crypto/include/cipher.h - platform/external/libsrtp2 - Gitiles

 /*
  * cipher.h
  *
  * common interface to ciphers
  *
  * David A. McGrew
  * Cisco Systems, Inc.
  */
 /*
  *
  * Copyright (c) 2001-2006,2013 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.
  *
  */


 #ifndef CIPHER_H
 #define CIPHER_H

 #include "srtp.h"
 #include "datatypes.h"
 #include "rdbx.h"               /* for srtp_xtd_seq_num_t */
 #include "err.h"                /* for error codes  */
 #include "crypto_types.h"       /* for values of cipher_type_id_t */


 /*
  * cipher_direction_t defines a particular cipher operation.
  *
  * A cipher_direction_t is an enum that describes a particular cipher
  * operation, i.e. encryption or decryption.  For some ciphers, this
  * distinction does not matter, but for others, it is essential.
  */
 typedef enum {
     direction_encrypt, /**< encryption (convert plaintext to ciphertext) */
     direction_decrypt, /**< decryption (convert ciphertext to plaintext) */
     direction_any      /**< encryption or decryption                     */
 } srtp_cipher_direction_t;

 /*
  * the cipher_pointer and cipher_type_pointer definitions are needed
  * as cipher_t and cipher_type_t are not yet defined
  */
 typedef struct srtp_cipher_t      *srtp_cipher_pointer_t;

 /*
  *  a cipher_alloc_func_t allocates (but does not initialize) a cipher_t
  */
 typedef srtp_err_status_t (*cipher_alloc_func_t)
     (srtp_cipher_pointer_t *cp, int key_len, int tag_len);

 /*
  * a cipher_init_func_t [re-]initializes a cipher_t with a given key
  */
 typedef srtp_err_status_t (*cipher_init_func_t)
     (void *state, const uint8_t *key, int key_len);

 /* a cipher_dealloc_func_t de-allocates a cipher_t */
 typedef srtp_err_status_t (*cipher_dealloc_func_t)(srtp_cipher_pointer_t cp);

 /* a cipher_set_segment_func_t sets the segment index of a cipher_t */
 typedef srtp_err_status_t (*cipher_set_segment_func_t)
     (void *state, srtp_xtd_seq_num_t idx);

 /*
  * a cipher_set_aad_func_t processes the AAD data for AEAD ciphers
  */
 typedef srtp_err_status_t (*cipher_set_aad_func_t)
     (void *state, uint8_t *aad, unsigned int aad_len);


 /* a cipher_encrypt_func_t encrypts data in-place */
 typedef srtp_err_status_t (*cipher_encrypt_func_t)
     (void *state, uint8_t *buffer, unsigned int *octets_to_encrypt);

 /* a cipher_decrypt_func_t decrypts data in-place */
 typedef srtp_err_status_t (*cipher_decrypt_func_t)
     (void *state, uint8_t *buffer, unsigned int *octets_to_decrypt);

 /*
  * a cipher_set_iv_func_t function sets the current initialization vector
  */
 typedef srtp_err_status_t (*cipher_set_iv_func_t)
     (srtp_cipher_pointer_t cp, void *iv, srtp_cipher_direction_t direction);

 /*
  * a cipher_get_tag_funct_t function is used to get the authentication
  * tag that was calculated by an AEAD cipher.
  */
 typedef srtp_err_status_t (*cipher_get_tag_func_t)
     (void *state, void *tag, int *len);


 /*
  * cipher_test_case_t is a (list of) key, salt, srtp_xtd_seq_num_t,
  * plaintext, and ciphertext values that are known to be correct for a
  * particular cipher.  this data can be used to test an implementation
  * in an on-the-fly self test of the correcness of the implementation.
  * (see the cipher_type_self_test() function below)
  */
 typedef struct srtp_cipher_test_case_t {
     int key_length_octets;                          /* octets in key            */
     uint8_t *key;                                   /* key                      */
     uint8_t *idx;                                   /* packet index             */
     int plaintext_length_octets;                    /* octets in plaintext      */
     uint8_t *plaintext;                             /* plaintext                */
     int ciphertext_length_octets;                   /* octets in plaintext      */
     uint8_t *ciphertext;                            /* ciphertext               */
     int aad_length_octets;                          /* octets in AAD            */
     uint8_t *aad;                                   /* AAD                      */
     int tag_length_octets;                          /* Length of AEAD tag       */
     struct srtp_cipher_test_case_t *next_test_case; /* pointer to next testcase */
 } srtp_cipher_test_case_t;

 /* cipher_type_t defines the 'metadata' for a particular cipher type */
 typedef struct srtp_cipher_type_t {
     cipher_alloc_func_t alloc;
     cipher_dealloc_func_t dealloc;
     cipher_init_func_t init;
     cipher_set_aad_func_t set_aad;
     cipher_encrypt_func_t encrypt;
     cipher_encrypt_func_t decrypt;
     cipher_set_iv_func_t set_iv;
     cipher_get_tag_func_t get_tag;
     char                       *description;
     srtp_cipher_test_case_t         *test_data;
     srtp_debug_module_t             *debug;
     srtp_cipher_type_id_t id;
 } srtp_cipher_type_t;

 /*
  * cipher_t defines an instantiation of a particular cipher, with fixed
  * key length, key and salt values
  */
 typedef struct srtp_cipher_t {
     srtp_cipher_type_t *type;
     void          *state;
     int key_len;
     int algorithm;
 } srtp_cipher_t;

 /* some syntactic sugar on these function types */
 #define cipher_type_alloc(ct, c, klen, tlen) ((ct)->alloc((c), (klen), (tlen)))

 #define cipher_dealloc(c) (((c)->type)->dealloc(c))

 #define cipher_init(c, k) (((c)->type)->init(((c)->state), (k), ((c)->key_len)))

 #define cipher_get_tag(c, buf, len) \
     (((c)->type)->get_tag(((c)->state), (buf), (len)))

 #define cipher_set_iv(c, n, dir)                           \
     ((c) ? (((c)->type)->set_iv(((srtp_cipher_pointer_t)(c)->state), (n), (dir))) :   \
      srtp_err_status_no_such_op)
 #define cipher_set_aad(c, a, l)                       \
     (((c) && (((c)->type)->set_aad)) ?                  \
      (((c)->type)->set_aad(((c)->state), (a), (l))) :    \
      srtp_err_status_no_such_op)


 /* some bookkeeping functions */
 int srtp_cipher_get_key_length(const srtp_cipher_t *c);


 /*
  * cipher_type_self_test() tests a cipher against test cases provided in
  * an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
  * that is known to be good
  */
 srtp_err_status_t srtp_cipher_type_self_test(const srtp_cipher_type_t *ct);


 /*
  * cipher_type_test() tests a cipher against external test cases provided in
  * an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
  * that is known to be good
  */
 srtp_err_status_t srtp_cipher_type_test(const srtp_cipher_type_t *ct, const srtp_cipher_test_case_t *test_data);


 /*
  * cipher_bits_per_second(c, l, t) computes (and 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, then the value 0 is returned
  */
 uint64_t srtp_cipher_bits_per_second(srtp_cipher_t *c, int octets_in_buffer, int num_trials);

 srtp_err_status_t srtp_cipher_output(srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output);
 srtp_err_status_t srtp_cipher_encrypt(srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output);
 srtp_err_status_t srtp_cipher_decrypt(srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output);

 #endif /* CIPHER_H */
	/*
	* cipher.h
	*
	* common interface to ciphers
	*
	* David A. McGrew
	* Cisco Systems, Inc.
	*/
	/*
	*
	* Copyright (c) 2001-2006,2013 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.
	*
	*/


	#ifndef CIPHER_H
	#define CIPHER_H

	#include "srtp.h"
	#include "datatypes.h"
	#include "rdbx.h" /* for srtp_xtd_seq_num_t */
	#include "err.h" /* for error codes */
	#include "crypto_types.h" /* for values of cipher_type_id_t */


	/*
	* cipher_direction_t defines a particular cipher operation.
	*
	* A cipher_direction_t is an enum that describes a particular cipher
	* operation, i.e. encryption or decryption. For some ciphers, this
	* distinction does not matter, but for others, it is essential.
	*/
	typedef enum {
	direction_encrypt, /*< encryption (convert plaintext to ciphertext) /
	direction_decrypt, /*< decryption (convert ciphertext to plaintext) /
	direction_any /*< encryption or decryption /
	} srtp_cipher_direction_t;

	/*
	* the cipher_pointer and cipher_type_pointer definitions are needed
	* as cipher_t and cipher_type_t are not yet defined
	*/
	typedef struct srtp_cipher_t *srtp_cipher_pointer_t;

	/*
	* a cipher_alloc_func_t allocates (but does not initialize) a cipher_t
	*/
	typedef srtp_err_status_t (*cipher_alloc_func_t)
	(srtp_cipher_pointer_t *cp, int key_len, int tag_len);

	/*
	* a cipher_init_func_t [re-]initializes a cipher_t with a given key
	*/
	typedef srtp_err_status_t (*cipher_init_func_t)
	(void state, const uint8_t key, int key_len);

	/* a cipher_dealloc_func_t de-allocates a cipher_t */
	typedef srtp_err_status_t (*cipher_dealloc_func_t)(srtp_cipher_pointer_t cp);

	/* a cipher_set_segment_func_t sets the segment index of a cipher_t */
	typedef srtp_err_status_t (*cipher_set_segment_func_t)
	(void *state, srtp_xtd_seq_num_t idx);

	/*
	* a cipher_set_aad_func_t processes the AAD data for AEAD ciphers
	*/
	typedef srtp_err_status_t (*cipher_set_aad_func_t)
	(void state, uint8_t aad, unsigned int aad_len);


	/* a cipher_encrypt_func_t encrypts data in-place */
	typedef srtp_err_status_t (*cipher_encrypt_func_t)
	(void state, uint8_t buffer, unsigned int *octets_to_encrypt);

	/* a cipher_decrypt_func_t decrypts data in-place */
	typedef srtp_err_status_t (*cipher_decrypt_func_t)
	(void state, uint8_t buffer, unsigned int *octets_to_decrypt);

	/*
	* a cipher_set_iv_func_t function sets the current initialization vector
	*/
	typedef srtp_err_status_t (*cipher_set_iv_func_t)
	(srtp_cipher_pointer_t cp, void *iv, srtp_cipher_direction_t direction);

	/*
	* a cipher_get_tag_funct_t function is used to get the authentication
	* tag that was calculated by an AEAD cipher.
	*/
	typedef srtp_err_status_t (*cipher_get_tag_func_t)
	(void state, void tag, int *len);


	/*
	* cipher_test_case_t is a (list of) key, salt, srtp_xtd_seq_num_t,
	* plaintext, and ciphertext values that are known to be correct for a
	* particular cipher. this data can be used to test an implementation
	* in an on-the-fly self test of the correcness of the implementation.
	* (see the cipher_type_self_test() function below)
	*/
	typedef struct srtp_cipher_test_case_t {
	int key_length_octets; /* octets in key */
	uint8_t key; / key */
	uint8_t idx; / packet index */
	int plaintext_length_octets; /* octets in plaintext */
	uint8_t plaintext; / plaintext */
	int ciphertext_length_octets; /* octets in plaintext */
	uint8_t ciphertext; / ciphertext */
	int aad_length_octets; /* octets in AAD */
	uint8_t aad; / AAD */
	int tag_length_octets; /* Length of AEAD tag */
	struct srtp_cipher_test_case_t next_test_case; / pointer to next testcase */
	} srtp_cipher_test_case_t;

	/* cipher_type_t defines the 'metadata' for a particular cipher type */
	typedef struct srtp_cipher_type_t {
	cipher_alloc_func_t alloc;
	cipher_dealloc_func_t dealloc;
	cipher_init_func_t init;
	cipher_set_aad_func_t set_aad;
	cipher_encrypt_func_t encrypt;
	cipher_encrypt_func_t decrypt;
	cipher_set_iv_func_t set_iv;
	cipher_get_tag_func_t get_tag;
	char *description;
	srtp_cipher_test_case_t *test_data;
	srtp_debug_module_t *debug;
	srtp_cipher_type_id_t id;
	} srtp_cipher_type_t;

	/*
	* cipher_t defines an instantiation of a particular cipher, with fixed
	* key length, key and salt values
	*/
	typedef struct srtp_cipher_t {
	srtp_cipher_type_t *type;
	void *state;
	int key_len;
	int algorithm;
	} srtp_cipher_t;

	/* some syntactic sugar on these function types */
	#define cipher_type_alloc(ct, c, klen, tlen) ((ct)->alloc((c), (klen), (tlen)))

	#define cipher_dealloc(c) (((c)->type)->dealloc(c))

	#define cipher_init(c, k) (((c)->type)->init(((c)->state), (k), ((c)->key_len)))

	#define cipher_get_tag(c, buf, len) \
	(((c)->type)->get_tag(((c)->state), (buf), (len)))

	#define cipher_set_iv(c, n, dir) \
	((c) ? (((c)->type)->set_iv(((srtp_cipher_pointer_t)(c)->state), (n), (dir))) : \
	srtp_err_status_no_such_op)
	#define cipher_set_aad(c, a, l) \
	(((c) && (((c)->type)->set_aad)) ? \
	(((c)->type)->set_aad(((c)->state), (a), (l))) : \
	srtp_err_status_no_such_op)


	/* some bookkeeping functions */
	int srtp_cipher_get_key_length(const srtp_cipher_t *c);


	/*
	* cipher_type_self_test() tests a cipher against test cases provided in
	* an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
	* that is known to be good
	*/
	srtp_err_status_t srtp_cipher_type_self_test(const srtp_cipher_type_t *ct);


	/*
	* cipher_type_test() tests a cipher against external test cases provided in
	* an array of values of key/srtp_xtd_seq_num_t/plaintext/ciphertext
	* that is known to be good
	*/
	srtp_err_status_t srtp_cipher_type_test(const srtp_cipher_type_t ct, const srtp_cipher_test_case_t test_data);


	/*
	* cipher_bits_per_second(c, l, t) computes (and 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, then the value 0 is returned
	*/
	uint64_t srtp_cipher_bits_per_second(srtp_cipher_t *c, int octets_in_buffer, int num_trials);

	srtp_err_status_t srtp_cipher_output(srtp_cipher_t c, uint8_t buffer, uint32_t *num_octets_to_output);
	srtp_err_status_t srtp_cipher_encrypt(srtp_cipher_t c, uint8_t buffer, uint32_t *num_octets_to_output);
	srtp_err_status_t srtp_cipher_decrypt(srtp_cipher_t c, uint8_t buffer, uint32_t *num_octets_to_output);

	#endif /* CIPHER_H */