/* See LICENSE file for copyright and license details. */
#ifndef LIBSHA1_H
#define LIBSHA1_H 1
#include <stdint.h>
#include <stddef.h>
/**
* Algorithms supported by libsha1
*/
enum libsha1_algorithm {
/**
* SHA-0, outputs 20 bytes
*/
LIBSHA1_0,
/**
* SHA-1, outputs 20 bytes
*/
LIBSHA1_1
};
/**
* Data structure that describes the state of a hashing process
*
* Data that could just as well be allocated (with `auto`) are
* allocated here so that is is easier to wipe the data without
* exposing two versions of each function: one to wipe data,
* and one not to wipe data to gain speed, now you can use use
* `explicit_bzero` (or `memset`) when you are done.
*/
struct libsha1_state {
/**
* The size of the message, as far as processed, in bits;
*/
size_t message_size;
/**
* Words
*
* Does not need to be marshalled
*/
uint32_t w[80];
/**
* Hashing values
*/
uint32_t h[5];
/**
* Space for chunks to process
*/
unsigned char chunk[64];
/**
* The algorithm that is used
*/
enum libsha1_algorithm algorithm;
int __padding1;
};
/**
* Data structure that describes the state of a HMAC hashing process
*
* Data that could just as well be allocated (with `auto`) are
* allocated here so that is is easier to wipe the data without
* exposing two versions of each function: one to wipe data,
* and one not to wipe data to gain speed, now you can use use
* `explicit_bzero` (or `memset`) when you are done.
*/
struct libsha1_hmac_state {
/**
* State of the underlaying hash function
*/
struct libsha1_state sha1_state;
/**
* The output size of the underlaying
* hash algorithm, in bits
*/
size_t outsize;
/**
* Whether `.sha1_state` has been initialised
* and whether the `ipad` has been feed into
* the algorithm
*/
unsigned char inited;
/**
* Inner pad XOR processed key
*/
unsigned char ipad[64];
/**
* Outer pad XOR processed key
*/
unsigned char opad[64];
};
/**
* Initialise a state
*
* @param state The state that should be initialised
* @param algorithm The hashing algorithm
* @return Zero on success, -1 on error
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nothrow__, __nonnull__))
#endif
int libsha1_init(struct libsha1_state *restrict, enum libsha1_algorithm);
/**
* Get the output size of the algorithm specified for a state
*
* @param state The state
* @return The number of bytes in the output, zero on error
*/
#if defined(__GNUC__)
__attribute__((__nothrow__, __nonnull__, __pure__))
#endif
size_t libsha1_state_output_size(const struct libsha1_state *restrict);
/**
* Get the output size of an algorithm
*
* @param algorithm The hashing algorithm
* @return The number of bytes in the output, zero on error
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nothrow__, __const__))
#endif
size_t libsha1_algorithm_output_size(enum libsha1_algorithm);
/**
* Absorb more of the message
*
* @param state The hashing state
* @param message The message, in bits, must be equivalent to 0 modulus 8
* @param msglen The length of the message
*/
#if defined(__GNUC__)
__attribute__((__nonnull__, __nothrow__))
#endif
void libsha1_update(struct libsha1_state *restrict, const void *restrict, size_t);
/**
* Absorb the last part of the message and output a hash
*
* @param state The hashing state
* @param message The message, in bits
* @param msglen The length of the message, zero if there is nothing more to absorb
* @param output The output buffer for the hash
*/
#if defined(__GNUC__)
__attribute__((__nonnull__(1, 4), __nothrow__))
#endif
void libsha1_digest(struct libsha1_state *restrict, const void *, size_t, void *);
/**
* Calculate the checksum for a file,
* the content of the file is assumed non-sensitive
*
* @param fd The file descriptor of the file
* @param algorithm The hashing algorithm
* @param hashsum Output buffer for the hash
* @return Zero on success, -1 on error
*/
#if defined(__GNUC__)
__attribute__((__nonnull__, __leaf__))
#endif
int libsha1_sum_fd(int, enum libsha1_algorithm, void *restrict);
/**
* Convert a binary hashsum to lower case hexadecimal representation
*
* @param output Output array, should have an allocation size of at least `2 * n + 1`
* @param hashsum The hashsum to convert
* @param n The size of `hashsum`
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
void libsha1_behex_lower(char *restrict, const void *restrict, size_t);
/**
* Convert a binary hashsum to upper case hexadecimal representation
*
* @param output Output array, should have an allocation size of at least `2 * n + 1`
* @param hashsum The hashsum to convert
* @param n The size of `hashsum`
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
void libsha1_behex_upper(char *restrict, const void *restrict, size_t);
/**
* Convert a hexadecimal hashsum (both lower case, upper
* case and mixed is supported) to binary representation
*
* @param output Output array, should have an allocation
* size of at least `strlen(hashsum) / 2`
* @param hashsum The hashsum to convert
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
void libsha1_unhex(void *restrict, const char *restrict);
/**
* Marshal a state into a buffer
*
* @param state The state to marshal
* @param buf Output buffer, `NULL` to only return the required size
* @return The number of bytes marshalled to `buf`
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__(1), __nothrow__))
#endif
size_t libsha1_marshal(const struct libsha1_state *restrict, void *restrict);
/**
* Unmarshal a state from a buffer
*
* @param state Output parameter for the unmarshalled state
* @param buf The buffer from which the state shall be unmarshalled
* @param bufsize The maximum number of bytes that can be unmarshalled
* @return The number of read bytes, 0 on failure
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
size_t libsha1_unmarshal(struct libsha1_state *restrict, const void *restrict, size_t);
/**
* Initialise an HMAC state
*
* @param state The state that should be initialised
* @param algorithm The hashing algorithm
* @param key The key
* @param key_length The length of key, in bits
* @return Zero on success, -1 on error
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
int libsha1_hmac_init(struct libsha1_hmac_state *restrict, enum libsha1_algorithm, const void *restrict, size_t);
/**
* Get the output size of the algorithm specified for an HMAC state
*
* @param state The state
* @return The number of bytes in the output, zero on error
*/
#if defined(__GNUC__)
__attribute__((__nothrow__, __nonnull__, __pure__))
#endif
size_t libsha1_hmac_state_output_size(const struct libsha1_hmac_state *restrict);
/**
* Feed data into the HMAC algorithm
*
* @param state The state of the algorithm
* @param data Data to feed into the algorithm
* @param n The number of bytes to feed into the
* algorithm, this must be a multiple of 8
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
void libsha1_hmac_update(struct libsha1_hmac_state *restrict, const void *restrict, size_t);
/**
* Feed data into the HMAC algorithm and
* get the result
*
* The state of the algorithm will be reset and
* `libsha1_hmac_update` and `libsha1_hmac_update`
* can be called again
*
* @param state The state of the algorithm
* @param data Data to feed into the algorithm
* @param n The number of bytes to feed into the algorithm
* @param output The output buffer for the hash, it will be as
* large as for the underlaying hash algorithm
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
void libsha1_hmac_digest(struct libsha1_hmac_state *restrict, const void *, size_t, void *);
/**
* Marshal an HMAC state into a buffer
*
* @param state The state to marshal
* @param buf Output buffer, `NULL` to only return the required size
* @return The number of bytes marshalled to `buf`
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__(1), __nothrow__))
#endif
size_t libsha1_hmac_marshal(const struct libsha1_hmac_state *restrict, void *restrict);
/**
* Unmarshal an HMAC state from a buffer
*
* @param state Output parameter for the unmarshalled state
* @param buf The buffer from which the state shall be unmarshalled
* @param bufsize The maximum number of bytes that can be unmarshalled
* @return The number of read bytes, 0 on failure
*/
#if defined(__GNUC__)
__attribute__((__leaf__, __nonnull__, __nothrow__))
#endif
size_t libsha1_hmac_unmarshal(struct libsha1_hmac_state *restrict, const void *restrict, size_t);
#endif
