ECSignature: account for SIGHASH being ignored

src/ecsignature.js

@@ -35,9 +35,11 @@ ECSignature.parseCompact = function (buffer) {
 // Strict DER - https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki
 // NOTE: SIGHASH byte ignored
 ECSignature.fromDER = function (buffer) {
+  // Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S]
+
   // Minimum and maximum size constraints.
-  if (buffer.length < 9) throw new Error('Invalid sequence length')
-  if (buffer.length > 73) throw new Error('Invalid sequence length')
+  if (buffer.length < 8) throw new Error('DER sequence too short')
+  if (buffer.length > 72) throw new Error('DER sequence too long')
 
   // A signature is of type 0x30 (compound).
   if (buffer[0] !== 0x30) throw new Error('Not a DER sequence')

test/fixtures/ecsignature.json

@@ -129,6 +129,14 @@
       }
     ],
     "DER": [
+      {
+        "exception": "DER sequence too short",
+        "hex": "ffffffffffffff"
+      },
+      {
+        "exception": "DER sequence too long",
+        "hex": "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+      },
       {
         "exception": "Invalid sequence length",
         "hex": "30ff020400ffffff020400ffffff"