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/* Copyright (c) 2010-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "mycrypt.h"
#include "password-scheme.h"
#include "crypt-blowfish.h"
#include "randgen.h"
/* Lengths and limits for some crypt() algorithms. */
#define CRYPT_BLF_ROUNDS_DEFAULT 5
#define CRYPT_BLF_ROUNDS_MIN 4
#define CRYPT_BLF_ROUNDS_MAX 31
#define CRYPT_BLF_SALT_LEN 16 /* raw salt */
#define CRYPT_BLF_PREFIX_LEN (7+22+1) /* $2.$nn$ + salt */
#define CRYPT_BLF_BUFFER_LEN 128
#define CRYPT_BLF_PREFIX "$2y"
#define CRYPT_SHA2_ROUNDS_DEFAULT 5000
#define CRYPT_SHA2_ROUNDS_MIN 1000
#define CRYPT_SHA2_ROUNDS_MAX 999999999
#define CRYPT_SHA2_SALT_LEN 16
static void
crypt_generate_des(const char *plaintext, const struct password_generate_params *params ATTR_UNUSED,
const unsigned char **raw_password_r, size_t *size_r)
{
#define CRYPT_SALT_LEN 2
const char *password, *salt;
salt = password_generate_salt(CRYPT_SALT_LEN);
password = t_strdup(mycrypt(plaintext, salt));
*raw_password_r = (const unsigned char *)password;
*size_r = strlen(password);
}
static void
crypt_generate_blowfish(const char *plaintext, const struct password_generate_params *params,
const unsigned char **raw_password_r, size_t *size_r)
{
char salt[CRYPT_BLF_SALT_LEN];
char password[CRYPT_BLF_BUFFER_LEN];
char magic_salt[CRYPT_BLF_PREFIX_LEN];
unsigned int rounds = params->rounds;
if (rounds == 0)
rounds = CRYPT_BLF_ROUNDS_DEFAULT;
else if (rounds < CRYPT_BLF_ROUNDS_MIN)
rounds = CRYPT_BLF_ROUNDS_MIN;
else if (rounds > CRYPT_BLF_ROUNDS_MAX)
rounds = CRYPT_BLF_ROUNDS_MAX;
random_fill(salt, CRYPT_BLF_SALT_LEN);
if (crypt_gensalt_blowfish_rn(CRYPT_BLF_PREFIX, rounds,
salt, CRYPT_BLF_SALT_LEN,
magic_salt, CRYPT_BLF_PREFIX_LEN) == NULL)
i_fatal("crypt_gensalt_blowfish_rn failed: %m");
if (crypt_blowfish_rn(plaintext, magic_salt, password,
CRYPT_BLF_BUFFER_LEN) == NULL)
i_fatal("crypt_blowfish_rn failed: %m");
*raw_password_r = (const unsigned char *)t_strdup(password);
*size_r = strlen(password);
}
static int
crypt_verify_blowfish(const char *plaintext, const struct password_generate_params *params ATTR_UNUSED,
const unsigned char *raw_password, size_t size,
const char **error_r)
{
const char *password;
const char *salt;
char crypted[CRYPT_BLF_BUFFER_LEN];
if (size == 0) {
/* the default mycrypt() handler would return match */
return 0;
}
password = t_strndup(raw_password, size);
if (size < CRYPT_BLF_PREFIX_LEN ||
!str_begins(password, "$2") ||
password[2] < 'a' || password[2] > 'z' ||
password[3] != '$') {
*error_r = "Password is not blowfish password";
return -1;
}
salt = t_strndup(password, CRYPT_BLF_PREFIX_LEN);
if (crypt_blowfish_rn(plaintext, salt, crypted, CRYPT_BLF_BUFFER_LEN) == NULL) {
/* really shouldn't happen unless the system is broken */
*error_r = t_strdup_printf("crypt_blowfish_rn failed: %m");
return -1;
}
return strcmp(crypted, password) == 0 ? 1 : 0;
}
static void
crypt_generate_sha256(const char *plaintext, const struct password_generate_params *params,
const unsigned char **raw_password_r, size_t *size_r)
{
const char *password, *salt, *magic_salt;
unsigned int rounds = params->rounds;
if (rounds == 0)
rounds = CRYPT_SHA2_ROUNDS_DEFAULT;
else if (rounds < CRYPT_SHA2_ROUNDS_MIN)
rounds = CRYPT_SHA2_ROUNDS_MIN;
else if (rounds > CRYPT_SHA2_ROUNDS_MAX)
rounds = CRYPT_SHA2_ROUNDS_MAX;
salt = password_generate_salt(CRYPT_SHA2_SALT_LEN);
if (rounds == CRYPT_SHA2_ROUNDS_DEFAULT)
magic_salt = t_strdup_printf("$5$%s", salt);
else
magic_salt = t_strdup_printf("$5$rounds=%u$%s", rounds, salt);
password = t_strdup(mycrypt(plaintext, magic_salt));
*raw_password_r = (const unsigned char *)password;
*size_r = strlen(password);
}
static void
crypt_generate_sha512(const char *plaintext, const struct password_generate_params *params,
const unsigned char **raw_password_r, size_t *size_r)
{
const char *password, *salt, *magic_salt;
unsigned int rounds = params->rounds;
if (rounds == 0)
rounds = CRYPT_SHA2_ROUNDS_DEFAULT;
else if (rounds < CRYPT_SHA2_ROUNDS_MIN)
rounds = CRYPT_SHA2_ROUNDS_MIN;
else if (rounds > CRYPT_SHA2_ROUNDS_MAX)
rounds = CRYPT_SHA2_ROUNDS_MAX;
salt = password_generate_salt(CRYPT_SHA2_SALT_LEN);
if (rounds == CRYPT_SHA2_ROUNDS_DEFAULT)
magic_salt = t_strdup_printf("$6$%s", salt);
else
magic_salt = t_strdup_printf("$6$rounds=%u$%s", rounds, salt);
password = t_strdup(mycrypt(plaintext, magic_salt));
*raw_password_r = (const unsigned char *)password;
*size_r = strlen(password);
}
/* keep in sync with the crypt_schemes struct below */
static const struct {
const char *key;
const char *salt;
const char *expected;
} sample[] = {
{ "08/15!test~4711", "JB", "JBOZ0DgmtucwE" },
{ "08/15!test~4711", "$5$rounds=1000$0123456789abcdef",
"$5$rounds=1000$0123456789abcdef$K/DksR0DT01hGc8g/kt"
"9McEgrbFMKi9qrb1jehe7hn4" },
{ "08/15!test~4711", "$6$rounds=1000$0123456789abcdef",
"$6$rounds=1000$0123456789abcdef$ZIAd5WqfyLkpvsVCVUU1GrvqaZTq"
"vhJoouxdSqJO71l9Ld3tVrfOatEjarhghvEYADkq//LpDnTeO90tcbtHR1" }
};
/* keep in sync with the sample struct above */
static const struct password_scheme crypt_schemes[] = {
{ "DES-CRYPT", PW_ENCODING_NONE, 0, crypt_verify,
crypt_generate_des },
{ "SHA256-CRYPT", PW_ENCODING_NONE, 0, crypt_verify,
crypt_generate_sha256 },
{ "SHA512-CRYPT", PW_ENCODING_NONE, 0, crypt_verify,
crypt_generate_sha512 }
};
static const struct password_scheme blf_crypt_scheme = {
"BLF-CRYPT", PW_ENCODING_NONE, 0, crypt_verify_blowfish,
crypt_generate_blowfish
};
static const struct password_scheme default_crypt_scheme = {
"CRYPT", PW_ENCODING_NONE, 0, crypt_verify,
crypt_generate_blowfish
};
void password_scheme_register_crypt(void)
{
unsigned int i;
const char *crypted;
i_assert(N_ELEMENTS(crypt_schemes) == N_ELEMENTS(sample));
for (i = 0; i < N_ELEMENTS(crypt_schemes); i++) {
crypted = mycrypt(sample[i].key, sample[i].salt);
if (crypted != NULL &&
(strcmp(crypted, sample[i].expected) == 0))
password_scheme_register(&crypt_schemes[i]);
}
password_scheme_register(&blf_crypt_scheme);
password_scheme_register(&default_crypt_scheme);
}
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