Fix PDF decryption issue for some empty password files #1079
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Some PDF's with an empty password can't be decrypted. Investigation found that the problem is a strlen check to prevent an overflow rather than passing down the actual length of the allocated field. Specifically, the UE buffer may have NULL values in it, so a strlen check will claim the field is shorter than it is and then later checks fail because the length is the wrong size. While at it, I improved code comments on the function reading dictionary key-value strings and switched a flag use a bool rather than an int.
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Code looks fine. Verified more files were extracted with the PR and with MAIN. |
ragusaa
approved these changes
Nov 8, 2023
Closed
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Some PDF's with an empty password can't be decrypted. Investigation found that the problem is a strlen check to prevent an overflow rather than passing down the actual length of the allocated field.
Specifically, the UE buffer may have NULL values in it, so a strlen check will claim the field is shorter than it is and then later checks fail because the length is the wrong size.
While at it, I improved code comments on the function reading dictionary key-value strings and switched a flag use a bool rather than an int.