操作系统：debian8.5_x64
freeswitch 版本 ： 1.6.8
本文仅描述sip注册的简单场景，即话机直接向处于同一个局域网的fs进行注册。
SIP协议的消息结构
消息框架
SIP协议是基于文本的协议，SIP协议的消息都遵从一个统一的消息结构： 起始行（Start-Line）、一个或多个头域（Message-Header）、表明域结束的空行（CRLF），以及 可选的消息体（Message-Body）
Start-Line
* Message-Header
CRLF
[Message-Body]
消息头结构
SIP协议定义了大量的消息头域，但在一个基本SIP请求中至少应该包含以下几个消息体头域：
From ： 请求发起端地址
To : 请求目的端地址
Call-ID ： 呼叫标识
Contract ：联系人信息
CSeq ： 消息序号
Max-Forward ：TTL，防止死循环
Via ： 消息转发记录
Content-Length : 消息体长度
消息体结构
SIP协议并没有规定消息体的结构，对消息体的应用完全取决于应用自身。
sip协议REGISTER请求格式
01 REGISTER sip:{remote_ip} SIP/2.0
02 Via: {viaInfo}
03 Max-Forwards: 70
04 From: {uacInfo}
05 To: {uasInfo}
06 Call-ID: {call_id}
07 User-Agent: {uaInfo}
08 CSeq: {csnum}
09 Contact: {contractInfo}
10 Expires: {expireSeconds}
11 Authorization: {authInfo}
12 Content-Length: {msgBodyLength}
- 第1行的REGISTER表示这是一条注册消息
- 第2行的via表示sip消息的路由
- 第3行指出消息最多可以转发多少次，防止死循环
- 第4行至第9行参考前面的消息头结构
- 第10行说明本次注册的有效期，单位为秒
- 第11行是sip认证信息，发送第一次sip register 请求时没有该字段
- 第12行sip消息体的长度，一般为0
注册流程
终端向服务器发送REGISTER请求
sip消息示例：
REGISTER sip:192.168.168.85 SIP/2.0
Via: SIP/2.0/UDP 192.168.168.168:25338;branch=z9hG4bK-d87543-1a71103b47634958-1--d87543-;rport
Max-Forwards: 70
Contact: <sip:1000@192.168.168.168:25338;rinstance=196b0ce810f2e6f5>
To: "1000"<sip:1000@192.168.168.85>
From: "1000"<sip:1000@192.168.168.85>;tag=2d1fbf20
Call-ID: ZTRiYTBhZmVlYTM1ZDkxOWQ3OWNkNjkwMmYxMWI5Yjk.
CSeq: 1 REGISTER
Expires: 3600
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO
User-Agent: eyeBeam release 1010f stamp 39239
Content-Length: 0
服务器回复401，并给出WWW-Authenticate信息
sofia协议栈：
tport :
tport_recv_event
=> tport_deliver
nta :
agent_recv_request
=> agent_aliases
nua :
nua_stack_process_request
sofia 应用层：
sofia_reg_handle_sip_i_register
=> sofia_reg_handle_register_token
=> sofia_reg_auth_challenge (回复401)sip消息示例：
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 192.168.168.168:25338;branch=z9hG4bK-d87543-1a71103b47634958-1--d87543-;rport=25338
From: "1000" <sip:1000@192.168.168.85>;tag=2d1fbf20
To: "1000" <sip:1000@192.168.168.85>;tag=m6ecFK1Fy3F0a
Call-ID: ZTRiYTBhZmVlYTM1ZDkxOWQ3OWNkNjkwMmYxMWI5Yjk.
CSeq: 1 REGISTER
User-Agent: FreeSWITCH-mod_sofia/1.6.8+git~20160505T153832Z~99de0ad502~64bit
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE
Supported: timer, path, replaces
WWW-Authenticate: Digest realm="192.168.168.85", nonce="d54e4bb9-fc22-4e08-8b69-442e1b8774eb", algorithm=MD5, qop="auth"
Content-Length: 0
终端再次向服务器发送REGISTER请求，并携带认证信息
REGISTER sip:192.168.168.85 SIP/2.0
Via: SIP/2.0/UDP 192.168.168.168:25338;branch=z9hG4bK-d87543-6371fe0e115be271-1--d87543-;rport
Max-Forwards: 70
Contact: <sip:1000@192.168.168.168:25338;rinstance=196b0ce810f2e6f5>
To: "1000"<sip:1000@192.168.168.85>
From: "1000"<sip:1000@192.168.168.85>;tag=2d1fbf20
Call-ID: ZTRiYTBhZmVlYTM1ZDkxOWQ3OWNkNjkwMmYxMWI5Yjk.
CSeq: 2 REGISTER
Expires: 3600
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO
User-Agent: eyeBeam release 1010f stamp 39239
Authorization: Digest username="1000",realm="192.168.168.85",nonce="d54e4bb9-fc22-4e08-8b69-442e1b8774eb",uri="sip:192.168.168.85",response="c46ae8e7eaa2ee63a1d61bf575d8c395",cnonce="71c1997e810fc38b53b97fbb33dc8b1e",nc=00000001,qop=auth,algorithm=MD5
Content-Length: 0
服务器认证后回复200
fs处理过程描述
sofia协议栈：
tport :
tport_recv_event
=> tport_deliver
nta :
agent_recv_request
=> agent_aliases
nua :
nua_stack_process_requestsofia应用层：
sofia_reg_handle_sip_i_register
=> sofia_reg_handle_register_token
=> sofia_reg_parse_auth (执行认证操作) for_the_sake_of_interop标签附近认证成功后发送200 OK给客户端。
认证算法描述
具体的认证过程可以参考sofia_reg_parse_auth函数，这里描述下sip注册的认证算法。
sip注册认证使用的是www-authenticate认证算法，具体可参考RFC2617文档。下面进行简单的描述
对用户名、认证域(realm)以及密码的合并值计算 MD5 哈希值，结果称为 HA1。
对HTTP方法以及URI的摘要的合并值计算 MD5 哈希值，例如，"REGISTER" 和 "sip:192.168.1.80"，结果称为 HA2。
对 HA1、服务器密码随机数(nonce)、请求计数(nc)、客户端密码随机数(cnonce)、保护质量(qop)以及 HA2 的合并值计算 MD5 哈希值。结果即为客户端提供的 response 值。 response 值由三步计算而成。当多个数值合并的时候，使用冒号作为分割符。
计算HA1
HA1 = MD5(A1) = MD5(username:realm:password)计算HA2
如果qop值为"auth"或未指定，那么HA2为
HA2 = MD5(A2) = MD5(method:digestURI)
如果qop值为"auth-init"，那么HA2为
HA2 = MD5(A2) = MD5(method:digestURI:MD5(entityBody))计算response
如果qop值为"auth"或"auth-init"，那么response为
response = MD5(HA1:nonce:nonceCount:clientNonce:qop:HA2)
如果qop未知道，那么response为
response = MD5(HA1:nonce:HA2)sip注册涉及数据库
- sip_authentication
- sip_registrations
注册过程模拟
python模拟注册过程
#! /usr/bin/env python
#-*- coding:utf-8 -*-
# sip reg test
# E-Mail : Mike_Zhang@live.com
import sys,socket,time,traceback
import uuid
import hashlib
svrIp,svrPort = "192.168.168.85",5060
transportType = "udp"
localIp,localPort = "192.168.168.168",17061
uid,passwd = "1000","1234"
g_branch,g_callId = uuid.uuid1(),uuid.uuid1()
def getRegHeader(seqNum):
retStr = "REGISTER sip:{remote_ip} SIP/2.0\r\n"
retStr += "Via: SIP/2.0/{transport} {local_ip}:{local_port};branch={branch}\r\n"
retStr += "Max-Forwards: 70\r\n"
retStr += "From: {uid} <sip:{uid}@{remote_ip}:{remote_port}>;tag={call_number}\r\n"
retStr += "To: {uid} <sip:{uid}@{remote_ip}:{remote_port}>\r\n"
retStr += "Call-ID: {call_id}\r\n"
retStr += "User-Agent: fs testing\r\n"
retStr += "CSeq: %d REGISTER\r\n"%seqNum
retStr += "Contact: sip:{uid}@{local_ip}:{local_port}\r\n"
retStr += "Expires: 3600\r\n"
return retStr
def formatRegHeader(patternStr):
retstr = patternStr.format(
remote_ip=svrIp,
transport=transportType,
local_ip=localIp,
local_port=localPort,
branch=g_branch,
uid=uid,
remote_port=svrPort,
call_number=uid,
call_id=g_callId)
return retstr
class SipRegObj(object):
def __init__(self,uid,passwd,
realm="",nonce="",algorithm="MD5",qop="auth"):
self.uid = uid # "1000"
self.password = passwd # "1234"
self.realm = realm
self.nonce = nonce
self.algorithm = algorithm
self.qop = qop
self.uri = ""
self.method = "REGISTER"
self.cnonce = ""
self.nc = "00000001"
self.svrIp = svrIp
#self.transportType = "udp"
def getReponse(self):
md5 = hashlib.md5
ha1 = md5("%s:%s:%s"%(self.uid,self.realm,self.password)).hexdigest()
ha2 = md5("%s:%s"%(self.method,self.uri)).hexdigest()
reponse = md5("%s:%s:%s:%s:%s:%s"%(ha1,self.nonce,self.nc,self.cnonce,self.qop,ha2)).hexdigest()
return reponse
def getAuthStr(self):
self.uri,self.cnonce = ("sip:%s"%self.svrIp),uuid.uuid1()
retStr = ""
response = self.getReponse()
retStr += 'Authorization: Digest username="%s",realm="%s",nonce="%s",uri="%s",response="%s",cnonce="%s",nc=%s,qop=%s,algorithm=%s\r\n'%(
self.uid,self.realm,self.nonce,self.uri,response,self.cnonce,self.nc,self.qop,self.algorithm)
retStr += 'Content-Length: 0\r\n'
return retStr
def genChallengeMsg(self):
# gen sip reg challenge message
str1=getRegHeader(1) + "Content-Length: 0\r\n"
return formatRegHeader(str1)
def genAuthMsg(self,retstr1):
# parse data
data1 = retstr1.split("\r\n")[-4].split(": Digest")[1]
data1 = str(data1).replace('MD5','"MD5"')
tmpList = data1.split(",")
for item in tmpList :
#print item
arrtmp = item.split("=")
setattr(self,arrtmp[0].strip(),arrtmp[1].strip('"'))
# gen sip reg message with auth
str2=getRegHeader(2)
str2 = formatRegHeader(str2)
str2 += self.getAuthStr()
return str2
if __name__ == "__main__":
treg = SipRegObj(uid,passwd)
client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
client.bind((localIp,localPort))
dstHost = (svrIp,svrPort)
client.sendto(treg.genChallengeMsg(),dstHost)
print time.time(),' : send success'
# get response (401 msg)
retstr1 = client.recv(1024)
print retstr1
client.sendto(treg.genAuthMsg(retstr1),dstHost)
print time.time(),' : send success'
retstr2 = client.recv(1024)
print "return str : \r\n",retstr2
time.sleep(30)
View Code
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