微信golang签名算法

type WXPrams struct {
    m    map[string]interface{} // 参数
    sign string                 // 签名
}

func (p *WXPrams) InitSign() {
    var keys []string
    for k, _ := range p.m {
        keys = append(keys, k)
    }
    sort.Strings(keys)

    builder := strings.Builder{}
    for _, v := range keys {
        builder.WriteString(v)
        builder.WriteString("=")
        builder.WriteString(fmt.Sprint(p.m[v]))
        builder.WriteString("&")
    }
    builder.WriteString("key=" + apiKey)
    p.sign = strings.ToUpper(lib.Md5(builder.String()))
}

func (p *WXPrams) ToPram() string {
    p.InitSign()
    builder := strings.Builder{}
    builder.WriteString("<xml>")
    for k, v := range p.m {
        builder.WriteString("<" + k + ">")
        builder.WriteString(fmt.Sprint(v))
        builder.WriteString("</" + k + ">")
    }
    builder.WriteString("<sign>")
    builder.WriteString(fmt.Sprint(p.sign))
    builder.WriteString("</sign>")
    builder.WriteString("</xml>")
    return builder.String()
}