Secure Client for exposing TLS (aka SSL) secured services as plain-text connections locally. Also ideal for multiplexing a single port with multiple protocols using SNI.
AJ ONeal 8042bcf41c update -servername => --servername 3 months ago
cmd/sclient v1.2.0 support --servername option for pentesting 3 months ago
tests support pipes and stdin 4 months ago
.gitignore add .gitignore 4 months ago
LICENSE v1.0.0: first working version 4 months ago
README.md update -servername => --servername 3 months ago
build-all.sh use conventional command and package paths 4 months ago
sclient.go v1.2.0 support --servername option for pentesting 3 months ago

README.md

sclient.go

Secure Client for exposing TLS (aka SSL) secured services as plain-text connections locally.

Also ideal for multiplexing a single port with multiple protocols using SNI.

Unwrap a TLS connection:

$ sclient whatever.com:443 localhost:3000
> [listening] whatever.com:443 <= localhost:3000

Connect via Telnet

$ telnet localhost 3000

Connect via netcat (nc)

$ nc localhost 3000

cURL

$ curl http://localhost:3000 -H 'Host: whatever.com'

A poor man’s (or Windows user’s) makeshift replacement for openssl s_client, stunnel, or socat.

Install

Downloads

Build from source

For the moment you’ll have to install go and compile sclient yourself:

git clone https://git.coolaj86.com/coolaj86/sclient.go.git
pushd sclient.go
go build -o dist/sclient cmd/sclient/main.go
rsync -av dist/sclient /usr/local/bin/sclient
go run cmd/sclient/main.go example.com:443 localhost:3000

Usage

sclient [flags] <remote> <local>
  • flags
    • -k, --insecure ignore invalid TLS (SSL/HTTPS) certificates
    • --servername spoof SNI (to disable use IP as <remote> and do not use this option)
  • remote
    • must have servername (i.e. example.com)
    • port is optional (default is 443)
  • local
    • address is optional (default is localhost)
    • must have port (i.e. 3000)

Examples

Bridge between telebit.cloud and local port 3000.

sclient telebit.cloud 3000

Same as above, but more explicit

sclient telebit.cloud:443 localhost:3000

Ignore a bad TLS/SSL/HTTPS certificate and connect anyway.

sclient -k badtls.telebit.cloud:443 localhost:3000

Reading from stdin

sclient telebit.cloud:443 -
sclient telebit.cloud:443 - </path/to/file

Piping

printf "GET / HTTP/1.1\r\nHost: telebit.cloud\r\n\r\n" | sclient telebit.cloud:443

Testing for security vulnerabilities on the remote:

sclient --servername "Robert'); DROP TABLE Students;" -k example.com localhost:3000
sclient --servername "../../../.hidden/private.txt" -k example.com localhost:3000