key_resolver/
did.rs

1use fi_common::error::Error;
2use serde::{Deserialize, Serialize};
3
4use crate::{
5    common::{AgreementKey, KeyPair, VerificationKey},
6    ed25519_verification_key2018, ed25519_verification_key2020,
7    x25519_key_agreement_key2019::X25519KeyAgreementKey2019,
8    x25519_key_agreement_key2020::X25519KeyAgreementKey2020,
9};
10
11const DID_CONTEXT_URL: &str = "https://www.w3.org/ns/did/v1";
12
13#[derive(Serialize, Deserialize, Debug)]
14pub struct DidDocument {
15    #[serde(rename = "@context")]
16    pub context: Vec<String>,
17    pub id: String,
18    #[serde(rename = "verificationMethod")]
19    pub verification_method: Vec<KeyPair>,
20    pub authentication: Vec<String>,
21    #[serde(rename = "assertionMethod")]
22    pub assertion_method: Vec<String>,
23    #[serde(rename = "capabilityDelegation")]
24    pub capability_delegation: Vec<String>,
25    #[serde(rename = "capabilityInvocation")]
26    pub capability_invocation: Vec<String>,
27    #[serde(rename = "keyAgreement")]
28    pub key_agreement: Vec<KeyPair>,
29}
30
31impl DidDocument {
32    pub fn key_pair_to_did_doc(
33        key_pair: &Box<dyn VerificationKey>,
34        fingerprint: &str,
35    ) -> Result<DidDocument, fi_common::error::Error> {
36        let did = format!("did:key:{}", fingerprint);
37
38        let mut contexts: Vec<String> = Vec::from([String::from(DID_CONTEXT_URL)]);
39
40        let agreement_key: Box<dyn AgreementKey> = match key_pair.get_current_suite_id() {
41            ed25519_verification_key2018::SUITE_ID => {
42                let agreement_key =
43                    match X25519KeyAgreementKey2019::from_ed25519_verification_key2018(&key_pair) {
44                        Ok(val) => val,
45                        Err(error) => return Err(error),
46                    };
47
48                contexts.push(String::from(key_pair.get_current_suite_context()));
49                contexts.push(String::from(agreement_key.get_current_suite_context()));
50
51                Box::new(agreement_key)
52            }
53            ed25519_verification_key2020::SUITE_ID => {
54                let agreement_key =
55                    match X25519KeyAgreementKey2020::from_ed25519_verification_key2020(&key_pair) {
56                        Ok(val) => val,
57                        Err(error) => return Err(error),
58                    };
59                contexts.push(String::from(key_pair.get_current_suite_context()));
60                contexts.push(String::from(agreement_key.get_current_suite_context()));
61
62                Box::new(agreement_key)
63            }
64            _ => {
65                return Err(Error::new(
66                    format!(
67                        "Cannot derive key agreement key from verification key type {}",
68                        key_pair.get_type()
69                    )
70                    .as_str(),
71                ))
72            }
73        };
74
75        let public_ed_key = key_pair.export(true, false, false);
76        let public_dh_key = agreement_key.export(true, false, false);
77
78        let ed_id = public_ed_key.id.clone();
79        let public_ed_key_id = match ed_id {
80            None => String::from(""),
81            Some(val) => val,
82        };
83
84        let did_doc = DidDocument {
85            id: did,
86            key_agreement: Vec::from([public_dh_key]),
87            context: contexts,
88            verification_method: Vec::from([public_ed_key]),
89            assertion_method: Vec::from([public_ed_key_id.clone()]),
90            authentication: Vec::from([public_ed_key_id.clone()]),
91            capability_delegation: Vec::from([public_ed_key_id.clone()]),
92            capability_invocation: Vec::from([public_ed_key_id]),
93        };
94
95        Ok(did_doc)
96    }
97
98    pub fn get_key(&self, key_id_fragment: &str) -> Result<KeyPair, Error> {
99        let key_id = format!("{}#{}", self.id, key_id_fragment);
100
101        let v_id = self.verification_method[0].id.clone();
102
103        let public_key: KeyPair;
104        if v_id.is_some_and(|val| val.eq(&key_id)) {
105            public_key = self.verification_method[0].clone();
106        } else {
107            public_key = self.key_agreement[0].clone();
108        }
109
110        Ok(public_key)
111    }
112}