ecu_diagnostics 0.90.0

//! Provides methods for security seed/key access to the ECU in order to unlock functions which
//! are considered secure such as writing or reading to specific memory regions on the ECU
//!
//! Currently, only default seed/key (0x01/0x02) are supported

use super::{UDSCommand, UdsDiagnosticServer};
use crate::{DiagServerResult, DiagnosticServer};

/// Security operation request
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub enum SecurityOperation {
    /// Asks the ECU for a security seed
    RequestSeed,
    /// Sends the computed key to the ECU
    SendKey,
}

impl From<SecurityOperation> for u8 {
    fn from(from: SecurityOperation) -> Self {
        match from {
            SecurityOperation::RequestSeed => 0x01,
            SecurityOperation::SendKey => 0x02,
        }
    }
}

impl UdsDiagnosticServer {
    /// Requests a seed from the ECU for security access.
    ///
    /// Once the key is calculated from the response seed, run [UdsDiagnosticServer::send_key] to send the computed key to the ECU
    ///
    /// ## Parameters
    /// * server - The UDS Diagnostic server
    ///
    /// ## Returns
    /// Returns the security key's seed
    pub fn request_seed(&mut self) -> DiagServerResult<Vec<u8>> {
        let mut resp = self.execute_command_with_response(
            UDSCommand::SecurityAccess,
            &[SecurityOperation::RequestSeed.into()],
        )?;
        resp.drain(0..2); // Remove SID and PID, so just seed value left
        Ok(resp)
    }

    /// Sends the computed key to the ECU.
    ///
    /// If this function is successful, then the ECU has now allows access to security protected memory regions and functions
    ///
    /// ## Parameters
    /// * server - The UDS Diagnostic server
    /// * key - The computed key to send to the ECU
    pub fn send_key(&mut self, key: &[u8]) -> DiagServerResult<()> {
        let mut payload = Vec::with_capacity(key.len() + 1);
        payload.push(SecurityOperation::SendKey.into());
        payload.extend_from_slice(key);
        self.execute_command_with_response(UDSCommand::SecurityAccess, &payload)
            .map(|_| ())
    }
}