feat: validate CID multicodec

- require CID with 'libp2p-key' (CIDv1) or 'dag-pb' (CIDv0 converted to CIDv1)
- delegate CID validation to CID constructor

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

src/index.js

@@ -198,15 +198,14 @@ exports.createFromB58String = (str) => {
   return exports.createFromCID(str) // B58String is CIDv0
 }
 
+const validMulticodec = (cid) => {
+  // supported: 'libp2p-key' (CIDv1) and 'dag-pb' (CIDv0 converted to CIDv1)
+  return cid.codec === 'libp2p-key' || cid.codec === 'dag-pb'
+}
+
 exports.createFromCID = (cid) => {
-  if (typeof cid === 'string' || Buffer.isBuffer(cid)) {
-    cid = new CID(cid)
-  } else if (CID.isCID(cid)) {
-    CID.validateCID(cid) // throws on error
-  } else {
-    // provide more meaningful error than the one in CID.validateCID
-    throw new Error('Supplied cid value is neither String|CID|Buffer')
-  }
+  cid = CID.isCID(cid) ? cid : new CID(cid)
+  if (!validMulticodec(cid)) throw new Error('Supplied PeerID CID has invalid multicodec: ' + cid.codec)
   return new PeerIdWithIs(cid.multihash)
 }
 

test/peer-id.spec.js

@@ -95,10 +95,21 @@ describe('PeerId', () => {
     expect(testIdBytes).to.deep.equal(id.toBytes())
   })
 
-  it('recreate from CIDv1 Base32', () => {
-    const id = PeerId.createFromCID(testIdCIDString)
-    expect(testIdCIDString).to.equal(id.toString())
-    expect(testId.id).to.equal(id.toHexString())
+  it('recreate from CIDv1 Base32 (libp2p-key multicodec)', () => {
+    const cid = new CID(1, 'libp2p-key', testIdBytes)
+    const cidString = cid.toBaseEncodedString('base32')
+    const id = PeerId.createFromCID(cidString)
+    expect(cidString).to.equal(id.toString())
+    expect(testIdBytes).to.deep.equal(id.toBytes())
+  })
+
+  it('recreate from CIDv1 Base32 (dag-pb multicodec)', () => {
+    const cid = new CID(1, 'dag-pb', testIdBytes)
+    const cidString = cid.toBaseEncodedString('base32')
+    const id = PeerId.createFromCID(cidString)
+    // toString should return CID with multicodec set to libp2p-key
+    expect(new CID(id.toString()).codec).to.equal('libp2p-key')
+    expect(testIdBytes).to.deep.equal(id.toBytes())
   })
 
   it('recreate from CID Buffer', () => {
@@ -107,6 +118,14 @@ describe('PeerId', () => {
     expect(testIdBytes).to.deep.equal(id.toBytes())
   })
 
+  it('throws on invalid CID multicodec', () => {
+    // only libp2p and dag-pb are supported
+    const invalidCID = new CID(1, 'raw', testIdBytes).toBaseEncodedString('base32')
+    expect(() => {
+      PeerId.createFromCID(invalidCID)
+    }).to.throw(/Supplied PeerID CID has invalid multicodec: raw/)
+  })
+
   it('throws on invalid CID value', () => {
     // using function code that does not represent valid hash function
     // https://github.com/multiformats/js-multihash/blob/b85999d5768bf06f1b0f16b926ef2cb6d9c14265/src/constants.js#L345
@@ -120,7 +139,14 @@ describe('PeerId', () => {
     const invalidCID = {}
     expect(() => {
       PeerId.createFromCID(invalidCID)
-    }).to.throw(/Supplied cid value is neither String|CID|Buffer/)
+    }).to.throw(/Invalid version, must be a number equal to 1 or 0/)
+  })
+
+  it('throws on invalid CID object', () => {
+    const invalidCID = {}
+    expect(() => {
+      PeerId.createFromCID(invalidCID)
+    }).to.throw(/Invalid version, must be a number equal to 1 or 0/)
   })
 
   it('recreate from a Public Key', async () => {