lib/crypto/aes.c

96 	/* multiply by polynomial 'x' (0b10) in GF(2^8) */
106 	/* multiply by polynomial 'x^2' (0b100) in GF(2^8) */
113 	 * Perform the following matrix multiplication in GF(2^8)
128 	 * Perform the following matrix multiplication in GF(2^8)
147 static __always_inline u32 subshift(u32 in[], int pos)
149 	return (aes_sbox[in[pos] & 0xff]) ^
150 	       (aes_sbox[(in[(pos + 1) % 4] >>  8) & 0xff] <<  8) ^
151 	       (aes_sbox[(in[(pos + 2) % 4] >> 16) & 0xff] << 16) ^
152 	       (aes_sbox[(in[(pos + 3) % 4] >> 24) & 0xff] << 24);
155 static __always_inline u32 inv_subshift(u32 in[], int pos)
157 	return (aes_inv_sbox[in[pos] & 0xff]) ^
158 	       (aes_inv_sbox[(in[(pos + 3) % 4] >>  8) & 0xff] <<  8) ^
159 	       (aes_inv_sbox[(in[(pos + 2) % 4] >> 16) & 0xff] << 16) ^
160 	       (aes_inv_sbox[(in[(pos + 1) % 4] >> 24) & 0xff] << 24);
163 static u32 subw(u32 in)
165 	return (aes_sbox[in & 0xff]) ^
166 	       (aes_sbox[(in >>  8) & 0xff] <<  8) ^
167 	       (aes_sbox[(in >> 16) & 0xff] << 16) ^
168 	       (aes_sbox[(in >> 24) & 0xff] << 24);
172  * aes_expandkey - Expands the AES key as described in FIPS-197
182  * described in FIPS-197. The first slot (16 bytes) of each key (enc or dec) is
256  * @in:		Buffer containing the plaintext
258 void aes_encrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in)
265 	st0[0] = ctx->key_enc[0] ^ get_unaligned_le32(in);
266 	st0[1] = ctx->key_enc[1] ^ get_unaligned_le32(in + 4);
267 	st0[2] = ctx->key_enc[2] ^ get_unaligned_le32(in + 8);
268 	st0[3] = ctx->key_enc[3] ^ get_unaligned_le32(in + 12);
307  * @in:		Buffer containing the ciphertext
309 void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in)
316 	st0[0] = ctx->key_dec[0] ^ get_unaligned_le32(in);
317 	st0[1] = ctx->key_dec[1] ^ get_unaligned_le32(in + 4);
318 	st0[2] = ctx->key_dec[2] ^ get_unaligned_le32(in + 8);
319 	st0[3] = ctx->key_dec[3] ^ get_unaligned_le32(in + 12);