ct-submit is a program that submits X.509 certificate chains to Certificate Transparency log servers. It returns the Signed Certificate Timestamp structure in a format suitable for use with Apache's mod_ssl_ct module and nginx-ct.

ct-submit is written in Go. Just run go build to build it.

ct-submit takes a single argument - the URL of the log server. If the scheme is not specified it defaults to https://. It reads the certificate chain in PEM format from stdin. The leaf certificate should be the first certificate in the chain, followed by any intermediate certificates and, optionally, the root certificate.

The encoded SCT structure is written in binary to stdout.

The following example demonstrates submitting the chain in gpe.pem to Google's pilot log server. The SCT is written to gpe.sct, which is in a format suitable for use with Apache's mod_ssl_ct module and nginx-ct.

$ ./ct-submit ct.googleapis.com/pilot <gpe.pem >gpe.sct
$ xxd gpe.sct
00000000: 00a4 b909 90b4 1858 1487 bb13 a2cc 6770  .......X......gp
00000010: 0a3c 3598 04f9 1bdf b8e3 77cd 0ec8 0ddc  .<5.......w.....
00000020: 1000 0001 4bc7 e617 c800 0004 0300 4830  ....K.........H0
00000030: 4602 2100 b9fe e206 f0f5 f600 93d5 e04c  F.!............L
00000040: d2fd 75c9 e1fc a5c8 4812 a8b7 bc2c eb0c  ..u.....H....,..
00000050: ee16 1fe9 0221 008a 5974 e1b6 a0e0 281a  .....!..Yt....(.
00000060: 61e8 3447 895f 7ad4 2f70 f528 6133 a445  a.4G._z./p.(a3.E
00000070: 4fd4 ab60 ba36 db                        O..`.6.
$ 

ct-submit is available under the terms of the ISC license, which is similar to the 2-clause BSD license. See the LICENSE file for the copyright information and licensing terms.