UUIDv5 using Vapor3's Crypto

UUID+Version5.Swift

// This is a direct port of https://github.com/download13/uuidv5 to Swift

import Foundation
import Crypto

public extension UUID {
    enum Namespace {
        case dns
        case url
        case oid
        case x500
        case null
        case custom(UUID)

        public var uuid: UUID {
            switch self {
            case .dns:
                return UUID(uuidString: "6ba7b810-9dad-11d1-80b4-00c04fd430c8")!
            case .url:
                return UUID(uuidString: "6ba7b811-9dad-11d1-80b4-00c04fd430c8")!
            case .oid:
                return UUID(uuidString: "6ba7b812-9dad-11d1-80b4-00c04fd430c8")!
            case .x500:
                return UUID(uuidString: "6ba7b814-9dad-11d1-80b4-00c04fd430c8")!
            case .null:
                return UUID(uuidString: "00000000-0000-0000-0000-000000000000")!
            case .custom(let uuid):
                return uuid
            }
        }
    }

    init(namespace: Namespace, name: String) throws {
        let rawNamespace = namespace.uuid.uuid

        var c = Data([
            rawNamespace.0,
            rawNamespace.1,
            rawNamespace.2,
            rawNamespace.3,
            rawNamespace.4,
            rawNamespace.5,
            rawNamespace.6,
            rawNamespace.7,
            rawNamespace.8,
            rawNamespace.9,
            rawNamespace.10,
            rawNamespace.11,
            rawNamespace.12,
            rawNamespace.13,
            rawNamespace.14,
            rawNamespace.15
        ])

        c.append(name.data(using: .utf8) ?? Data())

        let digest = try SHA1.hash(c)

        let result: uuid_t = (
            digest[0],
            digest[1],
            digest[2],
            digest[3],
            digest[4],
            digest[5],
            (digest[6] & 0x0f) | 0x50, // version, 4 most significant bits are set to version 5 (0101)
            digest[7],
            (digest[8] & 0x3f) | 0x80, // clock_seq_hi_and_reserved, 2msb are set to 10
            digest[9],
            digest[10],
            digest[11],
            digest[12],
            digest[13],
            digest[14],
            digest[15]
        )

        self.init(uuid: result)
    }
}

UUID+Version5_Tests.swift

import App
import XCTest

final class UUIDv5Tests: XCTestCase {
    func testUUIDv5() throws {
        XCTAssertEqual(try UUID(namespace: .dns, name: "www.example.org"), UUID("74738ff5-5367-5958-9aee-98fffdcd1876"))
        XCTAssertEqual(try UUID(namespace: .url, name: "http://example.org/page"), UUID("6b19973b-8154-5782-bca0-15e6b730ca00"))
        XCTAssertEqual(try UUID(namespace: .oid, name: "1.3.6.1.2.1"), UUID("2a7086de-bbf9-5cb9-9a66-a9e928c26504"))
        XCTAssertEqual(try UUID(namespace: .x500, name: "uid=user,ou=people,dc=example,dc=com"), UUID("5324d252-c0de-5365-a19c-389275462a9c"))
    }

    static let allTests = [
        ("testUUIDv5", testUUIDv5)
    ]
}

Nice!