Module: timestamp

Provides support for trusted timestamping (RFC 3161). See https://en.wikipedia.org/wiki/Trusted_timestamping for examples.

Note: The default Time Stamp Authority (TSA) server used here is run by the German National Research and Education Network (DFN), which doesn't allow commercial use. See https://www.pki.dfn.de/zeitstempeldienst/. You can easily switch to a different provider using (timestamp-host-set! hostname) and (timestamp-url-set! url)

Primary Functions	Short Description
(timestamp-gettimestamp filename)	Obtain trusted timestamp for given file
(timestamp-verify hash tsr cafile)	Verify a trusted timestamp
(timestamp-host-set! hostname)	Change the time stamping authority server name
(timestamp-url-set! url)	Change the time stamping authority URL

Additional Functions	Short Description
(timestamp-tsq-generate filename)	Generate a timestamp request
(timestamp-tsq-save filename tsp)	Save timestamp request to file
(timestamp-tsq-load filename)	Load timestamp request from file
(timestamp-tsq-getversion tsq)	Get version of timestamp request
(timestamp-tsq-getpolicy tsq)	Get policy of timestamp request
(timestamp-tsq-getnonce tsq)	Get nonce of timestamp request
(timestamp-tsq-getmessage tsq)	Get message imprint (file hash) of timestamp request
(timestamp-tsr-request tsq)	Submit timestamp request to server to get timestamp response
(timestamp-tsr-save filename tsr)	Save timestamp response to file
(timestamp-tsr-load filename)	Load timestamp response from file
(timestamp-tsr-getstatus tsr)	Get timestamp response status
(timestamp-tsr-granted? tsr)	Check if timestamp response was granted
(timestamp-tsr-getstatusstr tsr)	Get timestamp response status string
(timestamp-tsr-getpolicy tsr)	Get timestamp response policy
(timestamp-tsr-getmessage tsr)	Get timestamp response message imprint (file hash)
(timestamp-tsr-getserial tsr)	Get timestamp response serial number (from TSA)
(timestamp-tsr-getgentimestr tsr)	Get timestamp response generation time string
(timestamp-tsr-getepoch tsr)	Get timestamp response generation epoch
(timestamp-tsr-getaccuracy tsr)	Get timestamp response generation time accuracy
(timestamp-tsr-getordering tsr)	Get timestamp response serial number ordering
(timestamp-tsr-getnonce tsr)	Get timestamp response nonce
(timestamp-tsr-gettsa tsr)	Get timestamp response TSA section
(sha256sum filename)	Calculate the SHA-256 hash for a file
(sha512sum filename)	Calculate the SHA-512 hash for a file
(sha1sum filename)	Calculate the SHA-1 hash for a file
(shasum filename)	Calculate the SHA-1 hash for a file