Swift中的 RSA Sign

项目中，使用了Https+RSA Sign的认证方式

实现方式为使用了Github开源库SecrecySwift，但此项目有一段时间没有人维护，按照readme中的集成方式，在新的Xcode9.4 or Swift4中不能在真机中正常运行。

修复方式如下：

Xcode 9.3, Swift 4项目, 引入此项目，按readme中的直接部署源码的方式已无法正常运行。

解决办法：

1.删除CommonCrypto文件夹，在项目 Targets 的 Build Settings 中 Import Paths 中删除 CommonCrypto, 在 Library Search Path 中删除 /usr/lib/system

2.在自己项目的xxx-Bridging-Header.h文件中，#import <CommonCrypto/CommonCrypto.h>

3.删除此项目中出现的import CommonCrypto，成功在真机上运行。

 

在发现此修复方式的过程中，尝试自己手写一套RSA Sign，参考如下代码：

        let ts = Date().timeIntervalSince1970 * 1000000
        let signString = "xxx&ts=\(Int64(ts))"
        let pathPrivate = Bundle.main.path(forResource: "pri", ofType: "p12")
        let pathPublic = Bundle.main.path(forResource: "pub", ofType: "der")

        let privateUrl = URL(fileURLWithPath: pathPrivate!)
        let privateData = try! Data(contentsOf: privateUrl)
        let privatePwd = "xxx"
        let options = [kSecImportExportPassphrase as String: privatePwd]
        var rawItems: CFArray?
        let status = SecPKCS12Import(privateData as CFData, options as CFDictionary, &rawItems)
        guard status == errSecSuccess else { return }
        let items = rawItems! as! Array<Dictionary<String, Any>>
        let firstItem = items[0]
        let identity = firstItem[kSecImportItemIdentity as String] as! SecIdentity?

        var privateKey: SecKey?
        let status1 = SecIdentityCopyPrivateKey(identity!, &privateKey)
        guard status1 == errSecSuccess else { return }

        var signedStr = ""
        if #available(iOS 10.0, *) { // iOS10以后，系统原生实现方式
            let algorithm: SecKeyAlgorithm = .rsaSignatureMessagePKCS1v15SHA1
            guard SecKeyIsAlgorithmSupported(privateKey!, .sign, algorithm) else {
                return
            }
            var error: Unmanaged<CFError>?
            guard let signature = SecKeyCreateSignature(privateKey!,
                                                        algorithm,
                                                        signString.data(using: .utf8)! as CFData,
                                                        &error) as Data? else {
                                                            return
            }
            signedStr = signature.base64EncodedString()
        } else { // 老的实现方式，使用了SecrecySwift中的两个文件Digest.swift和SecrecyExtension.swift，在自己项目的xxx-Bridging-Header.h文件中，#import <CommonCrypto/CommonCrypto.h>，删除这两个文件中中出现的import CommonCrypto
            let signData = signString.data(using: .utf8)!
            let digestInputData = signData.digestData(.sha1)
            guard digestInputData.count > 0 && digestInputData.count < SecKeyGetBlockSize(privateKey!) - 11  else {
                return
            }
            let key_size = SecKeyGetBlockSize(privateKey!)
            var sign_bytes = [UInt8](repeating: 0, count: key_size)
            var sign_size : Int = key_size
            let result = SecKeyRawSign(privateKey!, SecPadding.PKCS1SHA1, digestInputData.arrayOfBytes(), digestInputData.count, &sign_bytes, &sign_size)
            guard result == errSecSuccess else {
                return
            }
            let resultData = Data(bytes: UnsafePointer<UInt8>(sign_bytes), count: sign_size)
            signedStr = resultData.base64EncodedString()
        }