如何在Swift中使用SHA1散列NSString？

Question

在objective-c中它看起来像这样:

#include <sys/xattr.h>

@implementation NSString (reverse)

-(NSString*)sha1
{
    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];
    uint8_t digest[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1(data.bytes, (int)data.length, digest);
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)
        [output appendFormat:@"%02x", digest[i]];
    return output;
}

@end

我需要Swift这样的东西,有可能吗？

请展示工作示例.

Answer 1

您的Objective-C代码(使用NSString类别)可以直接转换为Swift(使用String扩展名).

首先,你必须创建一个"桥接头"并添加

#import <CommonCrypto/CommonCrypto.h>

然后:

extension String {
    func sha1() -> String {
        let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
        var digest = [UInt8](count:Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
        CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
        let output = NSMutableString(capacity: Int(CC_SHA1_DIGEST_LENGTH))
        for byte in digest {
            output.appendFormat("%02x", byte)
        }
        return output as String
    }
}

println("Hello World".sha1())

这可以写得稍短,Swifter也可以

extension String {
    func sha1() -> String {
        let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
        var digest = [UInt8](count:Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
        CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
        let hexBytes = map(digest) { String(format: "%02hhx", $0) }
        return "".join(hexBytes)
    }
}

Swift 2更新:

extension String {
    func sha1() -> String {
        let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
        var digest = [UInt8](count:Int(CC_SHA1_DIGEST_LENGTH), repeatedValue: 0)
        CC_SHA1(data.bytes, CC_LONG(data.length), &digest)
        let hexBytes = digest.map { String(format: "%02hhx", $0) }
        return hexBytes.joinWithSeparator("")
    }
}

要返回Base-64编码的字符串而不是十六进制编码的字符串,只需替换

        let hexBytes = digest.map { String(format: "%02hhx", $0) }
        return hexBytes.joinWithSeparator("")

同

        return NSData(bytes: digest, length: digest.count).base64EncodedStringWithOptions([])

Swift 3更新:

extension String {
    func sha1() -> String {
        let data = self.data(using: String.Encoding.utf8)!
        var digest = [UInt8](repeating: 0, count:Int(CC_SHA1_DIGEST_LENGTH))
        data.withUnsafeBytes { 
            _ = CC_SHA1($0, CC_LONG(data.count), &digest)
        }
        let hexBytes = digest.map { String(format: "%02hhx", $0) }
        return hexBytes.joined()
    }
}

要返回Base-64编码的字符串而不是十六进制编码的字符串,只需替换

        let hexBytes = digest.map { String(format: "%02hhx", $0) }
        return hexBytes.joined()

通过

        return Data(bytes: digest).base64EncodedString()

Answer 2

随着CryptoKitiOS13 的加入，我们现在有了原生的 Swift API：

import Foundation
import CryptoKit

// CryptoKit.Digest utils
extension Digest {
    var bytes: [UInt8] { Array(makeIterator()) }
    var data: Data { Data(bytes) }

    var hexStr: String {
        bytes.map { String(format: "%02X", $0) }.joined()
    }
}

func example() {
    guard let data = "hello world".data(using: .utf8) else { return }
    let digest = Insecure.SHA1.hash(data: data)
    print(digest.data) // 20 bytes
    print(digest.hexStr) // 2AAE6C35C94FCFB415DBE95F408B9CE91EE846ED
}

Answer 3

Swift 5 的版本在 iOS 13 上使用 CryptoKit，否则会回退到 CommonCrypto：

import CommonCrypto
import CryptoKit
import Foundation

private func hexString(_ iterator: Array<UInt8>.Iterator) -> String {
    return iterator.map { String(format: "%02x", $0) }.joined()
}

extension Data {

    public var sha1: String {
        if #available(iOS 13.0, *) {
            return hexString(Insecure.SHA1.hash(data: self).makeIterator())
        } else {
            var digest = [UInt8](repeating: 0, count: Int(CC_SHA1_DIGEST_LENGTH))
            self.withUnsafeBytes { bytes in
                _ = CC_SHA1(bytes.baseAddress, CC_LONG(self.count), &digest)
            }
            return hexString(digest.makeIterator())
        }
    }

}

用法：

let string = "The quick brown fox jumps over the lazy dog"
let hexDigest = string.data(using: .ascii)!.sha1
assert(hexDigest == "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12")

也可通过 Swift 包管理器获取： https:
//github.com/ralfebert/TinyHashes

Answer 4

是的，有可能，将此类复制到您的项目中。 https://github.com/idrougge/sha1-swift

这将很容易，例如：

 SHA1.hexString(from: "myPhrase" )!

已针对 swift 3 和 swift 4 进行测试。