gmrtd ReadFile Vulnerable to Denial of Service via Excessive TLV Length Values

Summary

gmrtd is a Go library for reading Machine Readable Travel Documents (MRTDs). Prior to version 0.17.2, ReadFile accepts TLVs with lengths that can range up to 4GB, which can cause unconstrained resource consumption in both memory and cpu cycles. ReadFile can consume an extended TLV with lengths well outside what would be available in ICs. It can accept something all the way up to 4GB which would take too many iterations in 256 byte chunks, and would also try to allocate memory that might not be available in constrained environments like phones. Or if an API sends data to ReadFile, the same problem applies. The very small chunked read also locks the goroutine in accepting data for a very large number of iterations. projects using the gmrtd library to read files from NFCs can experience extreme slowdowns or memory consumption. A malicious NFC can just behave like the mock transceiver described above and by just sending dummy bytes as each chunk to be read, can make the receiving thread unresponsive and fill up memory on the host system. Version 0.17.2 patches the issue.