Generate keys with GYB (#22)

.swiftformat

@@ -13,4 +13,4 @@
 --header strip
 
 # file options
---exclude .build,Sources/secp256k1,Sources/K1/Support/ThirdyParty
+--exclude .build,Sources/secp256k1,Sources/K1/Support/ThirdyParty,**/*.swift.gyb

Package.swift

@@ -71,6 +71,9 @@ let package = Package(
  dependencies: [
  "secp256k1",
  ],
+ exclude: [
+ "K1/Keys/Keys.swift.gyb",
+ ],
  swiftSettings: [
  .define("CRYPTO_IN_SWIFTPM_FORCE_BUILD_API"),
  ]

README.md

@@ -250,6 +250,30 @@ Stand in root and run
 
 To clone the dependency [libsecp256k1][lib], using commit [427bc3cdcfbc74778070494daab1ae5108c71368](https://github.com/bitcoin-core/secp256k1/commit/427bc3cdcfbc74778070494daab1ae5108c71368) (semver 0.3.0)
 
+
+## `gyb`
+
+Some of the files in this project are autogenerated (metaprogramming) using the Swift Utils tools called [gyb](https://github.com/apple/swift/blob/main/utils/gyb.py) (_"generate your boilerplate"_). `gyb` is included in [`./scripts/gyb`](scripts/gyb).
+
+`gyb` will generate some `Foobar.swift` Swift file from some `Foobar.swift.gyb` _template_ file. **You should not edit `Foobar.swift` directly**, since all manual edits in that generated file will be overwritten the next time `gyb` is run.
+
+You run `gyb` for a single file like so:
+
+```bash
+./scripts/gyb --line-directive "" Sources/Foobar.swift.gyb -o Sources/Foobar.swift
+```
+
+More conveniently you can run the bash script `./scripts/generate_boilerplate_files_with_gyb.sh` to generate all Swift files from their corresponding gyb template.
+
+**If you add a new `.gyb` file, you should append a `// MARK: - Generated file, do NOT edit` warning** inside it, e.g.
+
+```swift
+// MARK: - Generated file, do NOT edit
+// any edits of this file WILL be overwritten and thus discarded
+// see section `gyb` in `README` for details.
+```
+
+
 # Alternatives
 
 - [GigaBitcoin/secp256k1.swift](https://github.com/GigaBitcoin/secp256k1.swift) (also using `libsecp256k1`, ⚠️ possibly unsafe, ✅ Schnorr support) 

Sources/K1/K1/ECDH/KeyAgreement.swift

@@ -1,20 +1,11 @@
 import struct CryptoKit.SharedSecret
 import Foundation
 
-// MARK: - K1Feature
-public protocol K1Feature {
- associatedtype PublicKey: K1PublicKeyProtocol
-}
-
 // MARK: - K1.KeyAgreement
 extension K1 {
  /// A mechanism used to create a shared secret between two users by performing `secp256k1` elliptic curve Diffie Hellman (ECDH) key exchange.
- public enum KeyAgreement: K1Feature {
- /// A `secp256k1` private key used for key agreement.
- public typealias PrivateKey = PrivateKeyOf<Self>
-
- /// A `secp256k1` public key used for key agreement.
- public typealias PublicKey = PublicKeyOf<Self>
+ public enum KeyAgreement {
+ // Just a namespace
  }
 }
 

Sources/K1/K1/ECDSA/ECDSASignatureNonRecoverable.swift

@@ -5,19 +5,15 @@ import Foundation
 // MARK: - K1.ECDSA.NonRecoverable
 extension K1.ECDSA {
  /// A mechanism used to create or verify a cryptographic signature using the `secp256k1` elliptic curve digital signature algorithm (ECDSA), signatures that do not offer recovery of the public key.
- public enum NonRecoverable: K1Feature {
- /// A `secp256k1` private key used to create cryptographic signatures,
- /// more specifically ECDSA signatures, that do not offer recovery of the public key.
- public typealias PrivateKey = PrivateKeyOf<Self>
-
- /// A `secp256k1` public key used to verify cryptographic signatures,
- /// more specifically ECDSA signatures, that do not offer recovery of the public key.
- public typealias PublicKey = PublicKeyOf<Self>
+ public enum NonRecoverable {
+ // Just a namespace
  }
 }
 
 // MARK: - K1.ECDSA.NonRecoverable.Signature
 extension K1.ECDSA.NonRecoverable {
+ /// A `secp256k1` elliptic curve digital signature algorithm (ECDSA) signature,
+ /// from which users can recover a public key with the message that was signed.
  public struct Signature: Sendable, Hashable, ContiguousBytes {
  typealias Wrapped = FFI.ECDSA.NonRecovery.Wrapped
  internal let wrapped: Wrapped

Sources/K1/K1/ECDSA/ECDSASignatureRecoverable.swift

@@ -5,14 +5,8 @@ import Foundation
 // MARK: - K1.ECDSA.Recoverable
 extension K1.ECDSA {
  /// A mechanism used to create or verify a cryptographic signature using the `secp256k1` elliptic curve digital signature algorithm (ECDSA), signatures that do offers recovery of the public key.
- public enum Recoverable: K1Feature {
- /// A `secp256k1` private key used to create cryptographic signatures,
- /// more specifically ECDSA signatures that offers recovery of the public key.
- public typealias PrivateKey = PrivateKeyOf<Self>
-
- /// A `secp256k1` public key used to verify cryptographic signatures.
- /// more specifically ECDSA signatures that offers recovery of the public key.
- public typealias PublicKey = PublicKeyOf<Self>
+ public enum Recoverable {
+ // Just a namespace
  }
 }
 
@@ -137,6 +131,8 @@ extension K1.ECDSA.Recoverable.PublicKey {
 
 // MARK: - K1.ECDSA.Recoverable.Signature
 extension K1.ECDSA.Recoverable {
+ /// A `secp256k1` elliptic curve digital signature algorithm (ECDSA) signature,
+ /// from which users **cannot** recover the public key, not without the `RecoveryID`.
  public struct Signature: Sendable, Hashable, ContiguousBytes {
  typealias Wrapped = FFI.ECDSA.Recovery.Wrapped
  private let wrapped: Wrapped