Time Stamping Protocol (TSP) HTTP Client

A simple HTTP client for requesting timestamps from a timestamp authority (TSA) using the RFC 3161 standard.

Examples

The following code can be used, if you already have a SHA digest of the data you want to timestamp:

usetsp_http_client::request_timestamp_for_digest;// The URI of a timestamp authority (TSA) that supports RFC 3161 timestamps.
lettsa_uri="http://timestamp.digicert.com";// The SHA-256 digest of the data to be timestamped (can also be different SHA lengths like SHA-512).
letdigest="00e3261a6e0d79c329445acd540fb2b07187a0dcf6017065c8814010283ac67f";// Request a timestamp for the given digest from the TSA (retrieving a TimeStampResponse object).
lettimestamp=request_timestamp_for_digest(tsa_uri,digest)?;// The content of the timestamp response can be written to a file then for example.
File::create("/tmp/timestamp-response.tsr")?.write_all(&timestamp.as_der_encoded())?;// Or the date and time of the timestamp can be accessed.
println!("Timestamped date and time: {}",timestamp.datetime()?);

Alternatively, the crate can calculate the digest on the content of a file:

usetsp_http_client::request_timestamp_for_file;// The URI of a timestamp authority (TSA) that supports RFC 3161 timestamps.
lettsa_uri="http://timestamp.digicert.com";// The file that should be timestamped.
letfilename="README.md";// Request a timestamp for the given digest from the TSA (retrieving a TimeStampResponse object).
lettimestamp=request_timestamp_for_file(tsa_uri,filename)?;// The content of the timestamp response can be written to a file then for example.
File::create("/tmp/timestamp-response.tsr")?.write_all(&timestamp.as_der_encoded())?;// Or the date and time of the timestamp can be accessed.
println!("Timestamped date and time: {}",timestamp.datetime()?);

Verification with OpenSSL

Signature verification is not (yet) included in this crate. You can, however, verify the timestamp response using OpenSSL if you wrote its DER encoding into a file, as shown in the example above.

openssl ts -verify -digest 00e3261a6e0d79c329445acd540fb2b07187a0dcf6017065c8814010283ac67f -in timestamp-response.tsr -CAfile tsa-cert.pem

The tsa-cert.pem file must contain the full certificate chain of the timestamp authority (TSA) that issued the timestamp.

Command Line Application

This repository also contains a command line application for requesting timestamps from a timestamp authority. It supports the following parameters:

Simple HTTP client for requesting timestamps from a timestamp authority (TSA) using the RFC 3161 standard
Usage: tsp-http-client-cmd [OPTIONS] <COMMAND>
Commands:
 digest Request timestamp for the given SHA digest
 file Request timestamp for the given file
 batch Request timestamp for all files in the given directory
 help Print this message or the help of the given subcommand(s)
Options:
 --tsa <TSA> URI of the timestamp authority (TSA) to use [default: http://timestamp.sectigo.com/qualified]
 -q, --quiet Disables console output
 -h, --help Print help
 -V, --version Print version