Add prf extension

[lgarron]

w3c/webauthn#1732 re-added this: https://w3c.github.io/webauthn/#prf-extension

We need to add support here:

webauthn-json/src/webauthn-json/extended/schema.ts

Lines 12 to 34 in 5206e71

	const authenticationExtensionsClientInputsSchema: Schema = {
	appid: optional(copyValue),
	appidExclude: optional(copyValue),
	uvm: optional(copyValue),
	credProps: optional(copyValue),
	largeBlob: optional({
	support: optional(copyValue),
	read: optional(copyValue),
	write: optional(convertValue),
	}),
	};
	const authenticationExtensionsClientOutputsSchema: Schema = {
	appid: optional(copyValue),
	appidExclude: optional(copyValue),
	uvm: optional(copyValue),
	credProps: optional(copyValue),
	largeBlob: optional({
	supported: optional(copyValue),
	blob: optional(convertValue),
	written: optional(copyValue),
	}),
	};

webauthn-json/src/webauthn-json/extended/json.ts

Lines 12 to 36 in 5206e71

	interface ExtendedExtensionsClientInputsJSON {
	appid?: string;
	appidExclude?: string;
	uvm?: boolean;
	credProps?: boolean;
	largeBlob?: {
	support?: "required" | "preferred";
	read?: boolean;
	write?: Base64urlString;
	};
	}
	interface ExtendedAuthenticationExtensionsClientOutputsJSON {
	appid?: boolean;
	appidExclude?: boolean;
	uvm?: Array<[number, number, number]>;
	credProps?: {
	rk: boolean;
	};
	largeBlob?: {
	supported?: boolean;
	blob?: Base64urlString;
	written?: boolean;
	};
	}

[imrishabh18]

Hey @lgarron, I am new to this codebase. But would like to take up this issue.

[lgarron]

Hey @lgarron, I am new to this codebase. But would like to take up this issue.

Feel free to tackle a PR. Do you need any help beyond the links above?

[fcorneli]

The following is working for me:

webauthnJSON.schema.credentialCreationOptions.publicKey.schema.extensions.schema.prf = {
            required: false,
            schema: {
                eval: {
                    required: false,
                    schema: {
                        first: {
                            required: true,
                            schema: "convert"
                        }
                    }
                },
                evalByCredential: {
                    required: false,
                    schema: "copy",
                    derive: function (input) {
                        console.log("derive");
                        console.log(input);
                        let evalByCredentialObject = input.evalByCredential;
                        if (!(evalByCredentialObject instanceof Object)) {
                            return;
                        }
                        for (const [key, value] of Object.entries(evalByCredentialObject)) {
                            console.log("first: " + value.first);
                            value.first = $this.base64urlToBuffer(value.first);
                        }
                        return evalByCredentialObject;
                    }
                }
            }
        };
        webauthnJSON.schema.credentialCreationOptions.publicKey.schema.extensions.schema.uvm = {
            required: false,
            schema: "copy"
        };
        webauthnJSON.schema.publicKeyCredentialWithAttestation.clientExtensionResults.schema.prf = {
            required: false,
            schema: {
                enabled: {
                    required: false,
                    schema: "copy"
                },
                results: {
                    required: false,
                    schema: {
                        first: {
                            required: true,
                            schema: "convert"
                        }
                    }
                }
            }
        };
        webauthnJSON.schema.publicKeyCredentialWithAttestation.clientExtensionResults.schema.uvm = {
            required: false,
            schema: "copy"
        };

Only getting evalByCredential right was a bit tricky.

[fcorneli]

See also:
https://github.com/e-Contract/enterprise-jsf/blob/master/ejsf-taglib/src/main/resources/META-INF/resources/ejsf/webauthn.js#L18

[raashidanwar]

Hey @lgarron 👋 ,

I want to take this up.

[lgarron]

@raashidanwar As I no longer work at GitHub, I can't maintain this project. Perhaps @KyFaSt or @fletchto99 can tell you if this project is open to contributions.