zephyr/include/data/jwt.h

105 lines
2.1 KiB
C

/*
* Copyright (c) 2018 Linaro Ltd
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DATA_JWT_H_
#define ZEPHYR_INCLUDE_DATA_JWT_H_
#include <zephyr/types.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief JSON Web Token (JWT)
* @defgroup jwt JSON Web Token (JWT)
* @ingroup structured_data
* @{
*/
/**
* @brief JWT data tracking.
*
* JSON Web Tokens contain several sections, each encoded in base-64.
* This structure tracks the token as it is being built, including
* limits on the amount of available space. It should be initialized
* with jwt_init().
*/
struct jwt_builder {
/** The base of the buffer we are writing to. */
char *base;
/** The place in this buffer where we are currently writing.
*/
char *buf;
/** The length remaining to write. */
size_t len;
/**
* Flag that is set if we try to write past the end of the
* buffer. If set, the token is not valid.
*/
bool overflowed;
/* Pending bytes yet to be converted to base64. */
unsigned char wip[3];
/* Number of pending bytes. */
int pending;
};
/**
* @brief Initialize the JWT builder.
*
* Initialize the given JWT builder for the creation of a fresh token.
* The buffer size should at least be as long as JWT_BUILDER_MAX_SIZE
* returns.
*
* @param builder The builder to initialize.
* @param buffer The buffer to write the token to.
* @param buffer_size The size of this buffer. The token will be NULL
* terminated, which needs to be allowed for in this size.
*
* @retval 0 Success
* @retval -ENOSPC Buffer is insufficient to initialize
*/
int jwt_init_builder(struct jwt_builder *builder,
char *buffer,
size_t buffer_size);
/**
* @brief add JWT primary payload.
*/
int jwt_add_payload(struct jwt_builder *builder,
s32_t exp,
s32_t iat,
const char *aud);
/**
* @brief Sign the JWT token.
*/
int jwt_sign(struct jwt_builder *builder,
const char *der_key,
size_t der_key_len);
static inline size_t jwt_payload_len(struct jwt_builder *builder)
{
return (builder->buf - builder->base);
}
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_DATA_JWT_H_ */