Support integrity proofs with DataIntegrityProof type

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 - Added support for content warnings.
 - Added `authentication_methods` field to `CredentialAccount` object (Mastodon API).
+- Support integrity proofs with `DataIntegrityProof` type.
 
 ### Changed
 

mitra-utils/src/crypto_rsa.rs

@@ -47,7 +47,7 @@ pub fn deserialize_public_key(
 }
 
 /// RSASSA-PKCS1-v1_5 signature
-pub fn create_rsa_signature(
+pub fn create_rsa_sha256_signature(
     private_key: &RsaPrivateKey,
     message: &str,
 ) -> Result<Vec<u8>, rsa::errors::Error> {
@@ -63,7 +63,7 @@ pub fn get_message_digest(message: &str) -> String {
     digest_b64
 }
 
-pub fn verify_rsa_signature(
+pub fn verify_rsa_sha256_signature(
     public_key: &RsaPublicKey,
     message: &str,
     signature: &[u8],
@@ -102,13 +102,13 @@ YsFtrgWDQ/s8k86sNBU+Ce2GOL7seh46kyAWgJeohh4Rcrr23rftHbvxOcRM8VzYuCeb1DgVhPGtA0xU
     fn test_verify_rsa_signature() {
         let private_key = generate_weak_rsa_key().unwrap();
         let message = "test".to_string();
-        let signature = create_rsa_signature(
+        let signature = create_rsa_sha256_signature(
             &private_key,
             &message,
         ).unwrap();
         let public_key = RsaPublicKey::from(&private_key);
 
-        let is_valid = verify_rsa_signature(
+        let is_valid = verify_rsa_sha256_signature(
             &public_key,
             &message,
             &signature,

src/http_signatures/create.rs

@@ -3,7 +3,7 @@ use chrono::Utc;
 use rsa::RsaPrivateKey;
 
 use mitra_utils::crypto_rsa::{
-    create_rsa_signature,
+    create_rsa_sha256_signature,
     get_message_digest,
 };
 
@@ -72,7 +72,7 @@ pub fn create_http_signature(
         .map(|(name, _)| name.to_string())
         .collect::<Vec<String>>()
         .join(" ");
-    let signature = create_rsa_signature(signer_key, &message)?;
+    let signature = create_rsa_sha256_signature(signer_key, &message)?;
     let signature_parameter = base64::encode(signature);
     let signature_header = format!(
         r#"keyId="{}",algorithm="{}",headers="{}",signature="{}""#,

src/http_signatures/verify.rs

@@ -5,7 +5,7 @@ use chrono::{DateTime, Duration, TimeZone, Utc};
 use regex::Regex;
 use rsa::RsaPublicKey;
 
-use mitra_utils::crypto_rsa::verify_rsa_signature;
+use mitra_utils::crypto_rsa::verify_rsa_sha256_signature;
 
 const SIGNATURE_PARAMETER_RE: &str = r#"^(?P<key>[a-zA-Z]+)="(?P<value>.+)"$"#;
 
@@ -134,7 +134,7 @@ pub fn verify_http_signature(
         log::warn!("signature has expired");
     };
     let signature = base64::decode(&signature_data.signature)?;
-    let is_valid_signature = verify_rsa_signature(
+    let is_valid_signature = verify_rsa_sha256_signature(
         signer_key,
         &signature_data.message,
         &signature,

src/json_signatures/create.rs

@@ -8,7 +8,7 @@ use mitra_utils::{
         canonicalize_object,
         CanonicalizationError,
     },
-    crypto_rsa::create_rsa_signature,
+    crypto_rsa::create_rsa_sha256_signature,
     did_key::DidKey,
     did_pkh::DidPkh,
     multibase::encode_multibase_base58btc,
@@ -30,6 +30,8 @@ pub(super) const PROOF_PURPOSE: &str = "assertionMethod";
 pub struct IntegrityProof {
     #[serde(rename = "type")]
     pub proof_type: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub cryptosuite: Option<String>,
     pub proof_purpose: String,
     pub verification_method: String,
     pub created: DateTime<Utc>,
@@ -43,6 +45,7 @@ impl IntegrityProof {
     ) -> Self {
         Self {
             proof_type: PROOF_TYPE_JCS_RSA.to_string(),
+            cryptosuite: None,
             proof_purpose: PROOF_PURPOSE.to_string(),
             verification_method: signer_key_id.to_string(),
             created: Utc::now(),
@@ -56,6 +59,7 @@ impl IntegrityProof {
     ) -> Self {
         Self {
             proof_type: PROOF_TYPE_JCS_EIP191.to_string(),
+            cryptosuite: None,
             proof_purpose: PROOF_PURPOSE.to_string(),
             verification_method: signer.to_string(),
             created: Utc::now(),
@@ -69,6 +73,7 @@ impl IntegrityProof {
     ) -> Self {
         Self {
             proof_type: PROOF_TYPE_JCS_ED25519.to_string(),
+            cryptosuite: None,
             proof_purpose: PROOF_PURPOSE.to_string(),
             verification_method: signer.to_string(),
             created: Utc::now(),
@@ -115,14 +120,17 @@ pub fn sign_object(
     signer_key_id: &str,
 ) -> Result<Value, JsonSignatureError> {
     // Canonicalize
-    let message = canonicalize_object(object)?;
+    let transformed_object = canonicalize_object(object)?;
     // Sign
-    let signature = create_rsa_signature(signer_key, &message)?;
+    let signature = create_rsa_sha256_signature(
+        signer_key,
+        &transformed_object,
+    )?;
     // Insert proof
     let proof = IntegrityProof::jcs_rsa(signer_key_id, &signature);
-    let mut object_value = serde_json::to_value(object)?;
+    let mut signed_object = object.clone();
-    add_integrity_proof(&mut object_value, proof)?;
+    add_integrity_proof(&mut signed_object, proof)?;
-    Ok(object_value)
+    Ok(signed_object)
 }
 
 pub fn is_object_signed(object: &Value) -> bool {

src/json_signatures/proofs.rs

@@ -9,12 +9,16 @@ pub const PROOF_TYPE_ID_EIP191: &str = "ethereum-eip191-00";
 // Identity proof, version 2022A
 pub const PROOF_TYPE_ID_MINISIGN: &str = "MitraMinisignSignature2022A";
 
+// https://w3c.github.io/vc-data-integrity/#dataintegrityproof
+pub const DATA_INTEGRITY_PROOF: &str = "DataIntegrityProof";
+
 // Similar to https://identity.foundation/JcsEd25519Signature2020/
 // - Canonicalization algorithm: JCS
 // - Digest algorithm: SHA-256
 // - Signature algorithm: RSASSA-PKCS1-v1_5
 pub const PROOF_TYPE_JCS_RSA: &str = "MitraJcsRsaSignature2022";
 pub const PROOF_TYPE_JCS_RSA_LEGACY: &str = "JcsRsaSignature2022";
+pub const CRYPTOSUITE_JCS_RSA: &str = "mitra-jcs-rsa-2022";
 
 // Similar to EthereumPersonalSignature2021 but with JCS
 pub const PROOF_TYPE_JCS_EIP191: &str = "MitraJcsEip191Signature2022";
@@ -49,3 +53,13 @@ impl FromStr for ProofType {
         Ok(proof_type)
     }
 }
+
+impl ProofType {
+    pub fn from_cryptosuite(value: &str) -> Result<Self, ConversionError> {
+        let proof_type = match value {
+            CRYPTOSUITE_JCS_RSA => Self::JcsRsaSignature,
+            _ => return Err(ConversionError),
+        };
+        Ok(proof_type)
+    }
+}

src/json_signatures/verify.rs

@@ -9,7 +9,7 @@ use mitra_utils::{
         canonicalize_object,
         CanonicalizationError,
     },
-    crypto_rsa::verify_rsa_signature,
+    crypto_rsa::verify_rsa_sha256_signature,
     did::Did,
     did_key::DidKey,
     did_pkh::DidPkh,
@@ -25,7 +25,7 @@ use super::create::{
     PROOF_KEY,
     PROOF_PURPOSE,
 };
-use super::proofs::ProofType;
+use super::proofs::{ProofType, DATA_INTEGRITY_PROOF};
 
 #[derive(Debug, PartialEq)]
 pub enum JsonSigner {
@@ -76,8 +76,15 @@ pub fn get_json_signature(
     if proof.proof_purpose != PROOF_PURPOSE {
         return Err(VerificationError::InvalidProof("invalid proof purpose"));
     };
-    let signature_type = proof.proof_type.parse()
+    let proof_type = if proof.proof_type == DATA_INTEGRITY_PROOF {
-        .map_err(|_| VerificationError::InvalidProof("unsupported proof type"))?;
+        let cryptosuite = proof.cryptosuite.as_ref()
+            .ok_or(VerificationError::InvalidProof("cryptosuite is not specified"))?;
+        ProofType::from_cryptosuite(cryptosuite)
+            .map_err(|_| VerificationError::InvalidProof("unsupported proof type"))?
+    } else {
+        proof.proof_type.parse()
+            .map_err(|_| VerificationError::InvalidProof("unsupported proof type"))?
+    };
     let signer = if let Ok(did) = Did::from_str(&proof.verification_method) {
         JsonSigner::Did(did)
     } else if Url::parse(&proof.verification_method).is_ok() {
@@ -85,12 +92,12 @@ pub fn get_json_signature(
     } else {
         return Err(VerificationError::InvalidProof("unsupported verification method"));
     };
-    let message = canonicalize_object(&object)?;
+    let transformed_object = canonicalize_object(&object)?;
     let signature = decode_multibase_base58btc(&proof.proof_value)?;
     let signature_data = SignatureData {
-        signature_type,
+        signature_type: proof_type,
         signer,
-        message,
+        message: transformed_object,
         signature,
     };
     Ok(signature_data)
@@ -100,7 +107,7 @@ pub fn verify_rsa_json_signature(
     signature_data: &SignatureData,
     signer_key: &RsaPublicKey,
 ) -> Result<(), VerificationError> {
-    let is_valid_signature = verify_rsa_signature(
+    let is_valid_signature = verify_rsa_sha256_signature(
         signer_key,
         &signature_data.message,
         &signature_data.signature,