Add fix for matchBytes32Prefix #24
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LGTM |
D-Nice
reviewed
Dec 5, 2017
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| for (var i=0; i<prefix.length; i++){ | ||
| for (var i=0; i< n_random_bytes; i++) { |
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if n_random_bytes exceeds 255, this loop will overflow, consider using uint256 over var, if there's no other overflow or length checks on n_random_bytes
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This PR fixes a mistake in matchBytes32Prefix, in both the new API version and the old one.
matchBytes32Prefix verify if the string sends by Oraclize as the result parameter of the callback is the SHA256 of the signature. Unfortunately, the comparison between the two byte arrays takes as a parameter the lenght of the string result, which is controlled by Oraclize. Therefore, it could be possible for the proof verification to pass even in the case Oraclize is returning an empty string in the callback.
If you see a more efficient way to do this, please suggest. Unfortunately, I was limited by the stack depth and I add to change the oraclize_randomDS_proofVerify__main to reduce the number of variables.