sm4_generic.c 6.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * SM4 Cipher Algorithm.
  4. *
  5. * Copyright (C) 2018 ARM Limited or its affiliates.
  6. * All rights reserved.
  7. */
  8. #include <crypto/sm4.h>
  9. #include <linux/module.h>
  10. #include <linux/init.h>
  11. #include <linux/types.h>
  12. #include <linux/errno.h>
  13. #include <linux/crypto.h>
  14. #include <asm/byteorder.h>
  15. #include <asm/unaligned.h>
  16. static const u32 fk[4] = {
  17. 0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc
  18. };
  19. static const u8 sbox[256] = {
  20. 0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7,
  21. 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
  22. 0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3,
  23. 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
  24. 0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a,
  25. 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
  26. 0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95,
  27. 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
  28. 0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba,
  29. 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
  30. 0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b,
  31. 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
  32. 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2,
  33. 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
  34. 0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52,
  35. 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
  36. 0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5,
  37. 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
  38. 0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55,
  39. 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
  40. 0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60,
  41. 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
  42. 0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f,
  43. 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
  44. 0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f,
  45. 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
  46. 0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd,
  47. 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
  48. 0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e,
  49. 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
  50. 0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20,
  51. 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48
  52. };
  53. static const u32 ck[] = {
  54. 0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
  55. 0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
  56. 0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
  57. 0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
  58. 0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
  59. 0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
  60. 0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
  61. 0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
  62. };
  63. static u32 sm4_t_non_lin_sub(u32 x)
  64. {
  65. int i;
  66. u8 *b = (u8 *)&x;
  67. for (i = 0; i < 4; ++i)
  68. b[i] = sbox[b[i]];
  69. return x;
  70. }
  71. static u32 sm4_key_lin_sub(u32 x)
  72. {
  73. return x ^ rol32(x, 13) ^ rol32(x, 23);
  74. }
  75. static u32 sm4_enc_lin_sub(u32 x)
  76. {
  77. return x ^ rol32(x, 2) ^ rol32(x, 10) ^ rol32(x, 18) ^ rol32(x, 24);
  78. }
  79. static u32 sm4_key_sub(u32 x)
  80. {
  81. return sm4_key_lin_sub(sm4_t_non_lin_sub(x));
  82. }
  83. static u32 sm4_enc_sub(u32 x)
  84. {
  85. return sm4_enc_lin_sub(sm4_t_non_lin_sub(x));
  86. }
  87. static u32 sm4_round(const u32 *x, const u32 rk)
  88. {
  89. return x[0] ^ sm4_enc_sub(x[1] ^ x[2] ^ x[3] ^ rk);
  90. }
  91. /**
  92. * crypto_sm4_expand_key - Expands the SM4 key as described in GB/T 32907-2016
  93. * @ctx: The location where the computed key will be stored.
  94. * @in_key: The supplied key.
  95. * @key_len: The length of the supplied key.
  96. *
  97. * Returns 0 on success. The function fails only if an invalid key size (or
  98. * pointer) is supplied.
  99. */
  100. int crypto_sm4_expand_key(struct crypto_sm4_ctx *ctx, const u8 *in_key,
  101. unsigned int key_len)
  102. {
  103. u32 rk[4], t;
  104. const u32 *key = (u32 *)in_key;
  105. int i;
  106. if (key_len != SM4_KEY_SIZE)
  107. return -EINVAL;
  108. for (i = 0; i < 4; ++i)
  109. rk[i] = get_unaligned_be32(&key[i]) ^ fk[i];
  110. for (i = 0; i < 32; ++i) {
  111. t = rk[0] ^ sm4_key_sub(rk[1] ^ rk[2] ^ rk[3] ^ ck[i]);
  112. ctx->rkey_enc[i] = t;
  113. rk[0] = rk[1];
  114. rk[1] = rk[2];
  115. rk[2] = rk[3];
  116. rk[3] = t;
  117. }
  118. for (i = 0; i < 32; ++i)
  119. ctx->rkey_dec[i] = ctx->rkey_enc[31 - i];
  120. return 0;
  121. }
  122. EXPORT_SYMBOL_GPL(crypto_sm4_expand_key);
  123. /**
  124. * crypto_sm4_set_key - Set the SM4 key.
  125. * @tfm: The %crypto_tfm that is used in the context.
  126. * @in_key: The input key.
  127. * @key_len: The size of the key.
  128. *
  129. * This function uses crypto_sm4_expand_key() to expand the key.
  130. * &crypto_sm4_ctx _must_ be the private data embedded in @tfm which is
  131. * retrieved with crypto_tfm_ctx().
  132. *
  133. * Return: 0 on success; -EINVAL on failure (only happens for bad key lengths)
  134. */
  135. int crypto_sm4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  136. unsigned int key_len)
  137. {
  138. struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  139. return crypto_sm4_expand_key(ctx, in_key, key_len);
  140. }
  141. EXPORT_SYMBOL_GPL(crypto_sm4_set_key);
  142. static void sm4_do_crypt(const u32 *rk, u32 *out, const u32 *in)
  143. {
  144. u32 x[4], i, t;
  145. for (i = 0; i < 4; ++i)
  146. x[i] = get_unaligned_be32(&in[i]);
  147. for (i = 0; i < 32; ++i) {
  148. t = sm4_round(x, rk[i]);
  149. x[0] = x[1];
  150. x[1] = x[2];
  151. x[2] = x[3];
  152. x[3] = t;
  153. }
  154. for (i = 0; i < 4; ++i)
  155. put_unaligned_be32(x[3 - i], &out[i]);
  156. }
  157. /* encrypt a block of text */
  158. void crypto_sm4_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  159. {
  160. const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  161. sm4_do_crypt(ctx->rkey_enc, (u32 *)out, (u32 *)in);
  162. }
  163. EXPORT_SYMBOL_GPL(crypto_sm4_encrypt);
  164. /* decrypt a block of text */
  165. void crypto_sm4_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  166. {
  167. const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  168. sm4_do_crypt(ctx->rkey_dec, (u32 *)out, (u32 *)in);
  169. }
  170. EXPORT_SYMBOL_GPL(crypto_sm4_decrypt);
  171. static struct crypto_alg sm4_alg = {
  172. .cra_name = "sm4",
  173. .cra_driver_name = "sm4-generic",
  174. .cra_priority = 100,
  175. .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
  176. .cra_blocksize = SM4_BLOCK_SIZE,
  177. .cra_ctxsize = sizeof(struct crypto_sm4_ctx),
  178. .cra_module = THIS_MODULE,
  179. .cra_u = {
  180. .cipher = {
  181. .cia_min_keysize = SM4_KEY_SIZE,
  182. .cia_max_keysize = SM4_KEY_SIZE,
  183. .cia_setkey = crypto_sm4_set_key,
  184. .cia_encrypt = crypto_sm4_encrypt,
  185. .cia_decrypt = crypto_sm4_decrypt
  186. }
  187. }
  188. };
  189. static int __init sm4_init(void)
  190. {
  191. return crypto_register_alg(&sm4_alg);
  192. }
  193. static void __exit sm4_fini(void)
  194. {
  195. crypto_unregister_alg(&sm4_alg);
  196. }
  197. subsys_initcall(sm4_init);
  198. module_exit(sm4_fini);
  199. MODULE_DESCRIPTION("SM4 Cipher Algorithm");
  200. MODULE_LICENSE("GPL v2");
  201. MODULE_ALIAS_CRYPTO("sm4");
  202. MODULE_ALIAS_CRYPTO("sm4-generic");