Update libsrtp to version 2.0

crypto/include/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 "crypto_types.h"       /* for values of cipher_type_id_t */
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * srtp_cipher_direction_t defines a particular cipher operation.
+ *
+ * A srtp_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 {
+    srtp_direction_encrypt, /**< encryption (convert plaintext to ciphertext) */
+    srtp_direction_decrypt, /**< decryption (convert ciphertext to plaintext) */
+    srtp_direction_any      /**< encryption or decryption                     */
+} srtp_cipher_direction_t;
+
+/*
+ * the srtp_cipher_pointer_t definition is needed
+ * as srtp_cipher_t is not yet defined
+ */
+typedef struct srtp_cipher_t      *srtp_cipher_pointer_t;
+
+/*
+ *  a srtp_cipher_alloc_func_t allocates (but does not initialize) a srtp_cipher_t
+ */
+typedef srtp_err_status_t (*srtp_cipher_alloc_func_t)
+    (srtp_cipher_pointer_t *cp, int key_len, int tag_len);
+
+/*
+ * a srtp_cipher_init_func_t [re-]initializes a cipher_t with a given key
+ */
+typedef srtp_err_status_t (*srtp_cipher_init_func_t)
+    (void *state, const uint8_t *key);
+
+/* a srtp_cipher_dealloc_func_t de-allocates a cipher_t */
+typedef srtp_err_status_t (*srtp_cipher_dealloc_func_t)(srtp_cipher_pointer_t cp);
+
+/*
+ * a srtp_cipher_set_aad_func_t processes the AAD data for AEAD ciphers
+ */
+typedef srtp_err_status_t (*srtp_cipher_set_aad_func_t)
+    (void *state, const uint8_t *aad, uint32_t aad_len);
+
+
+/* a srtp_cipher_encrypt_func_t encrypts data in-place */
+typedef srtp_err_status_t (*srtp_cipher_encrypt_func_t)
+    (void *state, uint8_t *buffer, unsigned int *octets_to_encrypt);
+
+/* a srtp_cipher_decrypt_func_t decrypts data in-place */
+typedef srtp_err_status_t (*srtp_cipher_decrypt_func_t)
+    (void *state, uint8_t *buffer, unsigned int *octets_to_decrypt);
+
+/*
+ * a srtp_cipher_set_iv_func_t function sets the current initialization vector
+ */
+typedef srtp_err_status_t (*srtp_cipher_set_iv_func_t)
+    (void *state, uint8_t *iv, srtp_cipher_direction_t direction);
+
+/*
+ * a cipher_get_tag_func_t function is used to get the authentication
+ * tag that was calculated by an AEAD cipher.
+ */
+typedef srtp_err_status_t (*srtp_cipher_get_tag_func_t)
+    (void *state, uint8_t *tag, uint32_t *len);
+
+
+/*
+ * srtp_cipher_test_case_t is a (list of) key, salt, plaintext, ciphertext,
+ * and aad 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 correctness of the implementation.
+ * (see the srtp_cipher_type_self_test() function below)
+ */
+typedef struct srtp_cipher_test_case_t {
+    int key_length_octets;                          /* octets in key            */
+    const uint8_t *key;                                   /* key                      */
+    uint8_t *idx;                                   /* packet index             */
+    int plaintext_length_octets;                    /* octets in plaintext      */
+    const uint8_t *plaintext;                             /* plaintext                */
+    int ciphertext_length_octets;                   /* octets in plaintext      */
+    const uint8_t *ciphertext;                            /* ciphertext               */
+    int aad_length_octets;                          /* octets in AAD            */
+    const uint8_t *aad;                                   /* AAD                      */
+    int tag_length_octets;                          /* Length of AEAD tag       */
+    const struct srtp_cipher_test_case_t *next_test_case; /* pointer to next testcase */
+} srtp_cipher_test_case_t;
+
+/* srtp_cipher_type_t defines the 'metadata' for a particular cipher type */
+typedef struct srtp_cipher_type_t {
+    srtp_cipher_alloc_func_t alloc;
+    srtp_cipher_dealloc_func_t dealloc;
+    srtp_cipher_init_func_t init;
+    srtp_cipher_set_aad_func_t set_aad;
+    srtp_cipher_encrypt_func_t encrypt;
+    srtp_cipher_encrypt_func_t decrypt;
+    srtp_cipher_set_iv_func_t set_iv;
+    srtp_cipher_get_tag_func_t get_tag;
+    const char                       *description;
+    const srtp_cipher_test_case_t         *test_data;
+    srtp_cipher_type_id_t id;
+} srtp_cipher_type_t;
+
+/*
+ * srtp_cipher_t defines an instantiation of a particular cipher, with fixed
+ * key length, key and salt values
+ */
+typedef struct srtp_cipher_t {
+    const srtp_cipher_type_t *type;
+    void          *state;
+    int key_len;
+    int algorithm;
+} srtp_cipher_t;
+
+/* some bookkeeping functions */
+int srtp_cipher_get_key_length(const srtp_cipher_t *c);
+
+
+/*
+ * srtp_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);
+
+
+/*
+ * srtp_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);
+
+
+/*
+ * srtp_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, 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_type_alloc(const srtp_cipher_type_t *ct, srtp_cipher_t **c, int key_len, int tlen);
+srtp_err_status_t srtp_cipher_dealloc(srtp_cipher_t *c);
+srtp_err_status_t srtp_cipher_init(srtp_cipher_t *c, const uint8_t *key);
+srtp_err_status_t srtp_cipher_set_iv(srtp_cipher_t *c, uint8_t *iv, int direction);
+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); 
+srtp_err_status_t srtp_cipher_get_tag(srtp_cipher_t *c, uint8_t *buffer, uint32_t *tag_len);
+srtp_err_status_t srtp_cipher_set_aad(srtp_cipher_t *c, const uint8_t *aad, uint32_t aad_len);
+
+/*
+ * srtp_replace_cipher_type(ct, id)
+ *
+ * replaces srtp's existing cipher implementation for the cipher_type id
+ * with a new one passed in externally.  The new cipher must pass all the
+ * existing cipher_type's self tests as well as its own.
+ */
+srtp_err_status_t srtp_replace_cipher_type(const srtp_cipher_type_t *ct, srtp_cipher_type_id_t id);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CIPHER_H */