expect/linux-tpm.exp

#
# Copyright (c) 2020-2022, Arm Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
# Expect script for Linux/Buildroot using Measured Boot & fTPM
#

source [file join [file dirname [info script]] utils.inc]
source [file join [file dirname [info script]] handle-arguments.inc]

# File to store the event log from the ftpm service.
set TFA_DIGEST [get_param tfa_digest "tfa_event_log"]
set FTPM_DIGEST [get_param ftpm_digest "ftpm_event_log"]

# regexp for non-zero PCR0
set non_zero_pcr "(?!(\\s00){16})((\\s(\[0-9a-f\]){2}){16}\\s)"
set zero_pcr "(\\s00){16}\\s+(00\\s){16}"

capture_log $TFA_DIGEST "Booting BL31"

expect {
        "login" {
                send "root\n"
        }
}

expect {
        "#" {
                # Load the fTPM driver and retrieves PCR0
                send "ftpm\n"
        }
}

expect {
        # Pass condition: PCR0 must not be all zeros.

        -re $non_zero_pcr {
                exp_continue
        }

        "#" {
                # get PCR1 value
                send "pcrread -ha 1\n"
        }
}

expect {
        # Pass condition: PCR1 must not be all zeros.

        -re $non_zero_pcr {
                exp_continue
        }

        "#" { }
}

# Iterate over the rest of PCRs and check that they all are zeros.
for {set i 2} {$i < 11} {incr i} {
        send "pcrread -ha $i\n"

        expect {
                -re $zero_pcr { }

                -re $non_zero_pcr {
                        exit_uart -1
                }
        }
}

expect_string "#" "finished reading PCRs"

compare_log $TFA_DIGEST $FTPM_DIGEST