postgres/contrib/pgcrypto/API

164 lines
3.5 KiB
Plaintext

C API for pgcrypto
==================
UN*X crypt()
============
#include <px-crypt.h>
char *
px_crypt(const char *psw, const char *salt, char *buf, unsigned buflen);
returns buf or NULL for error.
unsigned px_gen_salt(const char *salt_type, char *dst, int rounds);
returns salt size. dst should be PX_MAX_SALT_LEN bytes.
'rounds' is algorithm specific. 0 means default for
that algorithm.
Random
======
int px_get_random_bytes(uint8 *dst, int num)
Crypto "objects"
================
PX_MD - Message digest
PX_HMAC - HMAC (Hash MAC)
PX_Cipher - cipher+mode: provided by libs
PX_Combo - higher-level encryption -> padding, [MD]
Objects are activated with following functions:
int px_find_digest(const char *name, PX_MD **res);
int px_find_hmac(const char *name, PX_HMAC **res);
int px_find_cipher(const char *name, PX_Cipher **res);
int px_find_combo(const char *name, PX_Combo **res);
returns 0 on success, < 0 on error. If successful,
*res contains pointer to new object.
Message Digest
==============
uint px_md_result_size(PX_MD *md)
returns final result size in bytes
void px_md_reset(PX_MD *md)
resets md to clean state
uint px_md_block_size(PX_MD *md)
return algorithm block size in bytes
void px_md_update(PX_MD *md, const uint8 *data, uint dlen)
updates hash state with new data
void px_md_finish(PX_MD *md, uint8 *buf)
puts final hash state into buf. buf should have room
for px_md_result_size() bytes.
void px_md_free(PX_MD *md)
frees resources.
HMAC (Hash Message Authentication Code)
=======================================
int px_hmac_init(PX_HMAC *hmac, const uint8 *key, uint klen)
initalized hmac state with key.
uint px_hmac_result_size(PX_HMAC *md)
returns final result size in bytes
void px_hmac_reset(PX_HMAC *md)
resets md to state after _init()
uint px_hmac_block_size(PX_HMAC *md)
return algorithm block size in bytes
void px_hmac_update(PX_HMAC *md, const uint8 *data, uint dlen)
updates hash state with new data
void px_hmac_finish(PX_HMAC *md, uint8 *buf)
puts final hash state into buf. buf should have room
for px_hmac_result_size() bytes.
void px_hmac_free(PX_HMAC *md)
frees resources.
Cipher
======
uint px_cipher_key_size(PX_Cipher *c)
returns max key size in bytes
uint px_cipher_block_size(PX_Cipher *c)
returns cipher+mode block size in bytes. So blowfish
in CFB mode should return 1.
uint px_cipher_iv_size(PX_Cipher *c)
returns IV size in bytes.
int px_cipher_init(PX_Cipher *c, uint8 *key, uint klen, uint8 *iv)
initializes cipher with supplied key and iv.
int px_cipher_encrypt(PX_Cipher *c, uint8 *data, uint dlen, uint8 *res)
encrypts data. res must have room for dlen bytes.
data must be multiple of px_cipher_block_size().
int px_cipher_decrypt(PX_Cipher *c, uint8 *data, uint dlen, uint8 *res)
decrypts data. res must have room for dlen bytes.
void px_cipher_free(PX_Cipher *c)
frees resources assiocated.
PX_Combo
========
uint px_combo_encrypt_len(PX_Combo *c, uint dlen)
calculates max result length for dlen of data.
uint px_combo_decrypt_len(PX_Combo *c, uint dlen)
calculates result length for dlen of data.
int px_combo_init(PX_Combo *c, uint8 *key, uint klen, uint8 *iv, uint ivlen)
initializes c with key and iv. If cipher uses fixed length keys,
key will be padded with zeroes to needed length.
int px_combo_encrypt(PX_Combo *c, uint8 *data, uint dlen, uint8 *res, uint rlen)
int px_combo_decrypt(PX_Combo *c, uint8 *data, uint dlen, uint8 *res, uint rlen)
void px_combo_free(PX_Combo *c)
frees resources assiocated.