The old loop read one byte past the length. It also stopped the loop
too early on interior NUL. See also upstream's
https://github.com/openssl/openssl/pull/16433, though I've opted to
rewrite the function entirely rather than use their fix.
Also deduplicate the PrintableString check.
Change-Id: Ia8bd282047c2a2ed1d5e71a68a3947c7c108df95
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49066
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
David Benjamin
Adam Langley