AWS StrongSwan IPSec VPN

Question

最近，我一直在与StrongSwan打交道，作为Amazons的替代品，这需要花费很多钱。

我很难在远程服务器和运行IPSec的Ubuntu EC2机器之间完全配置一个StrongSwan隧道。

我的目标是让我们的远程服务器能够将VPN接入我们的VPC，并在AWS上的私有子网之间实现双向访问。

目前，我可以建立一条隧道。我可以从EC2机器(运行StrongSwan)到远程OSX服务器。我可以在公共计算机和VPC中的私有子网之间切换。

目前，我无法在运行强swan的AWS上从我的OSX服务器切换到EC2实例。我没有任何iptables设置来将流量从EC2 (StrongSwan)机器转发到私有子网中的其他计算机。

AWS

VPC: 10.0.0.0/16
Public Subnet: 10.0.1.0/24
Private Subnet: 10.0.2.0/24
Web EIP: 77.77.77.77 (default for VPC IGW)
VPN EIP: 66.66.66.66

AWS StrongSwan EC2

Ubuntu running StrongSwan 5.2.2
IP: 10.0.1.233

远程客户端网关(蜂窝调制解调器+带有静态IP的网关组合)

Running StrongSwan 5.2.2 internally for IPSec
Public (static) IP: 55.55.55.55
LAN: 10.1.1.0/24 (DHCP Server)

远程客户端服务器(OSX测试机器)

IP: 10.1.1.1

网络拓扑

公共子网中的安全组广泛开放，允许所有ICMP、UDP和TCP流量进行测试(忽略上面图像中的值)。

还请注意，在StrongSwan EC2实例上禁用了src/dst检查。

远程网关StrongSwan Config (StrongSwan 5.2.2)

version 2.0

config setup
#   charondebug="knl 4, asn 4, cfg 4, chd 4, dmn 4, enc 4, esp 4, ike 4, imc 4, imv 4, job 4, lib 4, mgr 4, net 4, pts 4,tls 4, tnc 4"

conn %default
    keyexchange=ikev2
    authby=secret

conn net-to-net
    ike=aes256-sha256-modp1536,aes256-sha1-modp1536,aes128-sha256-modp1536,aes128-sha1-modp1536,3des-sha256-modp1536,3des-sha1-modp1536
    esp=aes256-sha256_96-modp1536,aes256-sha1-modp1536,aes128-sha256_96-modp1536,aes128-sha1-modp1536,3des-sha256_96-modp1536,3des-sha1-modp1536
    mobike=no
    keyingtries=%forever
    dpdaction=restart
    dpddelay=5s
    dpdtimeout=10s
    #AWS
    leftid=%any
    left=10.0.1.233
    leftsubnet=10.0.0.0/16
    #CLIENT
    rightid=%any
    right=55.55.55.55
    rightsubnet=10.1.1.0/24
    auto=add

远程网关上的IPSec设置

eth0使用10.1.1.0/24 CIDR块运行DHCP服务器。我的OSX服务器有IP 10.1.1.1 (在eth0上)

系统登录StrongSwan EC2

Mar 30 18:43:58 ip-10-0-1-233 charon: 00[CFG] loading secrets from '/etc/ipsec.secrets'
Mar 30 18:43:58 ip-10-0-1-233 charon: 00[CFG]   loaded IKE secret for 66.66.66.66 55.55.55.55
Mar 30 18:43:58 ip-10-0-1-233 charon: 00[LIB] loaded plugins: charon test-vectors aes rc2 sha1 sha2 md4 md5 random nonce x509 revocation constraints pkcs1 pkcs7 pkcs8 pkcs12 pem openssl xcbc cmac hmac ctr ccm gcm attr kernel-netlink resolve socket-default stroke updown eap-identity addrblock
Mar 30 18:43:58 ip-10-0-1-233 charon: 00[LIB] unable to load 5 plugin features (5 due to unmet dependencies)
Mar 30 18:43:58 ip-10-0-1-233 charon: 00[LIB] dropped capabilities, running as uid 0, gid 0
Mar 30 18:43:58 ip-10-0-1-233 charon: 00[JOB] spawning 16 worker threads
Mar 30 18:43:58 ip-10-0-1-233 charon: 10[CFG] received stroke: add connection 'net-to-net'
Mar 30 18:43:58 ip-10-0-1-233 charon: 10[CFG] added configuration 'net-to-net'
Mar 30 18:44:01 ip-10-0-1-233 charon: 00[DMN] signal of type SIGINT received. Shutting down
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[DMN] Starting IKE charon daemon (strongSwan 5.1.2, Linux 3.13.0-44-generic, x86_64)
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading ca certificates from '/etc/ipsec.d/cacerts'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading aa certificates from '/etc/ipsec.d/aacerts'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading ocsp signer certificates from '/etc/ipsec.d/ocspcerts'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading attribute certificates from '/etc/ipsec.d/acerts'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading crls from '/etc/ipsec.d/crls'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG] loading secrets from '/etc/ipsec.secrets'
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[CFG]   loaded IKE secret for 66.66.66.66 55.55.55.55
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[LIB] loaded plugins: charon test-vectors aes rc2 sha1 sha2 md4 md5 random nonce x509 revocation constraints pkcs1 pkcs7 pkcs8 pkcs12 pem openssl xcbc cmac hmac ctr ccm gcm attr kernel-netlink resolve socket-default stroke updown eap-identity addrblock
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[LIB] unable to load 5 plugin features (5 due to unmet dependencies)
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[LIB] dropped capabilities, running as uid 0, gid 0
Mar 30 18:44:07 ip-10-0-1-233 charon: 00[JOB] spawning 16 worker threads
Mar 30 18:44:07 ip-10-0-1-233 charon: 10[CFG] received stroke: add connection 'net-to-net'
Mar 30 18:44:07 ip-10-0-1-233 charon: 10[CFG] added configuration 'net-to-net'
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[NET] received packet: from 55.55.55.55[500] to 10.0.1.233[500] (660 bytes)
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[ENC] parsed IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) ]
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[IKE] 55.55.55.55 is initiating an IKE_SA
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[IKE] local host is behind NAT, sending keep alives
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[IKE] DH group MODP_2048 inacceptable, requesting MODP_1536
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[ENC] generating IKE_SA_INIT response 0 [ N(INVAL_KE) ]
Mar 30 18:44:17 ip-10-0-1-233 charon: 11[NET] sending packet: from 10.0.1.233[500] to 55.55.55.55[500] (38 bytes)
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[NET] received packet: from 55.55.55.55[500] to 10.0.1.233[500] (596 bytes)
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[ENC] parsed IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) ]
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[IKE] 55.55.55.55 is initiating an IKE_SA
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[IKE] local host is behind NAT, sending keep alives
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[ENC] generating IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(MULT_AUTH) ]
Mar 30 18:44:17 ip-10-0-1-233 charon: 12[NET] sending packet: from 10.0.1.233[500] to 55.55.55.55[500] (376 bytes)
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[NET] received packet: from 55.55.55.55[4500] to 10.0.1.233[4500] (336 bytes)
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[ENC] parsed IKE_AUTH request 1 [ IDi AUTH N(IPCOMP_SUP) SA TSi TSr N(MULT_AUTH) N(EAP_ONLY) ]
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[CFG] looking for peer configs matching 10.0.1.233[%any]...55.55.55.55[55.55.55.55]
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[CFG] selected peer config 'net-to-net'
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] authentication of '55.55.55.55' with pre-shared key successful
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[CFG] no IDr configured, fall back on IP address
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] authentication of '10.0.1.233' (myself) with pre-shared key
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] IKE_SA net-to-net[2] established between 10.0.1.233[10.0.1.233]...55.55.55.55[55.55.55.55]
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] scheduling reauthentication in 10081s
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] maximum IKE_SA lifetime 10621s
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] received IPCOMP_SUPPORTED notify but IPComp is disabled, ignoring
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[IKE] CHILD_SA net-to-net{1} established with SPIs c2a08785_i cc1db76f_o and TS 10.0.1.0/24 === 10.1.1.0/24 
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[ENC] generating IKE_AUTH response 1 [ IDr AUTH SA TSi TSr N(AUTH_LFT) ]
Mar 30 18:44:18 ip-10-0-1-233 charon: 13[NET] sending packet: from 10.0.1.233[4500] to 55.55.55.55[4500] (224 bytes)
Mar 30 18:44:23 ip-10-0-1-233 charon: 14[IKE] sending DPD request

远程连接

时，AWS端的

tpcdump

18:41:14.660917 IP mobile-55-55-55-55.mycingular.net.isakmp > ip-10-0-1-233.ec2.internal.isakmp: isakmp: parent_sa ikev2_init[I]
18:41:14.681096 IP ip-10-0-1-233.ec2.internal.isakmp > mobile-55-55-55-55.mycingular.net.isakmp: isakmp: parent_sa ikev2_init[R]
18:41:15.259862 IP mobile-55-55-55-55.mycingular.net.isakmp > ip-10-0-1-233.ec2.internal.isakmp: isakmp: parent_sa ikev2_init[I]
18:41:15.271718 IP ip-10-0-1-233.ec2.internal.isakmp > mobile-55-55-55-55.mycingular.net.isakmp: isakmp: parent_sa ikev2_init[R]
18:41:15.809157 IP mobile-55-55-55-55.mycingular.net.ipsec-nat-t > ip-10-0-1-233.ec2.internal.ipsec-nat-t: NONESP-encap: isakmp: child_sa  ikev2_auth[I]
18:41:15.813883 IP ip-10-0-1-233.ec2.internal.ipsec-nat-t > mobile-55-55-55-55.mycingular.net.ipsec-nat-t: NONESP-encap: isakmp: child_sa  ikev2_auth[R]
18:41:20.812881 IP ip-10-0-1-233.ec2.internal.ipsec-nat-t > mobile-55-55-55-55.mycingular.net.ipsec-nat-t: NONESP-encap: isakmp: parent_sa inf2
18:41:21.139689 IP mobile-55-55-55-55.mycingular.net.ipsec-nat-t > ip-10-0-1-233.ec2.internal.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[I]
18:41:21.140103 IP ip-10-0-1-233.ec2.internal.ipsec-nat-t > mobile-55-55-55-55.mycingular.net.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[R]
18:41:21.289057 IP mobile-55-55-55-55.mycingular.net.ipsec-nat-t > ip-10-0-1-233.ec2.internal.ipsec-nat-t: NONESP-encap: isakmp: parent_sa inf2[IR]
18:41:26.088336 IP mobile-55-55-55-55.mycingular.net.ipsec-nat-t > ip-10-0-1-233.ec2.internal.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[I]
18:41:26.088827 IP ip-10-0-1-233.ec2.internal.ipsec-nat-t > mobile-55-55-55-55.mycingular.net.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[R]
18:41:31.103016 IP mobile-55-55-55-55.mycingular.net.ipsec-nat-t > ip-10-0-1-233.ec2.internal.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[I]
18:41:31.103931 IP ip-10-0-1-233.ec2.internal.ipsec-nat-t > mobile-55-55-55-55.mycingular.net.ipsec-nat-t: NONESP-encap: isakmp: child_sa  inf2[R]

我相信我的设计已经接近了，但我错过了一些基本的东西。知道为什么我的隧道不是双向工作的吗？我可以从AWS->遥控器点击，但不是相反的方式。注意:我没有在Ubuntu (StrongSwan) EC2实例上设置ip转发或任何自定义的iptable规则。

注意:还有一些本文件是由StrongSwan人员创建的，我查看了它，并试图实现它的运气比我当前的设置要低。

Answer 1

我发现，我犯了一个错误，在客户端网关上出现了一个路由后问题，因此为什么只能在一个方向上允许通信。正确配置了StrongSwan和AWS。