在Swift 4中我们可以使用
var md5: String? {
guard let data = self.data(using: .utf8) else { return nil }
let hash = data.withUnsafeBytes { (bytes: UnsafePointer<Data>) -> [UInt8] in
var hash: [UInt8] = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
CC_MD5(bytes, CC_LONG(data.count), &hash)
return hash
}
return hash.map { String(format: "%02x", $0) }.joined()
}
但在Swift 5中,withUnsafeBytes
使用UnsafeRawBufferPointer
而不是UnsafePointer
。如何更改md5功能?
Swift 5版本:使用UnsafeRawBufferPointer
作为闭包参数的类型,并使用bytes.baseAddress
将地址传递给Common Crypto函数:
extension String {
var md5: String {
let data = Data(self.utf8)
let hash = data.withUnsafeBytes { (bytes: UnsafeRawBufferPointer) -> [UInt8] in
var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
CC_MD5(bytes.baseAddress, CC_LONG(data.count), &hash)
return hash
}
return hash.map { String(format: "%02x", $0) }.joined()
}
}
(注意,将字符串转换为UTF-8数据不能失败,不需要返回可选项。)
以下是一个基于Eskimo提出的解决方案的变种,该解决方案来自Apple在Swift Forum post withUnsafeBytes Data API confusion:
extension String {
func md5() -> String {
let data = Data(utf8)
var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
data.withUnsafeBytes { buffer in
_ = CC_MD5(buffer.baseAddress, CC_LONG(buffer.count), &hash)
}
return hash.map { String(format: "%02hhx", $0) }.joined()
}
}
请注意,它实际上与Martin R的解决方案相同,但更短的线(没有return hash
)。
这是使用桥接到NSData的更短的解决方案。
extension String {
func md5() -> String {
let data = Data(utf8) as NSData
var hash = [UInt8](repeating: 0, count: Int(CC_MD5_DIGEST_LENGTH))
CC_MD5(data.bytes, CC_LONG(data.length), &hash)
return hash.map { String(format: "%02hhx", $0) }.joined()
}
}