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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* password checking routines */
/*****************************************************************************
The main idea is that no password are sent between client & server on
connection and that no password are saved in mysql in a decodable form.
On connection a random string is generated and sent to the client.
The client generates a new string with a random generator inited with
the hash values from the password and the sent string.
This 'check' string is sent to the server where it is compared with
a string generated from the stored hash_value of the password and the
random string.
The password is saved (in user.password) by using the PASSWORD() function in
mysql.
This is .c file because it's used in libmysqlclient, which is entirely in C.
(we need it to be portable to a variety of systems).
Example:
update user set password=PASSWORD("hello") where user="test"
This saves a hashed number as a string in the password field.
The new autentication is performed in following manner:
SERVER: public_seed=create_random_string()
send(public_seed)
CLIENT: recv(public_seed)
hash_stage1=sha1("password")
hash_stage2=sha1(hash_stage1)
reply=xor(hash_stage1, sha1(public_seed,hash_stage2)
// this three steps are done in scramble()
send(reply)
SERVER: recv(reply)
hash_stage1=xor(reply, sha1(public_seed,hash_stage2))
candidate_hash2=sha1(hash_stage1)
check(candidate_hash2==hash_stage2)
// this three steps are done in check_scramble()
*****************************************************************************/
#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <sha1.h>
#include "mysql.h"
/************ MySQL 3.23-4.0 authentification routines: untouched ***********/
/*
New (MySQL 3.21+) random generation structure initialization
SYNOPSIS
randominit()
rand_st OUT Structure to initialize
seed1 IN First initialization parameter
seed2 IN Second initialization parameter
*/
void randominit(struct rand_struct *rand_st, ulong seed1, ulong seed2)
{ /* For mysql 3.21.# */
#ifdef HAVE_purify
bzero((char*) rand_st,sizeof(*rand_st)); /* Avoid UMC varnings */
#endif
rand_st->max_value= 0x3FFFFFFFL;
rand_st->max_value_dbl=(double) rand_st->max_value;
rand_st->seed1=seed1%rand_st->max_value ;
rand_st->seed2=seed2%rand_st->max_value;
}
/*
Generate random number.
SYNOPSIS
my_rnd()
rand_st INOUT Structure used for number generation
RETURN VALUE
generated pseudo random number
*/
double my_rnd(struct rand_struct *rand_st)
{
rand_st->seed1=(rand_st->seed1*3+rand_st->seed2) % rand_st->max_value;
rand_st->seed2=(rand_st->seed1+rand_st->seed2+33) % rand_st->max_value;
return (((double) rand_st->seed1)/rand_st->max_value_dbl);
}
/*
Generate binary hash from raw text string
Used for Pre-4.1 password handling
SYNOPSIS
hash_password()
result OUT store hash in this location
password IN plain text password to build hash
*/
void hash_password(ulong *result, const char *password)
{
register ulong nr=1345345333L, add=7, nr2=0x12345671L;
ulong tmp;
for (; *password ; password++)
{
if (*password == ' ' || *password == '\t')
continue; /* skip space in password */
tmp= (ulong) (uchar) *password;
nr^= (((nr & 63)+add)*tmp)+ (nr << 8);
nr2+=(nr2 << 8) ^ nr;
add+=tmp;
}
result[0]=nr & (((ulong) 1L << 31) -1L); /* Don't use sign bit (str2int) */;
result[1]=nr2 & (((ulong) 1L << 31) -1L);
return;
}
/*
Create password to be stored in user database from raw string
Used for pre-4.1 password handling
SYNOPSIS
make_scrambled_password_323()
to OUT store scrambled password here
password IN user-supplied password
*/
void make_scrambled_password_323(char *to, const char *password)
{
ulong hash_res[2];
hash_password(hash_res, password);
sprintf(to, "%08lx%08lx", hash_res[0], hash_res[1]);
}
/*
Scramble string with password.
Used in pre 4.1 authentication phase.
SYNOPSIS
scramble_323()
to OUT Store scrambled message here. Buffer must be at least
SCRAMBLE_LENGTH_323+1 bytes long
message IN Message to scramble. Message must be exactly
SRAMBLE_LENGTH_323 long and NULL terminated.
password IN Password to use while scrambling
RETURN
End of scrambled string
*/
char *scramble_323(char *to, const char *message, const char *password)
{
struct rand_struct rand_st;
ulong hash_pass[2], hash_message[2];
if (password && password[0])
{
char *to_start=to;
hash_password(hash_pass,password);
hash_password(hash_message, message);
randominit(&rand_st,hash_pass[0] ^ hash_message[0],
hash_pass[1] ^ hash_message[1]);
while (*message++)
*to++= (char) (floor(my_rnd(&rand_st)*31)+64);
char extra=(char) (floor(my_rnd(&rand_st)*31));
while (to_start != to)
*(to_start++)^=extra;
}
*to= 0;
return to;
}
/*
Check scrambled message
Used in pre 4.1 password handling
SYNOPSIS
check_scramble_323()
scrambled IN scrambled message to check.
message IN original random message which was used for scrambling; must
be exactly SCRAMBLED_LENGTH_323 bytes long and
NULL-terminated.
hash_pass IN password which should be used for scrambling
RETURN VALUE
0 - password correct
!0 - password invalid
*/
my_bool
check_scramble_323(const char *scrambled, const char *message,
ulong *hash_pass)
{
struct rand_struct rand_st;
ulong hash_message[2];
char buff[16],*to,extra; /* Big enough for check */
const char *pos;
/* Check if this exactly N bytes. Overwise this is something fishy */
if (strlen(message) != SCRAMBLE_LENGTH_323)
return 1; /* Wrong password */
hash_password(hash_message,message);
randominit(&rand_st,hash_pass[0] ^ hash_message[0],
hash_pass[1] ^ hash_message[1]);
to=buff;
for (pos=scrambled ; *pos ; pos++)
*to++=(char) (floor(my_rnd(&rand_st)*31)+64);
extra=(char) (floor(my_rnd(&rand_st)*31));
to=buff;
while (*scrambled)
{
if (*scrambled++ != (char) (*to++ ^ extra))
return 1; /* Wrong password */
}
return 0;
}
static uint8 char_val(uint8 X)
{
return (uint) (X >= '0' && X <= '9' ? X-'0' :
X >= 'A' && X <= 'Z' ? X-'A'+10 : X-'a'+10);
}
/*
Convert password from hex string (as stored in mysql.user) to binary form.
SYNOPSIS
get_salt_from_password_323()
res OUT store salt here
password IN password string as stored in mysql.user
NOTE
This function does not have length check for passwords. It will just crash
Password hashes in old format must have length divisible by 8
*/
void get_salt_from_password_323(ulong *res, const char *password)
{
res[0]= res[1]= 0;
if (password)
{
while (*password)
{
ulong val=0;
uint i;
for (i=0 ; i < 8 ; i++)
val=(val << 4)+char_val(*password++);
*res++=val;
}
}
}
/*
Convert scrambled password from binary form to asciiz hex string.
SYNOPSIS
make_password_from_salt_323()
to OUT store resulting string password here, at least 17 bytes
salt IN password in salt format, 2 ulongs
*/
void make_password_from_salt_323(char *to, const ulong *salt)
{
sprintf(to,"%08lx%08lx", salt[0], salt[1]);
}
/******************* MySQL 4.1.1 authentification routines ******************/
/*
Generate string of printable random characters of requested length
SYNOPSIS
create_random_string()
to OUT buffer for generation; must be at least length+1 bytes
long; result string is always null-terminated
length IN how many random characters to put in buffer
rand_st INOUT structure used for number generation
*/
void create_random_string(char *to, uint length, struct rand_struct *rand_st)
{
char *end= to + length;
/* Use pointer arithmetics as it is faster way to do so. */
for (; to < end; to++)
*to= (char) (my_rnd(rand_st)*94+33);
*to= '\0';
}
/* Character to use as version identifier for version 4.1 */
#define PVERSION41_CHAR '*'
/*
Convert given octet sequence to asciiz string of hex characters;
str..str+len and 'to' may not overlap.
SYNOPSIS
octet2hex()
buf OUT output buffer. Must be at least 2*len+1 bytes
str, len IN the beginning and the length of the input string
*/
static
void
octet2hex(char *to, const uint8 *str, uint len)
{
static const char alphabet[] = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
const uint8 *str_end= str + len;
for (; str != str_end; ++str)
{
*to++= alphabet[(*str & 0xF0) >> 4];
*to++= alphabet[*str & 0x0F];
}
*to++= '\0';
}
/*
Convert given asciiz string of hex (0..9 a..f) characters to octet
sequence.
SYNOPSIS
hex2octet()
to OUT buffer to place result; must be at least len/2 bytes
str, len IN begin, length for character string; str and to may not
overlap; len % 2 == 0
*/
static
void
hex2octet(uint8 *to, const char *str, uint len)
{
const char *str_end= str + len;
while (str < str_end)
{
*to= char_val(*str++) << 4;
*to++|= char_val(*str++);
}
}
/*
Encrypt/Decrypt function used for password encryption in authentication.
Simple XOR is used here but it is OK as we crypt random strings. Note,
that XOR(s1, XOR(s1, s2)) == s2, XOR(s1, s2) == XOR(s2, s1)
SYNOPSIS
my_crypt()
to OUT buffer to hold crypted string; must be at least len bytes
long; to and s1 (or s2) may be the same.
s1, s2 IN input strings (of equal length)
len IN length of s1 and s2
*/
static
void
my_crypt(char *to, const uint8 *s1, const uint8 *s2, uint len)
{
const uint8 *s1_end= s1 + len;
while (s1 < s1_end)
*to++= *s1++ ^ *s2++;
}
/*
MySQL 4.1.1 password hashing: SHA conversion (see RFC 2289, 3174) twice
applied to the password string, and then produced octet sequence is
converted to hex string.
The result of this function is used as return value from PASSWORD() and
is stored in the database.
SYNOPSIS
make_scrambled_password()
buf OUT buffer of size 2*SHA1_HASH_SIZE + 2 to store hex string
password IN NULL-terminated password string
*/
void
make_scrambled_password(char *to, const char *password)
{
SHA1_CONTEXT sha1_context;
uint8 hash_stage2[SHA1_HASH_SIZE];
sha1_reset(&sha1_context);
/* stage 1: hash password */
sha1_input(&sha1_context, (uint8 *) password, strlen(password));
sha1_result(&sha1_context, (uint8 *) to);
/* stage 2: hash stage1 output */
sha1_reset(&sha1_context);
sha1_input(&sha1_context, (uint8 *) to, SHA1_HASH_SIZE);
/* separate buffer is used to pass 'to' in octet2hex */
sha1_result(&sha1_context, hash_stage2);
/* convert hash_stage2 to hex string */
*to++= PVERSION41_CHAR;
octet2hex(to, hash_stage2, SHA1_HASH_SIZE);
}
/*
Produce an obscure octet sequence from password and random
string, recieved from the server. This sequence corresponds to the
password, but password can not be easily restored from it. The sequence
is then sent to the server for validation. Trailing zero is not stored
in the buf as it is not needed.
This function is used by client to create authenticated reply to the
server's greeting.
SYNOPSIS
scramble()
buf OUT store scrambled string here. The buf must be at least
SHA1_HASH_SIZE bytes long.
message IN random message, must be exactly SCRAMBLE_LENGTH long and
NULL-terminated.
password IN users' password
*/
void
scramble(char *to, const char *message, const char *password)
{
SHA1_CONTEXT sha1_context;
uint8 hash_stage1[SHA1_HASH_SIZE];
uint8 hash_stage2[SHA1_HASH_SIZE];
sha1_reset(&sha1_context);
/* stage 1: hash password */
sha1_input(&sha1_context, (uint8 *) password, strlen(password));
sha1_result(&sha1_context, hash_stage1);
/* stage 2: hash stage 1; note that hash_stage2 is stored in the database */
sha1_reset(&sha1_context);
sha1_input(&sha1_context, hash_stage1, SHA1_HASH_SIZE);
sha1_result(&sha1_context, hash_stage2);
/* create crypt string as sha1(message, hash_stage2) */;
sha1_reset(&sha1_context);
sha1_input(&sha1_context, (const uint8 *) message, SCRAMBLE_LENGTH);
sha1_input(&sha1_context, hash_stage2, SHA1_HASH_SIZE);
/* xor allows 'from' and 'to' overlap: lets take advantage of it */
sha1_result(&sha1_context, (uint8 *) to);
my_crypt(to, (const uint8 *) to, hash_stage1, SCRAMBLE_LENGTH);
}
/*
Check that scrambled message corresponds to the password; the function
is used by server to check that recieved reply is authentic.
This function does not check lengths of given strings: message must be
null-terminated, reply and hash_stage2 must be at least SHA1_HASH_SIZE
long (if not, something fishy is going on).
SYNOPSIS
check_scramble()
scramble IN clients' reply, presumably produced by scramble()
message IN original random string, previously sent to client
(presumably second argument of scramble()), must be
exactly SCRAMBLE_LENGTH long and NULL-terminated.
hash_stage2 IN hex2octet-decoded database entry
RETURN VALUE
0 password is correct
!0 password is invalid
*/
my_bool
check_scramble(const char *scramble, const char *message,
const uint8 *hash_stage2)
{
SHA1_CONTEXT sha1_context;
uint8 buf[SHA1_HASH_SIZE];
uint8 hash_stage2_reassured[SHA1_HASH_SIZE];
sha1_reset(&sha1_context);
/* create key to encrypt scramble */
sha1_input(&sha1_context, (const uint8 *) message, SCRAMBLE_LENGTH);
sha1_input(&sha1_context, hash_stage2, SHA1_HASH_SIZE);
sha1_result(&sha1_context, buf);
/* encrypt scramble */
my_crypt((char *) buf, buf, (const uint8 *) scramble, SCRAMBLE_LENGTH);
/* now buf supposedly contains hash_stage1: so we can get hash_stage2 */
sha1_reset(&sha1_context);
sha1_input(&sha1_context, buf, SHA1_HASH_SIZE);
sha1_result(&sha1_context, hash_stage2_reassured);
return memcmp(hash_stage2, hash_stage2_reassured, SHA1_HASH_SIZE);
}
/*
Convert scrambled password from asciiz hex string to binary form.
SYNOPSIS
get_salt_from_password()
res OUT buf to hold password. Must be at least SHA1_HASH_SIZE
bytes long.
password IN 4.1.1 version value of user.password
*/
void get_salt_from_password(uint8 *hash_stage2, const char *password)
{
hex2octet(hash_stage2, password+1 /* skip '*' */, SHA1_HASH_SIZE * 2);
}
/*
Convert scrambled password from binary form to asciiz hex string.
SYNOPSIS
make_password_from_salt()
to OUT store resulting string here, 2*SHA1_HASH_SIZE+2 bytes
salt IN password in salt format
*/
void make_password_from_salt(char *to, const uint8 *hash_stage2)
{
*to++= PVERSION41_CHAR;
octet2hex(to, hash_stage2, SHA1_HASH_SIZE);
}
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