Add current version of libSRTP from CVS.

libsrtp/tables/aes_tables.c

+/*
+ * aes_tables.c
+ * 
+ * generate tables for the AES cipher
+ * 
+ * David A. McGrew
+ * Cisco Systems, Inc.
+ */
+/*
+ *      
+ * Copyright(c) 2001-2006 Cisco Systems, Inc.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ *   Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 
+ *   Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ * 
+ *   Neither the name of the Cisco Systems, Inc. nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <stdio.h>
+#include "gf2_8.h"
+#include "crypto_math.h"
+
+
+unsigned char aes_sbox[256];
+
+unsigned char aes_inv_sbox[256];
+
+uint32_t T0[256], T1[256], T2[256], T3[256], T4[256]; 
+
+
+#define AES_INVERSE_TEST 0  /* set to 1 to test forward/backwards aes */
+
+/* functions for precomputing AES values */
+
+/*
+ * A[] is the 8 x 8 binary matrix (represented as an array of columns,
+ * where each column is an octet) which defines the affine
+ * transformation used in the AES substitution table (Section
+ * 4.2.1 of the spec).
+ */
+
+uint8_t A[8] = { 31, 62, 124, 248, 241, 227, 199, 143 };
+
+/*
+ * b is the 8 bit vector (represented as an octet) used in the affine
+ * transform described above.
+ */
+
+uint8_t b = 99;
+
+
+void
+aes_init_sbox(void) {
+  unsigned int i;
+  uint8_t x;
+  
+  for (i=0; i < 256; i++) {
+    x = gf2_8_compute_inverse((gf2_8)i);
+    x = A_times_x_plus_b(A, x, b);
+    aes_sbox[i] = x;
+    aes_inv_sbox[x] = i;
+  }
+}
+
+void
+aes_compute_tables(void) {
+  int i;
+  uint32_t x1, x2, x3;
+  v32_t tmp;
+
+  /* initialize substitution table */
+  aes_init_sbox();
+
+  /* combine sbox with linear operations to form 8-bit to 32-bit tables */
+  for (i=0; i < 256; i++) {
+    x1 = aes_sbox[i];
+    x2 = gf2_8_shift(x1);
+    x3 = x2 ^ x1;
+
+    tmp.v8[0] = x2;
+    tmp.v8[1] = x1;
+    tmp.v8[2] = x1;
+    tmp.v8[3] = x3;
+    T0[i] = tmp.value;
+
+    tmp.v8[0] = x3;
+    tmp.v8[1] = x2;
+    tmp.v8[2] = x1;
+    tmp.v8[3] = x1;
+    T1[i] = tmp.value;
+     
+    tmp.v8[0] = x1;
+    tmp.v8[1] = x3;
+    tmp.v8[2] = x2;
+    tmp.v8[3] = x1;
+    T2[i] = tmp.value;
+
+    tmp.v8[0] = x1;
+    tmp.v8[1] = x1;
+    tmp.v8[2] = x3;
+    tmp.v8[3] = x2;
+    T3[i] = tmp.value;
+     
+  }
+}
+
+
+/*
+ * the tables U0, U1, U2, U3 implement the aes operations invSubBytes,
+ * invMixColumns, and invShiftRows 
+ */
+
+uint32_t U0[256], U1[256], U2[256], U3[256], U4[256];
+
+extern uint8_t aes_inv_sbox[256];
+
+void
+aes_compute_inv_tables(void) {
+  int i;
+  uint8_t x, xe, x9, xd, xb;
+  v32_t tmp;
+
+  /* combine sbox with linear operations to form 8-bit to 32-bit tables */
+  for (i=0; i < 256; i++) {
+     x = aes_inv_sbox[i];
+
+     xe = gf2_8_multiply(0x0e, x);     
+     x9 = gf2_8_multiply(0x09, x);     
+     xd = gf2_8_multiply(0x0d, x);     
+     xb = gf2_8_multiply(0x0b, x);     
+
+     tmp.v8[0] = xe;
+     tmp.v8[1] = x9;
+     tmp.v8[2] = xd;
+     tmp.v8[3] = xb;
+     U0[i] = tmp.value;
+
+     tmp.v8[0] = xb;
+     tmp.v8[1] = xe;
+     tmp.v8[2] = x9;
+     tmp.v8[3] = xd;
+     U1[i] = tmp.value;
+     
+     tmp.v8[0] = xd;
+     tmp.v8[1] = xb;
+     tmp.v8[2] = xe;
+     tmp.v8[3] = x9;
+     U2[i] = tmp.value;
+
+     tmp.v8[0] = x9;
+     tmp.v8[1] = xd;
+     tmp.v8[2] = xb;
+     tmp.v8[3] = xe;
+     U3[i] = tmp.value;
+
+     tmp.v8[0] = tmp.v8[1] = tmp.v8[2] = tmp.v8[3] = x;
+     U4[i] = tmp.value;
+   }
+}
+
+
+/*
+ * aes_test_inverse() returns err_status_ok if aes
+ * encryption and decryption are true inverses of each other, and
+ * returns err_status_algo_fail otherwise
+ */
+
+#include "err.h"
+
+err_status_t
+aes_test_inverse(void);
+
+#define TABLES_32BIT 1
+
+int
+main(void) {
+  int i;
+
+  aes_init_sbox();
+  aes_compute_inv_tables();
+
+#if TABLES_32BIT
+  printf("uint32_t U0 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%0x, ", U0[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U1 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%x, ", U1[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U2 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%x, ", U2[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U3 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%x, ", U3[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U4 = {");
+ for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%x, ", U4[i]);
+  }
+  printf("\n}\n");
+
+#else
+
+  printf("uint32_t U0 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%lx, ", U0[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U1 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%lx, ", U1[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U2 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%lx, ", U2[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U3 = {");
+  for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%lx, ", U3[i]);
+  }
+  printf("\n}\n");
+
+ printf("uint32_t U4 = {");
+ for (i=0; i < 256; i++) {
+    if ((i % 4) == 0)
+      printf("\n");
+    printf("0x%lx, ", U4[i]);
+  }
+  printf("\n}\n");
+
+
+#endif /* TABLES_32BIT */
+
+
+#if AES_INVERSE_TEST
+  /* 
+   * test that aes_encrypt and aes_decrypt are actually
+   * inverses of each other 
+   */
+    
+  printf("aes inverse test: ");
+  if (aes_test_inverse() == err_status_ok)
+    printf("passed\n");
+  else {
+    printf("failed\n");
+    exit(1);
+  }
+#endif
+  
+  return 0;
+}
+
+#if AES_INVERSE_TEST
+
+err_status_t
+aes_test_inverse(void) {
+  v128_t x, y;
+  aes_expanded_key_t expanded_key, decrypt_key;
+  uint8_t plaintext[16] = {
+    0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
+    0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff 
+  };
+  uint8_t key[16] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+  };
+  v128_t k;
+  v128_set_to_zero(&x);
+  
+  v128_copy_octet_string(&k, key);
+  v128_copy_octet_string(&x, plaintext);
+  aes_expand_encryption_key(k, expanded_key);
+  aes_expand_decryption_key(k, decrypt_key);
+  aes_encrypt(&x, expanded_key);
+  aes_decrypt(&x, decrypt_key);
+  
+  /* compare to expected value then report */
+  v128_copy_octet_string(&y, plaintext);
+
+  if (v128_is_eq(&x, &y))
+    return err_status_ok;
+  return err_status_algo_fail;
+  
+}
+ 
+#endif