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Diffstat (limited to 'arch/arm64/crypto/aes-ce-cipher.c')
-rw-r--r--arch/arm64/crypto/aes-ce-cipher.c112
1 files changed, 111 insertions, 1 deletions
diff --git a/arch/arm64/crypto/aes-ce-cipher.c b/arch/arm64/crypto/aes-ce-cipher.c
index 2075e1acae6b..ce47792a983d 100644
--- a/arch/arm64/crypto/aes-ce-cipher.c
+++ b/arch/arm64/crypto/aes-ce-cipher.c
@@ -14,6 +14,8 @@
#include <linux/crypto.h>
#include <linux/module.h>
+#include "aes-ce-setkey.h"
+
MODULE_DESCRIPTION("Synchronous AES cipher using ARMv8 Crypto Extensions");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
@@ -124,6 +126,114 @@ static void aes_cipher_decrypt(struct crypto_tfm *tfm, u8 dst[], u8 const src[])
kernel_neon_end();
}
+/*
+ * aes_sub() - use the aese instruction to perform the AES sbox substitution
+ * on each byte in 'input'
+ */
+static u32 aes_sub(u32 input)
+{
+ u32 ret;
+
+ __asm__("dup v1.4s, %w[in] ;"
+ "movi v0.16b, #0 ;"
+ "aese v0.16b, v1.16b ;"
+ "umov %w[out], v0.4s[0] ;"
+
+ : [out] "=r"(ret)
+ : [in] "r"(input)
+ : "v0","v1");
+
+ return ret;
+}
+
+int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
+ unsigned int key_len)
+{
+ /*
+ * The AES key schedule round constants
+ */
+ static u8 const rcon[] = {
+ 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
+ };
+
+ u32 kwords = key_len / sizeof(u32);
+ struct aes_block *key_enc, *key_dec;
+ int i, j;
+
+ if (key_len != AES_KEYSIZE_128 &&
+ key_len != AES_KEYSIZE_192 &&
+ key_len != AES_KEYSIZE_256)
+ return -EINVAL;
+
+ memcpy(ctx->key_enc, in_key, key_len);
+ ctx->key_length = key_len;
+
+ kernel_neon_begin_partial(2);
+ for (i = 0; i < sizeof(rcon); i++) {
+ u32 *rki = ctx->key_enc + (i * kwords);
+ u32 *rko = rki + kwords;
+
+ rko[0] = ror32(aes_sub(rki[kwords - 1]), 8) ^ rcon[i] ^ rki[0];
+ rko[1] = rko[0] ^ rki[1];
+ rko[2] = rko[1] ^ rki[2];
+ rko[3] = rko[2] ^ rki[3];
+
+ if (key_len == AES_KEYSIZE_192) {
+ if (i >= 7)
+ break;
+ rko[4] = rko[3] ^ rki[4];
+ rko[5] = rko[4] ^ rki[5];
+ } else if (key_len == AES_KEYSIZE_256) {
+ if (i >= 6)
+ break;
+ rko[4] = aes_sub(rko[3]) ^ rki[4];
+ rko[5] = rko[4] ^ rki[5];
+ rko[6] = rko[5] ^ rki[6];
+ rko[7] = rko[6] ^ rki[7];
+ }
+ }
+
+ /*
+ * Generate the decryption keys for the Equivalent Inverse Cipher.
+ * This involves reversing the order of the round keys, and applying
+ * the Inverse Mix Columns transformation on all but the first and
+ * the last one.
+ */
+ key_enc = (struct aes_block *)ctx->key_enc;
+ key_dec = (struct aes_block *)ctx->key_dec;
+ j = num_rounds(ctx);
+
+ key_dec[0] = key_enc[j];
+ for (i = 1, j--; j > 0; i++, j--)
+ __asm__("ld1 {v0.16b}, %[in] ;"
+ "aesimc v1.16b, v0.16b ;"
+ "st1 {v1.16b}, %[out] ;"
+
+ : [out] "=Q"(key_dec[i])
+ : [in] "Q"(key_enc[j])
+ : "v0","v1");
+ key_dec[i] = key_enc[0];
+
+ kernel_neon_end();
+ return 0;
+}
+EXPORT_SYMBOL(ce_aes_expandkey);
+
+int ce_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+ int ret;
+
+ ret = ce_aes_expandkey(ctx, in_key, key_len);
+ if (!ret)
+ return 0;
+
+ tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+}
+EXPORT_SYMBOL(ce_aes_setkey);
+
static struct crypto_alg aes_alg = {
.cra_name = "aes",
.cra_driver_name = "aes-ce",
@@ -135,7 +245,7 @@ static struct crypto_alg aes_alg = {
.cra_cipher = {
.cia_min_keysize = AES_MIN_KEY_SIZE,
.cia_max_keysize = AES_MAX_KEY_SIZE,
- .cia_setkey = crypto_aes_set_key,
+ .cia_setkey = ce_aes_setkey,
.cia_encrypt = aes_cipher_encrypt,
.cia_decrypt = aes_cipher_decrypt
}