Time Stamp Authority

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# 1. create a tsq file (SHA 512)
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openssl ts -query -data file.png -no_nonce -sha512 -out file.tsq

# Option -cert: FreeTSA is expected to include its signing certificate (Root + Intermediate Certificates) in the response. (Optional)
# If the tsq was created with the option "-cert", its verification does not require "-untrusted".
#$ openssl ts -query -data file.png -no_nonce -sha512 -cert -out file.tsq


# How to make Timestamps of many files?

# To timestamp multiple files, create a text file with all their SHA-512 hashes and timestamp it.
# Alternatively, you may pack all the files to be timestamped in a zip/rar/img/tar, etc file and timestamp it.

# Generate a text file with all the hashes of the /var/log/ files
$ find /var/log/ -type f -exec sha512sum {} + > compilation.txt

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# 2. cURL Time Stamp Request Input (HTTP / HTTPS)
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# 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

# Using the Tor-network.
#$ curl -k --socks5-hostname 127.0.0.1:9050 -H "Content-Type: application/timestamp-query" --data-binary '@file.tsq' https://4bvu5sj5xok272x6cjx4uurvsbsdigaxfmzqy3n3eita272vfopforqd.onion/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

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# 3. Verify tsr file
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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

$ 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

# By default the TSQ file asks for the certificate chain (Root and Intermediate) to be provided in the response. 
# If you do not wish to do this you must change line 16 to line 15 of the script.