{"action":"created","issue":{"url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/4","labels_url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/4/labels{/name}","comments_url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/4/comments","events_url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/4/events","html_url":"https://github.com/DevJPM/CryptoJPM/issues/4","id":64581219,"number":4,"title":"Prepend SHA256d with an all zero block","user":{"login":"isn-","id":2919539,"avatar_url":"https://avatars.githubusercontent.com/u/2919539?v=3","gravatar_id":"","url":"https://api.github.com/users/isn-","html_url":"https://github.com/isn-","followers_url":"https://api.github.com/users/isn-/followers","following_url":"https://api.github.com/users/isn-/following{/other_user}","gists_url":"https://api.github.com/users/isn-/gists{/gist_id}","starred_url":"https://api.github.com/users/isn-/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/isn-/subscriptions","organizations_url":"https://api.github.com/users/isn-/orgs","repos_url":"https://api.github.com/users/isn-/repos","events_url":"https://api.github.com/users/isn-/events{/privacy}","received_events_url":"https://api.github.com/users/isn-/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-03-26T16:54:55Z","updated_at":"2015-03-31T09:05:25Z","closed_at":null,"body":"An open question is whether this feature should be implemented in CryptoJPM (and crypto++ finally) or not.\r\n\r\nFor details, see related pull request in pycrypto project: https://github.com/dlitz/pycrypto/pull/127"},"comment":{"url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/comments/88005225","html_url":"https://github.com/DevJPM/CryptoJPM/issues/4#issuecomment-88005225","issue_url":"https://api.github.com/repos/DevJPM/CryptoJPM/issues/4","id":88005225,"user":{"login":"DevJPM","id":10398997,"avatar_url":"https://avatars.githubusercontent.com/u/10398997?v=3","gravatar_id":"","url":"https://api.github.com/users/DevJPM","html_url":"https://github.com/DevJPM","followers_url":"https://api.github.com/users/DevJPM/followers","following_url":"https://api.github.com/users/DevJPM/following{/other_user}","gists_url":"https://api.github.com/users/DevJPM/gists{/gist_id}","starred_url":"https://api.github.com/users/DevJPM/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/DevJPM/subscriptions","organizations_url":"https://api.github.com/users/DevJPM/orgs","repos_url":"https://api.github.com/users/DevJPM/repos","events_url":"https://api.github.com/users/DevJPM/events{/privacy}","received_events_url":"https://api.github.com/users/DevJPM/received_events","type":"User","site_admin":false},"created_at":"2015-03-31T09:05:25Z","updated_at":"2015-03-31T09:05:25Z","body":"I just re-read the parts in the book and saw that you're right about double-hashing and prepending zeros.\r\nThis implementation of double-hash will prepend zeroes.\r\nI'd say we prepend a blockszie of zeroes, if we know the blocksize and if not just the double digestsize (for SHA-3 which doesn't seem to have a Blocksize...)"}}