Accept 32 byte private key in sign function.

lukas2 · Sep 4, 2019 · ddd1f06 · ddd1f06
1 parent e986435
commit ddd1f06
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Showing 2 changed files with 21 additions and 1 deletion.
diff --git a/lib/ed25519.js b/lib/ed25519.js
@@ -161,9 +161,13 @@ ed25519.sign = function(options) {
     message: options.privateKey,
     encoding: 'binary'
   });
-  if(privateKey.length !== ed25519.constants.PRIVATE_KEY_BYTE_LENGTH) {
+  if(privateKey.length === ed25519.constants.SEED_BYTE_LENGTH) {
+    var keyPair = ed25519.generateKeyPair({seed: privateKey});
+    privateKey = keyPair.privateKey;
+  } else if(privateKey.length !== ed25519.constants.PRIVATE_KEY_BYTE_LENGTH) {
     throw new TypeError(
       '"options.privateKey" must have a byte length of ' +
+      ed25519.constants.SEED_BYTE_LENGTH + ' or ' +
       ed25519.constants.PRIVATE_KEY_BYTE_LENGTH);
   }
 

diff --git a/tests/unit/ed25519.js b/tests/unit/ed25519.js
@@ -60,6 +60,22 @@ var UTIL = require('../../lib/util');
       ASSERT.equal(eb64(signature), b64Sha256Signature);
     });
 
+    it('should sign a digest given 32 private key bytes', function() {
+      var pwd = 'password';
+      var md = SHA256.create();
+      md.update(pwd, 'utf8');
+      var seed = md.digest().getBytes();
+      var kp = ED25519.generateKeyPair({seed: seed});
+      md = SHA256.create();
+      md.update('test', 'utf8');
+      var privateKey = kp.privateKey.slice(0, 32);
+      var signature = ED25519.sign({
+        md: md,
+        privateKey: privateKey
+      });
+      ASSERT.equal(eb64(signature), b64Sha256Signature);
+    });
+
     it('should sign a UTF-8 message', function() {
       var pwd = 'password';
       var md = SHA256.create();