Add current version of libSRTP from CVS.

libsrtp/crypto/cipher/cipher.c

+/*
+ * cipher.c
+ *
+ * cipher meta-functions
+ *
+ * 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 "cipher.h"
+#include "rand_source.h"        /* used in invertibiltiy tests        */
+#include "alloc.h"              /* for crypto_alloc(), crypto_free()  */
+
+debug_module_t mod_cipher = {
+  0,                 /* debugging is off by default */
+  "cipher"           /* printable module name       */
+};
+
+err_status_t
+cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output) {
+  
+  /* zeroize the buffer */
+  octet_string_set_to_zero(buffer, num_octets_to_output);
+  
+  /* exor keystream into buffer */
+  return cipher_encrypt(c, buffer, (unsigned int *) &num_octets_to_output);
+}
+
+/* some bookkeeping functions */
+
+int
+cipher_get_key_length(const cipher_t *c) {
+  return c->key_len;
+}
+
+/* 
+ * cipher_type_test(ct, test_data) tests a cipher of type ct against
+ * test cases provided in a list test_data of values of key, salt, iv,
+ * plaintext, and ciphertext that is known to be good
+ */
+
+#define SELF_TEST_BUF_OCTETS 128
+#define NUM_RAND_TESTS       128
+#define MAX_KEY_LEN          64
+
+err_status_t
+cipher_type_test(const cipher_type_t *ct, const cipher_test_case_t *test_data) {
+  const cipher_test_case_t *test_case = test_data;
+  cipher_t *c;
+  err_status_t status;
+  uint8_t buffer[SELF_TEST_BUF_OCTETS];
+  uint8_t buffer2[SELF_TEST_BUF_OCTETS];
+  unsigned int len;
+  int i, j, case_num = 0;
+
+  debug_print(mod_cipher, "running self-test for cipher %s", 
+              ct->description);
+  
+  /*
+   * check to make sure that we have at least one test case, and
+   * return an error if we don't - we need to be paranoid here
+   */
+  if (test_case == NULL)
+    return err_status_cant_check;
+
+  /*
+   * loop over all test cases, perform known-answer tests of both the
+   * encryption and decryption functions
+   */  
+  while (test_case != NULL) {
+
+    /* allocate cipher */
+    status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
+    if (status)
+      return status;
+    
+    /*
+     * test the encrypt function 
+     */
+    debug_print(mod_cipher, "testing encryption", NULL);    
+    
+    /* initialize cipher */
+    status = cipher_init(c, test_case->key, direction_encrypt);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+    
+    /* copy plaintext into test buffer */
+    if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
+      cipher_dealloc(c);    
+      return err_status_bad_param;
+    }
+    for (i=0; i < test_case->plaintext_length_octets; i++)
+      buffer[i] = test_case->plaintext[i];
+
+    debug_print(mod_cipher, "plaintext:    %s",
+             octet_string_hex_string(buffer,
+                                     test_case->plaintext_length_octets));
+
+    /* set the initialization vector */
+    status = cipher_set_iv(c, test_case->idx);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    } 
+    
+    /* encrypt */
+    len = test_case->plaintext_length_octets;
+    status = cipher_encrypt(c, buffer, &len);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+    
+    debug_print(mod_cipher, "ciphertext:   %s",
+             octet_string_hex_string(buffer,
+                                     test_case->ciphertext_length_octets));
+
+    /* compare the resulting ciphertext with that in the test case */
+    if (len != test_case->ciphertext_length_octets)
+      return err_status_algo_fail;
+    status = err_status_ok;
+    for (i=0; i < test_case->ciphertext_length_octets; i++)
+      if (buffer[i] != test_case->ciphertext[i]) {
+        status = err_status_algo_fail;
+        debug_print(mod_cipher, "test case %d failed", case_num);
+        debug_print(mod_cipher, "(failure at byte %d)", i);
+        break;
+      }
+    if (status) {
+
+      debug_print(mod_cipher, "c computed: %s",
+             octet_string_hex_string(buffer,
+                  2*test_case->plaintext_length_octets));
+      debug_print(mod_cipher, "c expected: %s",
+                  octet_string_hex_string(test_case->ciphertext,
+                          2*test_case->plaintext_length_octets));
+
+      cipher_dealloc(c);
+      return err_status_algo_fail;
+    }
+
+    /*
+     * test the decrypt function
+     */
+    debug_print(mod_cipher, "testing decryption", NULL);    
+
+    /* re-initialize cipher for decryption */
+    status = cipher_init(c, test_case->key, direction_decrypt);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+
+    /* copy ciphertext into test buffer */
+    if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
+      cipher_dealloc(c);    
+      return err_status_bad_param;
+    }
+    for (i=0; i < test_case->ciphertext_length_octets; i++)
+      buffer[i] = test_case->ciphertext[i];
+
+    debug_print(mod_cipher, "ciphertext:    %s",
+                octet_string_hex_string(buffer,
+                                        test_case->plaintext_length_octets));
+
+    /* set the initialization vector */
+    status = cipher_set_iv(c, test_case->idx);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    } 
+    
+    /* decrypt */
+    len = test_case->ciphertext_length_octets;
+    status = cipher_decrypt(c, buffer, &len);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+    
+    debug_print(mod_cipher, "plaintext:   %s",
+             octet_string_hex_string(buffer,
+                                     test_case->plaintext_length_octets));
+
+    /* compare the resulting plaintext with that in the test case */
+    if (len != test_case->plaintext_length_octets)
+      return err_status_algo_fail;
+    status = err_status_ok;
+    for (i=0; i < test_case->plaintext_length_octets; i++)
+      if (buffer[i] != test_case->plaintext[i]) {
+        status = err_status_algo_fail;
+        debug_print(mod_cipher, "test case %d failed", case_num);
+        debug_print(mod_cipher, "(failure at byte %d)", i);
+      }
+    if (status) {
+
+      debug_print(mod_cipher, "p computed: %s",
+             octet_string_hex_string(buffer,
+                  2*test_case->plaintext_length_octets));
+      debug_print(mod_cipher, "p expected: %s",
+                  octet_string_hex_string(test_case->plaintext,
+                          2*test_case->plaintext_length_octets));
+
+      cipher_dealloc(c);
+      return err_status_algo_fail;
+    }
+
+    /* deallocate the cipher */
+    status = cipher_dealloc(c);
+    if (status)
+      return status;
+    
+    /* 
+     * the cipher passed the test case, so move on to the next test
+     * case in the list; if NULL, we'l proceed to the next test
+     */   
+    test_case = test_case->next_test_case;
+    ++case_num;
+  }
+  
+  /* now run some random invertibility tests */
+
+  /* allocate cipher, using paramaters from the first test case */
+  test_case = test_data;
+  status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
+  if (status)
+      return status;
+  
+  rand_source_init();
+  
+  for (j=0; j < NUM_RAND_TESTS; j++) {
+    unsigned length;
+    int plaintext_len;
+    uint8_t key[MAX_KEY_LEN];
+    uint8_t  iv[MAX_KEY_LEN];
+
+    /* choose a length at random (leaving room for IV and padding) */
+    length = rand() % (SELF_TEST_BUF_OCTETS - 64);
+    debug_print(mod_cipher, "random plaintext length %d\n", length);
+    status = rand_source_get_octet_string(buffer, length);
+    if (status) return status;
+
+    debug_print(mod_cipher, "plaintext:    %s",
+                octet_string_hex_string(buffer, length));
+
+    /* copy plaintext into second buffer */
+    for (i=0; (unsigned int)i < length; i++)
+      buffer2[i] = buffer[i];
+    
+    /* choose a key at random */
+    if (test_case->key_length_octets > MAX_KEY_LEN)
+      return err_status_cant_check;
+    status = rand_source_get_octet_string(key, test_case->key_length_octets);
+    if (status) return status;
+
+   /* chose a random initialization vector */
+    status = rand_source_get_octet_string(iv, MAX_KEY_LEN);
+    if (status) return status;
+        
+    /* initialize cipher */
+    status = cipher_init(c, key, direction_encrypt);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+
+    /* set initialization vector */
+    status = cipher_set_iv(c, test_case->idx);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    } 
+
+    /* encrypt buffer with cipher */
+    plaintext_len = length;
+    status = cipher_encrypt(c, buffer, &length);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+    debug_print(mod_cipher, "ciphertext:   %s",
+                octet_string_hex_string(buffer, length));
+
+    /* 
+     * re-initialize cipher for decryption, re-set the iv, then
+     * decrypt the ciphertext
+     */
+    status = cipher_init(c, key, direction_decrypt);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }
+    status = cipher_set_iv(c, test_case->idx);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    } 
+    status = cipher_decrypt(c, buffer, &length);
+    if (status) {
+      cipher_dealloc(c);
+      return status;
+    }    
+
+    debug_print(mod_cipher, "plaintext[2]: %s",
+                octet_string_hex_string(buffer, length));    
+
+    /* compare the resulting plaintext with the original one */
+    if (length != plaintext_len)
+      return err_status_algo_fail;
+    status = err_status_ok;
+    for (i=0; i < plaintext_len; i++)
+      if (buffer[i] != buffer2[i]) {
+        status = err_status_algo_fail;
+        debug_print(mod_cipher, "random test case %d failed", case_num);
+        debug_print(mod_cipher, "(failure at byte %d)", i);
+      }
+    if (status) {
+      cipher_dealloc(c);
+      return err_status_algo_fail;
+    }
+        
+  }
+
+  status = cipher_dealloc(c);
+  if (status)
+    return status;
+
+  return err_status_ok;
+}
+
+
+/* 
+ * cipher_type_self_test(ct) performs cipher_type_test on ct's internal
+ * list of test data.
+ */
+
+err_status_t
+cipher_type_self_test(const cipher_type_t *ct) {
+  return cipher_type_test(ct, ct->test_data);
+}
+
+/*
+ * cipher_bits_per_second(c, l, t) computes (an estimate of) the
+ * number of bits that a cipher implementation can encrypt in a second
+ * 
+ * c is a cipher (which MUST be allocated and initialized already), l
+ * is the length in octets of the test data to be encrypted, and t is
+ * the number of trials
+ *
+ * if an error is encountered, the value 0 is returned
+ */
+
+uint64_t
+cipher_bits_per_second(cipher_t *c, int octets_in_buffer, int num_trials) {
+  int i;
+  v128_t nonce;
+  clock_t timer;
+  unsigned char *enc_buf;
+  unsigned int len = octets_in_buffer;
+
+  enc_buf = (unsigned char*) crypto_alloc(octets_in_buffer);
+  if (enc_buf == NULL)
+    return 0;  /* indicate bad parameters by returning null */
+  
+  /* time repeated trials */
+  v128_set_to_zero(&nonce);
+  timer = clock();
+  for(i=0; i < num_trials; i++, nonce.v32[3] = i) {
+    cipher_set_iv(c, &nonce);
+    cipher_encrypt(c, enc_buf, &len);
+  }
+  timer = clock() - timer;
+
+  crypto_free(enc_buf);
+
+  if (timer == 0) {
+    /* Too fast! */
+    return 0;
+  }
+  
+  return (uint64_t)CLOCKS_PER_SEC * num_trials * 8 * octets_in_buffer / timer;
+}