refactor

lib/aes_acc/aesarm.c

@@ -0,0 +1,115 @@
+/*
+ * This file is adapted from https://github.com/CriticalBlue/mbedtls
+ */
+
+/*
+ *  ARMv8-A Cryptography Extension AES support functions
+ *
+ *  Copyright (C) 2016, CriticalBlue Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#include "aesarm.h"
+
+#if defined(HAVE_ARM64)
+
+#include <sys/auxv.h>
+#include <asm/hwcap.h>
+#include <arm_neon.h>
+
+/*
+ * ARMv8a Crypto Extension support detection routine
+ */
+int aesarm_supported( void )
+{
+    static int done = 0;
+    static unsigned int c = 0;
+
+    if ( ! done )
+    {
+        c = getauxval(AT_HWCAP);
+        done = 1;
+    }
+
+    return ( c & HWCAP_AES ) != 0;
+}
+
+/*
+ * ARMv8a AES-ECB block en(de)cryption
+ */
+void aesarm_crypt_ecb( int nr,
+                       unsigned char *rk,
+                       int mode,
+                       const unsigned char input[16],
+                       unsigned char output[16] )
+{
+    int i;
+    uint8x16_t state_vec, roundkey_vec;
+    uint8_t *RK = (uint8_t *) rk;
+
+    // Load input and round key into into their vectors
+    state_vec = vld1q_u8( input );
+
+    if ( mode == AES_ENCRYPT )
+    {
+        // Initial AddRoundKey is in the loop due to AES instruction always doing AddRoundKey first
+        for( i = 0; i < nr - 1; i++ )
+        {
+            // Load Round Key
+            roundkey_vec = vld1q_u8( RK );
+            // Forward (AESE) round (AddRoundKey, SubBytes and ShiftRows)
+            state_vec = vaeseq_u8( state_vec, roundkey_vec );
+            // Mix Columns (AESMC)
+            state_vec = vaesmcq_u8( state_vec );
+            // Move pointer ready to load next round key
+            RK += 16;
+        }
+
+        // Final Forward (AESE) round (AddRoundKey, SubBytes and ShiftRows). No Mix columns
+        roundkey_vec = vld1q_u8( RK ); /* RK already moved in loop */
+        state_vec = vaeseq_u8( state_vec, roundkey_vec );
+    }
+    else
+    {
+        // Initial AddRoundKey is in the loop due to AES instruction always doing AddRoundKey first
+        for( i = 0; i < nr - 1; i++ )
+        {
+            // Load Round Key
+            roundkey_vec = vld1q_u8( RK );
+            // Reverse (AESD) round (AddRoundKey, SubBytes and ShiftRows)
+            state_vec = vaesdq_u8( state_vec, roundkey_vec );
+            // Inverse Mix Columns (AESIMC)
+            state_vec = vaesimcq_u8( state_vec );
+            // Move pointer ready to load next round key
+            RK += 16;
+        }
+
+        // Final Reverse (AESD) round (AddRoundKey, SubBytes and ShiftRows). No Mix columns
+        roundkey_vec = vld1q_u8( RK ); /* RK already moved in loop */
+        state_vec = vaesdq_u8( state_vec, roundkey_vec );
+    }
+
+    // Manually apply final Add RoundKey step (EOR)
+    RK += 16;
+    roundkey_vec = vld1q_u8( RK );
+    state_vec = veorq_u8( state_vec, roundkey_vec );
+
+    // Write results back to output array
+    vst1q_u8( output, state_vec );
+}
+
+#endif /* HAVE_ARM64 */