Add rudimentary support for decoding Bignum values #2
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It turns out that even a simple Unix timestamp is enough to cause Ruby Marshal to output a Bignum. The encoding is reasonably simple: a sign byte (ASCII + or -), half the byte length, then the Bignum's bytes. Note that as the math/big package requires a big-endian byte encoding, we assume that the input is little-endian and reverse it as needed. For details, see https://docs.ruby-lang.org/en/master/doc/marshal_rdoc.html#label-Bignum.
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@leocassarani thanks! :) |
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It turns out that even a simple Unix timestamp is enough to cause Ruby Marshal to output a Bignum. The encoding is reasonably simple: a sign byte (ASCII + or -), half the byte length, then the Bignum's bytes.
Note that as the math/big package requires a big-endian byte encoding, we assume that the input is little-endian and reverse it as needed.
For details, see https://docs.ruby-lang.org/en/master/doc/marshal_rdoc.html#label-Bignum.