给定常量值的名称 [英] Name of a constant given its value

问题描述

如何根据给定的值获取常量的名称?

How do you get the name of a constant given its value ?

更具体地说(为了获得更易理解的理解)，我正在使用 crypto/tls 包.密码套件定义为常量:

More specifically (and to get a more readable understanding), I'm working with the crypto/tls package. Cipher suites are defined as constants:

const (
    TLS_RSA_WITH_RC4_128_SHA            uint16 = 0x0005
    TLS_RSA_WITH_3DES_EDE_CBC_SHA       uint16 = 0x000a
    TLS_RSA_WITH_AES_128_CBC_SHA        uint16 = 0x002f
    TLS_RSA_WITH_AES_256_CBC_SHA        uint16 = 0x0035
    TLS_ECDHE_RSA_WITH_RC4_128_SHA      uint16 = 0xc011
    TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xc012
    TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA  uint16 = 0xc013
    TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA  uint16 = 0xc014
)

与服务器成功握手后，我可以通过连接到达商定的Ciphersuite:

After a successful handshake with a server, I can get to the Ciphersuite agreed on through the connection:

c, _ := tls.Dial("tcp", "somedomain.com:443", nil)
// Suppose everything went right

// This is the Ciphersuite for the conn:
cipher := c.ConnectionState().Ciphersuite

密码这是一个uint16.有没有办法将其显示为字符串，例如 TLS_RSA_WITH_3DES_EDE_CBC_SHA ?

cipher here is an uint16. Is there a way to display it as a string, for instance TLS_RSA_WITH_3DES_EDE_CBC_SHA if that's what was agreed upon ?

推荐答案

恐怕不可能.
常量在编译时解析，并且 reflect 包中没有任何内容可让您检索名称.

I am afraid that is not possible.
The constants are resolved at compile time and there is nothing in the reflect package that allows you to retrieve the name.

我建议使用以下名称创建地图:

What I suggest is creating a map with the names:

var constLookup = map[uint16]string{
    tls.TLS_RSA_WITH_RC4_128_SHA:      `TLS_RSA_WITH_RC4_128_SHA`,
    tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA: `TLS_RSA_WITH_3DES_EDE_CBC_SHA`,
    ...
}

这篇关于给定常量值的名称的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！