RE: ssl-enum-ciphers not returning all ciphers

["Lemons, Terry" <Terry.Lemons () dell com>]

Hi Matt

Thanks very much for the help!

Thanks for pointing out that I was wrong in identifying the two ciphers shown in nmap; that makes the results make more 
sense.

I ran the openssl command you suggested; stripping out some of the possibly-sensitive information; here is the output:

lava93141:/tmp # openssl s_client -connect 10.7.110.234:5671 -cipher DHE-RSA-AES256-GCM-SHA384
CONNECTED(00000003)
.
.
.
verify error:num=19:self signed certificate in certificate chain
139674829317776:error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure:s3_pkt.c:1498:SSL alert 
number 40
139674829317776:error:140790E5:SSL routines:ssl23_write:ssl handshake failure:s23_lib.c:177:
---
Certificate chain
.
.
.
---
Server certificate
-----BEGIN CERTIFICATE-----
.
.
.
-----END CERTIFICATE-----
subject=...
issuer=...
---
Acceptable client certificate CA names
.
.
.
Client Certificate Types: ECDSA sign, RSA sign, DSA sign
Requested Signature Algorithms: 
ECDSA+SHA512:RSA+SHA512:ECDSA+SHA384:RSA+SHA384:ECDSA+SHA256:RSA+SHA256:ECDSA+SHA224:RSA+SHA224:ECDSA+SHA1:RSA+SHA1:DSA+SHA1
Shared Requested Signature Algorithms: 
ECDSA+SHA512:RSA+SHA512:ECDSA+SHA384:RSA+SHA384:ECDSA+SHA256:RSA+SHA256:ECDSA+SHA224:RSA+SHA224:ECDSA+SHA1:RSA+SHA1:DSA+SHA1
Peer signing digest: SHA512
Server Temp Key: DH, 2048 bits
---
SSL handshake has read 3122 bytes and written 330 bytes
---
New, TLSv1/SSLv3, Cipher is DHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : DHE-RSA-AES256-GCM-SHA384
    Session-ID: xxxxxx
    Session-ID-ctx:
    Master-Key: xxxxxxx
    Key-Arg   : None
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    Start Time: 1561490298
    Timeout   : 300 (sec)
    Verify return code: 19 (self signed certificate in certificate chain)
---
#

Thoughts?

Thanks
tl

From: Matthew.Snyder () mt com <Matthew.Snyder () mt com>
Sent: Tuesday, June 25, 2019 3:14 PM
To: Lemons, Terry; dev () nmap org
Subject: RE: ssl-enum-ciphers not returning all ciphers


[EXTERNAL EMAIL]
I actually see this pushing only the first two (RSA-only, non-ephemeral, non-Diffie-Hellman ---- follow highlights).  
But that's not really the issue being questioned.

Can you confirm, is there a different result if you were to use "openssl s_client -connect 10.7.110.234:5671 -cipher 
DHE-RSA-AES256-GCM-SHA384"???

If by running an example that we are not seeing in NMAP, we get an incomplete handshake, it's likely that NMAP is 
accurate in its result.

Regards,
Matt

From: dev <dev-bounces () nmap org<mailto:dev-bounces () nmap org>> On Behalf Of Lemons, Terry
Sent: Tuesday, June 25, 2019 2:47 PM
To: dev () nmap org<mailto:dev () nmap org>
Subject: ssl-enum-ciphers not returning all ciphers

Hi

I'm using nmap 7.70 on a Linux system to probe a different Linux system that is using RabbitMQ/Erlang.

The cipher list, specified in the RabbitMQ-specific format, is:

ssl_options.ciphers.1 = AES128-GCM-SHA256
ssl_options.ciphers.2 = AES256-GCM-SHA384
ssl_options.ciphers.3 = DHE-RSA-AES256-GCM-SHA384
ssl_options.ciphers.4 = DHE-RSA-AES128-GCM-SHA256
ssl_options.ciphers.5 = DHE-RSA-AES256-SHA256
ssl_options.ciphers.6 = DHE-RSA-AES128-SHA256
ssl_options.ciphers.7 = DHE-RSA-AES256-SHA
ssl_options.ciphers.8 = DHE-RSA-AES128-SHA
ssl_options.ciphers.9 = ECDHE-RSA-AES128-GCM-SHA256
ssl_options.ciphers.10 = ECDHE-RSA-AES256-SHA384
ssl_options.ciphers.11 = ECDHE-RSA-AES128-GCM-SHA256
ssl_options.ciphers.12 = ECDHE-RSA-AES128-SHA256
ssl_options.ciphers.13 = ECDHE-RSA-AES256-SHA
ssl_options.ciphers.14 = ECDHE-RSA-AES128-SHA

When I run nmap (with -d option, below), it returns only the third and fourth cipher:

nmap -sV -p 5671 -d --script ssl-enum-ciphers 10.7.110.234
Starting Nmap 7.70 ( https://nmap.org ) at 2019-06-25 12:36 MDT
--------------- Timing report ---------------
  hostgroups: min 1, max 100000
  rtt-timeouts: init 1000, min 100, max 10000
  max-scan-delay: TCP 1000, UDP 1000, SCTP 1000
  parallelism: min 0, max 0
  max-retries: 10, host-timeout: 0
  min-rate: 0, max-rate: 0
---------------------------------------------
NSE: Using Lua 5.3.
NSE: Arguments from CLI:
NSE: Loaded 44 scripts for scanning.
NSE: Script Pre-scanning.
NSE: Starting runlevel 1 (of 2) scan.
Initiating NSE at 12:36
Completed NSE at 12:36, 0.00s elapsed
NSE: Starting runlevel 2 (of 2) scan.
Initiating NSE at 12:36
Completed NSE at 12:36, 0.00s elapsed
Initiating Ping Scan at 12:36
Scanning 10.7.110.234 [4 ports]
Packet capture filter (device eth0): dst host 10.7.93.141 and (icmp or icmp6 or ((tcp or udp or sctp) and (src host 
10.7.110.234)))
We got a ping packet back from 10.7.110.234: id = 48554 seq = 0 checksum = 16981
Completed Ping Scan at 12:36, 0.00s elapsed (1 total hosts)
Overall sending rates: 1114.21 packets / s, 42339.83 bytes / s.
mass_rdns: Using DNS server 10.7.93.100
Initiating Parallel DNS resolution of 1 host. at 12:36
mass_rdns: 13.00s 0/1 [#: 1, OK: 0, NX: 0, DR: 0, SF: 0, TR: 3]
Completed Parallel DNS resolution of 1 host. at 12:37, 13.00s elapsed
DNS resolution of 1 IPs took 13.00s. Mode: Async [#: 1, OK: 0, NX: 0, DR: 1, SF: 0, TR: 3, CN: 0]
Initiating SYN Stealth Scan at 12:37
Scanning 10.7.110.234 [1 port]
Packet capture filter (device eth0): dst host 10.7.93.141 and (icmp or icmp6 or ((tcp or udp or sctp) and (src host 
10.7.110.234)))
Discovered open port 5671/tcp on 10.7.110.234
Completed SYN Stealth Scan at 12:37, 0.00s elapsed (1 total ports)
Overall sending rates: 354.99 packets / s, 15619.45 bytes / s.
Initiating Service scan at 12:37
Scanning 1 service on 10.7.110.234
Got nsock CONNECT response with status ERROR - aborting this service
Completed Service scan at 12:37, 5.05s elapsed (1 service on 1 host)
NSE: Script scanning 10.7.110.234.
NSE: Starting runlevel 1 (of 2) scan.
Initiating NSE at 12:37
NSE: Starting ssl-enum-ciphers against 10.7.110.234:5671.
NSE: [ssl-enum-ciphers 10.7.110.234:5671] Trying protocol TLSv1.1.
NSE: [ssl-enum-ciphers 10.7.110.234:5671] Trying protocol SSLv3.
NSE: [ssl-enum-ciphers 10.7.110.234:5671] Trying protocol TLSv1.2.
NSE: [ssl-enum-ciphers 10.7.110.234:5671] Trying protocol TLSv1.0.
NSE: Finished ssl-enum-ciphers against 10.7.110.234:5671.
NSE: Finished ssl-enum-ciphers against 10.7.110.234:5671.
NSE: Finished ssl-enum-ciphers against 10.7.110.234:5671.
NSE: [ssl-enum-ciphers 10.7.110.234:5671] (TLSv1.2) Comparing TLS_RSA_WITH_AES_128_GCM_SHA256 to 
TLS_RSA_WITH_AES_256_GCM_SHA384
NSE: Finished ssl-enum-ciphers against 10.7.110.234:5671.
NSE: Finished ssl-enum-ciphers against 10.7.110.234:5671.
Completed NSE at 12:37, 0.07s elapsed
NSE: Starting runlevel 2 (of 2) scan.
Initiating NSE at 12:37
NSE: Starting rpc-grind against 10.7.110.234:5671.
NSE: [rpc-grind 10.7.110.234:5671] isRPC didn't receive response.
NSE: [rpc-grind 10.7.110.234:5671] Target port 5671 is not a RPC port.
NSE: Finished rpc-grind against 10.7.110.234:5671.
Completed NSE at 12:37, 0.01s elapsed
Nmap scan report for 10.7.110.234
Host is up, received echo-reply ttl 62 (0.0013s latency).
Scanned at 2019-06-25 12:36:49 MDT for 18s

PORT     STATE SERVICE    REASON         VERSION
5671/tcp open  ssl/amqps? syn-ack ttl 62
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: client
|_  least strength: A
Final times for host: srtt: 1292 rttvar: 3833  to: 100000

NSE: Script Post-scanning.
NSE: Starting runlevel 1 (of 2) scan.
Initiating NSE at 12:37
Completed NSE at 12:37, 0.00s elapsed
NSE: Starting runlevel 2 (of 2) scan.
Initiating NSE at 12:37
Completed NSE at 12:37, 0.00s elapsed
Read from /usr/bin/../share/nmap: nmap-payloads nmap-service-probes nmap-services.
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 18.80 seconds
           Raw packets sent: 5 (196B) | Rcvd: 2 (72B)
#

Is this a known problem? Should I be running nmap with different options?  I tried '-T1' but it didn't change the 
behavior.

Thanks!
tl


Terry Lemons

[DellEMC_Logo_Hz_Blue_rgb_10percent]
Data Protection Division

176 South Street, MS 2/B-34
Hopkinton MA 01748
terry.lemons () dell com<mailto:terry.lemons () dell com>

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