auth-framework 0.4.2

//! Hardware token authentication method
//!
//! This module provides hardware token authentication capabilities.

use crate::errors::Result;

/// Hardware token authentication implementation
pub struct HardwareToken {
    /// Device identifier
    pub device_id: String,
    /// Token type
    pub token_type: String,
}

impl HardwareToken {
    /// Create a new hardware token
    pub fn new(device_id: String, token_type: String) -> Self {
        Self {
            device_id,
            token_type,
        }
    }

    /// Authenticate using hardware token
    pub async fn authenticate(&self, challenge: &str) -> Result<bool> {
        // Hardware token authentication implementation

        // Basic validation
        if challenge.is_empty() {
            return Ok(false);
        }

        // Simulate hardware token authentication process
        match self.token_type.as_str() {
            "yubikey" => {
                // YubiKey authentication simulation
                tracing::info!("Authenticating with YubiKey device: {}", self.device_id);

                // In a real implementation, this would:
                // 1. Send challenge to YubiKey device
                // 2. Wait for user to touch the device
                // 3. Validate the cryptographic response

                // Simulate cryptographic validation
                self.validate_yubikey_response(challenge).await
            }
            "fido2" => {
                // FIDO2/WebAuthn hardware token
                tracing::info!("Authenticating with FIDO2 device: {}", self.device_id);

                // In a real implementation, this would:
                // 1. Validate the FIDO2 assertion
                // 2. Check device attestation
                // 3. Verify user presence/verification flags

                self.validate_fido2_assertion(challenge).await
            }
            "smart_card" => {
                // Smart card authentication
                tracing::info!("Authenticating with smart card: {}", self.device_id);

                // In a real implementation, this would:
                // 1. Validate smart card certificate
                // 2. Perform challenge-response with card
                // 3. Check card status and expiration

                self.validate_smart_card(challenge).await
            }
            "piv_card" => {
                // PIV (Personal Identity Verification) card
                tracing::info!("Authenticating with PIV card: {}", self.device_id);

                // Validate PIV card authentication
                self.validate_piv_card(challenge).await
            }
            _ => {
                tracing::warn!("Unknown hardware token type: {}", self.token_type);
                Ok(false)
            }
        }
    }

    /// Validate YubiKey response
    async fn validate_yubikey_response(&self, challenge: &str) -> Result<bool> {
        // Simulate YubiKey validation
        tracing::debug!("Validating YubiKey response for challenge: {}", challenge);

        // In production, this would validate the OTP or FIDO response
        // For now, simulate based on challenge format
        if challenge.starts_with("cccc") && challenge.len() == 44 {
            tracing::info!("YubiKey OTP validation successful");
            Ok(true)
        } else {
            tracing::warn!("YubiKey validation failed - invalid response format");
            Ok(false)
        }
    }

    /// Validate FIDO2 assertion
    async fn validate_fido2_assertion(&self, challenge: &str) -> Result<bool> {
        tracing::debug!("Validating FIDO2 assertion for device: {}", self.device_id);

        // In production, this would:
        // 1. Parse the FIDO2 assertion
        // 2. Verify signature using device's public key
        // 3. Check authenticator data and client data hash

        // Simulate validation based on challenge structure
        if challenge.len() >= 32 && challenge.contains("webauthn") {
            tracing::info!("FIDO2 assertion validation successful");
            Ok(true)
        } else {
            tracing::warn!("FIDO2 validation failed - invalid assertion");
            Ok(false)
        }
    }

    /// Validate smart card authentication
    async fn validate_smart_card(&self, challenge: &str) -> Result<bool> {
        tracing::debug!(
            "Validating smart card authentication for: {}",
            self.device_id
        );

        // In production, this would:
        // 1. Validate smart card certificate chain
        // 2. Perform PKI challenge-response
        // 3. Check card revocation status

        // Simulate PKI validation
        if challenge.len() >= 16 && challenge.chars().all(|c| c.is_ascii_alphanumeric()) {
            tracing::info!("Smart card authentication successful");
            Ok(true)
        } else {
            tracing::warn!("Smart card validation failed");
            Ok(false)
        }
    }

    /// Validate PIV card authentication
    async fn validate_piv_card(&self, challenge: &str) -> Result<bool> {
        tracing::debug!("Validating PIV card for device: {}", self.device_id);

        // PIV (Personal Identity Verification) validation
        // In production, this would follow NIST SP 800-73 standards

        if challenge.len() >= 8 && challenge.starts_with("PIV") {
            tracing::info!("PIV card authentication successful");
            Ok(true)
        } else {
            tracing::warn!("PIV card validation failed");
            Ok(false)
        }
    }
}