PCLCrypto to .NET 8 Cryptography Migration

This repository contains the migration of legacy PCLCrypto cryptographic implementations to modern .NET 8 cryptography APIs. The migration ensures compatibility while leveraging the improved security and performance features of .NET 8's cryptographic stack.

Overview

The migration covers the following cryptographic operations:

1. Checksum calculation (SHA-256)
2. Key derivation (PBKDF2-SHA1)
3. AES encryption (CBC mode with PKCS7 padding)
4. AES decryption

Migration Details

Checksum Calculation

• Migrated from WinRTCrypto.HashAlgorithmProvider to System.Security.Cryptography.SHA256
• Maintains identical hash output
• Improved performance with modern implementations

Key Derivation

• Migrated from NetFxCrypto.DeriveBytes to System.Security.Cryptography.Rfc2898DeriveBytes
• Maintains compatibility with PBKDF2-SHA1
• Proper resource disposal with using statements

AES Encryption/Decryption

• Migrated from WinRTCrypto.SymmetricKeyAlgorithmProvider to System.Security.Cryptography.Aes
• Maintains CBC mode and PKCS7 padding for compatibility
• Explicit IV handling for better security control

Security Considerations

While maintaining compatibility with legacy implementations, consider these security enhancements for production use:

1. Use unique random IVs for each encryption operation
2. Implement message authentication (HMAC)
3. Increase PBKDF2 iteration count (recommend 100,000+)
4. Consider upgrading to stronger algorithms where possible:
   • PBKDF2-SHA256 instead of PBKDF2-SHA1
   • AES-GCM instead of AES-CBC

Usage

Replace the old PCLCrypto implementations with their .NET 8 counterparts:

// Old PCLCrypto implementation
var hasher = WinRTCrypto.HashAlgorithmProvider.OpenAlgorithm(HashAlgorithm.Sha256);
byte[] hash = hasher.HashData(inputBytes);

// New .NET 8 implementation
byte[] hash = SHA256.HashData(inputBytes);

Dependencies

• .NET 8 SDK
• Original PCLCrypto package (for testing only)

Migration Testing

Run the included test programs to verify the migration:

1. dotnet run --project PCLCryptoSample

Contributing

Feel free to submit issues and enhancement requests.

License

This project is licensed under the MIT License - see the LICENSE file for details.