Amazing-Mirror/fragattacks
1
0
Fork 0
mirror of https://github.com/vanhoefm/fragattacks.git synced 2024-11-29 18:58:21 -05:00
Code Issues Projects Releases Wiki Activity
7824bf77d6
fragattacks/src/crypto/ms_funcs.c
Jouni Malinen 5a55c9b411 Fix MSCHAP UTF-8 to UCS-2 conversion check for three-byte encoding 
The utf8_string_len comparison was off by one and ended up accepting a
truncated three-byte encoded UTF-8 character at the end of the string if
the octet was missing. Since the password string gets null terminated in
the configuration, this did not result in reading beyond the buffer, but
anyway, it is better to explicitly reject the string rather than try to
use an incorrectly encoded UTF-8 string as the password.

Signed-off-by: Jouni Malinen <j@w1.fi>
2015-10-10 18:38:37 +03:00

525 lines
16 KiB
C
Raw Blame History

/*
* WPA Supplicant / shared MSCHAPV2 helper functions / RFC 2433 / RFC 2759
* Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "sha1.h"
#include "ms_funcs.h"
#include "crypto.h"
/**
* utf8_to_ucs2 - Convert UTF-8 string to UCS-2 encoding
* @utf8_string: UTF-8 string (IN)
* @utf8_string_len: Length of utf8_string (IN)
* @ucs2_buffer: UCS-2 buffer (OUT)
* @ucs2_buffer_size: Length of UCS-2 buffer (IN)
* @ucs2_string_size: Number of 2-byte words in the resulting UCS-2 string
* Returns: 0 on success, -1 on failure
*/
static int utf8_to_ucs2(const u8 *utf8_string, size_t utf8_string_len,
u8 *ucs2_buffer, size_t ucs2_buffer_size,
size_t *ucs2_string_size)
{
size_t i, j;
for (i = 0, j = 0; i < utf8_string_len; i++) {
u8 c = utf8_string[i];
if (j >= ucs2_buffer_size) {
/* input too long */
return -1;
}
if (c <= 0x7F) {
WPA_PUT_LE16(ucs2_buffer + j, c);
j += 2;
} else if (i == utf8_string_len - 1 ||
j >= ucs2_buffer_size - 1) {
/* incomplete surrogate */
return -1;
} else {
u8 c2 = utf8_string[++i];
if ((c & 0xE0) == 0xC0) {
/* two-byte encoding */
WPA_PUT_LE16(ucs2_buffer + j,
((c & 0x1F) << 6) | (c2 & 0x3F));
j += 2;
} else if (i == utf8_string_len - 1 ||
j >= ucs2_buffer_size - 1) {
/* incomplete surrogate */
return -1;
} else {
/* three-byte encoding */
u8 c3 = utf8_string[++i];
WPA_PUT_LE16(ucs2_buffer + j,
((c & 0xF) << 12) |
((c2 & 0x3F) << 6) | (c3 & 0x3F));
j += 2;
}
}
}
if (ucs2_string_size)
*ucs2_string_size = j / 2;
return 0;
}
/**
* challenge_hash - ChallengeHash() - RFC 2759, Sect. 8.2
* @peer_challenge: 16-octet PeerChallenge (IN)
* @auth_challenge: 16-octet AuthenticatorChallenge (IN)
* @username: 0-to-256-char UserName (IN)
* @username_len: Length of username
* @challenge: 8-octet Challenge (OUT)
* Returns: 0 on success, -1 on failure
*/
int challenge_hash(const u8 *peer_challenge, const u8 *auth_challenge,
const u8 *username, size_t username_len, u8 *challenge)
{
u8 hash[SHA1_MAC_LEN];
const unsigned char *addr[3];
size_t len[3];
addr[0] = peer_challenge;
len[0] = 16;
addr[1] = auth_challenge;
len[1] = 16;
addr[2] = username;
len[2] = username_len;
if (sha1_vector(3, addr, len, hash))
return -1;
os_memcpy(challenge, hash, 8);
return 0;
}
/**
* nt_password_hash - NtPasswordHash() - RFC 2759, Sect. 8.3
* @password: 0-to-256-unicode-char Password (IN; UTF-8)
* @password_len: Length of password
* @password_hash: 16-octet PasswordHash (OUT)
* Returns: 0 on success, -1 on failure
*/
int nt_password_hash(const u8 *password, size_t password_len,
u8 *password_hash)
{
u8 buf[512], *pos;
size_t len, max_len;
max_len = sizeof(buf);
if (utf8_to_ucs2(password, password_len, buf, max_len, &len) < 0)
return -1;
len *= 2;
pos = buf;
return md4_vector(1, (const u8 **) &pos, &len, password_hash);
}
/**
* hash_nt_password_hash - HashNtPasswordHash() - RFC 2759, Sect. 8.4
* @password_hash: 16-octet PasswordHash (IN)
* @password_hash_hash: 16-octet PasswordHashHash (OUT)
* Returns: 0 on success, -1 on failure
*/
int hash_nt_password_hash(const u8 *password_hash, u8 *password_hash_hash)
{
size_t len = 16;
return md4_vector(1, &password_hash, &len, password_hash_hash);
}
/**
* challenge_response - ChallengeResponse() - RFC 2759, Sect. 8.5
* @challenge: 8-octet Challenge (IN)
* @password_hash: 16-octet PasswordHash (IN)
* @response: 24-octet Response (OUT)
*/
void challenge_response(const u8 *challenge, const u8 *password_hash,
u8 *response)
{
u8 zpwd[7];
des_encrypt(challenge, password_hash, response);
des_encrypt(challenge, password_hash + 7, response + 8);
zpwd[0] = password_hash[14];
zpwd[1] = password_hash[15];
os_memset(zpwd + 2, 0, 5);
des_encrypt(challenge, zpwd, response + 16);
}
/**
* generate_nt_response - GenerateNTResponse() - RFC 2759, Sect. 8.1
* @auth_challenge: 16-octet AuthenticatorChallenge (IN)
* @peer_challenge: 16-octet PeerChallenge (IN)
* @username: 0-to-256-char UserName (IN)
* @username_len: Length of username
* @password: 0-to-256-unicode-char Password (IN; UTF-8)
* @password_len: Length of password
* @response: 24-octet Response (OUT)
* Returns: 0 on success, -1 on failure
*/
int generate_nt_response(const u8 *auth_challenge, const u8 *peer_challenge,
const u8 *username, size_t username_len,
const u8 *password, size_t password_len,
u8 *response)
{
u8 challenge[8];
u8 password_hash[16];
if (challenge_hash(peer_challenge, auth_challenge, username,
username_len, challenge) ||
nt_password_hash(password, password_len, password_hash))
return -1;
challenge_response(challenge, password_hash, response);
return 0;
}
/**
* generate_nt_response_pwhash - GenerateNTResponse() - RFC 2759, Sect. 8.1
* @auth_challenge: 16-octet AuthenticatorChallenge (IN)
* @peer_challenge: 16-octet PeerChallenge (IN)
* @username: 0-to-256-char UserName (IN)
* @username_len: Length of username
* @password_hash: 16-octet PasswordHash (IN)
* @response: 24-octet Response (OUT)
* Returns: 0 on success, -1 on failure
*/
int generate_nt_response_pwhash(const u8 *auth_challenge,
const u8 *peer_challenge,
const u8 *username, size_t username_len,
const u8 *password_hash,
u8 *response)
{
u8 challenge[8];
if (challenge_hash(peer_challenge, auth_challenge,
username, username_len,
challenge))
return -1;
challenge_response(challenge, password_hash, response);
return 0;
}
/**
* generate_authenticator_response_pwhash - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7
* @password_hash: 16-octet PasswordHash (IN)
* @nt_response: 24-octet NT-Response (IN)
* @peer_challenge: 16-octet PeerChallenge (IN)
* @auth_challenge: 16-octet AuthenticatorChallenge (IN)
* @username: 0-to-256-char UserName (IN)
* @username_len: Length of username
* @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually
* encoded as a 42-octet ASCII string (S=hexdump_of_response)
* Returns: 0 on success, -1 on failure
*/
int generate_authenticator_response_pwhash(
const u8 *password_hash,
const u8 *peer_challenge, const u8 *auth_challenge,
const u8 *username, size_t username_len,
const u8 *nt_response, u8 *response)
{
static const u8 magic1[39] = {
0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76,
0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65,
0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67,
0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74
};
static const u8 magic2[41] = {
0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B,
0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F,
0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E,
0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F,
0x6E
};
u8 password_hash_hash[16], challenge[8];
const unsigned char *addr1[3];
const size_t len1[3] = { 16, 24, sizeof(magic1) };
const unsigned char *addr2[3];
const size_t len2[3] = { SHA1_MAC_LEN, 8, sizeof(magic2) };
addr1[0] = password_hash_hash;
addr1[1] = nt_response;
addr1[2] = magic1;
addr2[0] = response;
addr2[1] = challenge;
addr2[2] = magic2;
if (hash_nt_password_hash(password_hash, password_hash_hash) ||
sha1_vector(3, addr1, len1, response) ||
challenge_hash(peer_challenge, auth_challenge, username,
username_len, challenge))
return -1;
return sha1_vector(3, addr2, len2, response);
}
/**
* generate_authenticator_response - GenerateAuthenticatorResponse() - RFC 2759, Sect. 8.7
* @password: 0-to-256-unicode-char Password (IN; UTF-8)
* @password_len: Length of password
* @nt_response: 24-octet NT-Response (IN)
* @peer_challenge: 16-octet PeerChallenge (IN)
* @auth_challenge: 16-octet AuthenticatorChallenge (IN)
* @username: 0-to-256-char UserName (IN)
* @username_len: Length of username
* @response: 20-octet AuthenticatorResponse (OUT) (note: this value is usually
* encoded as a 42-octet ASCII string (S=hexdump_of_response)
* Returns: 0 on success, -1 on failure
*/
int generate_authenticator_response(const u8 *password, size_t password_len,
const u8 *peer_challenge,
const u8 *auth_challenge,
const u8 *username, size_t username_len,
const u8 *nt_response, u8 *response)
{
u8 password_hash[16];
if (nt_password_hash(password, password_len, password_hash))
return -1;
return generate_authenticator_response_pwhash(
password_hash, peer_challenge, auth_challenge,
username, username_len, nt_response, response);
}
/**
* nt_challenge_response - NtChallengeResponse() - RFC 2433, Sect. A.5
* @challenge: 8-octet Challenge (IN)
* @password: 0-to-256-unicode-char Password (IN; UTF-8)
* @password_len: Length of password
* @response: 24-octet Response (OUT)
* Returns: 0 on success, -1 on failure
*/
int nt_challenge_response(const u8 *challenge, const u8 *password,
size_t password_len, u8 *response)
{
u8 password_hash[16];
if (nt_password_hash(password, password_len, password_hash))
return -1;
challenge_response(challenge, password_hash, response);
return 0;
}
/**
* get_master_key - GetMasterKey() - RFC 3079, Sect. 3.4
* @password_hash_hash: 16-octet PasswordHashHash (IN)
* @nt_response: 24-octet NTResponse (IN)
* @master_key: 16-octet MasterKey (OUT)
* Returns: 0 on success, -1 on failure
*/
int get_master_key(const u8 *password_hash_hash, const u8 *nt_response,
u8 *master_key)
{
static const u8 magic1[27] = {
0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74,
0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d,
0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79
};
const unsigned char *addr[3];
const size_t len[3] = { 16, 24, sizeof(magic1) };
u8 hash[SHA1_MAC_LEN];
addr[0] = password_hash_hash;
addr[1] = nt_response;
addr[2] = magic1;
if (sha1_vector(3, addr, len, hash))
return -1;
os_memcpy(master_key, hash, 16);
return 0;
}
/**
* get_asymetric_start_key - GetAsymetricStartKey() - RFC 3079, Sect. 3.4
* @master_key: 16-octet MasterKey (IN)
* @session_key: 8-to-16 octet SessionKey (OUT)
* @session_key_len: SessionKeyLength (Length of session_key) (IN)
* @is_send: IsSend (IN, BOOLEAN)
* @is_server: IsServer (IN, BOOLEAN)
* Returns: 0 on success, -1 on failure
*/
int get_asymetric_start_key(const u8 *master_key, u8 *session_key,
size_t session_key_len, int is_send,
int is_server)
{
static const u8 magic2[84] = {
0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69,
0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20,
0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20, 0x6b, 0x65, 0x79,
0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73,
0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73, 0x69, 0x64, 0x65,
0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20,
0x6b, 0x65, 0x79, 0x2e
};
static const u8 magic3[84] = {
0x4f, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x69,
0x65, 0x6e, 0x74, 0x20, 0x73, 0x69, 0x64, 0x65, 0x2c, 0x20,
0x74, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74, 0x68,
0x65, 0x20, 0x72, 0x65, 0x63, 0x65, 0x69, 0x76, 0x65, 0x20,
0x6b, 0x65, 0x79, 0x3b, 0x20, 0x6f, 0x6e, 0x20, 0x74, 0x68,
0x65, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x73,
0x69, 0x64, 0x65, 0x2c, 0x20, 0x69, 0x74, 0x20, 0x69, 0x73,
0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x65, 0x6e, 0x64, 0x20,
0x6b, 0x65, 0x79, 0x2e
};
static const u8 shs_pad1[40] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
static const u8 shs_pad2[40] = {
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2,
0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2
};
u8 digest[SHA1_MAC_LEN];
const unsigned char *addr[4];
const size_t len[4] = { 16, 40, 84, 40 };
addr[0] = master_key;
addr[1] = shs_pad1;
if (is_send) {
addr[2] = is_server ? magic3 : magic2;
} else {
addr[2] = is_server ? magic2 : magic3;
}
addr[3] = shs_pad2;
if (sha1_vector(4, addr, len, digest))
return -1;
if (session_key_len > SHA1_MAC_LEN)
session_key_len = SHA1_MAC_LEN;
os_memcpy(session_key, digest, session_key_len);
return 0;
}
#ifndef CONFIG_NO_RC4
#define PWBLOCK_LEN 516
/**
* encrypt_pw_block_with_password_hash - EncryptPwBlockWithPasswordHash() - RFC 2759, Sect. 8.10
* @password: 0-to-256-unicode-char Password (IN; UTF-8)
* @password_len: Length of password
* @password_hash: 16-octet PasswordHash (IN)
* @pw_block: 516-byte PwBlock (OUT)
* Returns: 0 on success, -1 on failure
*/
int encrypt_pw_block_with_password_hash(
const u8 *password, size_t password_len,
const u8 *password_hash, u8 *pw_block)
{
size_t ucs2_len, offset;
u8 *pos;
os_memset(pw_block, 0, PWBLOCK_LEN);
if (utf8_to_ucs2(password, password_len, pw_block, 512, &ucs2_len) < 0
|| ucs2_len > 256)
return -1;
offset = (256 - ucs2_len) * 2;
if (offset != 0) {
os_memmove(pw_block + offset, pw_block, ucs2_len * 2);
if (os_get_random(pw_block, offset) < 0)
return -1;
}
/*
* PasswordLength is 4 octets, but since the maximum password length is
* 256, only first two (in little endian byte order) can be non-zero.
*/
pos = &pw_block[2 * 256];
WPA_PUT_LE16(pos, password_len * 2);
rc4_skip(password_hash, 16, 0, pw_block, PWBLOCK_LEN);
return 0;
}
/**
* new_password_encrypted_with_old_nt_password_hash - NewPasswordEncryptedWithOldNtPasswordHash() - RFC 2759, Sect. 8.9
* @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8)
* @new_password_len: Length of new_password
* @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8)
* @old_password_len: Length of old_password
* @encrypted_pw_block: 516-octet EncryptedPwBlock (OUT)
* Returns: 0 on success, -1 on failure
*/
int new_password_encrypted_with_old_nt_password_hash(
const u8 *new_password, size_t new_password_len,
const u8 *old_password, size_t old_password_len,
u8 *encrypted_pw_block)
{
u8 password_hash[16];
if (nt_password_hash(old_password, old_password_len, password_hash))
return -1;
if (encrypt_pw_block_with_password_hash(new_password, new_password_len,
password_hash,
encrypted_pw_block))
return -1;
return 0;
}
#endif /* CONFIG_NO_RC4 */
/**
* nt_password_hash_encrypted_with_block - NtPasswordHashEncryptedWithBlock() - RFC 2759, Sect 8.13
* @password_hash: 16-octer PasswordHash (IN)
* @block: 16-octet Block (IN)
* @cypher: 16-octer Cypher (OUT)
*/
void nt_password_hash_encrypted_with_block(const u8 *password_hash,
const u8 *block, u8 *cypher)
{
des_encrypt(password_hash, block, cypher);
des_encrypt(password_hash + 8, block + 7, cypher + 8);
}
/**
* old_nt_password_hash_encrypted_with_new_nt_password_hash - OldNtPasswordHashEncryptedWithNewNtPasswordHash() - RFC 2759, Sect. 8.12
* @new_password: 0-to-256-unicode-char NewPassword (IN; UTF-8)
* @new_password_len: Length of new_password
* @old_password: 0-to-256-unicode-char OldPassword (IN; UTF-8)
* @old_password_len: Length of old_password
* @encrypted_password_hash: 16-octet EncryptedPasswordHash (OUT)
* Returns: 0 on success, -1 on failure
*/
int old_nt_password_hash_encrypted_with_new_nt_password_hash(
const u8 *new_password, size_t new_password_len,
const u8 *old_password, size_t old_password_len,
u8 *encrypted_password_hash)
{
u8 old_password_hash[16], new_password_hash[16];
if (nt_password_hash(old_password, old_password_len,
old_password_hash) ||
nt_password_hash(new_password, new_password_len,
new_password_hash))
return -1;
nt_password_hash_encrypted_with_block(old_password_hash,
new_password_hash,
encrypted_password_hash);
return 0;
}
Reference in New Issue View Git Blame Copy Permalink