server/src/util/password.c
2016-01-13 16:16:02 +01:00

71 lines
2 KiB
C

#include <platform.h>
#include "password.h"
#include <md5.h>
#include <assert.h>
#include <string.h>
#include <stdio.h>
#define MAXSALTLEN 32 // maximum length in characters of any salt
static const char * password_hash_i(const char * passwd, const char *salt, int algo, char *result, size_t len) {
assert(passwd);
assert(salt);
if (algo==PASSWORD_PLAIN) {
_snprintf(result, len, "$0$%s$%s", salt, passwd);
}
else if (algo == PASSWORD_MD5) {
md5_state_t ms;
md5_byte_t digest[16];
md5_init(&ms);
md5_append(&ms, (const md5_byte_t *)passwd, strlen(passwd));
md5_append(&ms, (const md5_byte_t *)salt, strlen(salt));
md5_finish(&ms, digest);
_snprintf(result, len, "$1$%s$%s", salt, digest); // FIXME: need to build a hex string first!
}
else {
return NULL;
}
return result;
}
const char * password_hash(const char * passwd, int algo) {
static char result[64]; // TODO: static result buffers are bad mojo!
if (algo < 0) algo = PASSWORD_DEFAULT;
return password_hash_i(passwd, "saltyfish", PASSWORD_DEFAULT, result, sizeof(result));
}
static bool password_is_implemented(int algo) {
return algo==PASSWORD_PLAIN || algo==PASSWORD_MD5;
}
int password_verify(const char * pwhash, const char * passwd) {
char salt[MAXSALTLEN+1];
char hash[64];
size_t len;
int algo;
char *pos;
const char *dol;
assert(pwhash);
assert(passwd);
assert(pwhash[0] == '$');
algo = pwhash[1] - '0';
pos = strchr(pwhash+2, '$');
assert(pos[0] == '$');
++pos;
dol = strchr(pos, '$');
assert(dol>pos && dol[0] == '$');
len = dol - pos;
assert(len <= MAXSALTLEN);
strncpy(salt, pos, len);
salt[len] = 0;
password_hash_i(passwd, salt, algo, hash, sizeof(hash));
if (!password_is_implemented(algo)) {
return VERIFY_UNKNOWN;
}
if (strcmp(pwhash, hash) == 0) {
return VERIFY_OK;
}
return VERIFY_FAIL;
}