[U-Boot] [PATCH 1/3] tools: k3_get_x509 cert: Add a script to generate x509 certificate for K3 devices

Lokesh Vutla
2019-05-02T10:05:50Z

TI's K3 boot architecture mandates a x509 certificate for every boot image.
While signing the image K3 ROM allows for two types of keys based on which
the boot image gets loaded in different ways:
- Degenerate RSA keys: This generates a signature which is equal to the digest.
When ROM sees this, it does a DMA for copying the images,
which significantly improves the boot time.
- Any other key: Does a memcpy to load the image. This is introduced as a
fallback for DMA copy.

Add a script for generating boot images with the above options. Default
generates image using rsa degenerate key in order to improve boot time.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
---
tools/k3_gen_x509_cert.sh | 244 ++++++++++++++++++++++++++++++++++++++
1 file changed, 244 insertions(+)
create mode 100755 tools/k3_gen_x509_cert.sh

diff --git a/tools/k3_gen_x509_cert.sh b/tools/k3_gen_x509_cert.sh
new file mode 100755
index 0000000000..b6d055f6f5
--- /dev/null
+++ b/tools/k3_gen_x509_cert.sh
@@ -0,0 +1,244 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+#
+# Script to add K3 specific x509 cetificate to a binary.
+#
+
+# Variables
+OUTPUT=tiboot3.bin
+TEMP_X509=x509-temp.cert
+CERT=certificate.bin
+RAND_KEY=eckey.pem
+LOADADDR=0x41c00000
+BOOTCORE_OPTS=0
+BOOTCORE=16
+
+gen_degen_template() {
+cat << 'EOF' > degen-template.txt
+
+asn1=SEQUENCE:rsa_key
+
+[rsa_key]
+version=INTEGER:0
+modulus=INTEGER:0xDEGEN_MODULUS
+pubExp=INTEGER:1
+privExp=INTEGER:1
+p=INTEGER:0xDEGEN_P
+q=INTEGER:0xDEGEN_Q
+e1=INTEGER:1
+e2=INTEGER:1
+coeff=INTEGER:0xDEGEN_COEFF
+EOF
+}
+
+# Generate x509 Template
+gen_template() {
+cat << 'EOF' > x509-template.txt
+ [ req ]
+ distinguished_name = req_distinguished_name
+ x509_extensions = v3_ca
+ prompt = no
+ dirstring_type = nobmp
+
+ [ req_distinguished_name ]
+ C = US
+ ST = TX
+ L = Dallas
+ O = Texas Instruments Incorporated
+ OU = Processors
+ CN = TI support
+ emailAddress = support at ti.com
+
+ [ v3_ca ]
+ basicConstraints = CA:true
+ 1.3.6.1.4.1.294.1.1 = ASN1:SEQUENCE:boot_seq
+ 1.3.6.1.4.1.294.1.2 = ASN1:SEQUENCE:image_integrity
+ 1.3.6.1.4.1.294.1.3 = ASN1:SEQUENCE:swrv
+# 1.3.6.1.4.1.294.1.4 = ASN1:SEQUENCE:encryption
+ 1.3.6.1.4.1.294.1.8 = ASN1:SEQUENCE:debug
+
+ [ boot_seq ]
+ certType = INTEGER:TEST_CERT_TYPE
+ bootCore = INTEGER:TEST_BOOT_CORE
+ bootCoreOpts = INTEGER:TEST_BOOT_CORE_OPTS
+ destAddr = FORMAT:HEX,OCT:TEST_BOOT_ADDR
+ imageSize = INTEGER:TEST_IMAGE_LENGTH
+
+ [ image_integrity ]
+ shaType = OID:2.16.840.1.101.3.4.2.3
+ shaValue = FORMAT:HEX,OCT:TEST_IMAGE_SHA_VAL
+
+ [ swrv ]
+ swrv = INTEGER:0
+
+# [ encryption ]
+# initalVector = FORMAT:HEX,OCT:TEST_IMAGE_ENC_IV
+# randomString = FORMAT:HEX,OCT:TEST_IMAGE_ENC_RS
+# iterationCnt = INTEGER:TEST_IMAGE_KEY_DERIVE_INDEX
+# salt = FORMAT:HEX,OCT:TEST_IMAGE_KEY_DERIVE_SALT
+
+ [ debug ]
+ debugUID = FORMAT:HEX,OCT:0000000000000000000000000000000000000000000000000000000000000000
+ debugType = INTEGER:4
+ coreDbgEn = INTEGER:0
+ coreDbgSecEn = INTEGER:0
+EOF
+}
+
+parse_key() {
+ sed '/\ \ \ \ /s/://g' key.txt | awk '!/\ \ \ \ / {printf("\n%s\n", $0)}; /\ \ \ \ / {printf("%s", $0)}' | sed 's/\ \ \ \ //g' | awk "/$1:/{getline; print}"
+}
+
+gen_degen_key() {
+# Generate a 4096 bit RSA Key
+ openssl genrsa -out key.pem 1024 >>/dev/null 2>&1
+ openssl rsa -in key.pem -text -out key.txt >>/dev/null 2>&1
+ DEGEN_MODULUS=$( parse_key 'modulus' )
+ DEGEN_P=$( parse_key 'prime1' )
+ DEGEN_Q=$( parse_key 'prime2' )
+ DEGEN_COEFF=$( parse_key 'coefficient' )
+ gen_degen_template
+
+ sed -e "s/DEGEN_MODULUS/$DEGEN_MODULUS/"\
+ -e "s/DEGEN_P/$DEGEN_P/" \
+ -e "s/DEGEN_Q/$DEGEN_Q/" \
+ -e "s/DEGEN_COEFF/$DEGEN_COEFF/" \
+ degen-template.txt > degenerateKey.txt
+
+ openssl asn1parse -genconf degenerateKey.txt -out degenerateKey.der >>/dev/null 2>&1
+ openssl rsa -in degenerateKey.der -inform DER -outform PEM -out $RAND_KEY >>/dev/null 2>&1
+ KEY=$RAND_KEY
+ rm key.pem key.txt degen-template.txt degenerateKey.txt degenerateKey.der
+}
+
+declare -A options_help
+usage() {
+ if [ -n "$*" ]; then
+ echo "ERROR: $*"
+ fi
+ echo -n "Usage: $0 "
+ for option in "${!options_help[@]}"
+ do
+ arg=`echo ${options_help[$option]}|cut -d ':' -f1`
+ if [ -n "$arg" ]; then
+ arg=" $arg"
+ fi
+ echo -n "[-$option$arg] "
+ done
+ echo
+ echo -e "\nWhere:"
+ for option in "${!options_help[@]}"
+ do
+ arg=`echo ${options_help[$option]}|cut -d ':' -f1`
+ txt=`echo ${options_help[$option]}|cut -d ':' -f2`
+ tb="\t\t\t"
+ if [ -n "$arg" ]; then
+ arg=" $arg"
+ tb="\t"
+ fi
+ echo -e " -$option$arg:$tb$txt"
+ done
+ echo
+ echo "Examples of usage:-"
+ echo "# Example of signing the SYSFW binary with rsa degenerate key"
+ echo " $0 -c 0 -b ti-sci-firmware-am6x.bin -o sysfw.bin -l 0x40000"
+ echo "# Example of signing the SPL binary with rsa degenerate key"
+ echo " $0 -c 16 -b spl/u-boot-spl.bin -o tiboot3.bin -l 0x41c00000"
+}
+
+options_help[b]="bin_file:Bin file that needs to be signed"
+options_help[k]="key_file:file with key inside it. If not provided script generates a rsa degenerate key."
+options_help[o]="output_file:Name of the final output file. default to $OUTPUT"
+options_help[c]="core_id:target core id on which the image would be running. Default to $BOOTCORE"
+options_help[l]="loadaddr: Target load address of the binary in hex. Default to $LOADADDR"
+
+while getopts "b:k:o:c:l:h" opt
+do
+ case $opt in
+ b)
+ BIN=$OPTARG
+ ;;
+ k)
+ KEY=$OPTARG
+ ;;
+ o)
+ OUTPUT=$OPTARG
+ ;;
+ l)
+ LOADADDR=$OPTARG
+ ;;
+ c)
+ BOOTCORE=$OPTARG
+ ;;
+ h)
+ usage
+ exit 0
+ ;;
+ \?)
+ usage "Invalid Option '-$OPTARG'"
+ exit 1
+ ;;
+ :)
+ usage "Option '-$OPTARG' Needs an argument."
+ exit 1
+ ;;
+ esac
+done
+
+if [ "$#" -eq 0 ]; then
+ usage "Arguments missing"
+ exit 1
+fi
+
+if [ -z "$BIN" ]; then
+ usage "Bin file missing in arguments"
+ exit 1
+fi
+
+# Generate rsa degenerate key if user doesn't provide a key
+if [ -z "$KEY" ]; then
+ gen_degen_key
+fi
+
+if [ $BOOTCORE == 0 ]; then # BOOTCORE M3, loaded by ROM
+ CERTTYPE=2
+elif [ $BOOTCORE == 16 ]; then # BOOTCORE R5, loaded by ROM
+ CERTTYPE=1
+else # Non BOOTCORE, loaded by SYSFW
+ BOOTCORE_OPTS_VER=$(printf "%01x" 1)
+ # Add input args option for SET and CLR flags.
+ BOOTCORE_OPTS_SETFLAG=$(printf "%08x" 0)
+ BOOTCORE_OPTS_CLRFLAG=$(printf "%08x" 0x100) # Clear FLAG_ARMV8_AARCH32
+ BOOTCORE_OPTS="0x$BOOTCORE_OPTS_VER$BOOTCORE_OPTS_SETFLAG$BOOTCORE_OPTS_CLRFLAG"
+ # Set the cert type to zero.
+ # We are not using public/private key store now
+ CERTTYPE=$(printf "0x%08x" 0)
+fi
+
+SHA_VAL=`openssl dgst -sha512 -hex $BIN | sed -e "s/^.*= //g"`
+BIN_SIZE=`cat $BIN | wc -c`
+ADDR=`printf "%08x" $LOADADDR`
+
+gen_cert() {
+ #echo "Certificate being generated :"
+ #echo " LOADADDR = 0x$ADDR"
+ #echo " IMAGE_SIZE = $BIN_SIZE"
+ #echo " CERT_TYPE = $CERTTYPE"
+ sed -e "s/TEST_IMAGE_LENGTH/$BIN_SIZE/" \
+ -e "s/TEST_IMAGE_SHA_VAL/$SHA_VAL/" \
+ -e "s/TEST_CERT_TYPE/$CERTTYPE/" \
+ -e "s/TEST_BOOT_CORE_OPTS/$BOOTCORE_OPTS/" \
+ -e "s/TEST_BOOT_CORE/$BOOTCORE/" \
+ -e "s/TEST_BOOT_ADDR/$ADDR/" x509-template.txt > $TEMP_X509
+ openssl req -new -x509 -key $KEY -nodes -outform DER -out $CERT -config $TEMP_X509 -sha512
+}
+
+gen_template
+gen_cert
+cat $CERT $BIN > $OUTPUT
+
+# Remove all intermediate files
+rm $TEMP_X509 $CERT x509-template.txt
+if [ "$KEY" == "$RAND_KEY" ]; then
+ rm $RAND_KEY
+fi
--
2.21.0