add example auth

Cargo.toml

@@ -15,4 +15,10 @@ sha2 = "0.10"
 base64 = "0.21"
 thiserror = "1.0"
 
+[dev-dependencies]
+clap = { version = "4.4", features = ["derive"] }
+
+[[example]]
+name = "auth"
+
 [package.metadata.playground]

examples/auth.rs

@@ -0,0 +1,92 @@
+use std::io::{self, BufRead, Write};
+
+use clap::{Parser, Subcommand};
+use django_auth::*;
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+#[command(propagate_version = true)]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    /// Encode a password in Django-style
+    Encode,
+
+    /// Verify a Django stored hashed password
+    Verify,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    match &cli.command {
+        Commands::Encode => {
+            let (password, salt, iterations) = {
+                (
+                    get_user_input("Input password: "),
+                    get_user_input("Input salt: "),
+                    get_user_input_number("Input number of iterations: "),
+                )
+            };
+
+            println!(
+                "✅ Encoded password: {}",
+                django_encode_password(&password, &salt, iterations).unwrap()
+            );
+        }
+        Commands::Verify => {
+            let (password, hashed_password) = {
+                (
+                    get_user_input("Input password: "),
+                    get_user_input("Input Django stored password: "),
+                )
+            };
+
+            let res = django_auth(&password, &hashed_password);
+            match res {
+                Ok(ok) => {
+                    if ok {
+                        println!("✅ Password verified!")
+                    } else {
+                        println!("❌ Password verification failed!")
+                    }
+                }
+                Err(err) => println!("💔 Verification error: {:?}", err),
+            }
+        }
+    }
+}
+
+fn get_user_input(prompt: &str) -> String {
+    print!("{prompt}");
+    io::stdout().flush().expect("failed to write to stdout");
+
+    let stdin = io::stdin();
+    let line = stdin
+        .lock()
+        .lines()
+        .next()
+        .expect("failed to read password")
+        .expect("failed to read from stdin");
+
+    line
+}
+
+fn get_user_input_number(prompt: &str) -> u32 {
+    let res = get_user_input(prompt).parse::<u32>();
+    if let Ok(n) = res {
+        return n;
+    }
+
+    loop {
+        println!("Please input a number, try again!");
+        let res = get_user_input(prompt).parse::<u32>();
+        if let Ok(n) = res {
+            return n;
+        }
+    }
+}