start work on encryption

3 files changed, 59 insertions, 0 deletions

diff --git a/azalea-auth/Cargo.toml b/azalea-auth/Cargo.toml
index aa9b7bdb..cb807776 100644
--- a/azalea-auth/Cargo.toml
+++ b/azalea-auth/Cargo.toml
@@ -6,4 +6,7 @@ version = "0.1.0"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+num-bigint = "^0.4.3"
+rand = {version = "^0.8.4", features = ["getrandom"]}
+sha-1 = "^0.10.0"
 uuid = "^0.8.2"
diff --git a/azalea-auth/src/encryption.rs b/azalea-auth/src/encryption.rs
new file mode 100644
index 00000000..334d8cb3
--- /dev/null
+++ b/azalea-auth/src/encryption.rs
@@ -0,0 +1,53 @@
+use rand::{rngs::OsRng, RngCore};
+use sha1::{Digest, Sha1};
+
+fn generate_secret_key() -> [u8; 16] {
+    let mut key = [0u8; 16];
+    OsRng.fill_bytes(&mut key);
+    key
+}
+
+fn digest_data(server_id: &[u8], public_key: &[u8], private_key: &[u8]) -> Vec<u8> {
+    let mut digest = Sha1::new();
+    digest.update(server_id);
+    digest.update(public_key);
+    digest.update(private_key);
+    digest.finalize().to_vec()
+}
+
+fn hex_digest(digest: &[u8]) -> String {
+    // Note that the Sha1.hexdigest() method used by minecraft is non standard.
+    // It doesn't match the digest method found in most programming languages
+    // and libraries. It works by treating the sha1 output bytes as one large
+    // integer in two's complement and then printing the integer in base 16,
+    // placing a minus sign if the interpreted number is negative.
+    num_bigint::BigInt::from_signed_bytes_be(digest).to_str_radix(16)
+}
+
+fn encrypt(public_key: &[u8], server_id: String, nonce: &[u8]) {
+    let secret_key = generate_secret_key();
+    let hash = hex_digest(&digest_data(server_id.as_bytes(), public_key, &secret_key));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_generate_secret_key() {
+        let key = generate_secret_key();
+        assert_eq!(key.len(), 16);
+    }
+
+    #[test]
+    fn test_hex_digest() {
+        let digest = hex_digest(&digest_data(b"Notch", &[], &[]));
+        assert_eq!(digest, "4ed1f46bbe04bc756bcb17c0c7ce3e4632f06a48");
+
+        let digest = hex_digest(&digest_data(b"jeb_", &[], &[]));
+        assert_eq!(digest, "-7c9d5b0044c130109a5d7b5fb5c317c02b4e28c1");
+
+        let digest = hex_digest(&digest_data(b"simon", &[], &[]));
+        assert_eq!(digest, "88e16a1019277b15d58faf0541e11910eb756f6");
+    }
+}
diff --git a/azalea-auth/src/lib.rs b/azalea-auth/src/lib.rs
index 773ea1d9..afe9eb33 100644
--- a/azalea-auth/src/lib.rs
+++ b/azalea-auth/src/lib.rs
@@ -1,3 +1,6 @@
 //! Handle Minecraft authentication.
 
 pub mod game_profile;
+pub mod encryption;
+
+