Why ommiting payload in signature
I was guided by gaia-x-101 to create valid Gaia-X Credentials and I struggled with the creation of proof. You are using JWS as proof mechanism and serializes signature as compact string. According to compact serialization in JWS spec, compact signature looks as follows: [header].[payload].[signature]
. However, your string omits payload in line #9. Your serialized signature looks like [header]..[signature]
.
I think, this is to reduce size of credential, however, I did not find any official source to do so. If this is a special feature of Gaia-X, it should be mentioned explicitly in official Gaia-X documents. Otherwise, verification of signature fails.