defarm-sdk/lib/core/ICPBrasilIntegration.ts

DeFarm SDK - On-premise blockchain data processing and tokenization engine for agriculture supply chain

/**
 * ICP-Brasil Integration for DeFarm SDK
 * 
 * Integrates with Brazilian Public Key Infrastructure (ICP-Brasil)
 * while solving the certificate expiration problem
 * 
 * Key features:
 * - Uses ICP-Brasil certificates for authentication
 * - DeFarm provides long-term decryption keys
 * - Hybrid approach: ICP-Brasil for identity + DeFarm for continuity
 */

import { X509Certificate, randomBytes } from 'crypto';
import { KeyDerivationService, DerivedKey } from './KeyDerivationService';

export interface ICPBrasilCertificate {
  type: 'e-CPF' | 'e-CNPJ' | 'e-SERVIDOR' | 'e-APLICACAO';
  subject: {
    cn: string;  // Common Name
    cpf?: string;
    cnpj?: string;
    organization?: string;
  };
  serialNumber: string;
  validFrom: Date;
  validTo: Date;
  issuer: string;
  publicKey: string;
}

export interface HybridEncryptionConfig {
  // ICP-Brasil certificate for authentication/signing
  icpCertificate: ICPBrasilCertificate;
  
  // DeFarm derived key for long-term encryption
  defarmKey: DerivedKey;
  
  // Encryption strategy
  strategy: 'hybrid' | 'icpOnly' | 'defarmOnly';
}

export class ICPBrasilIntegration {
  /**
   * Create hybrid encryption solution
   * ICP-Brasil authenticates + DeFarm encrypts
   */
  static createHybridEncryption(
    icpCertPath: string,
    governmentId: string
  ): HybridEncryptionConfig {
    // Parse ICP-Brasil certificate
    const icpCert = this.parseICPBrasilCertificate(icpCertPath);
    
    // Request DeFarm key based on ICP-Brasil identity
    const defarmKey = this.requestKeyForICPIdentity(icpCert, governmentId);
    
    return {
      icpCertificate: icpCert,
      defarmKey,
      strategy: 'hybrid'
    };
  }
  
  /**
   * Encrypt data with hybrid approach
   * 1. Sign with ICP-Brasil certificate
   * 2. Encrypt with DeFarm derived key
   */
  static async hybridEncrypt(
    data: string,
    config: HybridEncryptionConfig
  ): Promise<{
    encrypted: string;
    signature: string;
    envelope: {
      version: number;
      strategy: string;
      icpSerialNumber: string;
      defarmKeyId: string;
      timestamp: string;
      validUntil: string; // Considers both cert expiry and key validity
    };
  }> {
    // Step 1: Sign with ICP-Brasil certificate
    const signature = await this.signWithICPBrasil(data, config.icpCertificate);
    
    // Step 2: Create signed payload
    const signedPayload = {
      data,
      signature,
      signer: {
        type: config.icpCertificate.type,
        serialNumber: config.icpCertificate.serialNumber,
        cn: config.icpCertificate.subject.cn
      },
      timestamp: new Date().toISOString()
    };
    
    // Step 3: Encrypt with DeFarm key
    const encryptionEnvelope = KeyDerivationService.encryptWithFallback(
      JSON.stringify(signedPayload),
      config.defarmKey,
      [] // Can add fallback keys
    );
    
    // Step 4: Create hybrid envelope
    const validUntil = new Date(
      Math.min(
        config.icpCertificate.validTo.getTime(),
        config.defarmKey.validUntil?.getTime() || Infinity
      )
    );
    
    return {
      encrypted: JSON.stringify(encryptionEnvelope),
      signature,
      envelope: {
        version: 1,
        strategy: config.strategy,
        icpSerialNumber: config.icpCertificate.serialNumber,
        defarmKeyId: config.defarmKey.keyId,
        timestamp: new Date().toISOString(),
        validUntil: validUntil.toISOString()
      }
    };
  }
  
  /**
   * Decrypt with certificate renewal support
   */
  static async hybridDecrypt(
    encryptedData: string,
    currentICPCert: ICPBrasilCertificate,
    availableDefarmKeys: DerivedKey[]
  ): Promise<{
    success: boolean;
    data?: string;
    signature?: string;
    originalSigner?: any;
    error?: string;
  }> {
    try {
      // Parse encrypted envelope
      const encryptionEnvelope = JSON.parse(encryptedData);
      
      // Decrypt with DeFarm keys (works even if ICP cert expired)
      const decryptResult = KeyDerivationService.decrypt(
        encryptionEnvelope,
        availableDefarmKeys
      );
      
      if (!decryptResult.success) {
        return { success: false, error: decryptResult.error };
      }
      
      // Parse signed payload
      const signedPayload = JSON.parse(decryptResult.data!);
      
      // Verify signature if certificate is still valid
      let signatureValid = false;
      if (currentICPCert.validTo > new Date()) {
        signatureValid = await this.verifyICPBrasilSignature(
          signedPayload.data,
          signedPayload.signature,
          currentICPCert
        );
      }
      
      return {
        success: true,
        data: signedPayload.data,
        signature: signedPayload.signature,
        originalSigner: signedPayload.signer
      };
      
    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : 'Decryption failed'
      };
    }
  }
  
  /**
   * Certificate renewal workflow
   */
  static async renewCertificateEncryption(
    oldCertPath: string,
    newCertPath: string,
    governmentId: string,
    existingDefarmKey: DerivedKey
  ): Promise<{
    newConfig: HybridEncryptionConfig;
    migrationKey: DerivedKey;
  }> {
    // Parse new certificate
    const newCert = this.parseICPBrasilCertificate(newCertPath);
    
    // Create migration key that can decrypt old data
    const migrationKey = await this.requestMigrationKey(
      governmentId,
      oldCertPath,
      newCertPath
    );
    
    return {
      newConfig: {
        icpCertificate: newCert,
        defarmKey: existingDefarmKey, // Keep same encryption key
        strategy: 'hybrid'
      },
      migrationKey
    };
  }
  
  /**
   * Parse ICP-Brasil certificate
   */
  private static parseICPBrasilCertificate(certPath: string): ICPBrasilCertificate {
    // In real implementation, would parse actual certificate
    // For now, simulate ICP-Brasil certificate structure
    
    return {
      type: 'e-CNPJ',
      subject: {
        cn: 'MINISTERIO DA AGRICULTURA:00.000.000/0001-00',
        cnpj: '00.000.000/0001-00',
        organization: 'MINISTERIO DA AGRICULTURA, PECUARIA E ABASTECIMENTO'
      },
      serialNumber: '1234567890ABCDEF',
      validFrom: new Date('2024-01-01'),
      validTo: new Date('2027-01-01'), // 3 years
      issuer: 'AC SERASA RFB v5',
      publicKey: 'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A...'
    };
  }
  
  /**
   * Request DeFarm key for ICP-Brasil identity
   */
  private static requestKeyForICPIdentity(
    icpCert: ICPBrasilCertificate,
    governmentId: string
  ): DerivedKey {
    // Map ICP-Brasil identity to DeFarm key
    const keyConfig = {
      masterKeyId: 'defarm-master-icp-brasil',
      governmentId,
      purpose: 'encryption' as const,
      validFrom: new Date(),
      validUntil: new Date(Date.now() + 10 * 365 * 24 * 60 * 60 * 1000), // 10 years
      metadata: {
        icpSerialNumber: icpCert.serialNumber,
        icpType: icpCert.type,
        icpCN: icpCert.subject.cn
      }
    };
    
    // In production, this would call DeFarm API
    // Generate a valid 32-byte key for testing
    const mockKey = randomBytes(32).toString('hex');
    
    return {
      keyId: `dk_icp_${governmentId}_${Date.now()}`,
      governmentId,
      derivedKey: mockKey,
      validFrom: keyConfig.validFrom,
      validUntil: keyConfig.validUntil,
      derivationPath: `icp-brasil/${icpCert.type}/${icpCert.serialNumber}`,
      canDecryptHistorical: true
    };
  }
  
  /**
   * Sign with ICP-Brasil certificate
   */
  private static async signWithICPBrasil(
    data: string,
    cert: ICPBrasilCertificate
  ): Promise<string> {
    // In production, would use actual ICP-Brasil signing
    // This would integrate with token/smartcard
    const crypto = require('crypto');
    const sign = crypto.createSign('SHA256');
    sign.update(data);
    
    // Simulate signing with ICP-Brasil private key
    return 'icp-brasil-signature-' + Buffer.from(data).toString('base64').substring(0, 32);
  }
  
  /**
   * Verify ICP-Brasil signature
   */
  private static async verifyICPBrasilSignature(
    data: string,
    signature: string,
    cert: ICPBrasilCertificate
  ): Promise<boolean> {
    // In production, would verify against ICP-Brasil chain
    return signature.startsWith('icp-brasil-signature-');
  }
  
  /**
   * Request migration key for certificate renewal
   */
  private static async requestMigrationKey(
    governmentId: string,
    oldCertPath: string,
    newCertPath: string
  ): Promise<DerivedKey> {
    // This would call DeFarm API with both certificates
    // to create a migration key
    return {
      keyId: `dk_migration_${governmentId}_${Date.now()}`,
      governmentId,
      derivedKey: 'migration-key',
      validFrom: new Date(),
      validUntil: new Date(Date.now() + 90 * 24 * 60 * 60 * 1000), // 90 days
      derivationPath: 'migration/icp-brasil',
      canDecryptHistorical: true
    };
  }
}

/**
 * ICP-Brasil Compliance Utilities
 */
export class ICPBrasilCompliance {
  /**
   * Validate certificate chain
   */
  static async validateCertificateChain(certPath: string): Promise<{
    valid: boolean;
    chain: string[];
    errors?: string[];
  }> {
    // Would validate against ICP-Brasil root CAs
    return {
      valid: true,
      chain: [
        'User Certificate',
        'AC SERASA RFB v5',
        'AC Raiz Brasileira v5'
      ]
    };
  }
  
  /**
   * Check certificate revocation
   */
  static async checkRevocation(serialNumber: string): Promise<{
    revoked: boolean;
    reason?: string;
    revokedAt?: Date;
  }> {
    // Would check ICP-Brasil CRL/OCSP
    return {
      revoked: false
    };
  }
  
  /**
   * Generate audit trail
   */
  static generateAuditTrail(
    operation: string,
    cert: ICPBrasilCertificate,
    data: any
  ): {
    timestamp: string;
    operation: string;
    actor: {
      type: string;
      identifier: string;
      organization: string;
    };
    hash: string;
  } {
    const crypto = require('crypto');
    const hash = crypto.createHash('sha256');
    hash.update(JSON.stringify({ operation, data }));
    
    return {
      timestamp: new Date().toISOString(),
      operation,
      actor: {
        type: cert.type,
        identifier: cert.subject.cpf || cert.subject.cnpj || cert.serialNumber,
        organization: cert.subject.organization || 'Unknown'
      },
      hash: hash.digest('hex')
    };
  }
}