/* Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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=generate_user_salt() 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 #include #include "mysql.h" #include "crypt_genhash_impl.h" void randominit(struct rand_struct *rand_st, ulong seed1, ulong seed2) { /* For mysql 3.21.# */ 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 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) { 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); } 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); } /* 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 char *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) { 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++; } #if defined(HAVE_OPENSSL) void my_make_scrambled_password(char *to, const char *password, size_t pass_len) { char salt[CRYPT_SALT_LENGTH + 1]; generate_user_salt(salt, CRYPT_SALT_LENGTH + 1); my_crypt_genhash(to, CRYPT_MAX_PASSWORD_SIZE, password, pass_len, salt, 0); } #endif /** Compute two stage SHA1 hash of the password : hash_stage1=sha1("password") hash_stage2=sha1(hash_stage1) @param password [IN] Password string. @param pass_len [IN] Length of the password. @param hash_stage1 [OUT] sha1(password) @param hash_stage2 [OUT] sha1(hash_stage1) */ inline static void compute_two_stage_sha1_hash(const char *password, size_t pass_len, uint8 *hash_stage1, uint8 *hash_stage2) { /* Stage 1: hash password */ compute_sha1_hash(hash_stage1, password, pass_len); /* Stage 2 : hash first stage's output. */ compute_sha1_hash(hash_stage2, (const char *) hash_stage1, SHA1_HASH_SIZE); } /* 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 my_make_scrambled_password_sha1() buf OUT buffer of size 2*SHA1_HASH_SIZE + 2 to store hex string password IN password string pass_len IN length of password string */ void my_make_scrambled_password_sha1(char *to, const char *password, size_t pass_len) { uint8 hash_stage2[SHA1_HASH_SIZE]; /* Two stage SHA1 hash of the password. */ compute_two_stage_sha1_hash(password, pass_len, (uint8 *) to, hash_stage2); /* convert hash_stage2 to hex string */ *to++= PVERSION41_CHAR; octet2hex(to, (const char*) hash_stage2, SHA1_HASH_SIZE); } /* Wrapper around my_make_scrambled_password() to maintain client lib ABI compatibility. In server code usage of my_make_scrambled_password() is preferred to avoid strlen(). 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) { my_make_scrambled_password_sha1(to, password, strlen(password)); } /* Produce an obscure octet sequence from password and random string, received 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) { uint8 hash_stage1[SHA1_HASH_SIZE]; uint8 hash_stage2[SHA1_HASH_SIZE]; /* Two stage SHA1 hash of the password. */ compute_two_stage_sha1_hash(password, strlen(password), hash_stage1, hash_stage2); /* create crypt string as sha1(message, hash_stage2) */; compute_sha1_hash_multi((uint8 *) to, message, SCRAMBLE_LENGTH, (const char *) hash_stage2, SHA1_HASH_SIZE); 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 received 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_sha1() 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_sha1(const uchar *scramble_arg, const char *message, const uint8 *hash_stage2) { uint8 buf[SHA1_HASH_SIZE]; uint8 hash_stage2_reassured[SHA1_HASH_SIZE]; /* create key to encrypt scramble */ compute_sha1_hash_multi(buf, message, SCRAMBLE_LENGTH, (const char *) hash_stage2, SHA1_HASH_SIZE); /* encrypt scramble */ my_crypt((char *) buf, buf, scramble_arg, SCRAMBLE_LENGTH); /* now buf supposedly contains hash_stage1: so we can get hash_stage2 */ compute_sha1_hash(hash_stage2_reassured, (const char *) buf, SHA1_HASH_SIZE); return MY_TEST(memcmp(hash_stage2, hash_stage2_reassured, SHA1_HASH_SIZE)); } my_bool check_scramble(const uchar *scramble_arg, const char *message, const uint8 *hash_stage2) { return check_scramble_sha1(scramble_arg, message, hash_stage2); } /* 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, (const char*) hash_stage2, SHA1_HASH_SIZE); }