Re: [Anima-bootstrap] [Anima] Voucher signing method

[Kent Watsen <[e-mail]>]

> You can see this by exploding the output from openssl dgst via asn1parse: 
> pritikin@ubuntu:~/tmp/jwt$ openssl asn1parse -in signature.sign -inform DER
>     0:d=0  hl=2 l=  69 cons: SEQUENCE          
>     2:d=1  hl=2 l=  32 prim: INTEGER           :1EF9060ADA81C288C4FE2E3585BFF6379FF03467EB0D7D848D568604A1C53864
>    36:d=1  hl=2 l=  33 prim: INTEGER           :EAD5AD3F8FB7092D14903C8B08D0D83EE91E898EA8D3A5944F13F8B6652372D1
>
> So to do everything in script-land with openssl tools you need to extract
> the r and s values and format them correctly as specified in JWA [RFC7518,
> section 3.4 step 2 and 3). I’ll have to think about how you could do this
> from a shell script. 


Your signature.sign file is probably 66 bytes, right?   Assuming 'R' and 'S' are in order, I think you can snip 2-bytes off the front of the file and have the signature.


> Its interesting to note here that we have almost the simplest example of
> ASN1 possible and it still sounds hard to work with. :) Shrug, it isn’t
> like the JWA 64-octet sequence is actually that much easier from shell
> commands. 

But all we need to do is compute the encoded signature value BASE64URL(JWS Signature), we can use the script I found before for this part...


Kent