SSL/TLS protocol and cipher suite scanner with JSON output

-- [email protected], 2013

Sslprobe does rudimentary SSL/TLS handshakes, from ClientHello up until ServerHello Done and extracts a list of supported ciphers, certificates and features such as session ID assignment and common TLS extensions.

A report is printed on stdout in JSON (it's not ASN.1, but it's simple!), suitable for later inspection/processing. Various protocol details are sent to stderr/syslog (filter with: 2>/dev/null).

The certificates and the trust chain are not inspected at this time, even though it would be interesting to to extract features such as subjectAltName, expiry dates and bits. The JSON output however includes an array of each of the server's presented certificates, encoded in PEM-format (i.e, chunked base64 representation of the DER), which is suitable for offline evaluation.

Usage

$ ./sslprobe
Usage: ./sslprobe <host> [port (= 443)] [output file]

Sslprobe assumes that the server speaks SSL/TLS natively on the choosen TCP port, i.e, what many protocols such as HTTPS (443), POP3S (995), IMAPS (993) or IRCS (6697) do.

Some protocols, notably SMTP, FTP and IMAP, allow SSL/TLS to be negotiated using STARTTLS (see for instance RFC3207).

Sslprobe supports STARTTLS on SMTP if the port argument is set to 25. No other STARTTLS protocols are supported at the moment. It's however quite easy to implement support for new protocols (see smtp.c and proto.c for an example).

Related work

https://www.ssllabs.com provides an extensive test of HTTPS sites online
https://github.com/iSECPartners/sslyze contains one of the tools behind SSL Labs
EFF.org SSL Observatory documents and investigates certificate use on the public internet

Useful RFCs

SSLv2 SSL 0.2 Protocol specification
RFC6101 The Secure Sockets Layer (SSL) Protocol Version 3.0
RFC5246 The Transport Layer Security (TLS) Protocol Version 1.2
RFC5077 Transport Layer Security (TLS) Session Resumption without Server-Side State
RFC5746 Transport Layer Security (TLS) Renegotiation Indication Extension
RFC3207 SMTP Service Extension for Secure SMTP over Transport Layer Security

JSON examples

(scroll down to the end of file to see an example of actual JSON output)

First dump SSL/TLS features from facebook.com's HTTPS service to fb.json

$ ./sslprobe facebook.com > fb.json
...

The jq tool (see http://stedolan.github.io/jq/) can then be used to slice and dice the information in our sample fb.json.

jq is like sed but for data scientists and journalists.

Extract certificate chain for a single host and protocol:

To extract all certificates presented for SSLv3 (second protocol), try:

 $ jq -r '.[0] | .protocols[1] | .certificates[]' fb.json

The contents of fb.json is an array of tests made against one or more IP addresses that facebook.com resolved to. Each test is a JSON object describing that particular test.

.[0] extracts the first object (tested IP) in the array in fb.json.

That information is piped to '.protocols[1]', which extracts the object for the second tested protocol. For each tested IP address, five protocols are checked: SSLv2, SSLv3, TLSv1, TLSv1.1 and TLSV1.2 (in that order). So far we've selected the object for the SSLv3 protocol in the first test.

.certificates[] then selects all entries in the certificate array, which contains PEM-encoded certificates presented by the server for that protocol.

Finally, the -r option to jq makes it output raw data instead of JSON.

Inspect the first certificate presented in the TLSv1 protocol:

Almost equivalent to the previous example, but this time we also make use of openssl x509 to extract information from the certficate.

$ jq -r '.[] | .protocols[2] | .certificates[0]' fb.json > server.pem
$ openssl x509 -noout -text < server.pem
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            33:b4:f7:da:c2:82:d4:f6:d9:76:88:f3:f4:77:91:06
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=US, O=VeriSign, Inc., OU=VeriSign Trust Network, OU=Terms of use at https://www.verisign.com/rpa (c)10, CN=VeriSign Class 3 Secure Server CA - G3
        Validity
            Not Before: Apr 11 00:00:00 2013 GMT
            Not After : Mar  5 23:59:59 2016 GMT
...

Merge files and compile report on TLSv1.2 statuses

A slightly more advanced example.

$ ./sslprobe google.com > google.json
$ ./sslprobe facebook.com > facebook.json
$ jq '.[] | [ { host: .host,  ip: .ip,  proto: (.protocols[4] | { name: .name,  supported: .supported } ) } ]' google.json facebook.json
[
  {
    "proto": {
      "supported": true,
      "name": "TLS 1.2"
    },
    "ip": "173.252.110.27",
    "host": "facebook.com"
  }
]
[
  {
    "proto": {
      "supported": true,
      "name": "TLS 1.2"
    },
    "ip": "173.194.32.9",
    "host": "google.com"
  }
]

Sample JSON output:

Here's some sample output from a test against Facebook. The certificate data was stripped down to reduce output size.

[
  {
    "ip":"173.252.110.27",
    "port":443,
    "host":"facebook.com",
    "protocols":[
      {
        "name":"SSL 2.0",
        "version":2,
        "supported":false,
        "establishedConnections":1,
        "lastError":"Connection reset by peer",
        "compressionAlgorithm":0,
        "sessionIdBytes":0,
        "cipherSuites":[
        ],
        "cipherSuitePreference":0,
        "certificateChainSize":0,
        "certificates":[
        ]
      },
      {
        "name":"SSL 3.0",
        "version":768,
        "supported":true,
        "establishedConnections":11,
        "lastError":null,
        "compressionAlgorithm":0,
        "sessionIdBytes":32,
        "cipherSuites":[
          { "id":49169,	"name":"TLS_ECDHE_RSA_WITH_RC4_128_SHA" },
          { "id":5,	"name":"RSA_WITH_RC4_128_SHA" },
          { "id":49171,	"name":"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA" },
          { "id":49172,	"name":"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA" },
          { "id":47,	"name":"RSA_WITH_AES_128_CBC_SHA" },
          { "id":53,	"name":"RSA_WITH_AES_256_CBC_SHA" },
          { "id":4,	"name":"RSA_WITH_RC4_128_MD5" },
          { "id":49170,	"name":"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA" },
          { "id":10,	"name":"RSA_WITH_3DES_EDE_CBC_SHA" }
        ],
        "cipherSuitePreference":1,
        "extensions":{
          "sni":1,
          "sniNameUnknown":0,
          "sessionTicket":0,
          "secureRenegotiation":1,
          "heartbeat":0,
          "npn":[
            "spdy/3.1",
            "spdy/3",
            "http/1.1"
          ]
        },
        "lastAlert":{
          "level":0,
          "description":0
        },
        "bugs":{
          "brokenTlsExt":0,
          "csLimit":0,
          "forcedCs":0
        },
        "certificateChainSize":4152,
        "certificates":[
            "-----BEGIN CERTIFICATE-----\nMIIFNjCCBB6gAw....-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIF7DCCBNSg...-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIE0.....JjhJ+xr3AAAAAAAA-----END CERTIFICATE-----\n"
        ]
      },
      {
        "name":"TLS 1.0",
        "version":769,
        "supported":true,
        "establishedConnections":11,
        "lastError":null,
        "compressionAlgorithm":0,
        "sessionIdBytes":0,
        "cipherSuites":[
          { "id":49169,	"name":"TLS_ECDHE_RSA_WITH_RC4_128_SHA" },
          { "id":5,	"name":"RSA_WITH_RC4_128_SHA" },
          { "id":49171,	"name":"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA" },
          { "id":49172,	"name":"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA" },
          { "id":47,	"name":"RSA_WITH_AES_128_CBC_SHA" },
          { "id":53,	"name":"RSA_WITH_AES_256_CBC_SHA" },
          { "id":4,	"name":"RSA_WITH_RC4_128_MD5" },
          { "id":49170,	"name":"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA" },
          { "id":10,	"name":"RSA_WITH_3DES_EDE_CBC_SHA" }
        ],
        "cipherSuitePreference":1,
        "extensions":{
          "sni":1,
          "sniNameUnknown":0,
          "sessionTicket":1,
          "secureRenegotiation":1,
          "heartbeat":0,
          "npn":[
            "spdy/3.1",
            "spdy/3",
            "http/1.1"
          ]
        },
        "lastAlert":{
          "level":0,
          "description":0
        },
        "bugs":{
          "brokenTlsExt":0,
          "csLimit":0,
          "forcedCs":0
        },
        "certificateChainSize":4152,
        "certificates":[
            "-----BEGIN CERTIFICATE-----\nMIIFNjCCBB6gAw....-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIF7DCCBNSg...-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIE0.....JjhJ+xr3AAAAAAAA-----END CERTIFICATE-----\n"
        ]
      },
      {
        "name":"TLS 1.1",
        "version":770,
        "supported":true,
        "establishedConnections":11,
        "lastError":null,
        "compressionAlgorithm":0,
        "sessionIdBytes":0,
        "cipherSuites":[
          { "id":49171,	"name":"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA" },
          { "id":49172,	"name":"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA" },
          { "id":47,	"name":"RSA_WITH_AES_128_CBC_SHA" },
          { "id":53,	"name":"RSA_WITH_AES_256_CBC_SHA" },
          { "id":49169,	"name":"TLS_ECDHE_RSA_WITH_RC4_128_SHA" },
          { "id":5,	"name":"RSA_WITH_RC4_128_SHA" },
          { "id":4,	"name":"RSA_WITH_RC4_128_MD5" },
          { "id":49170,	"name":"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA" },
          { "id":10,	"name":"RSA_WITH_3DES_EDE_CBC_SHA" }
        ],
        "cipherSuitePreference":1,
        "extensions":{
          "sni":1,
          "sniNameUnknown":0,
          "sessionTicket":1,
          "secureRenegotiation":1,
          "heartbeat":0,
          "npn":[
            "spdy/3.1",
            "spdy/3",
            "http/1.1"
          ]
        },
        "lastAlert":{
          "level":0,
          "description":0
        },
        "bugs":{
          "brokenTlsExt":0,
          "csLimit":0,
          "forcedCs":0
        },
        "certificateChainSize":4152,
        "certificates":[
            "-----BEGIN CERTIFICATE-----\nMIIFNjCCBB6gAw....-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIF7DCCBNSg...-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIE0.....JjhJ+xr3AAAAAAAA-----END CERTIFICATE-----\n"
        ]
      },
      {
        "name":"TLS 1.2",
        "version":771,
        "supported":true,
        "establishedConnections":15,
        "lastError":null,
        "compressionAlgorithm":0,
        "sessionIdBytes":0,
        "cipherSuites":[
          { "id":49199,	"name":"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256" },
          { "id":49200,	"name":"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384" },
          { "id":49171,	"name":"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA" },
          { "id":49172,	"name":"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA" },
          { "id":156,	"name":"TLS_RSA_WITH_AES_128_GCM_SHA256" },
          { "id":157,	"name":"TLS_RSA_WITH_AES_256_GCM_SHA384" },
          { "id":47,	"name":"RSA_WITH_AES_128_CBC_SHA" },
          { "id":53,	"name":"RSA_WITH_AES_256_CBC_SHA" },
          { "id":49169,	"name":"TLS_ECDHE_RSA_WITH_RC4_128_SHA" },
          { "id":5,	"name":"RSA_WITH_RC4_128_SHA" },
          { "id":4,	"name":"RSA_WITH_RC4_128_MD5" },
          { "id":49170,	"name":"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA" },
          { "id":10,	"name":"RSA_WITH_3DES_EDE_CBC_SHA" }
        ],
        "cipherSuitePreference":1,
        "extensions":{
          "sni":1,
          "sniNameUnknown":0,
          "sessionTicket":1,
          "secureRenegotiation":1,
          "heartbeat":0,
          "npn":[
            "spdy/3.1",
            "spdy/3",
            "http/1.1"
          ]
        },
        "lastAlert":{
          "level":0,
          "description":0
        },
        "bugs":{
          "brokenTlsExt":0,
          "csLimit":0,
          "forcedCs":0
        },
        "certificateChainSize":4152,
        "certificates":[
            "-----BEGIN CERTIFICATE-----\nMIIFNjCCBB6gAw....-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIF7DCCBNSg...-----END CERTIFICATE-----\n",
            "-----BEGIN CERTIFICATE-----\nMIIE0.....JjhJ+xr3AAAAAAAA-----END CERTIFICATE-----\n"
        ]
      }
    ]
  }
]

Name		Name	Last commit message	Last commit date
Latest commit History 35 Commits
.gitignore		.gitignore
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
addr.c		addr.c
addr.h		addr.h
buf.c		buf.c
buf.h		buf.h
connection.c		connection.c
connection.h		connection.h
cs.h		cs.h
main.c		main.c
proto.c		proto.c
proto.h		proto.h
smtp.c		smtp.c
smtp.h		smtp.h
sslv2.c		sslv2.c
sslv2.h		sslv2.h
tls.c		tls.c
tls.h		tls.h
x509.c		x509.c
x509.h		x509.h

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Repository files navigation

SSL/TLS protocol and cipher suite scanner with JSON output

Usage

Related work

Useful RFCs

JSON examples

Extract certificate chain for a single host and protocol:

Inspect the first certificate presented in the TLSv1 protocol:

Merge files and compile report on TLSv1.2 statuses

Sample JSON output:

About

Releases

Packages

Languages

License

noahwilliamsson/sslprobe

Folders and files

Latest commit

History

Repository files navigation

SSL/TLS protocol and cipher suite scanner with JSON output

Usage

Related work

Useful RFCs

JSON examples

Extract certificate chain for a single host and protocol:

Inspect the first certificate presented in the TLSv1 protocol:

Merge files and compile report on TLSv1.2 statuses

Sample JSON output:

About

Resources

License

Stars

Watchers

Forks

Releases

Packages 0

Languages

Packages