ECSignature: verbose comments are overly verbose, see BIP if necessary
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@ -36,53 +36,25 @@ ECSignature.parseCompact = function (buffer) {
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// NOTE: SIGHASH byte ignored
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ECSignature.fromDER = function (buffer) {
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// Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S]
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// Minimum and maximum size constraints.
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if (buffer.length < 8) throw new Error('DER sequence too short')
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if (buffer.length > 72) throw new Error('DER sequence too long')
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// A signature is of type 0x30 (compound).
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if (buffer[0] !== 0x30) throw new Error('Not a DER sequence')
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// Make sure the length covers the entire signature.
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if (buffer[1] !== buffer.length - 2) throw new Error('Invalid sequence length')
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// Check whether the R element is an integer.
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if (buffer[2] !== 0x02) throw new Error('Expected a DER integer')
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// Extract the length of the R element.
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var lenR = buffer.readUInt8(3)
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// Zero-length integers are not allowed for R.
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if (lenR === 0) throw new Error('R length is zero')
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// Make sure the length of the R element is still inside the signature.
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if (5 + lenR >= buffer.length) throw new Error('Invalid DER encoding')
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// Check whether the S element is an integer.
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if (buffer[4 + lenR] !== 0x02) throw new Error('Expected a DER integer (2)')
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var lenS = buffer[5 + lenR]
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// Zero-length integers are not allowed for S.
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if (lenS === 0) throw new Error('S length is zero')
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// Verify that the length of the signature matches the sum of the length
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// of the elements.
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if ((lenR + lenS + 6) !== buffer.length) throw new Error('Invalid DER encoding (2)')
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// Negative numbers are not allowed for R.
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if (buffer[4] & 0x80) throw new Error('R value is negative')
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// Null bytes at the start of R are not allowed, unless R would
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// otherwise be interpreted as a negative number.
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if (lenR > 1 && (buffer[4] === 0x00) && !(buffer[5] & 0x80)) throw new Error('R value excessively padded')
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// Negative numbers are not allowed for S.
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if (buffer[lenR + 6] & 0x80) throw new Error('S value is negative')
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// Null bytes at the start of S are not allowed, unless S would otherwise be
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// interpreted as a negative number.
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if (lenS > 1 && (buffer[lenR + 6] === 0x00) && !(buffer[lenR + 7] & 0x80)) throw new Error('S value excessively padded')
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// non-BIP66 - extract R, S values
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