SSL/TLS

Index

• Transport Layer Security/ Secure Sockets Layer (SSL/TLS)

  • Check a SSL/TLS connection to a server

  • Get a server digital certificate

  • SSLscan

  • SSLyze

  • testssl.sh

  • SSL/TLS online tools

• References/Additional information

Transport Layer Security/ Secure Sockets Layer (SSL/TLS)

Secure Sockets Layer (SSL) is a widely used protocol for secure and authenticated connections between Web browsers and Web servers.

Check a SSL/TLS connection to a server

OpenSSL can be used to check the parameters of an SSL connection to a particular server, for example:

openssl s_client -connect www.microsoft.com:443

Resulting in:

CONNECTED(00000005)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G2
verify return:1
depth=1 C = US, O = Microsoft Corporation, CN = Microsoft Azure TLS Issuing CA 06
verify return:1
depth=0 C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = www.microsoft.com
verify return:1
---
Certificate chain
0 s:C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = www.microsoft.com
i:C = US, O = Microsoft Corporation, CN = Microsoft Azure TLS Issuing CA 06
1 s:C = US, O = Microsoft Corporation, CN = Microsoft Azure TLS Issuing CA 06
i:C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G2
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = www.microsoft.com

issuer=C = US, O = Microsoft Corporation, CN = Microsoft Azure TLS Issuing CA 06

---
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: RSA-PSS
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 4368 bytes and written 399 bytes
Verification: OK
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
Server public key is 2048 bit
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---
---
Post-Handshake New Session Ticket arrived:
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: 79E4C98601A3400F12807C54D26202A9145A2205ECE8A9ECCF35B82D5391C3C8
    Session-ID-ctx:
    Resumption PSK: BB1D8D7E0BD3B11DB702120DDB89809AA71CDC723FF9912D86142E38BA243E64C5E8FD2EA71A00FB954E5E3475703B1D
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 83100 (seconds)
    TLS session ticket:
    0000 - 00 00 35 6e 11 51 4f da-c0 0e 4e bb 71 b8 9b 41   ..5n.QO...N.q..A
    0010 - 5a be dc a8 31 fa b3 21-d9 a1 77 0f a9 5e 66 c5   Z...1..!..w..^f.
    0020 - 92 9f 82 00 e8 c8 48 cf-ff 16 8a 62 6d 94 af 59   ......H....bm..Y
    0030 - 5d 61 03 77 31 96 aa d2-5b 91 e4 92 29 8c 3d c2   ]a.w1...[...).=.
    0040 - d9 c6 79 eb 0b ce 2a 0d-fe 47 46 2a a9 7f eb a8   ..y...*..GF*....
    0050 - 7e be b6 a2 10 db 75 5c-12 77 3b 96 f5 cd 45 81   ~.....u\.w;...E.
    0060 - 5f ad e0 ff 43 a8 58 77-db 39 36 81 ab b2 6b 36   _...C.Xw.96...k6
    0070 - c4 c1 a9 0b 99 e1 5e a8-34 a1 b4 72 97 78 86 a7   ......^.4..r.x..
    0080 - 33 c7 ab ba 93 cf d7 a9-0c e4 54 4b 83 74 a0 5e   3.........TK.t.^
    0090 - ba e1 a2 99 f7 14 86 79-e4 bd 41 4a cf 8f 93 de   .......y..AJ....
    00a0 - c4 87 80 4e 18 ee 65 68-15 53 8f 2d 56 5c 53 72   ...N..eh.S.-V\Sr
    00b0 - 0b d3 40 05 9a ec 26 ff-2f e7 e0 24 e4 27 02 9c   ..@...&./..$.'..
    00c0 - 22 0b 84 36 39 ac 3a 15-7b 0b 3c 56 83 e2 82 43   "..69.:.{.<V...C
    00d0 - c9 77 41 28 1b cf 45 c7-bc ef 3d f2 9b c1 3b 1b   .wA(..E...=...;.

    Start Time: 1667493148
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
---
Post-Handshake New Session Ticket arrived:
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: FDF5369ABC630434B2E11B78E29A2FC43FC0732A147D6D7EE1D370FF0D50595E
    Session-ID-ctx:
    Resumption PSK: D63C7DE07685AB98AF1C6CEEBAE63DE012A22290964DB41AC1D3B2817851C8F38677ECD4EE67E9405CE6A44F0F12688B
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 83100 (seconds)
    TLS session ticket:
    0000 - 00 00 35 6e 11 51 4f da-c0 0e 4e bb 71 b8 9b 41   ..5n.QO...N.q..A
    0010 - ad 56 82 f3 74 6d 6d 53-d5 a8 b5 a9 e6 c5 55 e7   .V..tmmS......U.
    0020 - c2 52 2e f2 d6 b5 cb 18-bd 23 82 63 df a6 8e 29   .R.......#.c...)
    0030 - f3 32 c4 51 e5 c6 e2 29-d9 2f 78 43 45 51 5d c0   .2.Q...)./xCEQ].
    0040 - be d8 8e 3b f5 b5 5b 2f-b8 ee ad ae fb bf 2b a7   ...;..[/......+.
    0050 - 42 42 b7 af 4a 23 09 13-f4 2e 1f 58 9a d6 46 90   BB..J#.....X..F.
    0060 - c4 76 f9 41 05 99 af 2e-77 85 d7 12 32 f0 21 97   .v.A....w...2.!.
    0070 - 79 92 8e 39 31 97 f3 56-9b 06 fd 43 be 97 16 aa   y..91..V...C....
    0080 - 66 49 d8 2e 44 54 8f fe-e5 56 e9 5c 70 ed 79 b7   fI..DT...V.\p.y.
    0090 - 93 4c 74 7b db d2 7f 97-76 84 a6 34 d0 67 0f e4   .Lt{....v..4.g..
    00a0 - 3f a3 86 66 14 86 ae 19-0b e8 3d bf 43 ad df 83   ?..f......=.C...
    00b0 - 29 95 b3 8c 52 9d 2d b4-95 7f e8 50 8f ea 05 04   )...R.-....P....
    00c0 - d5 42 b9 07 b9 10 d5 ae-03 ca 16 18 b7 c4 dc f1   .B..............
    00d0 - cc 8a 49 d7 4a 09 8d b2-e5 d8 3a 9a 98 ea b2 0c   ..I.J.....:.....

    Start Time: 1667493148
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
closed

Get a server digital certificate

We can obtain a server's digital certificate by doing the following:

echo | openssl s_client -connect www.google.com:443 2>&1 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > google.crt

After we have the certificate saved in a file (google.crt) we can view it.

openssl x509 -noout -text -in ./google.crt 

Resulting:

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            31:68:f6:7c:25:93:0f:e5
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, O=Google Inc, CN=Google Internet Authority G2
        Validity
            Not Before: Oct 28 17:50:22 2015 GMT
            Not After : Jan 26 00:00:00 2016 GMT
        Subject: C=US, ST=California, L=Mountain View, O=Google Inc, CN=www.google.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
            RSA Public Key: (2048 bit)
                Modulus (2048 bit):
                    00:b4:4a:88:99:2c:74:01:6a:d4:4a:17:8a:b6:22:
                    34:e1:b7:91:c2:63:22:68:13:3f:f4:31:57:cd:91:
                    d8:c9:b6:b5:f4:77:19:7a:21:67:88:f4:b3:3e:cd:
                    64:2f:0d:ca:bf:f7:20:0c:1b:03:db:27:3e:46:da:
                    82:0f:fe:81:41:85:40:ae:bc:fe:8d:a8:a5:a6:92:
                    54:90:e2:d1:74:c6:1e:a5:ce:3e:32:4f:04:b9:67:
                    d1:e2:59:a3:1b:7d:d9:68:15:b2:f0:90:a4:a5:30:
                    16:3e:5f:6a:d9:07:14:d1:86:05:9c:38:e0:73:65:
                    e4:d4:4a:94:b3:93:e5:b2:06:23:14:d4:f3:e7:cf:
                    35:b7:45:ec:e9:07:dd:e0:bc:cb:5b:23:88:3a:1e:
                    8e:7e:02:fa:b7:83:2e:8f:9a:5c:f5:50:10:f2:f0:
                    3d:9b:d5:af:29:19:b3:39:7f:31:69:cb:bc:a7:36:
                    54:87:a0:c0:2a:55:d3:91:57:3e:97:83:98:e3:47:
                    65:8b:e8:32:98:43:cd:c1:b1:8b:a7:55:1e:73:0e:
                    81:2f:b4:5d:9c:e1:c1:cf:a7:2e:6f:b0:30:60:5d:
                    61:a7:02:b7:bc:6b:e9:0d:b8:00:78:ca:9f:fa:70:
                    8d:1f:f1:2b:a4:f0:a6:02:72:f4:23:35:e0:78:1c:
                    19:3d
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Extended Key Usage: 
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Subject Alternative Name: 
                DNS:www.google.com
            Authority Information Access: 
                CA Issuers - URI:http://pki.google.com/GIAG2.crt
                OCSP - URI:http://clients1.google.com/ocsp

            X509v3 Subject Key Identifier: 
                95:CA:1C:F5:FB:39:28:C9:1C:7D:D2:3C:0E:85:68:01:7E:98:7B:4C
            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Authority Key Identifier: 
                keyid:4A:DD:06:16:1B:BC:F6:68:B5:76:F5:81:B6:BB:62:1A:BA:5A:81:2F

            X509v3 Certificate Policies: 
                Policy: 1.3.6.1.4.1.11129.2.5.1
                Policy: 2.23.140.1.2.2

            X509v3 CRL Distribution Points: 
                URI:http://pki.google.com/GIAG2.crl

    Signature Algorithm: sha256WithRSAEncryption
        36:57:20:af:df:78:82:4b:bf:83:98:01:06:db:c6:f1:c0:b8:
        6d:b3:8c:ba:38:f3:46:d6:0b:2e:7a:5e:01:42:ca:29:90:37:
        51:05:3c:e8:b3:f8:e8:42:91:0b:25:11:94:5d:f5:bc:eb:d3:
        f0:37:79:a3:c0:03:f9:f3:1e:d9:61:a7:2a:a1:81:12:db:29:
        2f:31:ee:8c:80:b2:e3:a0:5c:e4:03:97:93:31:94:44:23:fb:
        4a:48:e2:39:e1:0d:1b:b6:49:66:6d:7b:2d:fb:69:9d:00:2c:
        62:7c:dd:5c:cd:f1:4c:a0:35:cd:57:36:12:49:10:33:3e:7f:
        e7:55:ac:f5:a5:f8:0e:e9:cd:51:fc:1a:25:fe:41:8c:6f:1a:
        c1:f8:70:f9:f0:e2:b4:28:b1:ea:d9:49:f9:5e:1e:e3:51:4d:
        51:59:6e:0f:26:91:2c:a6:69:37:df:98:a8:95:dd:3e:bc:fd:
        9a:ee:4f:d4:bc:31:40:11:2c:e7:d1:2f:36:e6:26:7b:af:e6:
        6f:41:9e:f4:27:3d:0b:b8:11:f4:67:09:08:ef:40:de:0c:ad:
        fe:81:65:b6:4a:2d:de:02:78:73:43:c7:2c:06:18:b3:75:fd:
        54:dd:f7:c9:1d:ad:6c:b2:aa:70:56:7b:e3:9f:8e:e3:86:63:
        e6:b8:10:fc

SSLscan

SSLscan is a tool that can be used to test the SSL/TLS protocol on a specific server and potencialy find some problems or even vulnerabilities.

Using it is quite simple:

sslscan www.google.com

Which results in the fllowing output.

Version: 2.0.15
OpenSSL 3.0.7 1 Nov 2022

Connected to 172.217.17.4

Testing SSL server www.google.com on port 443 using SNI name www.google.com

SSL/TLS Protocols:
SSLv2     disabled
SSLv3     disabled
TLSv1.0   enabled
TLSv1.1   enabled
TLSv1.2   enabled
TLSv1.3   enabled

TLS Fallback SCSV:
Server supports TLS Fallback SCSV

TLS renegotiation:
Secure session renegotiation supported

TLS Compression:
OpenSSL version does not support compression
Rebuild with zlib1g-dev package for zlib support

Heartbleed:
TLSv1.3 not vulnerable to heartbleed
TLSv1.2 not vulnerable to heartbleed
TLSv1.1 not vulnerable to heartbleed
TLSv1.0 not vulnerable to heartbleed

Supported Server Cipher(s):
Preferred TLSv1.3  128 bits  TLS_AES_128_GCM_SHA256        Curve 25519 DHE 253
Accepted  TLSv1.3  256 bits  TLS_AES_256_GCM_SHA384        Curve 25519 DHE 253
Accepted  TLSv1.3  256 bits  TLS_CHACHA20_POLY1305_SHA256  Curve 25519 DHE 253
Preferred TLSv1.2  256 bits  ECDHE-ECDSA-CHACHA20-POLY1305 Curve 25519 DHE 253
Accepted  TLSv1.2  128 bits  ECDHE-ECDSA-AES128-GCM-SHA256 Curve 25519 DHE 253
Accepted  TLSv1.2  256 bits  ECDHE-ECDSA-AES256-GCM-SHA384 Curve 25519 DHE 253
Accepted  TLSv1.2  128 bits  ECDHE-ECDSA-AES128-SHA        Curve 25519 DHE 253
Accepted  TLSv1.2  256 bits  ECDHE-ECDSA-AES256-SHA        Curve 25519 DHE 253
Accepted  TLSv1.2  256 bits  ECDHE-RSA-CHACHA20-POLY1305   Curve 25519 DHE 253
Accepted  TLSv1.2  128 bits  ECDHE-RSA-AES128-GCM-SHA256   Curve 25519 DHE 253
Accepted  TLSv1.2  256 bits  ECDHE-RSA-AES256-GCM-SHA384   Curve 25519 DHE 253
Accepted  TLSv1.2  128 bits  ECDHE-RSA-AES128-SHA          Curve 25519 DHE 253
Accepted  TLSv1.2  256 bits  ECDHE-RSA-AES256-SHA          Curve 25519 DHE 253
Accepted  TLSv1.2  128 bits  AES128-GCM-SHA256
Accepted  TLSv1.2  256 bits  AES256-GCM-SHA384
Accepted  TLSv1.2  128 bits  AES128-SHA
Accepted  TLSv1.2  256 bits  AES256-SHA
Accepted  TLSv1.2  112 bits  TLS_RSA_WITH_3DES_EDE_CBC_SHA
Preferred TLSv1.1  128 bits  ECDHE-ECDSA-AES128-SHA        Curve 25519 DHE 253
Accepted  TLSv1.1  256 bits  ECDHE-ECDSA-AES256-SHA        Curve 25519 DHE 253
Accepted  TLSv1.1  128 bits  ECDHE-RSA-AES128-SHA          Curve 25519 DHE 253
Accepted  TLSv1.1  256 bits  ECDHE-RSA-AES256-SHA          Curve 25519 DHE 253
Accepted  TLSv1.1  128 bits  AES128-SHA
Accepted  TLSv1.1  256 bits  AES256-SHA
Accepted  TLSv1.1  112 bits  TLS_RSA_WITH_3DES_EDE_CBC_SHA
Preferred TLSv1.0  128 bits  ECDHE-ECDSA-AES128-SHA        Curve 25519 DHE 253
Accepted  TLSv1.0  256 bits  ECDHE-ECDSA-AES256-SHA        Curve 25519 DHE 253
Accepted  TLSv1.0  128 bits  ECDHE-RSA-AES128-SHA          Curve 25519 DHE 253
Accepted  TLSv1.0  256 bits  ECDHE-RSA-AES256-SHA          Curve 25519 DHE 253
Accepted  TLSv1.0  128 bits  AES128-SHA
Accepted  TLSv1.0  256 bits  AES256-SHA
Accepted  TLSv1.0  112 bits  TLS_RSA_WITH_3DES_EDE_CBC_SHA

Server Key Exchange Group(s):
TLSv1.3  128 bits  secp256r1 (NIST P-256)
TLSv1.3  128 bits  x25519
TLSv1.2  128 bits  secp256r1 (NIST P-256)
TLSv1.2  128 bits  x25519

SSL Certificate:
Signature Algorithm: sha256WithRSAEncryption
ECC Curve Name:      prime256v1
ECC Key Strength:    128

Subject:  www.google.com
Altnames: DNS:www.google.com
Issuer:   GTS CA 1C3

Not valid before: Sep 26 08:23:57 2022 GMT
Not valid after:  Dec 19 08:23:56 2022 GMT

SSLyze

SSLyze is also a tool that might be use to scan for SSL/TLS on a server. Using it is also very simple.

sslyze www.google.com

Which results in the following.

CHECKING CONNECTIVITY TO SERVER(S)
----------------------------------

www.google.com:443        => 142.250.200.132


SCAN RESULTS FOR WWW.GOOGLE.COM:443 - 142.250.200.132
-----------------------------------------------------

* Certificates Information:
    Hostname sent for SNI:             www.google.com
    Number of certificates detected:   2


    Certificate #0 ( _EllipticCurvePublicKey )
    SHA1 Fingerprint:                  8d451b91f4f3d1beaf7dfd745739a0a1ff9bb7b2
    Common Name:                       www.google.com
    Issuer:                            GTS CA 1C3
    Serial Number:                     172338986348961426169022814442718324929
    Not Before:                        2022-10-17
    Not After:                         2023-01-09
    Public Key Algorithm:              _EllipticCurvePublicKey
    Signature Algorithm:               sha256
    Key Size:                          256
    Curve:                             secp256r1
    DNS Subject Alternative Names:     ['www.google.com']

    Certificate #0 - Trust
    Hostname Validation:               OK - Certificate matches server hostname
    Android CA Store (13.0.0_r8):      OK - Certificate is trusted
    Apple CA Store (iOS 15.1, iPadOS 15.1, macOS 12.1, tvOS 15.1, and watchOS 8.1):OK - Certificate is trusted
    Java CA Store (jdk-13.0.2):        OK - Certificate is trusted
    Mozilla CA Store (2022-09-18):     OK - Certificate is trusted
    Windows CA Store (2022-08-15):     OK - Certificate is trusted
    Symantec 2018 Deprecation:         OK - Not a Symantec-issued certificate
    Received Chain:                    www.google.com --> GTS CA 1C3 --> GTS Root R1
    Verified Chain:                    www.google.com --> GTS CA 1C3 --> GTS Root R1
    Received Chain Contains Anchor:    OK - Anchor certificate not sent
    Received Chain Order:              OK - Order is valid
    Verified Chain contains SHA1:      OK - No SHA1-signed certificate in the verified certificate chain

    Certificate #0 - Extensions
    OCSP Must-Staple:                  NOT SUPPORTED - Extension not found
    Certificate Transparency:          WARNING - Only 2 SCTs included but Google recommends 3 or more

    Certificate #0 - OCSP Stapling
                                        NOT SUPPORTED - Server did not send back an OCSP response


    Certificate #1 ( _RSAPublicKey )
    SHA1 Fingerprint:                  bb181548dc5db04f8194e588b4f19f1cc4d12a0d
    Common Name:                       www.google.com
    Issuer:                            GTS CA 1C3
    Serial Number:                     265906118735752094790635674560926019293
    Not Before:                        2022-10-17
    Not After:                         2023-01-09
    Public Key Algorithm:              _RSAPublicKey
    Signature Algorithm:               sha256
    Key Size:                          2048
    Exponent:                          65537
    DNS Subject Alternative Names:     ['www.google.com']

    Certificate #1 - Trust
    Hostname Validation:               OK - Certificate matches server hostname
    Android CA Store (13.0.0_r8):      OK - Certificate is trusted
    Apple CA Store (iOS 15.1, iPadOS 15.1, macOS 12.1, tvOS 15.1, and watchOS 8.1):OK - Certificate is trusted
    Java CA Store (jdk-13.0.2):        OK - Certificate is trusted
    Mozilla CA Store (2022-09-18):     OK - Certificate is trusted
    Windows CA Store (2022-08-15):     OK - Certificate is trusted
    Symantec 2018 Deprecation:         OK - Not a Symantec-issued certificate
    Received Chain:                    www.google.com --> GTS CA 1C3 --> GTS Root R1
    Verified Chain:                    www.google.com --> GTS CA 1C3 --> GTS Root R1
    Received Chain Contains Anchor:    OK - Anchor certificate not sent
    Received Chain Order:              OK - Order is valid
    Verified Chain contains SHA1:      OK - No SHA1-signed certificate in the verified certificate chain

    Certificate #1 - Extensions
    OCSP Must-Staple:                  NOT SUPPORTED - Extension not found
    Certificate Transparency:          WARNING - Only 2 SCTs included but Google recommends 3 or more

    Certificate #1 - OCSP Stapling
                                        NOT SUPPORTED - Server did not send back an OCSP response

* SSL 2.0 Cipher Suites:
    Attempted to connect using 7 cipher suites; the server rejected all cipher suites.

* SSL 3.0 Cipher Suites:
    Attempted to connect using 80 cipher suites; the server rejected all cipher suites.

* TLS 1.0 Cipher Suites:
    Attempted to connect using 80 cipher suites.

    The server accepted the following 5 cipher suites:
        TLS_RSA_WITH_AES_256_CBC_SHA                      256
        TLS_RSA_WITH_AES_128_CBC_SHA                      128
        TLS_RSA_WITH_3DES_EDE_CBC_SHA                     168
        TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA                256       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA                128       ECDH: prime256v1 (256 bits)

    The group of cipher suites supported by the server has the following properties:
    Forward Secrecy                    OK - Supported
    Legacy RC4 Algorithm               OK - Not Supported


* TLS 1.1 Cipher Suites:
    Attempted to connect using 80 cipher suites.

    The server accepted the following 5 cipher suites:
        TLS_RSA_WITH_AES_256_CBC_SHA                      256
        TLS_RSA_WITH_AES_128_CBC_SHA                      128
        TLS_RSA_WITH_3DES_EDE_CBC_SHA                     168
        TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA                256       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA                128       ECDH: prime256v1 (256 bits)

    The group of cipher suites supported by the server has the following properties:
    Forward Secrecy                    OK - Supported
    Legacy RC4 Algorithm               OK - Not Supported


* TLS 1.2 Cipher Suites:
    Attempted to connect using 156 cipher suites.

    The server accepted the following 11 cipher suites:
        TLS_RSA_WITH_AES_256_GCM_SHA384                   256
        TLS_RSA_WITH_AES_256_CBC_SHA                      256
        TLS_RSA_WITH_AES_128_GCM_SHA256                   128
        TLS_RSA_WITH_AES_128_CBC_SHA                      128
        TLS_RSA_WITH_3DES_EDE_CBC_SHA                     168
        TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256       256       ECDH: X25519 (253 bits)
        TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384             256       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA                256       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256             128       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA                128       ECDH: prime256v1 (256 bits)
        TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256     256       ECDH: X25519 (253 bits)

    The group of cipher suites supported by the server has the following properties:
    Forward Secrecy                    OK - Supported
    Legacy RC4 Algorithm               OK - Not Supported


* TLS 1.3 Cipher Suites:
    Attempted to connect using 5 cipher suites.

    The server accepted the following 3 cipher suites:
        TLS_CHACHA20_POLY1305_SHA256                      256       ECDH: X25519 (253 bits)
        TLS_AES_256_GCM_SHA384                            256       ECDH: X25519 (253 bits)
        TLS_AES_128_GCM_SHA256                            128       ECDH: X25519 (253 bits)


* Deflate Compression:
                                        OK - Compression disabled

* OpenSSL CCS Injection:
                                        OK - Not vulnerable to OpenSSL CCS injection

* OpenSSL Heartbleed:
                                        OK - Not vulnerable to Heartbleed

* ROBOT Attack:
                                        OK - Not vulnerable.

* Session Renegotiation:
    Client Renegotiation DoS Attack:   OK - Not vulnerable
    Secure Renegotiation:              OK - Supported

* Elliptic Curve Key Exchange:
    Supported curves:                  X25519, prime256v1
    Rejected curves:                   X448, prime192v1, secp160k1, secp160r1, secp160r2, secp192k1, secp224k1, secp224r1, secp256k1, secp384r1, secp521r1, sect163k1, sect163r1, sect163r2, sect193r1, sect193r2, sect233k1, sect233r1, sect239k1, sect283k1, sect283r1, sect409k1, sect409r1, sect571k1, sect571r1

SCANS COMPLETED IN 4.242441 S
-----------------------------

COMPLIANCE AGAINST MOZILLA TLS CONFIGURATION
--------------------------------------------

    Checking results against Mozilla's "intermediate" configuration. See https://ssl-config.mozilla.org/ for more details.

    www.google.com:443: FAILED - Not compliant.
        * tls_versions: TLS versions {'TLSv1', 'TLSv1.1'} are supported, but should be rejected.
        * ciphers: Cipher suites {'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA', 'TLS_RSA_WITH_AES_256_CBC_SHA', 'TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA', 'TLS_RSA_WITH_AES_128_CBC_SHA', 'TLS_RSA_WITH_3DES_EDE_CBC_SHA', 'TLS_RSA_WITH_AES_256_GCM_SHA384', 'TLS_RSA_WITH_AES_128_GCM_SHA256'} are supported, but should be rejected.

testssl.sh

Another interesting tool to test SSL/TLS is to use the testssl.sh tool. It is also adequate to find problems on SSL/TLS servers.

To use it simply execute:

testssl.sh carlos.serrao.me

The obtained output is something like this (just a small portion):

Testing vulnerabilities

Heartbleed (CVE-2014-0160)                not vulnerable (OK), no heartbeat extension
CCS (CVE-2014-0224)                       not vulnerable (OK)
Ticketbleed (CVE-2016-9244), experiment.  not vulnerable (OK), no session ticket extension
ROBOT                                     Server does not support any cipher suites that use RSA key transport
Secure Renegotiation (RFC 5746)           supported (OK)
Secure Client-Initiated Renegotiation     not vulnerable (OK)
CRIME, TLS (CVE-2012-4929)                not vulnerable (OK)
BREACH (CVE-2013-3587)                    potentially NOT ok, "gzip" HTTP compression detected. - only supplied "/" tested
                                        Can be ignored for static pages or if no secrets in the page
POODLE, SSL (CVE-2014-3566)               not vulnerable (OK), no SSLv3 support
TLS_FALLBACK_SCSV (RFC 7507)              No fallback possible (OK), no protocol below TLS 1.2 offered
SWEET32 (CVE-2016-2183, CVE-2016-6329)    not vulnerable (OK)
FREAK (CVE-2015-0204)                     not vulnerable (OK)
DROWN (CVE-2016-0800, CVE-2016-0703)      not vulnerable on this host and port (OK)
                                        make sure you don't use this certificate elsewhere with SSLv2 enabled services
                                        https://search.censys.io/search?resource=hosts&virtual_hosts=INCLUDE&q=C5D0C2C5E14B71CF7342F4BEAB81322EF9AD9B9BEEBB3D72ACB5E6360EA08C15
LOGJAM (CVE-2015-4000), experimental      common prime with 2048 bits detected: RFC3526/Oakley Group 14 (2048 bits),
                                        but no DH EXPORT ciphers
BEAST (CVE-2011-3389)                     not vulnerable (OK), no SSL3 or TLS1
LUCKY13 (CVE-2013-0169), experimental     not vulnerable (OK)
RC4 (CVE-2013-2566, CVE-2015-2808)        no RC4 ciphers detected (OK)

SSL/TLS online tools

The following list presents some online tools for testing also SSL/TLS.

1. SSL Server Test by Qualys

2. SSL Checker by SSL Shopper

3. SSL Scanner by SSL Tools

4. SSL Certificate Checker by Digicert

5. SSL Check by JitBit

6. SSL Checker by SSL Store

7. SSL Tester by Wormly

8. SSL Security Test by ImmuniWeb

9. SSL Certificate Checker

10. SSLv3 Poodle Vulnerability Scanner

References/Additional information

1. https://openssl.org/docs/manmaster/apps/openssl.html

2. http://www.g-loaded.eu/2005/11/10/be-your-own-ca/

3. https://jamielinux.com/docs/openssl-certificate-authority/index.html

4. http://www.tldp.org/HOWTO/SSL-Certificates-HOWTO/index.html

5. https://www.openssl.org/docs/manmaster/apps/config.html

6. https://www.mkssoftware.com/docs/man1/openssl_smime.1.asp

7. https://www.madboa.com/geek/openssl/

8. https://www.misterpki.com/openssl-verify/

9. https://www.misterpki.com/openssl-s-client/