🔐 Add ability to choose proofPurpose on sign VC

[bdeneux]

📝 Purpose

Following this discussion, when signing a Verifiable Credential (VC) through the CLI command axoned credential sign <vc.jsonld>, we need to add the possibility to choose the proofPurpose field value instead of the default one currently set (assertionMethod).

👩‍💻 Solution

I am seeking clarification on whether the possible values for the proofPurpose field are limited to those listed in the W3C specification or if it can accept any string value.

To implement this feature, we will add a command flag --purpose to the sign command. If the possible values for proofPurpose are limited, we will validate the input against the allowed values. If the field can accept any string, we will allow any input. The logic for adding the signature with the specified purpose should be implemented here: sign.go#L262-L276.

🔗 Related links

• https://www.w3.org/TR/vc-data-integrity/#proof-purposes
• Add authenticate proxy axone-sdk#10 (comment)
• 🔐 Check authentication proofPurpose on VC  axone-sdk#11

[bdeneux]

@amimart @ccamel Is this proposed solution sounds good to you ? Any other idea ?

Linked issue that need this feature : axone-protocol/axone-sdk#11

[amimart]

@amimart @ccamel Is this proposed solution sounds good to you ? Any other idea ?

Sounds good to me, regarding the possible values I don't have a strong opinion, allow to enter an arbitrary string seems ok to me