Just another update

Task/SQL-based-authentication/Go/sql-based-authentication.go

@@ -0,0 +1,79 @@
+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`)
+}

Task/SQL-based-authentication/Objeck/sql-based-authentication.objeck

@@ -0,0 +1,104 @@
+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;
+  }
+}