <crypto/speck.h> |
| #include <linux/bitops.h> |
| #include <linux/crypto.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| |
| /* Speck128 */ |
| |
| static __always_inline void speck128_round(u64 *x, u64 *y, u64 k) |
| { |
| *x = ror64(*x, 8); |
| *x += *y; |
| *x ^= k; |
| *y = rol64(*y, 3); |
| *y ^= *x; |
| } |
| |
| static __always_inline void speck128_unround(u64 *x, u64 *y, u64 k) |
| { |
| *y ^= *x; |
| *y = ror64(*y, 3); |
| *x ^= k; |
| *x -= *y; |
| *x = rol64(*x, 8); |
| } |
| |
| void crypto_speck128_encrypt(const struct speck128_tfm_ctx *ctx, |
| u8 *out, const u8 *in) |
| { |
| u64 y = get_unaligned_le64(in); |
| u64 x = get_unaligned_le64(in + 8); |
| int i; |
| |
| for (i = 0; i < ctx->nrounds; i++) |
| speck128_round(&x, &y, ctx->round_keys[i]); |
| |
| put_unaligned_le64(y, out); |
| put_unaligned_le64(x, out + 8); |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck128_encrypt); |
| |
| static void speck128_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| crypto_speck128_encrypt(crypto_tfm_ctx(tfm), out, in); |
| } |
| |
| void crypto_speck128_decrypt(const struct speck128_tfm_ctx *ctx, |
| u8 *out, const u8 *in) |
| { |
| u64 y = get_unaligned_le64(in); |
| u64 x = get_unaligned_le64(in + 8); |
| int i; |
| |
| for (i = ctx->nrounds - 1; i >= 0; i--) |
| speck128_unround(&x, &y, ctx->round_keys[i]); |
| |
| put_unaligned_le64(y, out); |
| put_unaligned_le64(x, out + 8); |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck128_decrypt); |
| |
| static void speck128_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| crypto_speck128_decrypt(crypto_tfm_ctx(tfm), out, in); |
| } |
| |
| int crypto_speck128_setkey(struct speck128_tfm_ctx *ctx, const u8 *key, |
| unsigned int keylen) |
| { |
| u64 l[3]; |
| u64 k; |
| int i; |
| |
| switch (keylen) { |
| case SPECK128_128_KEY_SIZE: |
| k = get_unaligned_le64(key); |
| l[0] = get_unaligned_le64(key + 8); |
| ctx->nrounds = SPECK128_128_NROUNDS; |
| for (i = 0; i < ctx->nrounds; i++) { |
| ctx->round_keys[i] = k; |
| speck128_round(&l[0], &k, i); |
| } |
| break; |
| case SPECK128_192_KEY_SIZE: |
| k = get_unaligned_le64(key); |
| l[0] = get_unaligned_le64(key + 8); |
| l[1] = get_unaligned_le64(key + 16); |
| ctx->nrounds = SPECK128_192_NROUNDS; |
| for (i = 0; i < ctx->nrounds; i++) { |
| ctx->round_keys[i] = k; |
| speck128_round(&l[i % 2], &k, i); |
| } |
| break; |
| case SPECK128_256_KEY_SIZE: |
| k = get_unaligned_le64(key); |
| l[0] = get_unaligned_le64(key + 8); |
| l[1] = get_unaligned_le64(key + 16); |
| l[2] = get_unaligned_le64(key + 24); |
| ctx->nrounds = SPECK128_256_NROUNDS; |
| for (i = 0; i < ctx->nrounds; i++) { |
| ctx->round_keys[i] = k; |
| speck128_round(&l[i % 3], &k, i); |
| } |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck128_setkey); |
| |
| static int speck128_setkey(struct crypto_tfm *tfm, const u8 *key, |
| unsigned int keylen) |
| { |
| return crypto_speck128_setkey(crypto_tfm_ctx(tfm), key, keylen); |
| } |
| |
| /* Speck64 */ |
| |
| static __always_inline void speck64_round(u32 *x, u32 *y, u32 k) |
| { |
| *x = ror32(*x, 8); |
| *x += *y; |
| *x ^= k; |
| *y = rol32(*y, 3); |
| *y ^= *x; |
| } |
| |
| static __always_inline void speck64_unround(u32 *x, u32 *y, u32 k) |
| { |
| *y ^= *x; |
| *y = ror32(*y, 3); |
| *x ^= k; |
| *x -= *y; |
| *x = rol32(*x, 8); |
| } |
| |
| void crypto_speck64_encrypt(const struct speck64_tfm_ctx *ctx, |
| u8 *out, const u8 *in) |
| { |
| u32 y = get_unaligned_le32(in); |
| u32 x = get_unaligned_le32(in + 4); |
| int i; |
| |
| for (i = 0; i < ctx->nrounds; i++) |
| speck64_round(&x, &y, ctx->round_keys[i]); |
| |
| put_unaligned_le32(y, out); |
| put_unaligned_le32(x, out + 4); |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck64_encrypt); |
| |
| static void speck64_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| crypto_speck64_encrypt(crypto_tfm_ctx(tfm), out, in); |
| } |
| |
| void crypto_speck64_decrypt(const struct speck64_tfm_ctx *ctx, |
| u8 *out, const u8 *in) |
| { |
| u32 y = get_unaligned_le32(in); |
| u32 x = get_unaligned_le32(in + 4); |
| int i; |
| |
| for (i = ctx->nrounds - 1; i >= 0; i--) |
| speck64_unround(&x, &y, ctx->round_keys[i]); |
| |
| put_unaligned_le32(y, out); |
| put_unaligned_le32(x, out + 4); |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck64_decrypt); |
| |
| static void speck64_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) |
| { |
| crypto_speck64_decrypt(crypto_tfm_ctx(tfm), out, in); |
| } |
| |
| int crypto_speck64_setkey(struct speck64_tfm_ctx *ctx, const u8 *key, |
| unsigned int keylen) |
| { |
| u32 l[3]; |
| u32 k; |
| int i; |
| |
| switch (keylen) { |
| case SPECK64_96_KEY_SIZE: |
| k = get_unaligned_le32(key); |
| l[0] = get_unaligned_le32(key + 4); |
| l[1] = get_unaligned_le32(key + 8); |
| ctx->nrounds = SPECK64_96_NROUNDS; |
| for (i = 0; i < ctx->nrounds; i++) { |
| ctx->round_keys[i] = k; |
| speck64_round(&l[i % 2], &k, i); |
| } |
| break; |
| case SPECK64_128_KEY_SIZE: |
| k = get_unaligned_le32(key); |
| l[0] = get_unaligned_le32(key + 4); |
| l[1] = get_unaligned_le32(key + 8); |
| l[2] = get_unaligned_le32(key + 12); |
| ctx->nrounds = SPECK64_128_NROUNDS; |
| for (i = 0; i < ctx->nrounds; i++) { |
| ctx->round_keys[i] = k; |
| speck64_round(&l[i % 3], &k, i); |
| } |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(crypto_speck64_setkey); |
| |
| static int speck64_setkey(struct crypto_tfm *tfm, const u8 *key, |
| unsigned int keylen) |
| { |
| return crypto_speck64_setkey(crypto_tfm_ctx(tfm), key, keylen); |
| } |
| |
| /* Algorithm definitions */ |
| |
| static struct crypto_alg speck_algs[] = { |
| { |
| .cra_name = "speck128", |
| .cra_driver_name = "speck128-generic", |
| .cra_priority = 100, |
| .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| .cra_blocksize = SPECK128_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct speck128_tfm_ctx), |
| .cra_module = THIS_MODULE, |
| .cra_u = { |
| .cipher = { |
| .cia_min_keysize = SPECK128_128_KEY_SIZE, |
| .cia_max_keysize = SPECK128_256_KEY_SIZE, |
| .cia_setkey = speck128_setkey, |
| .cia_encrypt = speck128_encrypt, |
| .cia_decrypt = speck128_decrypt |
| } |
| } |
| }, { |
| .cra_name = "speck64", |
| .cra_driver_name = "speck64-generic", |
| .cra_priority = 100, |
| .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| .cra_blocksize = SPECK64_BLOCK_SIZE, |
| .cra_ctxsize = sizeof(struct speck64_tfm_ctx), |
| .cra_module = THIS_MODULE, |
| .cra_u = { |
| .cipher = { |
| .cia_min_keysize = SPECK64_96_KEY_SIZE, |
| .cia_max_keysize = SPECK64_128_KEY_SIZE, |
| .cia_setkey = speck64_setkey, |
| .cia_encrypt = speck64_encrypt, |
| .cia_decrypt = speck64_decrypt |
| } |
| } |
| } |
| }; |
| |
| static int __init speck_module_init(void) |
| { |
| return crypto_register_algs(speck_algs, ARRAY_SIZE(speck_algs)); |
| } |
| |
| static void __exit speck_module_exit(void) |
| { |
| crypto_unregister_algs(speck_algs, ARRAY_SIZE(speck_algs)); |
| } |
| |
| module_init(speck_module_init); |
| module_exit(speck_module_exit); |
| |
| MODULE_DESCRIPTION("Speck block cipher (generic)"); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>"); |
| MODULE_ALIAS_CRYPTO("speck128"); |
| MODULE_ALIAS_CRYPTO("speck128-generic"); |
| MODULE_ALIAS_CRYPTO("speck64"); |
| MODULE_ALIAS_CRYPTO("speck64-generic"); |