SQL-based authentication: Difference between revisions
Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
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Hash[FromCharacterCode[data[[2, 1]]] <> pass, "MD5"] == |
Hash[FromCharacterCode[data[[2, 1]]] <> pass, "MD5"] == |
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FromDigits[data[[3, 1]], 256]]; CloseSQLConnection[db]; rtn];</lang> |
FromDigits[data[[3, 1]], 256]]; CloseSQLConnection[db]; rtn];</lang> |
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=={{header|Nim}}== |
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{{libheader|nimcrypto}} |
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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. |
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<lang Nim>import db_mysql, nimcrypto, md5, strutils |
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proc connectDb(user, password: string): DbConn = |
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## Connect to the database "user_db" and create |
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## the table "users" if it doesn’t exist yet. |
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result = open("localhost", user, password, "user_db") |
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result.exec(sql"""CREATE TABLE IF NOT EXISTS users ( |
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userid INT PRIMARY KEY AUTO_INCREMENT, |
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username VARCHAR(32) UNIQUE KEY NOT NULL, |
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pass_salt tinyblob NOT NULL, |
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pass_md5 tinyblob NOT NULL)""") |
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proc createUser(db: DbConn; username, password: string) = |
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## Create a new user in the table "users". |
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## The password salt and the password MD5 are managed as strings |
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## but stored in tinyblobs as required. |
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var passSalt = newString(16) |
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if randomBytes(passSalt) != 16: |
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raise newException(ValueError, "unable to build a salt.") |
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var passMd5 = newString(16) |
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for i, b in toMD5(passSalt & password): passMd5[i] = chr(b) |
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if db.tryExec(sql"INSERT INTO users (username, pass_salt, pass_md5) VALUES (?, ?, ?)", |
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username, passSalt, passMd5): |
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echo "User $1 created." % username |
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else: |
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echo "Could not create user $1." % username |
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proc authenticateUser(db: DbConn; user, password: string): bool = |
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## Try to authenticate the user. |
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## The authentication fails if the user doesn’t exist in "users" table or if the |
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## password doesn’t match with the salt and password MD5 retrieved from the table. |
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let row = db.getRow(sql"SELECT pass_salt, pass_md5 FROM users WHERE username = ?", user) |
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if row[0].len != 0: |
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let digest = toMd5(row[0] & password) |
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for i in 0..15: |
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if digest[i] != byte(row[1][i]): return |
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result = true |
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proc clean(db: DbConn) = |
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## Remove all users from "users" table. |
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db.exec(sql"DELETE FROM user_db.users") |
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when isMainModule: |
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proc authResult(status: bool): string = |
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if status: "Succeeded" else: "Failed" |
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# Connect to database and create user "Alice". |
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let db = connectDb("admin", "admin_password") |
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db.createUser("Alice", "Alice_password") |
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# Try to authenticate Alice... |
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# ... with a wrong password... |
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var result = db.authenticateUser("Alice", "another_password").authResult() |
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echo result, " to authenticate Alice with a wrong password." |
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# ... then with the right password. |
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result = db.authenticateUser("Alice", "Alice_password").authResult() |
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echo result, " to authenticate Alice with the right password." |
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# Clean-up and close. |
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db.clean() |
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db.close()</lang> |
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{{out}} |
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<pre>User Alice created. |
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Failed to authenticate Alice with a wrong password. |
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Succeeded to authenticate Alice with the right password.</pre> |
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=={{header|Objeck}}== |
=={{header|Objeck}}== |
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Revision as of 21:06, 13 April 2021
You are encouraged to solve this task according to the task description, using any language you may know.
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)
This is the table definition: <lang sql>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
);</lang> (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)
<lang c>#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;
}</lang>
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. <lang csharp>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);
}
}
}
}</lang> Class for creating and authenticating users. <lang csharp>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;
}
}
}
}
}</lang> Class with main method and database connection method. <lang csharp>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());
}
}
}
}</lang> Output
Bob has been created: True Bob has been duplicated: False Wrong password works: False Right password works: True
Go
<lang 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`)
}</lang>
- Output:
User sam authenticated sam d5d1ef775a89f2b504dc808e66087f3d a939f77466e91527e748377cc14dfd66 User sam already exits User pam unknown User sam invalid password
Java
<lang 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();
}
}
}</lang>
Julia
<lang 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: $(authenticate_user(mydb, "Mary", "123")==false)""") mysql_disconnect(mydb) </lang>
Kotlin
<lang scala>// Version 1.2.41
import java.sql.Connection import java.sql.DriverManager import java.sql.ResultSet import java.security.MessageDigest import java.security.SecureRandom import java.math.BigInteger
class UserManager {
private lateinit var dbConnection: Connection
private fun md5(message: String): String {
val hexString = StringBuilder()
val bytes = message.toByteArray()
val md = MessageDigest.getInstance("MD5")
val dig = md.digest(bytes)
for (i in 0 until dig.size) {
val hex = (0xff and dig[i].toInt()).toString(16)
if (hex.length == 1) hexString.append('0')
hexString.append(hex)
}
return hexString.toString()
}
fun connectDB(host: String, port: Int, db: String, user: String, pwd: String) {
Class.forName("com.mysql.jdbc.Driver")
dbConnection = DriverManager.getConnection(
"jdbc:mysql://$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()
}
}
}</lang>
Mathematica
<lang Mathematica>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[data2, 1] <> pass, "MD5"] ==
FromDigits[data3, 1, 256]]; CloseSQLConnection[db]; rtn];</lang>
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.
<lang Nim>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()</lang>
- Output:
User Alice created. Failed to authenticate Alice with a wrong password. Succeeded to authenticate Alice with the right password.
Objeck
<lang 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;
}
}</lang>
Perl
<lang 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
}</lang>
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.
<lang Phix>-- demo/rosetta/SQL-based_authentication.exw
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()</lang>
- Output:
user with correct password:true user with incorrect password:false
PHP
To use MySQL in PHP you need the php_mysql module installed <lang php> 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']; } </lang>
Python
Uses the official Python MySQL connector <lang python>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
</lang>
Racket
<lang 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!")))</lang>
Raku
(formerly Perl 6)
<lang perl6> 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;
}</lang>
Raven
MySQL connectivity is available out of the box. Below, we do not ever send the plain text password over the wire.
<lang raven> '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" print</lang>
Ruby
Uses the mysql2 gem <lang ruby>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</lang>
Sidef
<lang ruby>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
)
}</lang>
Tcl
Also requires the TDBC driver for MySQL. <lang Tcl>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\""
}</lang>
- Programming Tasks
- Database operations
- C
- Mysqlclient
- OpenSSL
- C sharp
- Go
- Java
- Julia
- Kotlin
- Mathematica
- DatabaseLink`
- Nim
- Nimcrypto
- Objeck
- Perl
- DBI
- Phix
- PHP
- Python
- Racket
- Raku
- Raven
- Ruby
- Sidef
- Tcl
- Batch File/Omit
- Brainf***/Omit
- Lotus 123 Macro Scripting/Omit
- M4/Omit
- Maxima/Omit
- ML/I/Omit
- PARI/GP/Omit
- PostScript/Omit
- Retro/Omit
- SNOBOL4/Omit
- SQL/Omit
- SQL PL/Omit
- TI-83 BASIC/Omit
- TI-89 BASIC/Omit
- Unlambda/Omit
- Yorick/Omit
- ZX Spectrum Basic/Omit