c-multihash/include/mh/multihash.h

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#ifndef MH_HULTIHASH_H
#define MH_HULTIHASH_H
#include <stddef.h>
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/**
* Functions for working with a multihash.
* A multihash is a hash with a prefix "code" that
* helps determine what type of hash this is.
* code name
* 0x00 identity
* 0x11 sha1
* 0x12 sha2-256
* 0x13 sha2-512
* 0x14 sha3-512
* 0x15 sha3-384
* 0x16 sha3-256
* 0x17 sha3-224
* 0x18 shake-128
* 0x19 shake-256
* 0x40 blake2b
* 0x41 blake2s
* # 0x0400-0x040f reserved for application specific functions
* # 0x14 formerly had the name "sha3", now deprecated
*/
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/**
* returns hash code or error (which is < 0)
* @param mh the multihash
* @param len the length of the multihash
* @returns errors ( < 0 ) or the multihash
*/
int mh_multihash_hash(const unsigned char *multihash, size_t len);
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/***
* returns the length of the multihash's data section
* @param mh the multihash
* @param len the length of the multihash
* @returns the length of the data section, or an error if < 0
*/
int mh_multihash_length(const unsigned char *multihash, size_t len);
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/**
* gives access to raw digest inside multihash buffer
* @param multihash the multihash
* @param len the length
* @param digest the results
* @returns error if less than zero, otherwise 0
*/
int mh_multihash_digest(const unsigned char *multihash, size_t len,
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unsigned char **digest, size_t *digest_len);
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/**
* determine the size of the multihash given the data size
* @param code currently not used
* @param hash_len the data size
* @returns hash_len + 2 (until the code parameter (varint) is added
*/
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int mh_new_length(int code, size_t digest_len);
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/***
* create a multihash based on some data
* @param buffer where to put the multihash
* @param code the code
* @param digest the data within the multihash
* @returns error (if < 0) or 0
*/
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int mh_new(unsigned char* buffer, int code, const unsigned char *digest,
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size_t digest_len);
#endif /* end of include guard */