如何使用swift进行RSA大数据块加解密呢？

1.使用RSA加密

 @objc public func encrypt(source: String) -> String {
        
        guard source.count > 0 && self.publicSecKey != nil else {
            return ""
        }
        
        let data: NSData = (source.data(using: String.Encoding.utf8)! as NSData)
        
 /*       if #available(iOS 10.0, *) {
            var error: Unmanaged<CFError>?
            resData =  SecKeyCreateEncryptedData(self.publicSecKey!, SecKeyAlgorithm.rsaEncryptionPKCS1, data as CFData, &error)

            print("res = \(String(describing: error?.takeUnretainedValue().localizedDescription))")
        }
*/
        // Fallback on earlier versions
        let blockLen =  SecKeyGetBlockSize(self.publicSecKey!)
        var outBuf = [UInt8](repeating: 0, count: blockLen)
        var outBufLen:Int = blockLen
        
        var index = 0
        let totalLen = data.length
        
        let resData = NSMutableData()
        
        while index < totalLen {
            var curDataLen = totalLen - index;
            if curDataLen  > blockLen - 11 {
                curDataLen = blockLen - 11;
            }
            
            let curData: NSData = (data.subdata(with: NSMakeRange(index, curDataLen)) as NSData)
            
            let status: OSStatus = SecKeyEncrypt(self.publicSecKey!, SecPadding.PKCS1, curData.bytes.assumingMemoryBound(to: UInt8.self), curData.length, &outBuf, &outBufLen)
            
            if status == noErr {
                resData.append(outBuf, length: outBufLen)
            }else{
                print("encrypt status = \(status)")
            }
            
            index += curDataLen
        }
        
        //base64 encode
        return resData.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: NSData.Base64EncodingOptions.lineLength64Characters.rawValue))
    }

2.使用RSA解密

@objc public func decrypt(source: String) -> String {
        
        guard source.count > 0 && self.privateSecKey != nil else {
            return ""
        }
        
        //base64 decode
        let data: Data = (NSData(base64Encoded: (source as String), options: NSData.Base64DecodingOptions.ignoreUnknownCharacters)! as Data)
        
        let blockLen =  SecKeyGetBlockSize(self.privateSecKey!)
        let outBuf = UnsafeMutablePointer<UInt8>.allocate(capacity: blockLen)
        defer {
            outBuf.deallocate()
        }
        
        var outBufLen: Int = blockLen
      
//        if #available(iOS 10.0, *) {
//            var error: Unmanaged<CFError>?
//            resData =  SecKeyCreateDecryptedData(self.privateSecKey!, SecKeyAlgorithm.rsaEncryptionPKCS1, data as CFData, &error)
//
//            print("res = \(String(describing: error?.takeUnretainedValue().localizedDescription))")
//        } else {
//            // Fallback on earlier versions
//            //let status = SecKeyEncrypt(seckey, SecPadding.PKCS1, chunkData, chunkData.count, outBuf, &encryptedDataLength)
//
//        }
        
        var index = 0
        let totalLen = data.count
        
        let resData = NSMutableData()
        
        while index < totalLen {
            var curDataLen = totalLen - index;
            if curDataLen  > blockLen {
                curDataLen = blockLen;
            }
            
            let curData: Data = data.subdata(in: index ..< index + curDataLen)
            
            var status:OSStatus = noErr
            curData.withUnsafeBytes { (bytes: UnsafePointer<UInt8>) in
                 status = SecKeyDecrypt(self.privateSecKey!, SecPadding.PKCS1, bytes, curData.count, outBuf, &outBufLen)
            }
            
            if status == noErr {
                resData.append(outBuf, length: outBufLen)
            }else{
                print("decrypt status = \(status)")
            }
            
            index += curDataLen
        }

        return String(data: (resData as Data), encoding: String.Encoding.utf8)!
    }

3.调用及输出

• 调用

    let originalString = "你从哪里来，要去哪里去，在你眼里，春天里，我们去了哪里啊，123456789，说不说都不知道，黄河之水天上来，奔流到海不复回。高堂明镜悲白发，朝如青丝，ksnowlv"
 
    let rsaSign: YKRSASign = YKRSASign()
    rsaSign.publicKey(fileFullPath: publicKeyPath as NSString, block: {(_ error: NSError?, _ secKey:SecKey?) in
        })
        
    rsaSign.privateKey(fileFullPath: privateKeyPath! as NSString, password: "", block: {(_ error: NSError?, _ secKey:SecKey?) in
        })
        
    let enString = rsaSign.encrypt(source: originalString)
    print("enString = \(enString)")
        
    let deString = rsaSign.decrypt(source: enString)
    print("deString = \(deString)")

• 日志

publicKeyPath = /Users/ksnowlv/Library/Developer/CoreSimulator/Devices/77E5D278-4788-499F-9B82-76BE66DA4676/data/Containers/Bundle/Application/2BD97FF3-B55D-4556-8232-888D0D858AD2/YKBaseSwiftFramework.app/public_key.der
privateKeyPath = Optional("/Users/ksnowlv/Library/Developer/CoreSimulator/Devices/77E5D278-4788-499F-9B82-76BE66DA4676/data/Containers/Bundle/Application/2BD97FF3-B55D-4556-8232-888D0D858AD2/YKBaseSwiftFramework.app/private_key.p12")
enString = HEP0mejSvIfOi4V0uziYNogUStMYG01DmIK25TDR340cc5snt4LGlkNVdGLRb0hP
aCMbKkgDKp1g+NNpaOF6FO2hongUcsDbwoPZ2Vl6ZHSFi1FGvv5vdUJ7ZGbLivS2
UTU+178ue//jW64fw4ujrH/OPvbSfBo4c65G9USbGkcWfSfGtWruWz3f7xFreq8Y
N+54y0XNA2GLw0S3N1Z3uQUZWqCCgPEYVCAW/w3BiGAKzrv+nby0yWXyLXbAdJEl
QvlLHGrdeS2i1J448s+/01UQ2MP9qDSlxJ+4GqE7/x3HEYlF/ZmukSsAzsk4xACG
4A+6YqgamtflnNdS3Eob6Q==
deString = 你从哪里来，要去哪里去，在你眼里，春天里，我们去了哪里啊，123456789，说不说都不知道，黄河之水天上来，奔流到海不复回。高堂明镜悲白发，朝如青丝，ksnowlv