Issue #936

Updated by Tobias Brunner over 7 years ago

When trying to connect two strongswan 5.3.0 configured both in the same way to use 3des-md5 for both IKE and ESP, they are not able to connect. They are not able to select DH group. Both nodes are running on Centos 6.8, with same configuration.
When connecting the same node with Cisco, connection is successful.

When lines specifying encryption/integrity are commented out on at least one side:
# ike=3des-md5
# esp=3des-md5
then connection between two StrongSwan nodes is established successfully successfuly, even though with different encryption/integrity.

Packet dump is attached. Relevant part of logfile is below.
If you need more information, please let me know.
If this is expected behavior, then sorry for distraction.

Relevant configuration in ipsec.conf:
conn %default

# strongswan statusall
Status of IKE charon daemon (strongSwan 5.3.0, Linux 2.6.32-504.16.2.el6.x86_64, x86_64):
uptime: 115 seconds, since Apr 23 12:54:26 2015
malloc: sbrk 405504, mmap 0, used 398080, free 7424
worker threads: 11 of 16 idle, 5/0/0/0 working, job queue: 0/0/0/0, scheduled: 0
loaded plugins: charon aes des rc2 sha1 sha2 md4 md5 random nonce x509 revocation constraints acert pubkey pkcs1 pkcs8 pkcs12 pgp dnskey sshkey pem openssl fips-prf gmp xcbc cmac hmac ctr ccm curl attr kernel-netlink resolve socket-default farp stroke vici updown eap-identity eap-md5 eap-gtc eap-mschapv2 eap-tls eap-ttls eap-peap xauth-generic xauth-eap xauth-pam xauth-noauth dhcp
Listening IP addresses:
teststub: IKEv1
teststub: local: [] uses pre-shared key authentication
teststub: remote: [] uses pre-shared key authentication
teststub: child:[gre] ===[gre] TUNNEL

$ rpm -q strongswan

$ uname -a
Linux test_stub 2.6.32-504.16.2.el6.x86_64 #1 SMP Wed Apr 22 06:48:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

2015-04-23 12:24:55 13[ENC] <teststub|1> found payload of type SECURITY_ASSOCIATION_V1
2015-04-23 12:24:55 13[ENC] <teststub|1> found payload of type VENDOR_ID_V1
2015-04-23 12:24:55 13[ENC] <teststub|1> found payload of type VENDOR_ID_V1
2015-04-23 12:24:55 13[ENC] <teststub|1> found payload of type VENDOR_ID_V1
2015-04-23 12:24:55 13[ENC] <teststub|1> parsed ID_PROT response 0 [ SA V V V ]
2015-04-23 12:24:55 13[IKE] <teststub|1> received XAuth vendor ID
2015-04-23 12:24:55 13[IKE] <teststub|1> received DPD vendor ID
2015-04-23 12:24:55 13[IKE] <teststub|1> received NAT-T (RFC 3947) vendor ID
2015-04-23 12:24:55 13[CFG] <teststub|1> selecting proposal:
2015-04-23 12:24:55 13[CFG] <teststub|1> proposal matches
2015-04-23 12:24:55 13[CFG] <teststub|1> received proposals: IKE:3DES_CBC/HMAC_MD5_96/PRF_HMAC_MD5
2015-04-23 12:24:55 13[CFG] <teststub|1> configured proposals: IKE:3DES_CBC/HMAC_MD5_96/PRF_HMAC_MD5, IKE:AES_CBC_128/AES_CBC_192/AES_CBC_256/3DES_CBC/CAMELLIA_CBC_128/CAMELLIA_CBC_192/CAMELLIA_CBC_256/AES_CTR_128/AES_CTR_192/AES_CTR_256/CAMELLIA_CTR_128/CAMELLIA_CTR_192/CAMELLIA_CTR_256/HMAC_MD5_96/HMAC_SHA1_96/HMAC_SHA2_256_128/HMAC_SHA2_384_192/HMAC_SHA2_512_256/AES_XCBC_96/AES_CMAC_96/PRF_HMAC_MD5/PRF_HMAC_SHA1/PRF_HMAC_SHA2_256/PRF_HMAC_SHA2_384/PRF_HMAC_SHA2_512/PRF_AES128_XCBC/PRF_AES128_CMAC/MODP_2048/MODP_2048_224/MODP_2048_256/MODP_1536/MODP_3072/MODP_4096/MODP_8192/MODP_1024/MODP_1024_160/ECP_256/ECP_384/ECP_521/ECP_224/ECP_192/ECP_224_BP/ECP_256_BP/ECP_384_BP/ECP_512_BP, IKE:AES_GCM_8_128/AES_GCM_8_192/AES_GCM_8_256/AES_GCM_12_128/AES_GCM_12_192/AES_GCM_12_256/AES_GCM_16_128/AES_GCM_16_192/AES_GCM_16_256/AES_CCM_8_128/AES_CCM_8_192/AES_CCM_8_256/AES_CCM_12_128/AES_CCM_12_192/AES_CCM_12_256/AES_CCM_16_128/AES_CCM_16_192/AES_CCM_16_256/CAMELLIA_CCM_8_128/CAMELLIA_CCM_8_192/CAMELLIA_CCM_8_256/CAMELLIA_CCM_12_128/CAMELLIA_CCM_12_192/CAMELLIA_CCM_12_256/CAMELLIA_CCM_16_128/CAMELLIA_CCM_16_192/CAMELLIA_CCM_16_256/PRF_HMAC_MD5/PRF_HMAC_SHA1/PRF_HMAC_SHA2_256/PRF_HMAC_SHA2_384/PRF_HMAC_SHA2_512/PRF_AES128_XCBC/PRF_AES128_CMAC/MODP_2048/MODP_2048_224/MODP_2048_256/MODP_1536/MODP_3072/MODP_4096/MODP_8192/MODP_1024/MODP_1024_160/ECP_256/ECP_384/ECP_521/ECP_224/ECP_192/ECP_224_BP/ECP_256_BP/ECP_384_BP/ECP_512_BP
2015-04-23 12:24:55 13[CFG] <teststub|1> selected proposal: IKE:3DES_CBC/HMAC_MD5_96/PRF_HMAC_MD5
2015-04-23 12:24:55 13[IKE] <teststub|1> reinitiating already active tasks
2015-04-23 12:24:55 13[IKE] <teststub|1> ISAKMP_VENDOR task
2015-04-23 12:24:55 13[IKE] <teststub|1> MAIN_MODE task
2015-04-23 12:24:55 13[IKE] <teststub|1> DH group selection failed
2015-04-23 12:24:55 13[IKE] <teststub|1> queueing INFORMATIONAL task