Generic Hash

Data Structures
struct	lws_genhash_ctx
struct	lws_genhmac_ctx

Macros
#define	LWS_GENHASH_LARGEST   64

Enumerations
enum	lws_genhash_types {   LWS_GENHASH_TYPE_UNKNOWN , LWS_GENHASH_TYPE_MD5 , LWS_GENHASH_TYPE_SHA1 , LWS_GENHASH_TYPE_SHA256 ,   LWS_GENHASH_TYPE_SHA384 , LWS_GENHASH_TYPE_SHA512 }
enum	lws_genhmac_types { LWS_GENHMAC_TYPE_UNKNOWN , LWS_GENHMAC_TYPE_SHA256 , LWS_GENHMAC_TYPE_SHA384 , LWS_GENHMAC_TYPE_SHA512 }

Functions
LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT	lws_genhash_size (enum lws_genhash_types type)
LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT	lws_genhmac_size (enum lws_genhmac_types type)
LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT	lws_genhash_init (struct lws_genhash_ctx *ctx, enum lws_genhash_types type)
LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT	lws_genhash_update (struct lws_genhash_ctx *ctx, const void *in, size_t len)
LWS_VISIBLE LWS_EXTERN int	lws_genhash_destroy (struct lws_genhash_ctx *ctx, void *result)
LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT	lws_genhmac_init (struct lws_genhmac_ctx *ctx, enum lws_genhmac_types type, const uint8_t *key, size_t key_len)
LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT	lws_genhmac_update (struct lws_genhmac_ctx *ctx, const void *in, size_t len)
LWS_VISIBLE LWS_EXTERN int	lws_genhmac_destroy (struct lws_genhmac_ctx *ctx, void *result)

Detailed Description

Generic Hash related functions

Lws provides generic hash / digest accessors that abstract the ones provided by whatever tls library you are linking against.

It lets you use the same code if you build against mbedtls or OpenSSL for example.

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Data Structure Documentation

lws_genhash_ctx

struct lws_genhash_ctx

Definition at line 54 of file lws-genhash.h.

Collaboration diagram for lws_genhash_ctx:

Data Fields
uint8_t	type
const EVP_MD *	evp_type
EVP_MD_CTX *	mdctx

lws_genhmac_ctx

struct lws_genhmac_ctx

Definition at line 70 of file lws-genhash.h.

Collaboration diagram for lws_genhmac_ctx:

Data Fields
uint8_t	type
const EVP_MD *	evp_type
HMAC_CTX	ctx

Macro Definition Documentation

LWS_GENHASH_LARGEST

#define LWS_GENHASH_LARGEST   64

#include <include/libwebsockets/lws-genhash.h>

Definition at line 52 of file lws-genhash.h.

Enumeration Type Documentation

lws_genhash_types

enum lws_genhash_types

#include <include/libwebsockets/lws-genhash.h>

Enumerator
LWS_GENHASH_TYPE_UNKNOWN
LWS_GENHASH_TYPE_MD5
LWS_GENHASH_TYPE_SHA1
LWS_GENHASH_TYPE_SHA256
LWS_GENHASH_TYPE_SHA384
LWS_GENHASH_TYPE_SHA512

Definition at line 36 of file lws-genhash.h.

                       {
        LWS_GENHASH_TYPE_UNKNOWN,
        LWS_GENHASH_TYPE_MD5,
        LWS_GENHASH_TYPE_SHA1,
        LWS_GENHASH_TYPE_SHA256,
        LWS_GENHASH_TYPE_SHA384,
        LWS_GENHASH_TYPE_SHA512,
};

lws_genhmac_types

enum lws_genhmac_types

#include <include/libwebsockets/lws-genhash.h>

Enumerator
LWS_GENHMAC_TYPE_UNKNOWN
LWS_GENHMAC_TYPE_SHA256
LWS_GENHMAC_TYPE_SHA384
LWS_GENHMAC_TYPE_SHA512

Definition at line 45 of file lws-genhash.h.

                       {
        LWS_GENHMAC_TYPE_UNKNOWN,
        LWS_GENHMAC_TYPE_SHA256,
        LWS_GENHMAC_TYPE_SHA384,
        LWS_GENHMAC_TYPE_SHA512,
};

Function Documentation

lws_genhash_size()

LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT lws_genhash_size

(

enum lws_genhash_types

type

)

#include <include/libwebsockets/lws-genhash.h>

lws_genhash_size() - get hash size in bytes

Parameters

type	one of LWS_GENHASH_TYPE_...

Returns number of bytes in this type of hash, if the hash type is unknown, it will return 0.

lws_genhmac_size()

LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT lws_genhmac_size

(

enum lws_genhmac_types

type

)

#include <include/libwebsockets/lws-genhash.h>

lws_genhmac_size() - get hash size in bytes

Parameters

type	one of LWS_GENHASH_TYPE_...

Returns number of bytes in this type of hmac, if the hmac type is unknown, it will return 0.

lws_genhash_init()

LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT lws_genhash_init	(	struct lws_genhash_ctx *	ctx,
		enum lws_genhash_types	type
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhash_init() - prepare your struct lws_genhash_ctx for use

Parameters

ctx	your struct lws_genhash_ctx
type	one of LWS_GENHASH_TYPE_...

Initializes the hash context for the type you requested

lws_genhash_update()

LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT lws_genhash_update	(	struct lws_genhash_ctx *	ctx,
		const void *	in,
		size_t	len
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhash_update() - digest len bytes of the buffer starting at in

Parameters

ctx	your struct lws_genhash_ctx
in	start of the bytes to digest
len	count of bytes to digest

Updates the state of your hash context to reflect digesting len bytes from in

lws_genhash_destroy()

LWS_VISIBLE LWS_EXTERN int lws_genhash_destroy	(	struct lws_genhash_ctx *	ctx,
		void *	result
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhash_destroy() - copy out the result digest and destroy the ctx

Parameters

ctx	your struct lws_genhash_ctx
result	NULL, or where to copy the result hash

Finalizes the hash and copies out the digest. Destroys any allocations such that ctx can safely go out of scope after calling this.

NULL result is supported so that you can destroy the ctx cleanly on error conditions, where there is no valid result.

lws_genhmac_init()

LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT lws_genhmac_init	(	struct lws_genhmac_ctx *	ctx,
		enum lws_genhmac_types	type,
		const uint8_t *	key,
		size_t	key_len
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhmac_init() - prepare your struct lws_genhmac_ctx for use

Parameters

ctx	your struct lws_genhmac_ctx
type	one of LWS_GENHMAC_TYPE_...
key	pointer to the start of the HMAC key
key_len	length of the HMAC key

Initializes the hash context for the type you requested

If the return is nonzero, it failed and there is nothing needing to be destroyed.

lws_genhmac_update()

LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT lws_genhmac_update	(	struct lws_genhmac_ctx *	ctx,
		const void *	in,
		size_t	len
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhmac_update() - digest len bytes of the buffer starting at in

Parameters

ctx	your struct lws_genhmac_ctx
in	start of the bytes to digest
len	count of bytes to digest

Updates the state of your hash context to reflect digesting len bytes from in

If the return is nonzero, it failed and needs destroying.

lws_genhmac_destroy()

LWS_VISIBLE LWS_EXTERN int lws_genhmac_destroy	(	struct lws_genhmac_ctx *	ctx,
		void *	result
	)

#include <include/libwebsockets/lws-genhash.h>

lws_genhmac_destroy() - copy out the result digest and destroy the ctx

Parameters

ctx	your struct lws_genhmac_ctx
result	NULL, or where to copy the result hash

Finalizes the hash and copies out the digest. Destroys any allocations such that ctx can safely go out of scope after calling this.

NULL result is supported so that you can destroy the ctx cleanly on error conditions, where there is no valid result.