chore: merge v1 into v2 for the last time

plugins/authenticator/src/u2f_crate/authorization.rs

@@ -0,0 +1,65 @@
+// Copyright 2021 Flavio Oliveira
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+use bytes::{Buf, BufMut};
+use openssl::sha::sha256;
+use serde::Serialize;
+use std::io::Cursor;
+
+use crate::u2f_crate::u2ferror::U2fError;
+
+/// The `Result` type used in this crate.
+type Result<T> = ::std::result::Result<T, U2fError>;
+
+#[derive(Serialize, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct Authorization {
+    pub counter: u32,
+    pub user_presence: bool,
+}
+
+pub fn parse_sign_response(
+    app_id: String,
+    client_data: Vec<u8>,
+    public_key: Vec<u8>,
+    sign_data: Vec<u8>,
+) -> Result<Authorization> {
+    if sign_data.len() <= 5 {
+        return Err(U2fError::InvalidSignatureData);
+    }
+
+    let user_presence_flag = &sign_data[0];
+    let counter = &sign_data[1..=4];
+    let signature = &sign_data[5..];
+
+    // Let's build the msg to verify the signature
+    let app_id_hash = sha256(&app_id.into_bytes());
+    let client_data_hash = sha256(&client_data[..]);
+
+    let mut msg = vec![];
+    msg.put(app_id_hash.as_ref());
+    msg.put_u8(*user_presence_flag);
+    msg.put(counter);
+    msg.put(client_data_hash.as_ref());
+
+    let public_key = super::crypto::NISTP256Key::from_bytes(&public_key)?;
+
+    // The signature is to be verified by the relying party using the public key obtained during registration.
+    let verified = public_key.verify_signature(signature, msg.as_ref())?;
+    if !verified {
+        return Err(U2fError::BadSignature);
+    }
+
+    let authorization = Authorization {
+        counter: get_counter(counter),
+        user_presence: true,
+    };
+
+    Ok(authorization)
+}
+
+fn get_counter(counter: &[u8]) -> u32 {
+    let mut buf = Cursor::new(counter);
+    buf.get_u32()
+}