X509Extensions.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift open source project
//
// Copyright (c) 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

import struct Foundation.Data

#if USE_IMPL_ONLY_IMPORTS
#if canImport(Security)
internal import Security
#endif

internal import SwiftASN1
internal import X509
#else
#if canImport(Security)
import Security
#endif

import SwiftASN1
import X509
#endif

import Basics

#if canImport(Security)
extension Certificate {
    init(secCertificate: SecCertificate) throws {
        let data = SecCertificateCopyData(secCertificate) as Data
        self = try Certificate(Array(data))
    }

    init(secIdentity: SecIdentity) throws {
        var secCertificate: SecCertificate?
        let status = SecIdentityCopyCertificate(secIdentity, &secCertificate)
        guard status == errSecSuccess, let secCertificate else {
            throw StringError("failed to get certificate from SecIdentity: status \(status)")
        }
        self = try Certificate(secCertificate: secCertificate)
    }
}
#endif

extension Certificate {
    func hasExtension(oid: ASN1ObjectIdentifier) -> Bool {
        self.extensions[oid: oid] != nil
    }
}

extension DistinguishedName {
    var commonName: String? {
        self.stringAttribute(oid: ASN1ObjectIdentifier.NameAttributes.commonName)
    }

    var organizationalUnitName: String? {
        self.stringAttribute(oid: ASN1ObjectIdentifier.NameAttributes.organizationalUnitName)
    }

    var organizationName: String? {
        self.stringAttribute(oid: ASN1ObjectIdentifier.NameAttributes.organizationName)
    }

    private func stringAttribute(oid: ASN1ObjectIdentifier) -> String? {
        for relativeDistinguishedName in self {
            for attribute in relativeDistinguishedName where attribute.type == oid {
                return attribute.value.description
            }
        }
        return nil
    }
}

// MARK: - Certificate cache

extension Certificate {
    private static let cache = ThreadSafeKeyValueStore<[UInt8], Certificate>()

    init(_ bytes: [UInt8]) throws {
        if let cached = Self.cache[bytes] {
            self = cached
        } else {
            let certificate = try Certificate(derEncoded: bytes)
            Self.cache[bytes] = certificate
            self = certificate
        }
    }
}