/* 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; version 2 of the License. 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 authentication 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 #include #include #include #include "mysql.h" /************ MySQL 3.23-4.0 authentication 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 password_len IN password length (password may be not null-terminated) */ void hash_password(ulong *result, const char *password, uint password_len) { register ulong nr=1345345333L, add=7, nr2=0x12345671L; ulong tmp; const char *password_end= password + password_len; for (; password < password_end; 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); } /* 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, (uint) strlen(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 at least SRAMBLE_LENGTH_323 bytes long. password IN Password to use while scrambling */ void 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 extra, *to_start=to; const char *message_end= message + SCRAMBLE_LENGTH_323; hash_password(hash_pass,password, (uint) strlen(password)); hash_password(hash_message, message, SCRAMBLE_LENGTH_323); randominit(&rand_st,hash_pass[0] ^ hash_message[0], hash_pass[1] ^ hash_message[1]); for (; message < message_end; message++) *to++= (char) (floor(my_rnd(&rand_st)*31)+64); extra=(char) (floor(my_rnd(&rand_st)*31)); while (to_start != to) *(to_start++)^=extra; } *to= 0; } /* Check scrambled message Used in pre 4.1 password handling SYNOPSIS check_scramble_323() scrambled scrambled message to check. message original random message which was used for scrambling; must be exactly SCRAMBLED_LENGTH_323 bytes long and NULL-terminated. hash_pass password which should be used for scrambling All params are IN. 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; hash_password(hash_message, message, SCRAMBLE_LENGTH_323); randominit(&rand_st,hash_pass[0] ^ hash_message[0], hash_pass[1] ^ hash_message[1]); to=buff; DBUG_ASSERT(sizeof(buff) > SCRAMBLE_LENGTH_323); for (pos=scrambled ; *pos && to < buff+sizeof(buff) ; pos++) *to++=(char) (floor(my_rnd(&rand_st)*31)+64); if (pos-scrambled != SCRAMBLE_LENGTH_323) return 1; extra=(char) (floor(my_rnd(&rand_st)*31)); to=buff; while (*scrambled) { if (*scrambled++ != (char) (*to++ ^ extra)) return 1; /* Wrong password */ } return 0; } static inline 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 authentication 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 RETURN buf+len*2 */ char *octet2hex(char *to, const char *str, uint len) { const byte *str_end= str + len; for (; str != str_end; ++str) { *to++= _dig_vec_upper[((uchar) *str) >> 4]; *to++= _dig_vec_upper[((uchar) *str) & 0x0F]; } *to= '\0'; return to; } /* 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) { register char tmp= char_val(*str++); *to++= (tmp << 4) | 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 uchar *s1, const uchar *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]; mysql_sha1_reset(&sha1_context); /* stage 1: hash password */ mysql_sha1_input(&sha1_context, (uint8 *) password, (uint) strlen(password)); mysql_sha1_result(&sha1_context, (uint8 *) to); /* stage 2: hash stage1 output */ mysql_sha1_reset(&sha1_context); mysql_sha1_input(&sha1_context, (uint8 *) to, SHA1_HASH_SIZE); /* separate buffer is used to pass 'to' in octet2hex */ mysql_sha1_result(&sha1_context, hash_stage2); /* convert hash_stage2 to hex string */ *to++= PVERSION41_CHAR; octet2hex(to, (char*) 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]; mysql_sha1_reset(&sha1_context); /* stage 1: hash password */ mysql_sha1_input(&sha1_context, (uint8 *) password, (uint) strlen(password)); mysql_sha1_result(&sha1_context, hash_stage1); /* stage 2: hash stage 1; note that hash_stage2 is stored in the database */ mysql_sha1_reset(&sha1_context); mysql_sha1_input(&sha1_context, hash_stage1, SHA1_HASH_SIZE); mysql_sha1_result(&sha1_context, hash_stage2); /* create crypt string as sha1(message, hash_stage2) */; mysql_sha1_reset(&sha1_context); mysql_sha1_input(&sha1_context, (const uint8 *) message, SCRAMBLE_LENGTH); mysql_sha1_input(&sha1_context, hash_stage2, SHA1_HASH_SIZE); /* xor allows 'from' and 'to' overlap: lets take advantage of it */ mysql_sha1_result(&sha1_context, (uint8 *) to); my_crypt(to, (const uchar *) 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 clients' reply, presumably produced by scramble() message original random string, previously sent to client (presumably second argument of scramble()), must be exactly SCRAMBLE_LENGTH long and NULL-terminated. hash_stage2 hex2octet-decoded database entry All params are IN. 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]; mysql_sha1_reset(&sha1_context); /* create key to encrypt scramble */ mysql_sha1_input(&sha1_context, (const uint8 *) message, SCRAMBLE_LENGTH); mysql_sha1_input(&sha1_context, hash_stage2, SHA1_HASH_SIZE); mysql_sha1_result(&sha1_context, buf); /* encrypt scramble */ my_crypt((char *) buf, buf, (const uchar *) scramble, SCRAMBLE_LENGTH); /* now buf supposedly contains hash_stage1: so we can get hash_stage2 */ mysql_sha1_reset(&sha1_context); mysql_sha1_input(&sha1_context, buf, SHA1_HASH_SIZE); mysql_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, (char*) hash_stage2, SHA1_HASH_SIZE); }