SQL-based authentication
This task has three parts:
- Connect to a MySQL database (connect_db)
- Create user/password records in the following table (create_user)
- Authenticate login requests against the table (authenticate_user)
You are encouraged to solve this task according to the task description, using any language you may know.
This is the table definition:
create table users (
userid int primary key auto_increment,
username varchar(32) unique key not null,
pass_salt tinyblob not null,
-- a string of 16 random bytes
pass_md5 tinyblob not null
-- binary MD5 hash of pass_salt concatenated with the password
);
(pass_salt and pass_md5 would be binary(16) values, but MySQL versions before 5.0.15 strip trailing spaces when selecting them.)
C
(MySQL client library)
(for MD5)
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <time.h>
#include <mysql.h>
#include <openssl/md5.h>
void end_with_db(void);
MYSQL *mysql = NULL; // global...
bool connect_db(const char *host, const char *user, const char *pwd,
const char *db, unsigned int port)
{
if ( mysql == NULL )
{
if (mysql_library_init(0, NULL, NULL)) return false;
mysql = mysql_init(NULL); if ( mysql == NULL ) return false;
MYSQL *myp = mysql_real_connect(mysql, host, user, pwd, db, port, NULL, 0);
if (myp == NULL) {
fprintf(stderr, "connection error: %s\n", mysql_error(mysql));
end_with_db();
return false;
}
}
return true; // already connected... ?
}
#define USERNAMELIMIT 32
// no part of the spec, but it is reasonable!!
#define PASSWORDLIMIT 32
#define SALTBYTE 16
bool create_user(const char *username, const char *password)
{
int i;
char binarysalt[SALTBYTE];
char salt[SALTBYTE*2+1];
char md5hash[MD5_DIGEST_LENGTH];
char saltpass[SALTBYTE+PASSWORDLIMIT+1];
char pass_md5[MD5_DIGEST_LENGTH*2 + 1];
char user[USERNAMELIMIT*2 + 1];
char *q = NULL;
static const char query[] =
"INSERT INTO users "
"(username,pass_salt,pass_md5) "
"VALUES ('%s', X'%s', X'%s')";
static const size_t qlen = sizeof query;
for(i=0; username[i] != '\0' && i < USERNAMELIMIT; i++) ;
if ( username[i] != '\0' ) return false;
for(i=0; password[i] != '\0' && i < PASSWORDLIMIT; i++) ;
if ( password[i] != '\0' ) return false;
srand(time(NULL));
for(i=0; i < SALTBYTE; i++)
{
// this skews the distribution but it is lazyness-compliant;)
binarysalt[i] = rand()%256;
}
(void)mysql_hex_string(salt, binarysalt, SALTBYTE);
for(i=0; i < SALTBYTE; i++) saltpass[i] = binarysalt[i];
strcpy(saltpass+SALTBYTE, password);
(void)MD5(saltpass, SALTBYTE + strlen(password), md5hash);
(void)mysql_hex_string(pass_md5, md5hash, MD5_DIGEST_LENGTH);
(void)mysql_real_escape_string(mysql, user, username, strlen(username));
// salt, pass_md5, user are db-query-ready
q = malloc(qlen + USERNAMELIMIT*2 + MD5_DIGEST_LENGTH*2 + SALTBYTE*2 + 1);
if ( q == NULL ) return false;
sprintf(q, query, user, salt, pass_md5);
#if defined(DEBUG)
fprintf(stderr, "QUERY:\n%s\n\n", q);
#endif
int res = mysql_query(mysql, q);
free(q);
if ( res != 0 )
{
fprintf(stderr, "create_user query error: %s\n", mysql_error(mysql));
return false;
}
return true;
}
bool authenticate_user(const char *username, const char *password)
{
char user[USERNAMELIMIT*2 + 1];
char md5hash[MD5_DIGEST_LENGTH];
char saltpass[SALTBYTE+PASSWORDLIMIT+1];
bool authok = false;
char *q = NULL;
int i;
static const char query[] =
"SELECT * FROM users WHERE username='%s'";
static const size_t qlen = sizeof query;
// can't be authenticated with invalid username or password
for(i=0; username[i] != '\0' && i < USERNAMELIMIT; i++) ;
if ( username[i] != '\0' ) return false;
for(i=0; password[i] != '\0' && i < PASSWORDLIMIT; i++) ;
if ( password[i] != '\0' ) return false;
(void)mysql_real_escape_string(mysql, user, username, strlen(username));
q = malloc(qlen + strlen(user) + 1);
if (q == NULL) return false;
sprintf(q, query, username);
int res = mysql_query(mysql, q);
free(q);
if ( res != 0 )
{
fprintf(stderr, "authenticate_user query error: %s\n", mysql_error(mysql));
return false;
}
MYSQL_RES *qr = mysql_store_result(mysql);
if ( qr == NULL ) return false;
// should be only a result, or none
if ( mysql_num_rows(qr) != 1 ) {
mysql_free_result(qr);
return false;
}
MYSQL_ROW row = mysql_fetch_row(qr); // 1 row must exist
unsigned long *len = mysql_fetch_lengths(qr); // and should have 4 cols...
memcpy(saltpass, row[2], len[2]); // len[2] should be SALTBYTE
memcpy(saltpass + len[2], password, strlen(password));
(void)MD5(saltpass, SALTBYTE + strlen(password), md5hash);
authok = memcmp(md5hash, row[3], len[3]) == 0;
mysql_free_result(qr);
return authok;
}
void end_with_db(void)
{
mysql_close(mysql); mysql = NULL;
mysql_library_end();
}
int main(int argc, char **argv)
{
if ( argc < 4 ) return EXIT_FAILURE;
if ( connect_db("localhost", "devel", "", "test", 0 ) )
{
if ( strcmp(argv[1], "add") == 0 )
{
if (create_user(argv[2], argv[3]))
printf("created\n");
} else if ( strcmp(argv[1], "auth") == 0 ) {
if (authenticate_user(argv[2], argv[3]))
printf("authorized\n");
else
printf("access denied\n");
} else {
printf("unknown command\n");
}
end_with_db();
}
return EXIT_SUCCESS;
}
From the command line, program add user password to add users, and program auth user password to see if the user with that password is authorized or not.
C#
Class for hashing and random salt generation.
using System.Security.Cryptography;
using System.Text;
namespace rosettaMySQL
{
class Hasher
{
private static string _BytesToHex(byte[] input)
{
var strBuilder = new StringBuilder();
foreach (byte _byte in input)
{
strBuilder.Append(_byte.ToString("x2"));
}
return strBuilder.ToString();
}
public static string Hash(string salt, string input)
{
using (MD5 md5 = new MD5CryptoServiceProvider())
{
var bytes = Encoding.Default.GetBytes(salt + input);
var data = md5.ComputeHash(bytes);
return _BytesToHex(data);
}
}
public static string GenSalt()
{
using (RandomNumberGenerator rng = new RNGCryptoServiceProvider())
{
var salt = new byte[16];
rng.GetBytes(salt);
return _BytesToHex(salt);
}
}
}
}
Class for creating and authenticating users.
using MySql.Data.MySqlClient;
namespace rosettaMySQL
{
class UserOperator
{
private MySqlConnection _connection;
public UserOperator(MySqlConnection connection)
{
_connection = connection;
}
public bool CreateUser(string username, string password)
{
try
{
var salt = Hasher.GenSalt();
var hash = Hasher.Hash(salt, password);
var sql = $"INSERT INTO users " +
$"(username, pass_salt, pass_md5) " +
$"VALUES ('{username}','{salt}','{hash}')";
using (var command = new MySqlCommand(sql, _connection))
{
command.ExecuteNonQuery();
return true;
}
}
catch (MySqlException e)
{
if (e.Number == 1062) //username is a duplicate
{
return false;
}
else
{
throw e;
}
}
}
public bool AuthenticateUser(string username, string password)
{
var sql = $"SELECT userid, username, pass_salt, pass_md5 " +
$"FROM users " +
$"WHERE username='{username}';";
using (var command = new MySqlCommand(sql, _connection))
using (var reader = command.ExecuteReader())
{
if (reader.HasRows)
{
reader.Read();
var salt = reader.GetString("pass_salt");
var hash = reader.GetString("pass_md5");
return (Hasher.Hash(salt, password) == hash);
}
else
{
return false;
}
}
}
}
}
Class with main method and database connection method.
using System;
using MySql.Data.MySqlClient;
namespace rosettaMySQL
{
class Program
{
public static MySqlConnection ConnectDB(string server, int port, string db,
string username, string password)
{
var connectStr = $"server={server};" +
$"user={username};" +
$"database={db};" +
$"port={port};" +
$"password={password}";
return new MySqlConnection(connectStr);
}
static void Main(string[] args)
{
try
{
var connection = ConnectDB("localhost", 3306, "test", "root", "password");
connection.Open();
var userOperator = new UserOperator(connection);
Console.WriteLine("Bob has been created: " + userOperator.CreateUser("Bob", "123456"));
Console.WriteLine("Bob has been duplicated: " + userOperator.CreateUser("Bob", "123456"));
Console.WriteLine("Wrong password works: " + userOperator.AuthenticateUser("BOB", "notpassword"));
Console.WriteLine("Right password works: " + userOperator.AuthenticateUser("BOB", "123456"));
}
catch(MySqlException e)
{
switch(e.Number)
{
case 0:
Console.WriteLine("Cannot connect to server");
break;
case 1045:
Console.WriteLine("Invalid database username/password");
break;
default:
Console.WriteLine(e.ToString());
Console.WriteLine(e.Number);
break;
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
}
Output
Bob has been created: True Bob has been duplicated: False Wrong password works: False Right password works: True
Go
package main
import (
"bytes"
"crypto/md5"
"crypto/rand"
"database/sql"
"fmt"
_ "github.com/go-sql-driver/mysql"
)
func connectDB() (*sql.DB, error) {
return sql.Open("mysql", "rosetta:code@/rc")
}
func createUser(db *sql.DB, user, pwd string) error {
salt := make([]byte, 16)
rand.Reader.Read(salt)
_, err := db.Exec(`insert into users (username, pass_salt, pass_md5)
values (?, ?, ?)`, user, salt, saltHash(salt, pwd))
if err != nil {
return fmt.Errorf("User %s already exits", user)
}
return nil
}
func authenticateUser(db *sql.DB, user, pwd string) error {
var salt, hash []byte
row := db.QueryRow(`select pass_salt, pass_md5 from users
where username=?`, user)
if err := row.Scan(&salt, &hash); err != nil {
return fmt.Errorf("User %s unknown", user)
}
if !bytes.Equal(saltHash(salt, pwd), hash) {
return fmt.Errorf("User %s invalid password", user)
}
return nil
}
func saltHash(salt []byte, pwd string) []byte {
h := md5.New()
h.Write(salt)
h.Write([]byte(pwd))
return h.Sum(nil)
}
func main() {
// demonstrate
db, err := connectDB()
defer db.Close()
createUser(db, "sam", "123")
err = authenticateUser(db, "sam", "123")
if err == nil {
fmt.Println("User sam authenticated")
}
// extra
fmt.Println()
// show contents of database
rows, _ := db.Query(`select username, pass_salt, pass_md5 from users`)
var user string
var salt, hash []byte
for rows.Next() {
rows.Scan(&user, &salt, &hash)
fmt.Printf("%s %x %x\n", user, salt, hash)
}
// try creating same user again
err = createUser(db, "sam", "123")
fmt.Println(err)
// try authenticating unknown user
err = authenticateUser(db, "pam", "123")
fmt.Println(err)
// try wrong password
err = authenticateUser(db, "sam", "1234")
fmt.Println(err)
// clear table to run program again
db.Exec(`truncate table users`)
}
- Output:
User sam authenticated sam d5d1ef775a89f2b504dc808e66087f3d a939f77466e91527e748377cc14dfd66 User sam already exits User pam unknown User sam invalid password
Java
import java.io.UnsupportedEncodingException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.math.BigInteger;
class UserManager {
private Connection dbConnection;
public UserManager() {
}
private String md5(String aString) throws NoSuchAlgorithmException, UnsupportedEncodingException {
MessageDigest md;
String hex;
StringBuffer hexString;
byte[] bytesOfMessage;
byte[] theDigest;
hexString = new StringBuffer();
bytesOfMessage = aString.getBytes("UTF-8");
md = MessageDigest.getInstance("MD5");
theDigest = md.digest(bytesOfMessage);
for (int i = 0; i < theDigest.length; i++) {
hex = Integer.toHexString(0xff & theDigest[i]);
if (hex.length() == 1) {
hexString.append('0');
}
hexString.append(hex);
}
return hexString.toString();
}
public void connectDB(String host, int port, String db, String user, String password)
throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
this.dbConnection = DriverManager.getConnection("jdbc:mysql://"
+ host
+ ":"
+ port
+ "/"
+ db, user, password);
}
public boolean createUser(String user, String password) {
SecureRandom random;
String insert;
String salt;
random = new SecureRandom();
salt = new BigInteger(130, random).toString(16);
insert = "INSERT INTO users "
+ "(username, pass_salt, pass_md5) "
+ "VALUES (?, ?, ?)";
try (PreparedStatement pstmt = this.dbConnection.prepareStatement(insert)) {
pstmt.setString(1, user);
pstmt.setString(2, salt);
pstmt.setString(3, this.md5(salt + password));
pstmt.executeUpdate();
return true;
} catch(NoSuchAlgorithmException | SQLException | UnsupportedEncodingException ex) {
return false;
}
}
public boolean authenticateUser(String user, String password) {
String pass_md5;
String pass_salt;
String select;
ResultSet res;
select = "SELECT pass_salt, pass_md5 FROM users WHERE username = ?";
res = null;
try(PreparedStatement pstmt = this.dbConnection.prepareStatement(select)) {
pstmt.setString(1, user);
res = pstmt.executeQuery();
res.next(); // We assume that username is unique
pass_salt = res.getString(1);
pass_md5 = res.getString(2);
if (pass_md5.equals(this.md5(pass_salt + password))) {
return true;
} else {
return false;
}
} catch(NoSuchAlgorithmException | SQLException | UnsupportedEncodingException ex) {
return false;
} finally {
try {
if (res instanceof ResultSet && !res.isClosed()) {
res.close();
}
} catch(SQLException ex) {
}
}
}
public void closeConnection() {
try {
this.dbConnection.close();
} catch(NullPointerException | SQLException ex) {
}
}
public static void main(String[] args) {
UserManager um;
um = new UserManager();
try {
um.connectDB("localhost", 3306, "test", "root", "admin");
if (um.createUser("johndoe", "test")) {
System.out.println("User created");
}
if (um.authenticateUser("johndoe", "test")) {
System.out.println("User authenticated");
}
} catch(ClassNotFoundException | SQLException ex) {
ex.printStackTrace();
} finally {
um.closeConnection();
}
}
}
Julia
using MySQL
using Nettle # for md5
function connect_db(uri, user, pw, dbname)
mydb = mysql_connect(uri, user, pw, dbname)
const command = """CREATE TABLE IF NOT EXISTS users (
userid INT PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(32) UNIQUE KEY NOT NULL,
pass_salt tinyblob NOT NULL,
-- a string of 16 random bytes
pass_md5 tinyblob NOT NULL
-- binary MD5 hash of pass_salt concatenated with the password
);"""
mysql_execute(mydb, command)
mydb
end
function create_user(dbh, user, pw)
mysql_stmt_prepare(dbh, "INSERT IGNORE INTO users (username, pass_salt, pass_md5) values (?, ?, ?);")
salt = join([Char(c) for c in rand(UInt8, 16)], "")
passmd5 = digest("md5", salt * pw)
mysql_execute(dbh, [MYSQL_TYPE_VARCHAR, MYSQL_TYPE_VARCHAR, MYSQL_TYPE_VARCHAR], [user, salt, passmd5])
end
function addusers(dbh, userdict)
for user in keys(userdict)
create_user(dbh, user, userdict[user])
end
end
"""
authenticate_user
Note this returns true if password provided authenticates as correct, false otherwise
"""
function authenticate_user(dbh, username, pw)
mysql_stmt_prepare(dbh, "SELECT pass_salt, pass_md5 FROM users WHERE username = ?;")
pass_salt, pass_md5 = mysql_execute(dbh, [MYSQL_TYPE_VARCHAR], [username], opformat=MYSQL_TUPLES)[1]
pass_md5 == digest("md5", pass_salt * pw)
end
const users = Dict("Joan" => "joanspw", "John" => "johnspw", "Mary" => "marpw", "Mark" => "markpw")
const mydb = connect_db("192.168.1.1", "julia", "julia", "mydb")
addusers(mydb, users)
println("""John authenticates correctly: $(authenticate_user(mydb, "John", "johnspw")==true)""")
println("""Mary does not authenticate with password of 123: $(authenticate_user(mydb, "Mary", "123")==false)""")
mysql_disconnect(mydb)
Kotlin
// Version 1.2.41
import java.sql.Connection
import java.sql.DriverManager
import java.sql.ResultSet
import java.security.MessageDigest
import java.security.SecureRandom
import java.math.BigInteger
class UserManager {
private lateinit var dbConnection: Connection
private fun md5(message: String): String {
val hexString = StringBuilder()
val bytes = message.toByteArray()
val md = MessageDigest.getInstance("MD5")
val dig = md.digest(bytes)
for (i in 0 until dig.size) {
val hex = (0xff and dig[i].toInt()).toString(16)
if (hex.length == 1) hexString.append('0')
hexString.append(hex)
}
return hexString.toString()
}
fun connectDB(host: String, port: Int, db: String, user: String, pwd: String) {
Class.forName("com.mysql.jdbc.Driver")
dbConnection = DriverManager.getConnection(
"jdbc:mysql://$host:$port/$db", user, pwd
)
}
fun createUser(user: String, pwd: String): Boolean {
val random = SecureRandom()
val salt = BigInteger(130, random).toString(16)
val insert = "INSERT INTO users " +
"(username, pass_salt, pass_md5) " +
"VALUES (?, ?, ?)"
try {
val pstmt = dbConnection.prepareStatement(insert)
with (pstmt) {
setString(1, user)
setString(2, salt)
setString(3, md5(salt + pwd))
val rowCount = executeUpdate()
close()
if (rowCount == 0) return false
}
return true
}
catch (ex: Exception) {
return false
}
}
fun authenticateUser(user: String, pwd: String): Boolean {
val select = "SELECT pass_salt, pass_md5 FROM users WHERE username = ?"
lateinit var res: ResultSet
try {
val pstmt = dbConnection.prepareStatement(select)
with (pstmt) {
setString(1, user)
res = executeQuery()
res.next() // assuming that username is unique
val passSalt = res.getString(1)
val passMD5 = res.getString(2)
close()
return passMD5 == md5(passSalt + pwd)
}
}
catch (ex: Exception) {
return false
}
finally {
if (!res.isClosed) res.close()
}
}
fun closeConnection() {
if (!dbConnection.isClosed) dbConnection.close()
}
}
fun main(args: Array<String>) {
val um = UserManager()
with (um) {
try {
connectDB("localhost", 3306, "test", "root", "admin")
if (createUser("johndoe", "test")) println("User created")
if (authenticateUser("johndoe", "test")) {
println("User authenticated")
}
}
catch(ex: Exception) {
ex.printStackTrace()
}
finally {
closeConnection()
}
}
}
Mathematica /Wolfram Language
Needs["DatabaseLink`"];
connectDb[dbUser_, dbPass_, dbUrl_] :=
OpenSQLConnection[JDBC["mysql", dbUrl], "Username" -> dbUser,
"Password" -> dbPass];
createUser::nameTaken = "The username '`1`' is already taken.";
createUser[dbUser_, dbPass_, dbUrl_, user_, pass_] :=
Module[{db = connectDb[dbUser, dbPass, dbUrl],
salt = RandomChoice[Range[32, 127], 16]},
If[MemberQ[SQLSelect[db, "users", {"username"}], {user}],
Message[createUser::nameTaken, user]; Return[]];
SQLInsert[db,
"users", {"username", "pass_salt", "pass_md5"}, {user,
SQLBinary[salt],
SQLBinary[
IntegerDigits[Hash[FromCharacterCode[salt] <> pass, "MD5"], 256,
16]]}]; CloseSQLConnection[db];];
authenticateUser[dbUser_, dbPass_, dbUrl_, user_, pass_] :=
Module[{db = connectDb[dbUser, dbPass, dbUrl], rtn},
rtn = MemberQ[SQLSelect[db, "users", {"username"}], {user}] &&
Module[{data =
SQLSelect[db, "users", {"username", "pass_salt", "pass_md5"},
SQLColumn["username"] == user][[1]]},
Hash[FromCharacterCode[data[[2, 1]]] <> pass, "MD5"] ==
FromDigits[data[[3, 1]], 256]]; CloseSQLConnection[db]; rtn];
Nim
Even if this program is only an example, we have chosen to generate the salt using the random number generator provided by the third-party module “nimcrypto” rather than using the PRNG from the standard module “random” which is totally inadequate for cryptographic usage.
import db_mysql, nimcrypto, md5, strutils
proc connectDb(user, password: string): DbConn =
## Connect to the database "user_db" and create
## the table "users" if it doesn’t exist yet.
result = open("localhost", user, password, "user_db")
result.exec(sql"""CREATE TABLE IF NOT EXISTS users (
userid INT PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(32) UNIQUE KEY NOT NULL,
pass_salt tinyblob NOT NULL,
pass_md5 tinyblob NOT NULL)""")
proc createUser(db: DbConn; username, password: string) =
## Create a new user in the table "users".
## The password salt and the password MD5 are managed as strings
## but stored in tinyblobs as required.
var passSalt = newString(16)
if randomBytes(passSalt) != 16:
raise newException(ValueError, "unable to build a salt.")
var passMd5 = newString(16)
for i, b in toMD5(passSalt & password): passMd5[i] = chr(b)
if db.tryExec(sql"INSERT INTO users (username, pass_salt, pass_md5) VALUES (?, ?, ?)",
username, passSalt, passMd5):
echo "User $1 created." % username
else:
echo "Could not create user $1." % username
proc authenticateUser(db: DbConn; user, password: string): bool =
## Try to authenticate the user.
## The authentication fails if the user doesn’t exist in "users" table or if the
## password doesn’t match with the salt and password MD5 retrieved from the table.
let row = db.getRow(sql"SELECT pass_salt, pass_md5 FROM users WHERE username = ?", user)
if row[0].len != 0:
let digest = toMd5(row[0] & password)
for i in 0..15:
if digest[i] != byte(row[1][i]): return
result = true
proc clean(db: DbConn) =
## Remove all users from "users" table.
db.exec(sql"DELETE FROM user_db.users")
when isMainModule:
proc authResult(status: bool): string =
if status: "Succeeded" else: "Failed"
# Connect to database and create user "Alice".
let db = connectDb("admin", "admin_password")
db.createUser("Alice", "Alice_password")
# Try to authenticate Alice...
# ... with a wrong password...
var result = db.authenticateUser("Alice", "another_password").authResult()
echo result, " to authenticate Alice with a wrong password."
# ... then with the right password.
result = db.authenticateUser("Alice", "Alice_password").authResult()
echo result, " to authenticate Alice with the right password."
# Clean-up and close.
db.clean()
db.close()
- Output:
User Alice created. Failed to authenticate Alice with a wrong password. Succeeded to authenticate Alice with the right password.
Objeck
use ODBC;
use Encryption;
class SqlTest {
@conn : Connection;
function : Main(args : String[]) ~ Nil {
SqlTest->New()->Run();
}
New() {
@conn := Connection->New("test", "root", "helloworld");
}
method : Run() ~ Nil {
CreateUser("objeck", "beer");
AuthenticateUser("objeck", "beer");
leaving {
@conn->Close();
};
}
method : AuthenticateUser(username : String, password : String) ~ Nil {
status := false;
ps : ParameterStatement;
result : ResultSet;
if(@conn->IsOpen()) {
sql := "SELECT pass_salt, pass_md5 FROM users WHERE username = ?";
ps := @conn->CreateParameterStatement(sql);
ps->SetVarchar(1, username);
result := ps->Select();
if(result <> Nil & result->Next()) {
salt_buffer := Byte->New[16];
result->GetBlob(1, salt_buffer);
salt := "";
for(i := 0; i < 16; i+=1;) {
salt->Append(salt_buffer[i]);
};
db_password_buffer := Byte->New[16];
result->GetBlob(2, db_password_buffer);
password->Append(salt);
user_password_buffer := Hash->MD5(password->ToByteArray());
IO.Console->Print("user: authenticated=")->PrintLine(IsEqual(db_password_buffer, user_password_buffer));
};
};
leaving {
if(ps <> Nil) {
ps->Close();
};
if(ps <> Nil) {
ps->Close();
};
};
}
method : CreateUser(username : String, password : String) ~ Nil {
salt := "";
for(i := 0; i < 16; i+=1;) { salt->Append((Float->Random() * 100)->As(Int)); };
salt := salt->SubString(16);
password->Append(salt);
md5_password := Hash->MD5(password->ToByteArray());
ps : ParameterStatement;
if(@conn->IsOpen()) {
sql := "INSERT INTO users(username, pass_salt, pass_md5) VALUES (?, ?, ?)";
ps := @conn->CreateParameterStatement(sql);
ps->SetVarchar(1, username);
ps->SetBytes(2, salt->ToByteArray());
ps->SetBytes(3, md5_password);
IO.Console->Print("adding user: username=")->Print(username)
->Print(", salt=")->Print(salt)
->Print(", status=")->PrintLine(ps->Update());
};
leaving {
if(ps <> Nil) {
ps->Close();
};
};
}
method : IsEqual(left : Byte[], right : Byte[]) ~ Bool {
if(left->Size() <> right->Size()) {
return false;
};
each(i : left) {
if(left[i] <> right[i]) {
return false;
};
};
return true;
}
}Perl
use DBI;
# returns a database handle configured to throw an exception on query errors
sub connect_db {
my ($dbname, $host, $user, $pass) = @_;
my $db = DBI->connect("dbi:mysql:$dbname:$host", $user, $pass)
or die $DBI::errstr;
$db->{RaiseError} = 1;
$db
}
# if the user was successfully created, returns its user id.
# if the name was already in use, returns undef.
sub create_user {
my ($db, $user, $pass) = @_;
my $salt = pack "C*", map {int rand 256} 1..16;
$db->do("INSERT IGNORE INTO users (username, pass_salt, pass_md5)
VALUES (?, ?, unhex(md5(concat(pass_salt, ?))))",
undef, $user, $salt, $pass)
and $db->{mysql_insertid} or undef
}
# if the user is authentic, returns its user id. otherwise returns undef.
sub authenticate_user {
my ($db, $user, $pass) = @_;
my $userid = $db->selectrow_array("SELECT userid FROM users WHERE
username=? AND pass_md5=unhex(md5(concat(pass_salt, ?)))",
undef, $user, $pass);
$userid
}
Phix
Uses SQLite, there is a MySQL wrapper in PCAN that I have not personally tried yet.
Uses code from MD5, now modified to be an executable library.
-- demo\rosetta\SQL-based_authentication.exw without js -- (file i/o) include pSQLite.e include md5.exw sqlite3_stmt pAddUser = NULL procedure add_user(sqlite3 db, string name, pw) if pAddUser=NULL then pAddUser = sqlite3_prepare(db,"INSERT INTO users (username,pass_salt,pass_md5) VALUES(:name, :salt, :md5);") end if string salt = sq_rand(repeat(#FF,16)), md5s = md5(salt&pw) sqlite3_bind_text(pAddUser,":name", name) sqlite3_bind_text(pAddUser,":salt", salt) sqlite3_bind_text(pAddUser,":md5", md5s) {} = sqlite3_step(pAddUser) -- (nb: ignores any errors.) sqlite3_reset(pAddUser) end procedure sqlite3_stmt pAuthUser = NULL function authenticate_user(sqlite3 db, string name, pw) if pAuthUser=NULL then pAuthUser = sqlite3_prepare(db,"SELECT pass_salt, pass_md5 FROM users WHERE username = :name;") end if sqlite3_bind_text(pAuthUser,":name", name) integer res = sqlite3_step(pAuthUser) if res!=SQLITE_ROW then res = false -- (no such user) else string salt = sqlite3_column_text(pAuthUser,1) string pass_md5 = sqlite3_column_text(pAuthUser,2) res = (pass_md5==md5(salt&pw)) end if sqlite3_reset(pAuthUser) return res end function constant create_cmd = """ CREATE TABLE IF NOT EXISTS users( userid INTEGER PRIMARY KEY AUTOINCREMENT, username VARCHAR(32) UNIQUE NOT NULL, pass_salt tinyblob, -- a string of 16 random bytes pass_md5 tinyblob); -- binary MD5 hash of pass_salt concatenated with the password """ procedure main() sequence sqlversion = sqlite3_libversion(true) if sqlversion<{3,3,0} then crash("a newer sqlite.dll/so is required (for IF NOT EXISTS)") end if sqlite3 db = sqlite3_open("users.sqlite") integer res = sqlite3_exec(db,create_cmd) if res!=SQLITE_OK then ?9/0 end if sqlite3_set_fatal_id(SQLITE3_NON_FATAL) -- (else trying to re-add user crashes) add_user(db,"user","password") printf(1,"user with correct password:%t\n",authenticate_user(db, "user", "password")) printf(1,"user with incorrect password:%t\n",authenticate_user(db, "user", "wrong")) if pAddUser!=NULL then if sqlite3_finalize(pAddUser)!=SQLITE_OK then ?9/0 end if end if if pAuthUser!=NULL then if sqlite3_finalize(pAuthUser)!=SQLITE_OK then ?9/0 end if end if sqlite3_close(db) ?"done" {} = wait_key() end procedure main()
- Output:
user with correct password:true user with incorrect password:false
PHP
To use MySQL in PHP you need the php_mysql module installed
function connect_db($database, $db_user, $db_password, $host = 'localhost', $port = NULL, $die = false) {
// Returns a MySQL link identifier (handle) on success
// Returns false or dies() on error depending on the setting of parameter $die
// Parameter $die configures error handling, setting it any non-false value will die() on error
// Parameters $host, $port and $die have sensible defaults and are not usually required
if(!$db_handle = @mysql_connect($host.($port ? ':'.$port : ''), $db_user, $db_password)) {
if($die)
die("Can't connect to MySQL server:\r\n".mysql_error());
else
return false;
}
if(!@mysql_select_db($database, $db_handle)) {
if($die)
die("Can't select database '$database':\r\n".mysql_error());
else
return false;
}
return $db_handle;
}
function create_user($username, $password, $db_handle) {
// Returns the record ID on success or false on failure
// Username limit is 32 characters (part of spec)
if(strlen($username) > 32)
return false;
// Salt limited to ASCII 32 thru 254 (not part of spec)
$salt = '';
do {
$salt .= chr(mt_rand(32, 254));
} while(strlen($salt) < 16);
// Create pass_md5
$pass_md5 = md5($salt.$password);
// Make it all binary safe
$username = mysql_real_escape_string($username);
$salt = mysql_real_escape_string($salt);
// Try to insert it into the table - Return false on failure
if(!@mysql_query("INSERT INTO users (username,pass_salt,pass_md5) VALUES('$username','$salt','$pass_md5')", $db_handle))
return false;
// Return the record ID
return mysql_insert_id($db_handle);
}
function authenticate_user($username, $password, $db_handle) {
// Checks a username/password combination against the database
// Returns false on failure or the record ID on success
// Make the username parmeter binary-safe
$safe_username = mysql_real_escape_string($username);
// Grab the record (if it exists) - Return false on failure
if(!$result = @mysql_query("SELECT * FROM users WHERE username='$safe_username'", $db_handle))
return false;
// Grab the row
$row = @mysql_fetch_assoc($result);
// Check the password and return false if incorrect
if(md5($row['pass_salt'].$password) != $row['pass_md5'])
return false;
// Return the record ID
return $row['userid'];
}
Python
Uses the official Python MySQL connector
import mysql.connector
import hashlib
import sys
import random
DB_HOST = "localhost"
DB_USER = "devel"
DB_PASS = "devel"
DB_NAME = "test"
def connect_db():
''' Try to connect DB and return DB instance, if not, return False '''
try:
return mysql.connector.connect(host=DB_HOST, user=DB_USER, passwd=DB_PASS, db=DB_NAME)
except:
return False
def create_user(username, passwd):
''' if user was successfully created, returns its ID; returns None on error '''
db = connect_db()
if not db:
print "Can't connect MySQL!"
return None
cursor = db.cursor()
salt = randomValue(16)
passwd_md5 = hashlib.md5(salt+passwd).hexdigest()
# If username already taken, inform it
try:
cursor.execute("INSERT INTO users (`username`, `pass_salt`, `pass_md5`) VALUES (%s, %s, %s)", (username, salt, passwd_md5))
cursor.execute("SELECT userid FROM users WHERE username=%s", (username,) )
id = cursor.fetchone()
db.commit()
cursor.close()
db.close()
return id[0]
except:
print 'Username was already taken. Please select another'
return None
def authenticate_user(username, passwd):
db = connect_db()
if not db:
print "Can't connect MySQL!"
return False
cursor = db.cursor()
cursor.execute("SELECT pass_salt, pass_md5 FROM users WHERE username=%s", (username,))
row = cursor.fetchone()
cursor.close()
db.close()
if row is None: # username not found
return False
salt = row[0]
correct_md5 = row[1]
tried_md5 = hashlib.md5(salt+passwd).hexdigest()
return correct_md5 == tried_md5
def randomValue(length):
''' Creates random value with given length'''
salt_chars = 'abcdefghijklmnopqrstuvwxyz0123456789'
return ''.join(random.choice(salt_chars) for x in range(length))
if __name__ == '__main__':
user = randomValue(10)
passwd = randomValue(16)
new_user_id = create_user(user, passwd)
if new_user_id is None:
print 'Failed to create user %s' % user
sys.exit(1)
auth = authenticate_user(user, passwd)
if auth:
print 'User %s authenticated successfully' % user
else:
print 'User %s failed' % user
Racket
#lang racket
(require db file/md5)
(define-logger authentication)
(current-logger authentication-logger)
(define DB-HOST "localhost")
(define DB-USER "devel")
(define DB-PASS "devel")
(define DB-NAME "test")
(define (connect-db)
(mysql-connect
#:user DB-USER
#:database DB-NAME
#:password DB-PASS))
(define (salt+password->hash salt password #:hex-encode? (hex-encode? #f))
(md5 (bytes-append salt password) hex-encode?))
(define (report-sql-error e)
(log-authentication-error "Failed to create user:~s" (exn-message e))
#f)
(define (create-user db username passwd)
; if user was successfully created, returns its ID else #f
(define salt (list->bytes (for/list ((i (in-range 16))) (random 256))))
(define hash (salt+password->hash salt passwd))
(with-handlers ((exn:fail:sql? report-sql-error))
(query db "INSERT INTO users (username, pass_salt, pass_md5) VALUES (?, ?, ?)"
username salt hash)))
(define (authenticate-user db username password)
(or
(match (query-maybe-row db "SELECT pass_salt, pass_md5 FROM users WHERE username = ?" username)
[#f #f]
[(vector salt hash) (bytes=? hash (salt+password->hash salt password))])
; don't let the deviants know whether it's the username or password that's dodgy
(error "the username, password combination does not exist in system")))
(module+ test
(require rackunit)
(define test-DB (connect-db))
; typically, you only do this the once (or risk upsetting your users bigtime!)
; call this just the once!
(define (create-users-table db)
(query-exec db "DROP TABLE IF EXISTS users")
(query-exec db #<<EOS
CREATE TABLE users (
userid INT PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(32) UNIQUE KEY NOT NULL,
pass_salt tinyblob NOT NULL,
-- a string of 16 random bytes
pass_md5 tinyblob NOT NULL
-- binary MD5 hash of pass_salt concatenated with the password
);
EOS
))
(create-users-table test-DB)
(create-user test-DB #"tim" #"shh! it's a secret!")
; ensure the user exists (for testing purposes)
(check-match (query-list test-DB "SELECT userid FROM users WHERE username = 'tim'") (list _))
; (ah... but tim exists!!!)
(check-false (create-user test-DB #"tim" #"tim's password"))
(check-exn exn:fail? (λ () (authenticate-user test-DB #"tim" #"password")))
(check-true (authenticate-user test-DB #"tim" #"shh! it's a secret!")))
Raku
(formerly Perl 6)
use v6;
use DBIish;
multi connect_db(:$dbname, :$host, :$user, :$pass) {
my $db = DBIish.connect("mysql",host => $host, database =>$dbname, user =>$user, password =>$pass, :RaiseError)
or die "ERROR: {DBIish.errstr}.";
$db;
}
multi create_user(:$db, :$user, :$pass) {
#https://stackoverflow.com/questions/53365101/converting-pack-to-perl6
my $salt = Buf.new((^256).roll(16));
my $sth = $db.prepare(q:to/STATEMENT/);
INSERT IGNORE INTO users (username, pass_salt, pass_md5)
VALUES (?, ?, unhex(md5(concat(pass_salt, ?))))
STATEMENT
$sth.execute($user,$salt,$pass);
$sth.insert-id or Any;
}
multi authenticate_user (:$db, :$user, :$pass) {
my $sth = $db.prepare(q:to/STATEMENT/);
SELECT userid FROM users WHERE
username=? AND pass_md5=unhex(md5(concat(pass_salt, ?)))
STATEMENT
$sth.execute($user,$pass);
my $userid = $sth.fetch;
$userid[0] or Any;
}
Raven
MySQL connectivity is available out of the box. Below, we do not ever send the plain text password over the wire.
'mysql://root@localhost/test' open as mysql
'abcdefghijklmnopqrstuvwxyz0123456789' as $salt_chars
# return userid for success and FALSE for failure.
define create_user use $user, $pass
group 16 each as i
$salt_chars choose chr
join as $pass_salt
"%($pass_salt)s%($pass)s" md5 as $pass_md5
$user copy mysql escape as $user_name
group 'INSERT IGNORE into users (username, pass_md5, pass_salt)'
" VALUES ('%($user_name)s', unhex('%($pass_md5)s'), '%($pass_salt)s')"
join mysql query inserted
# return userid for success and FALSE for failure.
define authenticate_user use $user, $pass
FALSE as $userid
$user copy mysql escape as $user_name
group 'SELECT userid, pass_salt, hex(pass_md5)'
" FROM users WHERE username = '%($user_name)s'"
join mysql query as rs
rs selected
if rs fetch values into $possible_userid, $pass_salt, $pass_md5
"%($pass_salt)s%($pass)s" md5 $pass_md5 lower =
if $possible_userid as $userid
$userid
'foo' 'bar' create_user !if "could not create user\n" print bye
'foo' 'bar' authenticate_user !if "could not authenticate user\n" print bye
"user successfully created and authenticated!\n" printRuby
Uses the mysql2 gem
require 'mysql2'
require 'securerandom'
require 'digest'
def connect_db(host, port = nil, username, password, db)
Mysql2::Client.new(
host: host,
port: port,
username: username,
password: password,
database: db
)
end
def create_user(client, username, password)
salt = SecureRandom.random_bytes(16)
password_md5 = Digest::MD5.hexdigest(salt + password)
statement = client.prepare('INSERT INTO users (username, pass_salt, pass_md5) VALUES (?, ?, ?)')
statement.execute(username, salt, password_md5)
statement.last_id
end
def authenticate_user(client, username, password)
user_record = client.prepare("SELECT SELECT pass_salt, pass_md5 FROM users WHERE username = '#{client.escape(username)}'").first
return false unless user_record
password_md5 = Digest::MD5.hexdigest(user_record['pass_salt'] + password)
password_md5 == user_record['pass_md5']
end
Sidef
require('DBI')
# returns a database handle configured to throw an exception on query errors
func connect_db(dbname, host, user, pass) {
var db = %s<DBI>.connect("dbi:mysql:#{dbname}:#{host}", user, pass)
db || die (global DBI::errstr)
db{:RaiseError} = 1
db
}
# if the user was successfully created, returns its user id.
# if the name was already in use, returns nil.
func create_user(db, user, pass) {
var salt = "C*".pack(16.of { 256.irand }...)
db.do(
"INSERT IGNORE INTO users (username, pass_salt, pass_md5)
VALUES (?, ?, unhex(md5(concat(pass_salt, ?))))", nil, user, salt, pass
) ? db{:mysql_insertid} : nil
}
# if the user is authentic, returns its user id. otherwise returns nil.
func authenticate_user(db, user, pass) {
db.selectrow_array("SELECT userid FROM users WHERE
username=? AND pass_md5=unhex(md5(concat(pass_salt, ?)))",
nil, user, pass
)
}
Tcl
Also requires the TDBC driver for MySQL.
package require tdbc
proc connect_db {handleName dbname host user pass} {
package require tdbc::mysql
tdbc::mysql::connection create $handleName -user $user -passwd $pass \
-host $host -database $dbname
return $handleName
}
# A simple helper to keep code shorter
proc r64k {} {
expr int(65536*rand())
}
proc create_user {handle user pass} {
set salt [binary format ssssssss \
[r64k] [r64k] [r64k] [r64k] [r64k] [r64k] [r64k] [r64k]]
# Note that we are using named parameters below, :user :salt :pass
# They are bound automatically to local variables with the same name
$handle allrows {
INSERT IGNORE INTO users (username, pass_salt, pass_md5)
VALUES (:user, :salt, unhex(md5(concat(:salt, :pass))))
}
return ;# Ignore the result of the allrows method
}
proc authenticate_user {handle user pass} {
$handle foreach row {
SELECT userid FROM users WHERE
username=:user AND pass_md5=unhex(md5(concat(pass_salt, :pass)))
} {
return [dict get $row userid]
}
# Only get here if no rows selected
error "authentication failed for user \"$user\""
}
Wren
As we don't have a MySQL wrapper (and it's hardly worth the effort of writing one specifically for this task), I've used our SQLite wrapper instead. SQLite can emulate SQL types used in other dialects even though it's native type system is quite simple.
Not an exact 'phiximile' but follows the same lines.
import "./sql" for Sql, Connection
import "./crypto" for Md5
var addUser = Fn.new { |db, name, pw|
var sql = "INSERT OR IGNORE INTO users (username,pass_salt,pass_md5) VALUES(?, ?, ?)"
var stmt = db.prepare(sql)
var salt = Sql.randomness(16)
var md5s = Md5.digest(salt + pw)
stmt.bindText(1, name)
stmt.bindText(2, salt)
stmt.bindText(3, md5s)
stmt.step()
}
var authenticateUser = Fn.new { |db, name, pw|
var sql = "SELECT pass_salt, pass_md5 FROM users WHERE username = ?"
var stmt = db.prepare(sql)
stmt.bindText(1, name)
var res = stmt.step()
if (res != Sql.row) {
res = false // no such user
} else {
var salt = stmt.columnText(0)
var passMd5 = stmt.columnText(1)
res = passMd5 == Md5.digest(salt + pw)
}
return res
}
var createSql = """
DROP TABLE IF EXISTS users;
CREATE TABLE users(
userid INTEGER PRIMARY KEY AUTOINCREMENT,
username VARCHAR(32) UNIQUE NOT NULL,
pass_salt tinyblob NOT NULL,
pass_md5 tinyblob NOT NULL);
"""
var db = Connection.open("users.db")
var res = db.exec(createSql)
if (res != Sql.ok) Fiber.abort("Error creating users table.")
addUser.call(db, "user", "password")
System.print("User with correct password: %(authenticateUser.call(db, "user", "password"))")
System.print("User with incorrect password: %(authenticateUser.call(db, "user", "wrong"))")
- Output:
User with correct password: true User with incorrect password: false