michael@0: /*
michael@0:  * cipher.c
michael@0:  *
michael@0:  * cipher meta-functions
michael@0:  *
michael@0:  * David A. McGrew
michael@0:  * Cisco Systems, Inc.
michael@0:  * 
michael@0:  */
michael@0: 
michael@0: /*
michael@0:  *	
michael@0:  * Copyright (c) 2001-2006, Cisco Systems, Inc.
michael@0:  * All rights reserved.
michael@0:  * 
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 
michael@0:  *   Redistributions of source code must retain the above copyright
michael@0:  *   notice, this list of conditions and the following disclaimer.
michael@0:  * 
michael@0:  *   Redistributions in binary form must reproduce the above
michael@0:  *   copyright notice, this list of conditions and the following
michael@0:  *   disclaimer in the documentation and/or other materials provided
michael@0:  *   with the distribution.
michael@0:  * 
michael@0:  *   Neither the name of the Cisco Systems, Inc. nor the names of its
michael@0:  *   contributors may be used to endorse or promote products derived
michael@0:  *   from this software without specific prior written permission.
michael@0:  * 
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
michael@0:  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
michael@0:  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
michael@0:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
michael@0:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
michael@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
michael@0:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
michael@0:  * OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: #include "cipher.h"
michael@0: #include "rand_source.h"        /* used in invertibiltiy tests        */
michael@0: #include "alloc.h"              /* for crypto_alloc(), crypto_free()  */
michael@0: 
michael@0: debug_module_t mod_cipher = {
michael@0:   0,                 /* debugging is off by default */
michael@0:   "cipher"           /* printable module name       */
michael@0: };
michael@0: 
michael@0: err_status_t
michael@0: cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output) {
michael@0:   
michael@0:   /* zeroize the buffer */
michael@0:   octet_string_set_to_zero(buffer, num_octets_to_output);
michael@0:   
michael@0:   /* exor keystream into buffer */
michael@0:   return cipher_encrypt(c, buffer, (unsigned int *) &num_octets_to_output);
michael@0: }
michael@0: 
michael@0: /* some bookkeeping functions */
michael@0: 
michael@0: int
michael@0: cipher_get_key_length(const cipher_t *c) {
michael@0:   return c->key_len;
michael@0: }
michael@0: 
michael@0: /* 
michael@0:  * cipher_type_test(ct, test_data) tests a cipher of type ct against
michael@0:  * test cases provided in a list test_data of values of key, salt, iv,
michael@0:  * plaintext, and ciphertext that is known to be good
michael@0:  */
michael@0: 
michael@0: #define SELF_TEST_BUF_OCTETS 128
michael@0: #define NUM_RAND_TESTS       128
michael@0: #define MAX_KEY_LEN          64
michael@0: 
michael@0: err_status_t
michael@0: cipher_type_test(const cipher_type_t *ct, const cipher_test_case_t *test_data) {
michael@0:   const cipher_test_case_t *test_case = test_data;
michael@0:   cipher_t *c;
michael@0:   err_status_t status;
michael@0:   uint8_t buffer[SELF_TEST_BUF_OCTETS];
michael@0:   uint8_t buffer2[SELF_TEST_BUF_OCTETS];
michael@0:   unsigned int len;
michael@0:   int i, j, case_num = 0;
michael@0: 
michael@0:   debug_print(mod_cipher, "running self-test for cipher %s", 
michael@0: 	      ct->description);
michael@0:   
michael@0:   /*
michael@0:    * check to make sure that we have at least one test case, and
michael@0:    * return an error if we don't - we need to be paranoid here
michael@0:    */
michael@0:   if (test_case == NULL)
michael@0:     return err_status_cant_check;
michael@0: 
michael@0:   /*
michael@0:    * loop over all test cases, perform known-answer tests of both the
michael@0:    * encryption and decryption functions
michael@0:    */  
michael@0:   while (test_case != NULL) {
michael@0: 
michael@0:     /* allocate cipher */
michael@0:     status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
michael@0:     if (status)
michael@0:       return status;
michael@0:     
michael@0:     /*
michael@0:      * test the encrypt function 
michael@0:      */
michael@0:     debug_print(mod_cipher, "testing encryption", NULL);    
michael@0:     
michael@0:     /* initialize cipher */
michael@0:     status = cipher_init(c, test_case->key, direction_encrypt);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0:     
michael@0:     /* copy plaintext into test buffer */
michael@0:     if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
michael@0:       cipher_dealloc(c);    
michael@0:       return err_status_bad_param;
michael@0:     }
michael@0:     for (i=0; i < test_case->plaintext_length_octets; i++)
michael@0:       buffer[i] = test_case->plaintext[i];
michael@0: 
michael@0:     debug_print(mod_cipher, "plaintext:    %s",
michael@0: 	     octet_string_hex_string(buffer,
michael@0: 				     test_case->plaintext_length_octets));
michael@0: 
michael@0:     /* set the initialization vector */
michael@0:     status = cipher_set_iv(c, test_case->idx);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     } 
michael@0:     
michael@0:     /* encrypt */
michael@0:     len = test_case->plaintext_length_octets;
michael@0:     status = cipher_encrypt(c, buffer, &len);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0:     
michael@0:     debug_print(mod_cipher, "ciphertext:   %s",
michael@0: 	     octet_string_hex_string(buffer,
michael@0: 				     test_case->ciphertext_length_octets));
michael@0: 
michael@0:     /* compare the resulting ciphertext with that in the test case */
michael@0:     if (len != (unsigned int)test_case->ciphertext_length_octets)
michael@0:       return err_status_algo_fail;
michael@0:     status = err_status_ok;
michael@0:     for (i=0; i < test_case->ciphertext_length_octets; i++)
michael@0:       if (buffer[i] != test_case->ciphertext[i]) {
michael@0: 	status = err_status_algo_fail;
michael@0: 	debug_print(mod_cipher, "test case %d failed", case_num);
michael@0: 	debug_print(mod_cipher, "(failure at byte %d)", i);
michael@0: 	break;
michael@0:       }
michael@0:     if (status) {
michael@0: 
michael@0:       debug_print(mod_cipher, "c computed: %s",
michael@0: 	     octet_string_hex_string(buffer,
michael@0: 		  2*test_case->plaintext_length_octets));
michael@0:       debug_print(mod_cipher, "c expected: %s",
michael@0: 		  octet_string_hex_string(test_case->ciphertext,
michael@0: 			  2*test_case->plaintext_length_octets));
michael@0: 
michael@0:       cipher_dealloc(c);
michael@0:       return err_status_algo_fail;
michael@0:     }
michael@0: 
michael@0:     /*
michael@0:      * test the decrypt function
michael@0:      */
michael@0:     debug_print(mod_cipher, "testing decryption", NULL);    
michael@0: 
michael@0:     /* re-initialize cipher for decryption */
michael@0:     status = cipher_init(c, test_case->key, direction_decrypt);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0: 
michael@0:     /* copy ciphertext into test buffer */
michael@0:     if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
michael@0:       cipher_dealloc(c);    
michael@0:       return err_status_bad_param;
michael@0:     }
michael@0:     for (i=0; i < test_case->ciphertext_length_octets; i++)
michael@0:       buffer[i] = test_case->ciphertext[i];
michael@0: 
michael@0:     debug_print(mod_cipher, "ciphertext:    %s",
michael@0: 		octet_string_hex_string(buffer,
michael@0: 					test_case->plaintext_length_octets));
michael@0: 
michael@0:     /* set the initialization vector */
michael@0:     status = cipher_set_iv(c, test_case->idx);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     } 
michael@0:     
michael@0:     /* decrypt */
michael@0:     len = test_case->ciphertext_length_octets;
michael@0:     status = cipher_decrypt(c, buffer, &len);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0:     
michael@0:     debug_print(mod_cipher, "plaintext:   %s",
michael@0: 	     octet_string_hex_string(buffer,
michael@0: 				     test_case->plaintext_length_octets));
michael@0: 
michael@0:     /* compare the resulting plaintext with that in the test case */
michael@0:     if (len != (unsigned int)test_case->plaintext_length_octets)
michael@0:       return err_status_algo_fail;
michael@0:     status = err_status_ok;
michael@0:     for (i=0; i < test_case->plaintext_length_octets; i++)
michael@0:       if (buffer[i] != test_case->plaintext[i]) {
michael@0: 	status = err_status_algo_fail;
michael@0: 	debug_print(mod_cipher, "test case %d failed", case_num);
michael@0: 	debug_print(mod_cipher, "(failure at byte %d)", i);
michael@0:       }
michael@0:     if (status) {
michael@0: 
michael@0:       debug_print(mod_cipher, "p computed: %s",
michael@0: 	     octet_string_hex_string(buffer,
michael@0: 		  2*test_case->plaintext_length_octets));
michael@0:       debug_print(mod_cipher, "p expected: %s",
michael@0: 		  octet_string_hex_string(test_case->plaintext,
michael@0: 			  2*test_case->plaintext_length_octets));
michael@0: 
michael@0:       cipher_dealloc(c);
michael@0:       return err_status_algo_fail;
michael@0:     }
michael@0: 
michael@0:     /* deallocate the cipher */
michael@0:     status = cipher_dealloc(c);
michael@0:     if (status)
michael@0:       return status;
michael@0:     
michael@0:     /* 
michael@0:      * the cipher passed the test case, so move on to the next test
michael@0:      * case in the list; if NULL, we'l proceed to the next test
michael@0:      */   
michael@0:     test_case = test_case->next_test_case;
michael@0:     ++case_num;
michael@0:   }
michael@0:   
michael@0:   /* now run some random invertibility tests */
michael@0: 
michael@0:   /* allocate cipher, using paramaters from the first test case */
michael@0:   test_case = test_data;
michael@0:   status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
michael@0:   if (status)
michael@0:       return status;
michael@0:   
michael@0:   rand_source_init();
michael@0:   
michael@0:   for (j=0; j < NUM_RAND_TESTS; j++) {
michael@0:     unsigned length;
michael@0:     int plaintext_len;
michael@0:     uint8_t key[MAX_KEY_LEN];
michael@0:     uint8_t  iv[MAX_KEY_LEN];
michael@0: 
michael@0:     /* choose a length at random (leaving room for IV and padding) */
michael@0:     length = rand() % (SELF_TEST_BUF_OCTETS - 64);
michael@0:     debug_print(mod_cipher, "random plaintext length %d\n", length);
michael@0:     status = rand_source_get_octet_string(buffer, length);
michael@0:     if (status) return status;
michael@0: 
michael@0:     debug_print(mod_cipher, "plaintext:    %s",
michael@0: 		octet_string_hex_string(buffer, length));
michael@0: 
michael@0:     /* copy plaintext into second buffer */
michael@0:     for (i=0; (unsigned int)i < length; i++)
michael@0:       buffer2[i] = buffer[i];
michael@0:     
michael@0:     /* choose a key at random */
michael@0:     if (test_case->key_length_octets > MAX_KEY_LEN)
michael@0:       return err_status_cant_check;
michael@0:     status = rand_source_get_octet_string(key, test_case->key_length_octets);
michael@0:     if (status) return status;
michael@0: 
michael@0:    /* chose a random initialization vector */
michael@0:     status = rand_source_get_octet_string(iv, MAX_KEY_LEN);
michael@0:     if (status) return status;
michael@0:         
michael@0:     /* initialize cipher */
michael@0:     status = cipher_init(c, key, direction_encrypt);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0: 
michael@0:     /* set initialization vector */
michael@0:     status = cipher_set_iv(c, test_case->idx);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     } 
michael@0: 
michael@0:     /* encrypt buffer with cipher */
michael@0:     plaintext_len = length;
michael@0:     status = cipher_encrypt(c, buffer, &length);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0:     debug_print(mod_cipher, "ciphertext:   %s",
michael@0: 		octet_string_hex_string(buffer, length));
michael@0: 
michael@0:     /* 
michael@0:      * re-initialize cipher for decryption, re-set the iv, then
michael@0:      * decrypt the ciphertext
michael@0:      */
michael@0:     status = cipher_init(c, key, direction_decrypt);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }
michael@0:     status = cipher_set_iv(c, test_case->idx);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     } 
michael@0:     status = cipher_decrypt(c, buffer, &length);
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return status;
michael@0:     }    
michael@0: 
michael@0:     debug_print(mod_cipher, "plaintext[2]: %s",
michael@0: 		octet_string_hex_string(buffer, length));    
michael@0: 
michael@0:     /* compare the resulting plaintext with the original one */
michael@0:     if (length != (unsigned)plaintext_len)
michael@0:       return err_status_algo_fail;
michael@0:     status = err_status_ok;
michael@0:     for (i=0; i < plaintext_len; i++)
michael@0:       if (buffer[i] != buffer2[i]) {
michael@0: 	status = err_status_algo_fail;
michael@0: 	debug_print(mod_cipher, "random test case %d failed", case_num);
michael@0: 	debug_print(mod_cipher, "(failure at byte %d)", i);
michael@0:       }
michael@0:     if (status) {
michael@0:       cipher_dealloc(c);
michael@0:       return err_status_algo_fail;
michael@0:     }
michael@0:         
michael@0:   }
michael@0: 
michael@0:   status = cipher_dealloc(c);
michael@0:   if (status)
michael@0:     return status;
michael@0: 
michael@0:   return err_status_ok;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* 
michael@0:  * cipher_type_self_test(ct) performs cipher_type_test on ct's internal
michael@0:  * list of test data.
michael@0:  */
michael@0: 
michael@0: err_status_t
michael@0: cipher_type_self_test(const cipher_type_t *ct) {
michael@0:   return cipher_type_test(ct, ct->test_data);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * cipher_bits_per_second(c, l, t) computes (an estimate of) the
michael@0:  * number of bits that a cipher implementation can encrypt in a second
michael@0:  * 
michael@0:  * c is a cipher (which MUST be allocated and initialized already), l
michael@0:  * is the length in octets of the test data to be encrypted, and t is
michael@0:  * the number of trials
michael@0:  *
michael@0:  * if an error is encountered, the value 0 is returned
michael@0:  */
michael@0: 
michael@0: uint64_t
michael@0: cipher_bits_per_second(cipher_t *c, int octets_in_buffer, int num_trials) {
michael@0:   int i;
michael@0:   v128_t nonce;
michael@0:   clock_t timer;
michael@0:   unsigned char *enc_buf;
michael@0:   unsigned int len = octets_in_buffer;
michael@0: 
michael@0:   enc_buf = (unsigned char*) crypto_alloc(octets_in_buffer);
michael@0:   if (enc_buf == NULL)
michael@0:     return 0;  /* indicate bad parameters by returning null */
michael@0:   
michael@0:   /* time repeated trials */
michael@0:   v128_set_to_zero(&nonce);
michael@0:   timer = clock();
michael@0:   for(i=0; i < num_trials; i++, nonce.v32[3] = i) {
michael@0:     cipher_set_iv(c, &nonce);
michael@0:     cipher_encrypt(c, enc_buf, &len);
michael@0:   }
michael@0:   timer = clock() - timer;
michael@0: 
michael@0:   crypto_free(enc_buf);
michael@0: 
michael@0:   if (timer == 0) {
michael@0:     /* Too fast! */
michael@0:     return 0;
michael@0:   }
michael@0:   
michael@0:   return (uint64_t)CLOCKS_PER_SEC * num_trials * 8 * octets_in_buffer / timer;
michael@0: }