2012-08-04 16:34:10 +00:00
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Overview
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=========
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2021-10-01 16:21:11 +00:00
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What is a key?
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It is a gpg symmetrically encrypted, ascii-armored file.
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The encryption key is a function (see below, on KDF section) of your tomb
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2012-08-04 16:34:10 +00:00
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passphrase.
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Layout
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======
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Before coming to the gpg part, there could be some "header" lines specifying
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metatada. They're done like this:
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_FIELD_params_params_and_more_params_
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where FIELD should be the description for the header.
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Pay much attention to the fact that there should ONLY be ASCII characters there,
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to avoid encoding issues and whatever. Needs something more? Use base64encode.
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(Of course, you're free to pack params into a single field, base64encoding
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whatever you want).
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And every header field should be in only one line.
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KDF
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===
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Key Derivation Functions, are functions which will make your key stronger
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spending some CPU time: the basic idea is that you have to compute that function
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just once in a while, but an attacker that wants to bruteforce has to compute it
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for every passphrase he's checking. This will make the bruteforce much more
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expensive.
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The header line format is _KDF_$method_$params_$params_... where $method is the
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method we are using (ie: scrypt) and params is something that it needs (ie:
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salt).
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