Library crypto-components
[ZRTP API REFERENCE ( for the library developers )]

Collaboration diagram for Library crypto-components:

Data Structures

struct zrtp_comp

Global structure for all crypto-component types. More...

struct zrtp_hash

Structure for defining the hash-value computing scheme The ZRTP context field zrtp_stream_ctx::_hash is initialized by the given type value and used for all hash calculations within the ZRTP sessions. Having implemented a structure of this type, it is possible to integrate new hash calculation schemes into libzrtp. More...

struct zrtp_auth_tag_length

Structure for defining the SRTP authentication scheme The ZRTP context field zrtp_stream_ctx::_authtaglength is initialized by the given type value and used for SRTP encryption configuration. More...

struct zrtp_pk_scheme

Structure for describing the public key scheme The ZRTP context field zrtp_stream_ctx::_pubkeyscheme is initialized by the given type value and used by libzrtp in public key exchange. More...

struct zrtp_sas_scheme

Structure for defining SAS generation scheme The type of the ZRTP context's field zrtp_stream_ctx::_sasscheme. It is used to generate short authentication strings. LibZRTP functionality can be augmented with a new SAS scheme by supplying your own instance of zrtp_sas_scheme. More...

struct zrtp_sig_scheme

Structure for describing the signature scheme The ZRTP context field zrtp_stream_ctx::_sigscheme is initialized by the given type value and used by libzrtp in public key exchange. More...

struct zrtp_cipher_mode

struct zrtp_cipher

Defines

#define ZRTP_COMP_UNKN   0

Typedefs

typedef enum zrtp_crypto_comp zrtp_crypto_comp_t

Enumeration for crypto-components types definition.

typedef enum zrtp_hash_id zrtp_hash_id_t

typedef enum zrtp_cipher_id zrtp_cipher_id_t

typedef enum zrtp_atl_id zrtp_atl_id_t

typedef enum zrtp_pktype_id zrtp_pktype_id_t

typedef enum zrtp_sigtype_id zrtp_sigtype_id_t

typedef enum zrtp_sas_id zrtp_sas_id_t

typedef zrtp_comp zrtp_comp_t

Global structure for all crypto-component types.

typedef enum zrtp_cipher_mode_values zrtp_cipher_mode_values_t

typedef zrtp_cipher_mode zrtp_cipher_mode_t

Enumerations

enum zrtp_crypto_comp {
  ZRTP_CC_HASH = 1, ZRTP_CC_SAS = 2, ZRTP_CC_CIPHER = 3, ZRTP_CC_PKT = 4,
  ZRTP_CC_ATL = 5, ZRTP_CC_SIG = 6
}

Enumeration for crypto-components types definition. More...

enum zrtp_hash_id { ZRTP_HASH_SHA256 = 1, ZRTP_HASH_SHA128 = 2 }

enum zrtp_cipher_id { ZRTP_CIPHER_AES128 = 1, ZRTP_CIPHER_AES256 = 2 }

enum zrtp_atl_id { ZRTP_ATL_HS32 = 1, ZRTP_ATL_HS80 = 2 }

enum zrtp_pktype_id { ZRTP_PKTYPE_PRESH = 1, ZRTP_PKTYPE_MULT = 2, ZRTP_PKTYPE_DH3072 = 3 }

enum zrtp_sigtype_id { ZRTP_SIGTYPE_EC256P = 1, ZRTP_SIGTYPE_EC384P = 2, ZRTP_SIGTYPE_EC521P = 3 }

enum zrtp_sas_id { ZRTP_SAS_BASE32 = 1, ZRTP_SAS_BASE256 = 2 }

enum zrtp_cipher_mode_values { ZRTP_CIPHER_MODE_CTR = 1, ZRTP_CIPHER_MODE_CFB = 2 }

Functions

zrtp_status_t zrtp_clear_comp (zrtp_crypto_comp_t type, zrtp_global_ctx_t *zrtp_global)

Clear components buffer This function clears the buffer of the components which are defined by the type parameter. It is used before registering a component.

zrtp_status_t zrtp_done_comp (zrtp_crypto_comp_t type, zrtp_global_ctx_t *zrtp_global)

Destroy components buffer This function clears the list of components of the specified type, destroys all components and releases all allocated resources. It is used on libzrtp down. zrtp_done_comp calls zrtp_comp_t::free() if it isn't NULL.

zrtp_status_t zrtp_register_comp (zrtp_crypto_comp_t type, void *comp, zrtp_global_ctx_t *zrtp_global)

Registering a new crypto-component Correctness of values in the necessary structure is the developer's responsibility. zrtp_register_comp calls zrtp_comp_t::init() if it isn't NULL.

void * zrtp_find_comp (zrtp_crypto_comp_t type, uint8_t id, zrtp_global_ctx_t *zrtp_global)

Search component by ID.

char * zrtp_comp_id2type (zrtp_crypto_comp_t type, uint8_t id)

uint8_t zrtp_comp_type2id (zrtp_crypto_comp_t type, char *name)

Detailed Description

This section describes functions and data types for managing crypto-components. All these functions and structures are used by the libZRTP kernel for the built-in crypt-components management. The developer has the option of implementing and integrating her own components into the library. This is not a full manual on creating crypto-components. Its purpose is only to elucidate the library functionality.

The concept behind crypto components is similar to that of classes in object oriented programming. The components are defined as structures and manipulated by functions. Component attributes are stored in 'contexts', and are defined during initialization. Resources allocated at initialization are freed with the 'free' function.

Components are divided into 5 functional groups (component types):

ciphers;
hash/hmac components;
public key exchange schemes;
components defined SRTP authentication scheme;
SAS calculation schemes. Within a group, components are distinguished by integer identifiers and by their defined functionality. So to fully identify a component, you need to know its type and its identifier. (For example an AES cipher with a 128 bit key is defined as: ZRTP_CC_CIPHER, zrtp_cipher_id_t::ZRTP_CIPHER_AES128). The high number of components means that every component must have a minimal set of attributes and functions: type identifier, and function initialization and deinitialization. The base type of all components is zrtp_comp_t. Every new component MUST start with definitions of this structure strictly in the given order.
Warning:
Every crypto-component included in libZRTP was developed and tested by professionals. Its presence is functionally based. Using only the built-in components gives you 100% crypto-strength and the guarantee of the fully tested code. Never use your own components without strong reasons. If you have noticed the absence of any important component in the library, contact the developers. Reasonable offers will be considered for implementation in the following versions.

Define Documentation

#define ZRTP_COMP_UNKN 0

This ID with code 0 is used as an error signal by all crypto-components groups to indicate a wrongly defined component identifier.

Definition at line 91 of file zrtp_crypto.h.

Typedef Documentation

typedef enum zrtp_atl_id zrtp_atl_id_t

Defines SRTP authentication schemes

typedef enum zrtp_cipher_id zrtp_cipher_id_t

Defines types of ciphers

typedef struct zrtp_cipher_mode zrtp_cipher_mode_t

typedef enum zrtp_cipher_mode_values zrtp_cipher_mode_values_t

Defines block cipher modes.

typedef struct zrtp_comp zrtp_comp_t

Global structure for all crypto-component types.

Warning:: All developed components must have these 4 fields at the beginning.

typedef enum zrtp_crypto_comp zrtp_crypto_comp_t

Enumeration for crypto-components types definition.

typedef enum zrtp_hash_id zrtp_hash_id_t

Defines types of hash functions

typedef enum zrtp_pktype_id zrtp_pktype_id_t

Defines public key exchange schemes

typedef enum zrtp_sas_id zrtp_sas_id_t

Defines modes of short authentication scheme calculation

typedef enum zrtp_sigtype_id zrtp_sigtype_id_t

Defines signature schemes

Enumeration Type Documentation

enum zrtp_atl_id

Defines SRTP authentication schemes

Enumerator:

ZRTP_ATL_HS32
ZRTP_ATL_HS80

Definition at line 108 of file zrtp_crypto.h.

enum zrtp_cipher_id

Defines types of ciphers

Enumerator:

ZRTP_CIPHER_AES128
ZRTP_CIPHER_AES256

Definition at line 101 of file zrtp_crypto.h.

enum zrtp_cipher_mode_values

Defines block cipher modes.

Enumerator:

ZRTP_CIPHER_MODE_CTR
ZRTP_CIPHER_MODE_CFB

Definition at line 522 of file zrtp_crypto.h.

enum zrtp_crypto_comp

Enumeration for crypto-components types definition.

Enumerator:

ZRTP_CC_HASH	hash calculation schemes
ZRTP_CC_SAS	short autentification scheme components
ZRTP_CC_CIPHER	ciphers
ZRTP_CC_PKT	public key exchange scheme
ZRTP_CC_ATL
ZRTP_CC_SIG	digital signature scheme

Definition at line 75 of file zrtp_crypto.h.

enum zrtp_hash_id

Defines types of hash functions

Enumerator:

ZRTP_HASH_SHA256
ZRTP_HASH_SHA128

Definition at line 94 of file zrtp_crypto.h.

enum zrtp_pktype_id

Defines public key exchange schemes

Enumerator:

ZRTP_PKTYPE_PRESH
ZRTP_PKTYPE_MULT
ZRTP_PKTYPE_DH3072

Definition at line 115 of file zrtp_crypto.h.

enum zrtp_sas_id

Defines modes of short authentication scheme calculation

Enumerator:

ZRTP_SAS_BASE32
ZRTP_SAS_BASE256

Definition at line 141 of file zrtp_crypto.h.

enum zrtp_sigtype_id

Defines signature schemes

Enumerator:

ZRTP_SIGTYPE_EC256P
ZRTP_SIGTYPE_EC384P
ZRTP_SIGTYPE_EC521P

Definition at line 132 of file zrtp_crypto.h.

Function Documentation

zrtp_status_t zrtp_clear_comp	(	zrtp_crypto_comp_t	type,
		zrtp_global_ctx_t *	zrtp_global
	)

Clear components buffer This function clears the buffer of the components which are defined by the type parameter. It is used before registering a component.

Parameters:

	zrtp_global	- the ZRTP global context where components are stored;
	type	- specifies the component pool type for clearing.

Returns:

zrtp_status_ok - if clearing was successful;
zrtp_status_fail - if error.

char* zrtp_comp_id2type	(	zrtp_crypto_comp_t	type,
		uint8_t	id
	)

Converts a component's integer ID to a symbolic ZRTP name

uint8_t zrtp_comp_type2id	(	zrtp_crypto_comp_t	type,
		char *	name
	)

Converts a component's ZRTP symbolic name to an integer ID

zrtp_status_t zrtp_done_comp	(	zrtp_crypto_comp_t	type,
		zrtp_global_ctx_t *	zrtp_global
	)

Destroy components buffer This function clears the list of components of the specified type, destroys all components and releases all allocated resources. It is used on libzrtp down. zrtp_done_comp calls zrtp_comp_t::free() if it isn't NULL.

Parameters:

	zrtp_global	- the ZRTP global context where components are stored;
	type	- specifies the component pool type for destroying.

Returns:

zrtp_status_ok - if clearing successful;
zrtp_status_fail - if error.

void* zrtp_find_comp	(	zrtp_crypto_comp_t	type,
		uint8_t	id,
		zrtp_global_ctx_t *	zrtp_global
	)

Search component by ID.

Parameters:

	type	- type of sought component;
	zrtp_global	- the ZRTP global context where components are stored;
	id	- integer identifier of the necessary element.

Returns:

the found structure if successful;
NULL if the element with the specified ID can't be found or other error.

zrtp_status_t zrtp_register_comp	(	zrtp_crypto_comp_t	type,
		void *	comp,
		zrtp_global_ctx_t *	zrtp_global
	)

Registering a new crypto-component Correctness of values in the necessary structure is the developer's responsibility. zrtp_register_comp calls zrtp_comp_t::init() if it isn't NULL.

Parameters:

	type	- type of registred component;
	comp	- registered crypto-component;
	zrtp_global	- the ZRTP global context where components are stored.

Returns:

zrtp_status_ok if registration successful;
zrtp_status_fail if error (conflicts with other components).

This file is part of the documentation for Zfone.


Data Structures
struct	zrtp_comp
	Global structure for all crypto-component types. More...
struct	zrtp_hash
	Structure for defining the hash-value computing scheme The ZRTP context field zrtp_stream_ctx::_hash is initialized by the given type value and used for all hash calculations within the ZRTP sessions. Having implemented a structure of this type, it is possible to integrate new hash calculation schemes into libzrtp. More...
struct	zrtp_auth_tag_length
	Structure for defining the SRTP authentication scheme The ZRTP context field zrtp_stream_ctx::_authtaglength is initialized by the given type value and used for SRTP encryption configuration. More...
struct	zrtp_pk_scheme
	Structure for describing the public key scheme The ZRTP context field zrtp_stream_ctx::_pubkeyscheme is initialized by the given type value and used by libzrtp in public key exchange. More...
struct	zrtp_sas_scheme
	Structure for defining SAS generation scheme The type of the ZRTP context's field zrtp_stream_ctx::_sasscheme. It is used to generate short authentication strings. LibZRTP functionality can be augmented with a new SAS scheme by supplying your own instance of zrtp_sas_scheme. More...
struct	zrtp_sig_scheme
	Structure for describing the signature scheme The ZRTP context field zrtp_stream_ctx::_sigscheme is initialized by the given type value and used by libzrtp in public key exchange. More...
struct	zrtp_cipher_mode
struct	zrtp_cipher
Defines
#define	ZRTP_COMP_UNKN 0
Typedefs
typedef enum zrtp_crypto_comp	zrtp_crypto_comp_t
	Enumeration for crypto-components types definition.
typedef enum zrtp_hash_id	zrtp_hash_id_t
typedef enum zrtp_cipher_id	zrtp_cipher_id_t
typedef enum zrtp_atl_id	zrtp_atl_id_t
typedef enum zrtp_pktype_id	zrtp_pktype_id_t
typedef enum zrtp_sigtype_id	zrtp_sigtype_id_t
typedef enum zrtp_sas_id	zrtp_sas_id_t
typedef zrtp_comp	zrtp_comp_t
	Global structure for all crypto-component types.
typedef enum zrtp_cipher_mode_values	zrtp_cipher_mode_values_t
typedef zrtp_cipher_mode	zrtp_cipher_mode_t
Enumerations
enum	zrtp_crypto_comp { ZRTP_CC_HASH = 1, ZRTP_CC_SAS = 2, ZRTP_CC_CIPHER = 3, ZRTP_CC_PKT = 4, ZRTP_CC_ATL = 5, ZRTP_CC_SIG = 6 }
	Enumeration for crypto-components types definition. More...
enum	zrtp_hash_id { ZRTP_HASH_SHA256 = 1, ZRTP_HASH_SHA128 = 2 }
enum	zrtp_cipher_id { ZRTP_CIPHER_AES128 = 1, ZRTP_CIPHER_AES256 = 2 }
enum	zrtp_atl_id { ZRTP_ATL_HS32 = 1, ZRTP_ATL_HS80 = 2 }
enum	zrtp_pktype_id { ZRTP_PKTYPE_PRESH = 1, ZRTP_PKTYPE_MULT = 2, ZRTP_PKTYPE_DH3072 = 3 }
enum	zrtp_sigtype_id { ZRTP_SIGTYPE_EC256P = 1, ZRTP_SIGTYPE_EC384P = 2, ZRTP_SIGTYPE_EC521P = 3 }
enum	zrtp_sas_id { ZRTP_SAS_BASE32 = 1, ZRTP_SAS_BASE256 = 2 }
enum	zrtp_cipher_mode_values { ZRTP_CIPHER_MODE_CTR = 1, ZRTP_CIPHER_MODE_CFB = 2 }
Functions
zrtp_status_t	zrtp_clear_comp (zrtp_crypto_comp_t type, zrtp_global_ctx_t *zrtp_global)
	Clear components buffer This function clears the buffer of the components which are defined by the `type` parameter. It is used before registering a component.
zrtp_status_t	zrtp_done_comp (zrtp_crypto_comp_t type, zrtp_global_ctx_t *zrtp_global)
	Destroy components buffer This function clears the list of components of the specified type, destroys all components and releases all allocated resources. It is used on libzrtp down. zrtp_done_comp calls zrtp_comp_t::free() if it isn't NULL.
zrtp_status_t	zrtp_register_comp (zrtp_crypto_comp_t type, void comp, zrtp_global_ctx_t zrtp_global)
	Registering a new crypto-component Correctness of values in the necessary structure is the developer's responsibility. zrtp_register_comp calls zrtp_comp_t::init() if it isn't NULL.
void *	zrtp_find_comp (zrtp_crypto_comp_t type, uint8_t id, zrtp_global_ctx_t *zrtp_global)
	Search component by ID.
char *	zrtp_comp_id2type (zrtp_crypto_comp_t type, uint8_t id)
uint8_t	zrtp_comp_type2id (zrtp_crypto_comp_t type, char *name)

Library crypto-components [ZRTP API REFERENCE ( for the library developers )]

Data Structures

Defines

Typedefs

Enumerations

Functions

Detailed Description

Define Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation

Library crypto-components
[ZRTP API REFERENCE ( for the library developers )]