Paperkey question

[ian at ushills.co.uk]

One you have split your key with gpgsplit do you just then add the relevant secret key packets to each key part and then cat them back together.

-----Original Message-----
From: David Shaw <dshaw at jabberwocky.com>
Sent: 09 February 2009 13:46
To: Ian Hill <ian at ushills.co.uk>
Cc: gnupg-users at gnupg.org List <gnupg-users at gnupg.org>
Subject: Re: Paperkey question

On Feb 9, 2009, at 7:07 AM, Ian Hill wrote:

>
> David
>
> I seem to be having some problems using the papertest key provided  
> with
> the application (attached) and the associated key to create a  
> paperkey I
> have extracted the following octets for each key and subkey.
>
> Key 1
> FE 03 03 02 56 AC A0 3D F2 14 48 D2 60 22 90 E7 0A 58 94 51 F7 3D
> 5B 2A 4D 9C 26 B9 C1 AF 27 34 D3 D0 95 FE 69 9A C8 7D A4 E8 00 4E
> 9A 52 11 E9 C3 68 E4 BC E7 0E B2 15 D8 47 8A 6A 19 95 A6
>
> Key 2
> FE 03 03 02 56 AC A0 3D F2 14 48 D2 60 91 84 44 F2 DB A1 1A E8 0E
> D4 72 82 18 FB E6 B6 85 6A 32 F6 15 E9 89 1C 7F 55 DD D5 45 EE 11
> E7 DE 44 4C 2B 5B EB 2C 30 91 1E 1F F0 03 6A 2C 30 AD 55 90 6C D0
> 9F 39 7C E7 53 06 F2 BE F7 AE 1B A1 DE A2 1A 58 8A C5 2C
>
> Key 3
> FE 03 03 02 33 E6 5A 12 FA 15 D4 24 60 91 E7 D2 F8 74 2D DB 04 38
> 78 DC 6B C8 A2 AC 25 6D 5D 6B DE E5 01 F8 12 19 D5 DB 33 16 2E A5
> C2 AA 9E AA 72 AB 8B 3B 4D D1 9D B5 6C EF E1 31 BF 99 19
>
> Using a hex-editor I have then appended these octets to the public key
> to give me the attached file.  This is not the same as the secret key
> and cannot be imported as a secret key.

You can't take a public key and just attach the blob to the end.  A  
secret key is made up of secret key packets.  You need to convert your  
individual public key packets to secret key packets.  Split the public  
key into packets, convert the individual packets, then reassemble the  
key.

Run "paperkey --file-format" and it will print out some pointers on  
how to do this.

David