dingdayu/dnsx

package dns

import (
    "strconv"
    "strings"

    "github.com/miekg/dns"

    "github.com/xyser/dnsx/model/dao"
)

// TypeTLSA TLSA记录格式: 保存证书关联数据
func TypeTLSA(msg *dns.Msg) error {
    domain := msg.Question[0].Name
    rrs, err := dao.GetRecordByNameAndType(domain, msg.Question[0].Qtype)
    if err != nil {
        return err
    }
    // TLSA 协议解释: https://www.dynu.com/Resources/DNS-Records/TLSA-Record
    for _, rr := range rrs {
        vs := strings.Split(rr.Value, " ")
        // 不够3位 不返回
        if len(vs) < 4 {
            continue
        }
        usage, _ := strconv.ParseUint(vs[0], 8, 8)
        selector, _ := strconv.ParseUint(vs[1], 8, 8)
        match, _ := strconv.ParseUint(vs[2], 8, 8)

        msg.Answer = append(msg.Answer, &dns.TLSA{
            Hdr:          dns.RR_Header{Name: msg.Question[0].Name, Rrtype: msg.Question[0].Qtype, Class: dns.ClassINET, Ttl: rr.TTL},
            Usage:        uint8(usage),    // 证书使用情况
            Selector:     uint8(selector), // 选择器,0-完整证书,1-使用主题公钥
            MatchingType: uint8(match),    // 匹配类型, 0-无哈希, 1-所选内容的SHA-256哈希,2-所选内容的SHA-512哈希
            Certificate:  "",              // 证书关联数据
        })
    }
    return nil
}