1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Common values for AES algorithms 4 */ 5 6 #ifndef _CRYPTO_AES_H 7 #define _CRYPTO_AES_H 8 9 #include <linux/types.h> 10 #include <linux/crypto.h> 11 12 #define AES_MIN_KEY_SIZE 16 13 #define AES_MAX_KEY_SIZE 32 14 #define AES_KEYSIZE_128 16 15 #define AES_KEYSIZE_192 24 16 #define AES_KEYSIZE_256 32 17 #define AES_BLOCK_SIZE 16 18 #define AES_MAX_KEYLENGTH (15 * 16) 19 #define AES_MAX_KEYLENGTH_U32 (AES_MAX_KEYLENGTH / sizeof(u32)) 20 21 /* 22 * Please ensure that the first two fields are 16-byte aligned 23 * relative to the start of the structure, i.e., don't move them! 24 */ 25 struct crypto_aes_ctx { 26 u32 key_enc[AES_MAX_KEYLENGTH_U32]; 27 u32 key_dec[AES_MAX_KEYLENGTH_U32]; 28 u32 key_length; 29 }; 30 31 extern const u32 crypto_ft_tab[4][256] ____cacheline_aligned; 32 extern const u32 crypto_it_tab[4][256] ____cacheline_aligned; 33 34 /* 35 * validate key length for AES algorithms 36 */ 37 static inline int aes_check_keylen(unsigned int keylen) 38 { 39 switch (keylen) { 40 case AES_KEYSIZE_128: 41 case AES_KEYSIZE_192: 42 case AES_KEYSIZE_256: 43 break; 44 default: 45 return -EINVAL; 46 } 47 48 return 0; 49 } 50 51 int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 52 unsigned int key_len); 53 54 /** 55 * aes_expandkey - Expands the AES key as described in FIPS-197 56 * @ctx: The location where the computed key will be stored. 57 * @in_key: The supplied key. 58 * @key_len: The length of the supplied key. 59 * 60 * Returns 0 on success. The function fails only if an invalid key size (or 61 * pointer) is supplied. 62 * The expanded key size is 240 bytes (max of 14 rounds with a unique 16 bytes 63 * key schedule plus a 16 bytes key which is used before the first round). 64 * The decryption key is prepared for the "Equivalent Inverse Cipher" as 65 * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is 66 * for the initial combination, the second slot for the first round and so on. 67 */ 68 int aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key, 69 unsigned int key_len); 70 71 /** 72 * aes_encrypt - Encrypt a single AES block 73 * @ctx: Context struct containing the key schedule 74 * @out: Buffer to store the ciphertext 75 * @in: Buffer containing the plaintext 76 */ 77 void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); 78 79 /** 80 * aes_decrypt - Decrypt a single AES block 81 * @ctx: Context struct containing the key schedule 82 * @out: Buffer to store the plaintext 83 * @in: Buffer containing the ciphertext 84 */ 85 void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); 86 87 extern const u8 crypto_aes_sbox[]; 88 extern const u8 crypto_aes_inv_sbox[]; 89 90 void aescfb_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, 91 int len, const u8 iv[AES_BLOCK_SIZE]); 92 void aescfb_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, 93 int len, const u8 iv[AES_BLOCK_SIZE]); 94 95 #endif 96