chaps: generate random bytes in software if TPM unavailable

On creation of an isolate when a TPM is unavailable, need to generate
random data without the assistance of the TPM.

TEST=Chaps unit tests (with ASAN) plus PKCS11 tests

Change-Id: I56e153d7560460da4c7341352f4b3f73418c8222
Reviewed-by: Darren Krahn <>
Commit-Queue: David Drysdale <>
Tested-by: David Drysdale <>
2 files changed