Guard against PSA generating invalid signature
Guard against PSA generating invalid signature

The goal is not to double-check everything PSA does, but to ensure that it
anything goes wrong, we fail cleanly rather than by overwriting a buffer.

NXPmicro/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls