Fix padding on EC coordinates that are not expected sizes

When encoding public EC keys, we should ensure that we don't have
extra leading 00s that make the key larger than expected.

Additionally, we should insert leading 00s if the key would otherwise
be too short.

Include new test data to verify these edge cases.

Bug: 286384153
Test: atest libhwtrust_tests
(cherry picked from https://android-review.googlesource.com/q/commit:6f75372e2b16584e893ac25426dc8692867ac724)
Merged-In: I28418e6d8b788576a410b974e38c5a6d7fc96578
Change-Id: I28418e6d8b788576a410b974e38c5a6d7fc96578
2 files changed
tree: 80087f9d35fe0f3852d5648ebfef68566b30ef20
  1. fuzzing/
  2. gdb/
  3. remote_provisioning/
  4. sanitizer-status/
  5. CleanSpec.mk
  6. OWNERS
  7. PREUPLOAD.cfg