Merge pull request #423 from bitcoinjs/bip66adherance

adhere more closely to BIP66
This commit is contained in:
Daniel Cousens 2015-07-20 09:20:40 +10:00
commit a8f36ba515
3 changed files with 36 additions and 26 deletions

View file

@ -32,39 +32,37 @@ ECSignature.parseCompact = function (buffer) {
}
}
// Strict DER - https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki
// NOTE: SIGHASH byte ignored
ECSignature.fromDER = function (buffer) {
assert.equal(buffer.readUInt8(0), 0x30, 'Not a DER sequence')
assert.equal(buffer.readUInt8(1), buffer.length - 2, 'Invalid sequence length')
assert.equal(buffer.readUInt8(2), 0x02, 'Expected a DER integer')
// Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S]
if (buffer.length < 8) throw new Error('DER sequence too short')
if (buffer.length > 72) throw new Error('DER sequence too long')
if (buffer[0] !== 0x30) throw new Error('Not a DER sequence')
if (buffer[1] !== buffer.length - 2) throw new Error('Invalid sequence length')
if (buffer[2] !== 0x02) throw new Error('Expected a DER integer')
var rLen = buffer.readUInt8(3)
assert(rLen > 0, 'R length is zero')
var lenR = buffer.readUInt8(3)
if (lenR === 0) throw new Error('R length is zero')
if (5 + lenR >= buffer.length) throw new Error('Invalid DER encoding')
if (buffer[4 + lenR] !== 0x02) throw new Error('Expected a DER integer (2)')
var offset = 4 + rLen
assert.equal(buffer.readUInt8(offset), 0x02, 'Expected a DER integer (2)')
var lenS = buffer[5 + lenR]
if (lenS === 0) throw new Error('S length is zero')
if ((lenR + lenS + 6) !== buffer.length) throw new Error('Invalid DER encoding (2)')
var sLen = buffer.readUInt8(offset + 1)
assert(sLen > 0, 'S length is zero')
if (buffer[4] & 0x80) throw new Error('R value is negative')
if (lenR > 1 && (buffer[4] === 0x00) && !(buffer[5] & 0x80)) throw new Error('R value excessively padded')
var rB = buffer.slice(4, offset)
var sB = buffer.slice(offset + 2)
offset += 2 + sLen
if (buffer[lenR + 6] & 0x80) throw new Error('S value is negative')
if (lenS > 1 && (buffer[lenR + 6] === 0x00) && !(buffer[lenR + 7] & 0x80)) throw new Error('S value excessively padded')
if (rLen > 1 && rB.readUInt8(0) === 0x00) {
assert(rB.readUInt8(1) & 0x80, 'R value excessively padded')
}
if (sLen > 1 && sB.readUInt8(0) === 0x00) {
assert(sB.readUInt8(1) & 0x80, 'S value excessively padded')
}
assert.equal(offset, buffer.length, 'Invalid DER encoding')
// non-BIP66 - extract R, S values
var rB = buffer.slice(4, 4 + lenR)
var sB = buffer.slice(lenR + 6)
var r = BigInteger.fromDERInteger(rB)
var s = BigInteger.fromDERInteger(sB)
assert(r.signum() >= 0, 'R value is negative')
assert(s.signum() >= 0, 'S value is negative')
return new ECSignature(r, s)
}

View file

@ -66,7 +66,7 @@ describe('ECSignature', function () {
})
fixtures.invalid.DER.forEach(function (f) {
it('throws on ' + f.hex, function () {
it('throws "' + f.exception + '" for ' + f.hex, function () {
var buffer = new Buffer(f.hex, 'hex')
assert.throws(function () {

View file

@ -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"
@ -147,7 +155,11 @@
},
{
"exception": "Invalid DER encoding",
"hex": "300c020400ffffff020200ffffff"
"hex": "300c0204ddffffff020200ffffff"
},
{
"exception": "Invalid DER encoding \\(2\\)",
"hex": "300c020400ffffff02dd00ffffff"
},
{
"exception": "R length is zero",