Reference

sslscan(1)

Fast SSL/TLS scanner

NAME

sslscan - Fast SSL/TLS scanner

SYNOPSIS

sslscan [options] [host:port | host]

DESCRIPTION

sslscan queries SSL/TLS services (such as HTTPS) and reports the protocol versions, cipher suites, key exchanges, signature algorithms, and certificates in use. This helps the user understand which parameters are weak from a security standpoint. sslscan can also output results into an XML file for easy consumption by external programs.

Terminal output is thus colour-coded as follows:

Red Background NULL ciphers (no encryption) or anonymous ciphers (no verification of peer)
Red Ciphers and algorithms with demonstrated vulnerabilities, or that are generally considered to be untrusted.
Yellow Ciphers and algorithms with known weaknesses or that are still too new to widely trusted, but that are not generally considered exploitable (even by the standards of TLS vulnerabilities).
Green Ciphers and algorithms that are aligned with current recommended best practices.

OPTIONS

--help

Show summary of options

--targets=<file>

A file containing a list of hosts to check. Hosts can be supplied with ports (i.e. host:port). One target per line

--sni-name=<name>

Use a different hostname for SNI

--ipv4, -4

Force IPv4 DNS resolution. Default is to try IPv4, and if that fails then fall back to IPv6.

--ipv6, -6

Force IPv6 DNS resolution. Default is to try IPv4, and if that fails then fall back to IPv6.

--show-certificate

Display certificate information.

--show-certificates

Display the full certificate chain.

--no-check-certificate

--no-check-certificate Don't flag certificates signed with weak algorithms (MD5 and SHA-1) or short (<2048 bit) RSA keys

--show-client-cas

Show a list of CAs that the server allows for client authentication. Will be blank for IIS/Schannel servers.

--show-ciphers

Show a complete list of ciphers supported by sslscan

--show-cipher-ids

Print the hexadecimal cipher IDs

--iana-names

Use IANA/RFC cipher names rather than OpenSSL ones

--show-times

Show the time taken for each handshake in milliseconds. Note that only a single request is made with each cipher, and that the size of the ClientHello is not constant, so this should not be used for proper benchmarking or performance testing.

You might want to also use --no-cipher-details to make the output a bit clearer.

--ssl2

Only check if SSLv2 is enabled

--ssl3

Only check if SSLv3 is enabled

--tls10

Only check TLS 1.0 ciphers

--tls11

Only check TLS 1.1 ciphers

--tls12

Only check TLS 1.2 ciphers

--tls13

Only check TLS 1.3 ciphers

--tlsall

Only check TLS ciphers (versions 1.0, 1.1, 1.2, and 1.3)

--ocsp

Display OCSP status

--pk=<file>

A file containing the private key or a PKCS#12 file containing a private key/certificate pair (as produced by MSIE and Netscape)

--pkpass=<password>

The password for the private key or PKCS#12 file

--certs=<file>

A file containing PEM/ASN1 formatted client certificates

--no-ciphersuites

Do not scan for supported ciphersuites.

--no-fallback

Do not check for TLS Fallback Signaling Cipher Suite Value (fallback)

--no-renegotiation

Do not check for secure TLS renegotiation

--no-compression

Do not check for TLS compression (CRIME)

--no-heartbleed

Do not check for OpenSSL Heartbleed (CVE-2014-0160)

--no-groups

Do not enumerate key exchange groups

--all-groups

Enumerate key exchange groups for all supported TLS versions, not just the highest among TLS 1.0, 1.1, and 1.2. Use when auditing servers that may have different group policies per protocol version.

--show-sigs

Enumerate signature algorithms

--starttls-ftp

STARTTLS setup for FTP

--starttls-imap

STARTTLS setup for IMAP

--starttls-irc

STARTTLS setup for IRC

--starttls-ldap

STARTTLS setup for LDAP

--starttls-pop3

STARTTLS setup for POP3

--starttls-smtp

STARTTLS setup for SMTP

--starttls-mysql

STARTTLS setup for MySQL

--starttls-xmpp

STARTTLS setup for XMPP

--starttls-psql

STARTTLS setup for PostgreSQL

--xmpp-server

Perform a server-to-server XMPP connection. Try this if --starttls-xmpp is failing.

--rdp

Send RDP preamble before starting scan.

--bugs

Enables workarounds for SSL bugs

--timeout=<sec>

Set socket timeout. Useful for hosts that fail to respond to ciphers they don't understand. Default is 3s.

--connect-timeout=<sec>

Set initial connection timeout. Useful for hosts that are slow to respond to the initial connect(). Default is 75s.

--sleep=<msec>

Pause between connections. Useful on STARTTLS SMTP services, or anything else that's performing rate limiting. Default is disabled.

--xml=<file>

Output results to an XML file. - can be used to mean stdout.

--version

Show version of program

--verbose

Display verbose output

--no-cipher-details

Hide NIST EC curve name and EDH/RSA key length.

--no-colour

Disable coloured output.

EXAMPLES

Scan a local HTTPS server

sslscan localhost
sslscan 127.0.0.1
sslscan 127.0.0.1:443
sslscan [::1]
sslscan [::1]:443

AUTHOR

sslscan was originally written by Ian Ventura-Whiting <[email protected]>.
sslscan was extended by Jacob Appelbaum <[email protected]>.
sslscan was extended by rbsec <[email protected]>.
This manual page was originally written by Marvin Stark <[email protected]>.

History

--all-groups since Arch Linux 2026-11-01; --bugs since Debian 6.0 (Squeeze); --connect-timeout since Debian 13 (Trixie); --iana-names since Debian 13 (Trixie); --ipv4 since Debian 9 (Stretch); --ipv6 since Debian 9 (Stretch); --no-check-certificate since Debian 9 (Stretch); --no-cipher-details since Debian 9 (Stretch); --no-ciphersuites since Debian 9 (Stretch); --no-colour since Debian 9 (Stretch); --no-compression since Debian 9 (Stretch); --no-fallback since Debian 11 (Bullseye); --no-groups since Debian 11 (Bullseye); --no-heartbleed since Debian 9 (Stretch); --no-renegotiation since Debian 9 (Stretch); --ocsp since Debian 9 (Stretch); --rdp since Debian 9 (Stretch); --show-certificate since Debian 9 (Stretch); --show-certificates since Debian 13 (Trixie); --show-cipher-ids since Debian 9 (Stretch); --show-ciphers since Debian 9 (Stretch); --show-client-cas since Debian 9 (Stretch); --show-sigs since Debian 11 (Bullseye); --show-times since Debian 9 (Stretch); --sleep since Debian 9 (Stretch); --sni-name since Debian 11 (Bullseye); --starttls-ftp since Debian 9 (Stretch); --starttls-imap since Debian 9 (Stretch); --starttls-irc since Debian 9 (Stretch); --starttls-ldap since Debian 11 (Bullseye); --starttls-mysql since Debian 11 (Bullseye); --starttls-pop3 since Debian 9 (Stretch); --starttls-psql since Debian 9 (Stretch); --starttls-smtp since Debian 9 (Stretch); --starttls-xmpp since Debian 9 (Stretch); --timeout since Debian 9 (Stretch); --tls10 since Debian 9 (Stretch); --tls11 since Debian 9 (Stretch); --tls12 since Debian 9 (Stretch); --tls13 since Debian 11 (Bullseye); --tlsall since Debian 9 (Stretch); --verbose since Debian 11 (Bullseye); --xmpp-server since Debian 9 (Stretch); -4 since Debian 11 (Bullseye); -6 since Debian 11 (Bullseye).

--html until Debian 8 (Jessie); --http until Debian 9 (Stretch); --no-failed until Debian 8 (Jessie); --starttls until Debian 8 (Jessie).