Trusted timestamping is the process of securely keeping track of the creation and modification times of a document. Security here means that no one - not even the owner of the document - should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. FreeTSA trusted timestamping Software as a Service (SaaS) provides an easy method to apply RFC 3161 trusted timestamps to time-sensitive transactions through independently verified and auditable date and UTC (Coordinated Universal Time) sources.
Adding a trusted timestamp to code or to an electronic signature provides a digital seal of data integrity and a trusted date and time of when the transaction took place. Recipients of documents and code with a trusted timestamp can verify when the document or code was digitally or electronically signed, as well as verify that the document or code was not altered after the date the timestamp vouches for. (Readme).
For multiple files, the general concept is that timestamping a single file that contains an aggregate list of fingerprints of other files, also proves that these other files must have existed before the aggregate file was created, provided that both the aggregate file and the referenced file are available during verification process. Freetsa also offers the possibility of URLs timestamps (do not abuse). If you are interested in implementing timestamps on your project / company using the FreeTSA service, you can contact me for specific requirements.
FreeTSA - Guide / Tips: Read.
Three possibilities are offered to obtain a timestamp: TCP-based, from webform and HTTP / HTTPS.
URL screenshot: Signature + URL timestamps.(Video)
Create evidence of illegal Internet content / non-repudiation of certain content.
- Deleted / Edited controversial news.
- Slander, threats or insults on Internet (social networks) / Scams.
- Misuse of intellectual property: articles, photographs, plagiarism, etc.
- Publication of unauthorized information
- Simply demonstrate the existence of a specific content at a specific time.
URL Screenshot content: Web content and links in PDF / PNG format (attachment) + Signature with Timestamping (SHA-512). Aprox wait time 25 secons.
$ curl --data "screenshot=https://www.fsf.org/" https://freetsa.org/screenshot.php > screenshot.pdf $ curl --data "screenshot=https://www.fsf.org/&delay=y" https://freetsa.org/screenshot.php > screenshot.pdf # (I'm Feeling Lucky) # HTTP 2.0 in cURL: Get the latest cURL release and use this command: curl --http2.
$ perl client.pl freetsa.org 318 file client: tsq file: file.tsq client: tsr file: file.tsr client: [Connected to freetsa.org:318] client: client: transfer of the file.tsq to the server completed client: 40 file.tsq $ wget https://freetsa.org/files/tsa.crt $ wget https://freetsa.org/files/cacert.pem # Timestamp Information. $ openssl ts -reply -in file.tsr -text # Verify (two diferent ways). $ openssl ts -verify -data file -in file.tsr -CAfile cacert.pem -untrusted tsa.crt $ openssl ts -verify -in file.tsr -queryfile file.tsq -CAfile cacert.pem -untrusted tsa.crt Verification: OK
$ openssl ts -query -data file.png -no_nonce -sha512 -out file.tsq # Option -cert: FreeTSA is expected to include its signing certificate in the response. (Optional) # If the tsq was created with the option "-cert", the verification does not need "-untrusted". $ openssl ts -query -data file.png -no_nonce -sha512 -cert -out file.tsq
# HTTP 2.0 in cURL: Get the latest cURL release and use this command: curl --http2. $ curl -H "Content-Type: application/timestamp-query" --data-binary '@file.tsq' https://freetsa.org/tsr > file.tsr # tsget is very useful to stamp multiple time-stamp-queries: https://www.openssl.org/docs/manmaster/apps/tsget.html $ tsget -h https://freetsa.org/tsr file1.tsq file2.tsq file3.tsq
$ openssl ocsp -sha512 -CAfile cacert.pem -issuer cacert.pem -cert tsa.crt -url http://freetsa.org:2560 -resp_text
$ wget http://www.freetsa.org/crl/root_ca.crl $ openssl crl -in root_ca.crl -noout -text
$ curl -s https://freetsa.org/logs.txt | grep -i 2f9462a4dbcb4af4f05a0d5
FreeTSA IPv6 Addresses
2605:6400:20:6c8:d91a:d514:17f7:92be 2605:6400:20:6c8:51b1:66a5:8c48:77e4 2605:6400:20:6c8:727a:e557:8b6b:7335 2605:6400:20:6c8:636e:c6bb:1331:1c36
Security based HTTP response headers
- HPKP helps prevent Man in the Middle attack (MitM) by mitigating fake certificates.
- HSTS forces your browser to use HTTPS, which also mitigages some mitm attacks.
- CSP is a way to combat xss and malware via malicious ad-injection.