Only the latest release receives fixes.

Please do not open a public issue for security problems.

Use GitHub's private reporting instead: open the Security tab of this repository and click Report a vulnerability. You will get a private channel with the maintainer.

Useful details to include:

• script version (./ndm_file-timestamp.sh --version) and the output of ./ndm_file-timestamp.sh --requirements;
• operating system;
• steps to reproduce, using a throw-away test file, never a file of yours that must stay private: the proof folders contain its name and SHA-256 hash;
• the impact you expect (for example "command injection" or "a modified file reported as valid").

• Unsafe handling of the file name, command-line options, configuration file or environment (code execution, injection, writing outside the proof and archive folders, overwriting earlier proofs). The configuration file must only be read, never executed.
• --check-script or SCRIPT_CHECK=on reporting a script as identical to the published one when it is not, for a script that was not itself modified to lie.
• Data sent over the network other than the SHA-256 hash of the file, or sent to services other than the three Time Stamping Authorities listed in the help, the download of their root certificates and, only with --check-script or SCRIPT_CHECK=on, the published script on GitHub.
• --verify reporting a timestamp as valid when the file was modified, when the signature or the certificate chain is not valid, or when the response was not granted by the TSA.
• --verify trusting a root certificate that comes with the proofs (a proof folder or an archive) instead of the ones listed in the script (TSA_ROOTS), a root whose SHA-256 is not the listed one, or the root of one TSA for a timestamp named after another.
• A wrong "earliest date proved", or a date taken from the local clock instead of a timestamp signed by a TSA.
• Responses that make the script hang indefinitely or fill the disk.

• Content of the proof folders: they hold your file's name, size, dates and hash in plain text; protecting them is up to you.
• Availability or correctness of the Time Stamping Authorities, and the security of their keys and certificates.
• Plain HTTP towards DigiCert and Sectigo: it is normal for RFC 3161, because every response is digitally signed and checked, so it cannot be altered without detection.
• The legal value of the proofs: these TSAs are not qualified eIDAS providers, as stated in the help.
• A deliberately modified script that passes its own --check-script: a script cannot vouch for itself. The README describes the independent check for this case.

This is a personal project maintained on a best-effort basis. Reports are acknowledged as soon as reasonably possible and fixes are released before any public disclosure.