urbit/pkg/urcrypt/scrypt/libscrypt.h

78 lines
2.5 KiB
C

/*-
*/
#ifndef _CRYPTO_SCRYPT_H_
#define _CRYPTO_SCRYPT_H_
#include <stdint.h>
#include <stddef.h>
#ifdef __cplusplus
extern "C"{
#endif
/**
* crypto_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
* Compute scrypt(passwd[0 .. passwdlen - 1], salt[0 .. saltlen - 1], N, r,
* p, buflen) and write the result into buf. The parameters r, p, and buflen
* must satisfy r * p < 2^30 and buflen <= (2^32 - 1) * 32. The parameter N
* must be a power of 2 greater than 1.
*
* libscrypt_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
* password; duh
* N: CPU AND RAM cost (first modifier)
* r: RAM Cost
* p: CPU cost (parallelisation)
* In short, N is your main performance modifier. Values of r = 8, p = 1 are
* standard unless you want to modify the CPU/RAM ratio.
* Return 0 on success; or -1 on error.
*/
int libscrypt_scrypt(const uint8_t *, size_t, const uint8_t *, size_t, uint64_t,
uint32_t, uint32_t, /*@out@*/ uint8_t *, size_t);
/* Converts a series of input parameters to a MCF form for storage */
int libscrypt_mcf(uint32_t N, uint32_t r, uint32_t p, const char *salt,
const char *hash, char *mcf);
#ifndef _MSC_VER
/* Generates a salt. Uses /dev/urandom/
*/
int libscrypt_salt_gen(/*@out@*/ uint8_t *rand, size_t len);
/* Creates a hash of a passphrase using a randomly generated salt */
/* Returns >0 on success, or 0 for fail */
int libscrypt_hash(char *dst, const char* passphrase, uint32_t N, uint8_t r,
uint8_t p);
#endif
/* Checks a given MCF against a password */
int libscrypt_check(char *mcf, const char *password);
#ifdef __cplusplus
}
#endif
/* Sane default values */
#define SCRYPT_HASH_LEN 64 /* This can be user defined -
*but 64 is the reference size
*/
#define SCRYPT_SAFE_N 30 /* This is much higher than you want. It's just
* a blocker for insane defines
*/
#define SCRYPT_SALT_LEN 16 /* This is just a recommended size */
/* Standard MCF is:
$s1 Identifier, three chars
$0e0810 Work order and separator, six chars
Formula for binary to base64 length = ceil(n/3)*4
$pcL+DWle903AXcKJVwMffA== Salt is 16 bytes, or 24 in Base64
$dn+9ujljVc5JTJMC2fYu1ZEHdJyqYkOurmcrBQbMHUfnD6qxbTmNiR075ohNBZjvp66E2aV1pfOrmyNHUefjMg== Hash is 64 bytes, or 88 in Base64.
Work order, salt and hash have separators (3)
3 + 6 + 24 + 88 + 3 + null byte = 125
This is rounded up to a multiple of four for alignment
*/
#define SCRYPT_MCF_LEN 128
#define SCRYPT_MCF_ID "$s1"
#define SCRYPT_N 16384
#define SCRYPT_r 8
#define SCRYPT_p 16
#endif /* !_CRYPTO_SCRYPT_H_ */