Cryptography Skill

Sorcha.Cryptography provides multi-algorithm support (ED25519, P-256, RSA-4096), symmetric encryption (AES, ChaCha20), and BIP39/44 HD wallet derivation. All operations return CryptoResult<T> for explicit error handling—no exceptions for crypto failures.

Quick Start

Key Generation

// Inject ICryptoModule var keySetResult = await _cryptoModule.GenerateKeySetAsync(WalletNetworks.ED25519); if (!keySetResult.IsSuccess) throw new InvalidOperationException($"Key generation failed: {keySetResult.Status}");

var keySet = keySetResult.Value!; // keySet.PrivateKey.Key = 64 bytes (ED25519) // keySet.PublicKey.Key = 32 bytes (ED25519)

Signing & Verification

// Hash then sign byte[] hash = SHA256.HashData(transactionData); var signResult = await _cryptoModule.SignAsync( hash, (byte)WalletNetworks.ED25519, keySet.PrivateKey.Key!);

// Verify var status = await _cryptoModule.VerifyAsync( signResult.Value!, hash, (byte)WalletNetworks.ED25519, keySet.PublicKey.Key!); bool isValid = status == CryptoStatus.Success;

HD Wallet Creation

var keyRing = await _keyManager.CreateMasterKeyRingAsync(WalletNetworks.ED25519, password: null); // keyRing.Mnemonic = "word1 word2 ... word12" — user must backup // keyRing.MasterKeySet contains derived keys

Key Concepts

Concept Usage Example

WalletNetworks

Algorithm selection ED25519 , NISTP256 , RSA4096

CryptoResult<T>

Error handling .IsSuccess , .Status , .Value

KeySet

Public/private pair .PrivateKey.Key , .PublicKey.Key

KeyRing

Full wallet with mnemonic .Mnemonic , .MasterKeySet

.Zeroize()

Secure memory clearing Call when done with keys

Common Patterns

Platform-Specific Key Storage

// Encryption provider abstraction handles platform differences var encrypted = await _encryptionProvider.EncryptAsync(privateKey, "wallet-key-id"); // Windows: DPAPI, Linux: Secret Service, Dev: AES-GCM

Address Generation

var address = _walletUtilities.PublicKeyToWallet(publicKey, (byte)WalletNetworks.ED25519); // Returns: "ws1q8tuvvdykly8n0fy5jkuu8cjw0fu0p6jl5rp9g..."

See Also

• patterns - Algorithm selection, signing workflows, key management

• workflows - Wallet creation, transaction signing, encryption

Related Skills

• See the nbitcoin skill for HD wallet derivation paths (BIP32/39/44)

• See the postgresql skill for encrypted key storage patterns

• See the xunit and fluent-assertions skills for testing crypto code

Documentation Resources

Fetch latest cryptography documentation with Context7.

How to use Context7:

• Use mcp__context7__resolve-library-id to search for "libsodium" or "System.Security.Cryptography"

• Query with mcp__context7__query-docs using the resolved library ID

Recommended Queries:

• "ED25519 signing verification"

• "AES-GCM authenticated encryption"

• "BIP39 mnemonic seed derivation"