dcrtime_checker

README

dcrtime_checker

There are circumstances where one may want to verify a prior server anchor against the blockchain directly. This tool takes the original anchor response and verifies proof of existence using the following process:

1. Ensure file digest is included in the anchor record
2. Verify the merkle root and path
3. Verify that the anchor exists in the blockchain

Flags

  -f		Original filename
  -h		Non default block explorer host. Defaults based on -testnet flag.
  -p		Original JSON anchor record
  -testnet	Use testnet.
  -v		Verbose

Important

One must store the original anchor record in order to use this tool.

For example, use the dcrtime command line utility to verify that the record has been anchored.

$ dcrtime -v d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517
d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517 Verify
d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517 OK
  Chain Timestamp: 1531224216
  Merkle Root    : fe9680ca605b6af488b8ded0d5ef28506758745eedca56c220d6b7c89226c85c
  TxID           : 0066578e01764c65fbc48870d8315d9bb7ead3a25e0318a0d8e7fdb52ef4ff87

Store proof:

$ dcrtime -json d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517 > proof.json

This proof looks like this:

{"id":"dcrtime cli","digests":[{"digest":"d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517","servertimestamp":1553799600,"result":0,"chaininformation":{"chaintimestamp":1531224216,"transaction":"0066578e01764c65fbc48870d8315d9bb7ead3a25e0318a0d8e7fdb52ef4ff87","merkleroot":"fe9680ca605b6af488b8ded0d5ef28506758745eedca56c220d6b7c89226c85c","merklepath":{"NumLeaves":3,"Hashes":[[127,70,80,89,228,171,127,105,76,251,211,241,162,43,49,165,124,141,27,134,120,100,70,162,253,181,237,147,238,244,53,98],[209,114,25,24,177,172,201,175,93,182,41,71,167,174,82,115,139,124,76,85,226,209,24,156,80,107,235,114,209,7,149,23]],"Flags":"DQ=="}}}],"timestamps":[]}

Examples

Verify proof of existence:

$ dcrtime_checker -v -f LICENSE -p proof.json                              
d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517  LICENSE
d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517  Proof  OK
d1721918b1acc9af5db62947a7ae52738b7c4c55e2d1189c506beb72d1079517  Anchor OK