feat: add toCID function and tests

ucan-wasm/Cargo.toml

@@ -22,6 +22,7 @@ path = "src/lib.rs"
 # all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
 # code size when deploying.
 base64 = "0.21"
+cid = "0.10"
 console_error_panic_hook = { version = "0.1", optional = true }
 instant = { version = "0.1", features = ["wasm-bindgen"] }
 js-sys = { version = "0.3", optional = true }

ucan-wasm/src/ucan/cid.rs

@@ -0,0 +1,43 @@
+use crate::ucan::JsResult;
+use ::ucan::Ucan;
+use cid::multihash::Code;
+use js_sys::Error;
+use wasm_bindgen::prelude::wasm_bindgen;
+
+/// Compute CID for a UCAN
+///
+/// Hashers include SHA2-256, SHA2-512, SHA3-224
+/// SHA3-256, SHA3-384, SHA3-512, Keccak-224, Keccak-256, Keccak-384
+/// Keccak-512, BLAKE2b-256, BLAKE2b-512, BLAKE2s-128, and BLAKE3-256.
+///
+/// Defaults to BLAKE3-256 hash function.
+///
+#[wasm_bindgen(js_name = "toCID")]
+pub async fn to_cid(token: String, hasher: Option<String>) -> JsResult<String> {
+    let ucan = Ucan::try_from(token).map_err(|e| Error::new(&format!("{e}")))?;
+
+    let hasher_code = get_hasher_code(&hasher.unwrap_or(String::from("BLAKE3-256")));
+    let cid = Ucan::to_cid(&ucan, hasher_code).map_err(|e| Error::new(&format!("{e}")))?;
+
+    Ok(cid.into())
+}
+
+fn get_hasher_code(hasher: &str) -> Code {
+    match hasher {
+        "SHA2-256" => Code::Sha2_256,
+        "SHA2-512" => Code::Sha2_512,
+        "SHA3-224" => Code::Sha3_224,
+        "SHA3-256" => Code::Sha3_256,
+        "SHA3-384" => Code::Sha3_384,
+        "SHA3-512" => Code::Sha3_512,
+        "Keccak-224" => Code::Keccak224,
+        "Keccak-256" => Code::Keccak256,
+        "Keccak-384" => Code::Keccak384,
+        "Keccak-512" => Code::Keccak512,
+        "BLAKE2b-256" => Code::Blake2b256,
+        "BLAKE2b-512" => Code::Blake2b512,
+        "BLAKE2s-128" => Code::Blake2s128,
+        "BLAKE3-256" => Code::Blake3_256,
+        _ => Code::Blake3_256,
+    }
+}

ucan-wasm/src/ucan/mod.rs

@@ -1,3 +1,4 @@
+pub mod cid;
 pub mod token;
 pub mod verify;
 

ucan-wasm/tests/browser.test.ts

@@ -1,6 +1,7 @@
-import init, { checkSignature, decode, isExpired, isTooEarly, validate } from '../lib/browser/ucan_wasm.js'
-import { runVerifyTests } from "./ucan/verify.test.js"
+import init, { checkSignature, decode, isExpired, isTooEarly, toCID, validate } from '../lib/browser/ucan_wasm.js'
+import { runCIDTests } from "./ucan/cid.test.js"
 import { runTokenTests } from "./ucan/token.test.js"
+import { runVerifyTests } from "./ucan/verify.test.js"
 
 before(async () => {
   await init()
@@ -21,3 +22,10 @@ runTokenTests({
     decode
   }
 })
+
+runCIDTests({
+  runner: { describe, it },
+  ucan: {
+    toCID
+  }
+})

ucan-wasm/tests/fixtures/cid.json

@@ -0,0 +1,13 @@
+
+[
+  {
+    "hasher": "SHA2-256",
+    "token": "eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCIsInVjdiI6IjAuOS4wLWNhbmFyeSJ9.eyJhdHQiOlt7ImNhbiI6ImVtYWlsL3NlbmQiLCJuYiI6bnVsbCwid2l0aCI6Im1haWx0bzphbGljZUBlbWFpbC5jb20ifV0sImF1ZCI6ImRpZDprZXk6ejZNa3RhZlpUUkVqSmt2VjVtZkp4Y0xwTkJvVlB3RExoVHVNZzluZzdkWTR6TUFMIiwiZXhwIjo5MjQ2MjExMjAwLCJmY3QiOlt7ImNoYWxsZW5nZSI6ImFiY2RlZiJ9XSwiaXNzIjoiZGlkOmtleTp6Nk1rZmZEWkNrQ1RXcmVnODg2OGZHMUZHRm9nY0pqNVg2UFk5M3BQY1dEbjlib2IiLCJwcmYiOlsiYmFma3I0aWdmM3N6N2tqNWRoeHJkanVmeHZhdmtraW5wazJpNzNpNXBzdXA2Y3h1dmR5bTJqZWN3MmUiXX0.nTJl6kKrEKYzp6D4tTc-xYgNxH4urv8tfGU7so6ZIf5s86yMnb6bLpSPMeRchbOafVIy9vil9vjjYACzY1GvBg",
+    "cid": "bafkreigzlstpwdjhxgjexfm3njsidz3iusyys3d2way35re3gbcghjzsqa"
+  },
+  {
+    "hasher": "BLAKE3-256",
+    "token": "eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCIsInVjdiI6IjAuOS4wLWNhbmFyeSJ9.eyJhdHQiOlt7ImNhbiI6ImVtYWlsL3NlbmQiLCJuYiI6bnVsbCwid2l0aCI6Im1haWx0bzphbGljZUBlbWFpbC5jb20ifV0sImF1ZCI6ImRpZDprZXk6ejZNa3RhZlpUUkVqSmt2VjVtZkp4Y0xwTkJvVlB3RExoVHVNZzluZzdkWTR6TUFMIiwiZXhwIjo5MjQ2MjExMjAwLCJmY3QiOlt7ImNoYWxsZW5nZSI6ImFiY2RlZiJ9XSwiaXNzIjoiZGlkOmtleTp6Nk1rZmZEWkNrQ1RXcmVnODg2OGZHMUZHRm9nY0pqNVg2UFk5M3BQY1dEbjlib2IiLCJwcmYiOlsiYmFma3I0aWdmM3N6N2tqNWRoeHJkanVmeHZhdmtraW5wazJpNzNpNXBzdXA2Y3h1dmR5bTJqZWN3MmUiXX0.nTJl6kKrEKYzp6D4tTc-xYgNxH4urv8tfGU7so6ZIf5s86yMnb6bLpSPMeRchbOafVIy9vil9vjjYACzY1GvBg",
+    "cid": "bafkr4igg7afrwmgzugre2zxd62t3ycs73hto3pe24bavabroxbjpfam57y"
+  }
+]

ucan-wasm/tests/fixtures/index.ts

@@ -1,6 +1,10 @@
+import cid from './cid.json'
 import invalid from './invalid.json'
 import valid from './valid.json'
 
+
+// VERIFICATION
+
 type Expectation = 'valid' | 'invalid'
 
 type Fixture = {
@@ -27,6 +31,7 @@ type Fixture = {
   },
 }
 
+
 export function getFixture(expectation: Expectation, comment: string): Fixture {
   let fixture
 
@@ -38,3 +43,16 @@ export function getFixture(expectation: Expectation, comment: string): Fixture {
 
   return fixture
 }
+
+
+// CID
+
+type CIDFixture = {
+  hasher: string
+  token: string
+  cid: string
+}
+
+export function getCIDFixture(hasher: string): CIDFixture {
+  return cid.find(f => f.hasher === hasher)
+}

ucan-wasm/tests/node.test.ts

@@ -1,16 +1,17 @@
 import { describe, it } from 'vitest'
 
-import { checkSignature, decode, isExpired, isTooEarly, validate } from '../lib/node/ucan_wasm.js'
+import { checkSignature, decode, isExpired, isTooEarly, toCID, validate } from '../lib/node/ucan_wasm.js'
+import { runCIDTests } from "./ucan/cid.test.js"
 import { runTokenTests } from "./ucan/token.test.js"
 import { runVerifyTests } from "./ucan/verify.test.js"
 
 runVerifyTests({
   runner: { describe, it },
   ucan: {
-      isExpired,
-      isTooEarly,
-      checkSignature,
-      validate
+    isExpired,
+    isTooEarly,
+    checkSignature,
+    validate
   }
 })
 
@@ -20,3 +21,10 @@ runTokenTests({
     decode
   }
 })
+
+runCIDTests({
+  runner: { describe, it },
+  ucan: {
+    toCID
+  }
+})

ucan-wasm/tests/ucan/cid.test.ts

@@ -0,0 +1,37 @@
+import assert from 'assert'
+import { getCIDFixture } from '../fixtures/index.js'
+
+export function runCIDTests(
+  impl: {
+    runner?: { describe, it },
+    ucan: {
+      toCID: (token: string, hasher?: string) => Promise<string>
+    }
+  }) {
+
+  // Use runner or fallback to implicit mocha implementations
+  const describe = impl.runner?.describe ?? globalThis.describe
+  const it = impl.runner?.it ?? globalThis.it
+
+  const { toCID } = impl.ucan
+
+  describe('toCID', async () => {
+    it('should compute CID for a UCAN using a SHA2-256 hasher', async () => {
+      const fixture = getCIDFixture('SHA2-256')
+      const cid = await toCID(fixture.token, 'SHA2-256')
+      assert.equal(cid, fixture.cid)
+    })
+
+    it('should compute CID for a UCAN using a BLAKE3-256 hasher', async () => {
+      const fixture = getCIDFixture('BLAKE3-256')
+      const cid = await toCID(fixture.token, 'BLAKE3-256')
+      assert.equal(cid, fixture.cid)
+    })
+
+    it('should compute CID for a UCAN deafulting to the BLAKE3-256 hasher', async () => {
+      const fixture = getCIDFixture('BLAKE3-256')
+      const cid = await toCID(fixture.token)
+      assert.equal(cid, fixture.cid)
+    })
+  })
+}