Package split

debian/changelog

@@ -1,3 +1,11 @@
+safeboot (0.9) unstable; urgency=medium
+
+  * Add enrollment server functionality
+  * Add helper scripts for enrolled host credential bootstrapping
+  * Split Debian packaging
+
+ -- Nico Williams <[email protected]>  Wed, 24 Nov 2021 16:22:53 -0600
+
 safeboot (0.8) unstable; urgency=medium
 
   * `tpm2-attest` and `attest-server` to perform attestations

debian/control

@@ -9,10 +9,55 @@ Homepage: https://github.com/osresearch/safeboot/
 #Vcs-Git: https://salsa.debian.org/debian/safeboot.git
 
 Package: safeboot
-Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}, efitools, opensc, yubico-piv-tool, libengine-pkcs11-openssl, uuid, binutils, libqrencode-dev, libjson-c4, libcurl4
+Architecture: all
+Depends: ${shlibs:Depends}, ${misc:Depends}, binutils, safeboot-tpm2-tools | tpm2-tools (>= 5.1.1), safeboot-tpm2-totp | tpm2-totp (>= 3.1.0)
+Description: Common (core) package for Safeboot
+ Safeboot is a collection of utilities and services for securing the boot
+ process.
+
+Package: safeboot-boot
+Architecture: all
+Breaks: safeboot (<<0.9)
+Replaces: safeboot (<<0.9)
+Depends: ${shlibs:Depends}, ${misc:Depends}, safeboot, efitools, opensc, yubico-piv-tool, libengine-pkcs11-openssl, uuid, binutils, libqrencode-dev, libjson-c4, libcurl4
 Description: Boot Linux more safely
  Makes the Linux boot process slightly safer by enabling UEFI Secure Boot,
  signing kernel and initrd with Yubikey hardware tokens, storing disk
  encryption secrets in the TPM, and preventing persistence with 
  dmverity read-only root filesystems.
+
+Package: safeboot-attest-client
+Architecture: all
+Breaks: safeboot (<<0.9)
+Replaces: safeboot (<<0.9)
+Depends: ${shlibs:Depends}, ${misc:Depends}, safeboot
+Description: Safeboot attestation client
+ Attestation client for Safeboot, which is intended to be used for securely
+ fetching local filesystem encryption keys (including for the root
+ filesystem), and other secrets (including device credentials).
+
+Package: safeboot-attest-server
+Architecture: all
+Breaks: safeboot (<<0.9)
+Replaces: safeboot (<<0.9)
+Depends: ${shlibs:Depends}, ${misc:Depends}, safeboot
+Description: Safeboot attestation server
+ Enrollment and attestation server for Safeboot, which is intended to be
+ used for securely fetching local filesystem encryption keys (including for
+ the root filesyste), and other secrets (including device credentials).
+
+Package: safeboot-tpm2-tools
+Architecture: any
+Breaks: safeboot (<<0.9)
+Replaces: safeboot (<<0.9)
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: tpm2-tools at version needed by Safeboot
+ Safeboot depends on more recent versions of tpm2-tools than are packaged.
+
+Package: safeboot-tpm2-totp
+Architecture: any
+Breaks: safeboot (<<0.9)
+Replaces: safeboot (<<0.9)
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: tpm2-totp at version needed by Safeboot
+ Safeboot depends on more recent versions of tpm2-totp than are packaged.

debian/safeboot-attest-client.install

@@ -0,0 +1,6 @@
+# shell script commands
+sbin/tpm2-attest		usr/sbin/
+sbin/tpm2-pcr-validate		usr/sbin/
+
+# libexec shell scripts
+sbin/getkeytab			usr/libexec/safeboot/

debian/safeboot-attest-server.install

@@ -0,0 +1,14 @@
+# shell scripts in the tree
+sbin/attest-enroll		usr/sbin/
+sbin/attest-verify
+sbin/attest-server		usr/sbin/
+# XXX
+sbin/attest-server-sub.py	usr/sbin/
+
+# These are delivered by safeboot-attest-client for now until we split them up
+# sbin/tpm2-attest		usr/sbin/
+# sbin/tpm2-pcr-validate		usr/sbin/
+
+# libexec shell scripts
+sbin/gencert			usr/libexec/safeboot/
+sbin/genkeytab			usr/libexec/safeboot/

debian/install → debian/safeboot-boot.install

@@ -1,26 +1,13 @@
 # shell scripts in the tree
 sbin/safeboot			usr/sbin/
 sbin/safeboot-tpm-unseal	usr/sbin/
-sbin/tpm2-attest		usr/sbin/
-sbin/tpm2-pcr-validate		usr/sbin/
-
-# configuration files and helper functions
-safeboot.conf			etc/safeboot/
-functions.sh			etc/safeboot/
-
-# TPM certs and a script to refresh them
-tpm-certs.txt			etc/safeboot/
-refresh-certs			etc/safeboot/
-certs/*				etc/safeboot/certs/
 
 # Compiled with modifications from source
 # to add support for the pkcs11 engine (sbsign),
 # hostnames and small qrcodes (tpm2-totp), 
 # and bundle all tpm2 applications in a single script (tpm2)
 bin/sbsign.safeboot		usr/sbin/
 bin/sign-efi-sig-list.safeboot	usr/sbin/
-bin/tpm2-totp			usr/sbin/
-bin/tpm2			usr/sbin/
 
 # scripts to interface with secure boot in the initramfs
 initramfs/hooks/dmverity-root	etc/initramfs-tools/hooks/

debian/safeboot-tpm2-tools.install

@@ -0,0 +1,5 @@
+# Compiled with modifications from source
+# to add support for the pkcs11 engine (sbsign),
+# hostnames and small qrcodes (tpm2-totp), 
+# and bundle all tpm2 applications in a single script (tpm2)
+bin/tpm2			usr/sbin/

debian/safeboot-tpm2-totp.install

@@ -0,0 +1,5 @@
+# Compiled with modifications from source
+# to add support for the pkcs11 engine (sbsign),
+# hostnames and small qrcodes (tpm2-totp), 
+# and bundle all tpm2 applications in a single script (tpm2)
+bin/tpm2-totp			usr/sbin/

debian/safeboot.install

@@ -0,0 +1,8 @@
+# Shell functions library
+functions.sh			etc/safeboot/
+functions.sh			usr/lib/safeboot/
+
+# TPM certs and a script to refresh them
+tpm-certs.txt                   usr/share/safeboot/
+refresh-certs                   usr/share/safeboot/
+certs/*                         usr/share/safeboot/certs/

debian/source/format

@@ -1 +1 @@
-3.0 (quilt)
+3.0 (native)

functions.sh

@@ -24,8 +24,17 @@ safeboot_dir() {
 	[[ -n $1 ]]	\
 	|| die "Internal error in caller of safeboot_dir"
 	case "$1" in
-	bin)	echo "$TOP/bin";;
+	bin)	echo "$TOP/sbin";;
 	lib)	echo "$TOP/lib";;
+	libexec|share)
+		if [[ $TOP = /usr && -d /usr/${1}/safeboot ]]; then
+			echo "/usr/${1}/safeboot"
+		elif [[ -d $TOP/${1} ]]; then
+			echo "$TOP/${1}"
+		else
+			echo "/etc/safeboot"
+		fi;;
+	certs)	echo "$(safeboot_dir libexec)/certs";;
 	etc)	if [[ $TOP = /usr ]]; then
 			echo "/etc/safeboot"
 		elif [[ -d $TOP/etc/safeboot ]]; then

sbin/attest-enroll

@@ -15,13 +15,21 @@ shopt -s extglob
 PROG=${0##*/}
 BINDIR=$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")
 TOP=$(dirname "$BINDIR")
+if [[ $TOP = /usr ]]; then
+	PATH=${TOP}/libexec/safeboot:$PATH
+else
+	PATH=${TOP}/libexec/:$PATH
+fi
 
 if [[ -s $TOP/lib/safeboot/functions.sh ]]; then
 	# shellcheck source=functions.sh
 	. "$TOP/lib/safeboot/functions.sh"
 elif [[ -s $TOP/functions.sh ]]; then
 	# shellcheck source=functions.sh
 	. "$TOP/functions.sh"
+elif [[ -s /etc/safeboot/functions.sh ]]; then
+	# shellcheck source=functions.sh
+	. /etc/safeboot/functions.sh
 else
 	echo "Unable to find Safeboot function library" 1>&2
 	exit 1

sbin/gencert

@@ -15,24 +15,36 @@ if [[ -s $TOP/lib/safeboot/functions.sh ]]; then
 elif [[ -s $TOP/functions.sh ]]; then
 	# shellcheck disable=SC1090 source=functions.sh
 	. "$TOP/functions.sh"
+elif [[ -s /etc/safeboot/functions.sh ]]; then
+	# shellcheck source=functions.sh
+	. /etc/safeboot/functions.sh
 else
 	echo "Unable to find Safeboot function library" 1>&2
 	exit 1
 fi
 
-GENCERT_CRED=PEM-FILE:/etc/safeboot/gencert-ca.pem
+GENCERT_CA_PRIV=
+GENCERT_CA_CERT=PEM-FILE:/etc/safeboot/gencert-ca.pem
 GENCERT_REALM=
 GENCERT_KEY_BITS=2048
 GENCERT_INCLUDE_SAN_PKINIT=true
 GENCERT_INCLUDE_SAN_DNSNAME=false
-GENCERT_EKUS=()
+GENCERT_X509_TOOLING=OpenSSL # Or Heimdal
+declare -a GENCERT_EKUS
 declare -A GENCERT_DOMAIN_REALM
+declare -A POLICIES
+GENCERT_EKUS=()
+GENCERT_DOMAIN_REALM=()
 
-cf=$(safeboot_file etc enroll.conf)
-if [[ -n $cf && -f $cf ]]; then
+if [[ -n ${SAFEBOOT_ENROLL_CONF:-} ]]; then
 	# shellcheck disable=SC1090
-	. "$cf"
-	export SAFEBOOT_ENROLL_CONF="$cf"
+	. "$SAFEBOOT_ENROLL_CONF"
+else
+	cf=$(safeboot_file etc enroll.conf)
+	if [[ -n $cf && -f $cf ]]; then
+		# shellcheck disable=SC1090
+		. "$cf"
+	fi
 fi
 
 die() { echo "skip: $*"; echo >&2 "Error: $PROG" "$@" ; exit 1 ; }
@@ -43,6 +55,23 @@ outdir=$2
 hostname=$3
 shift 3
 
+${GENCERT_INCLUDE_SAN_PKINIT}					\
+|| ${GENCERT_INCLUDE_SAN_DNSNAME}				\
+|| die 'One of GENCERT_INCLUDE_SAN_{PKINIT,DNSNAME} must be set to true'
+
+declare -a hxtool_ca_opts
+declare -a openssl_x509_opts
+
+hxtool_ca_opts=("--ca-certificate=$GENCERT_CA_CERT")
+openssl_x509_opts=("-CA" "$GENCERT_CA_CERT")
+
+if [[ -n $GENCERT_CA_PRIV ]]; then
+	[[ -n $GENCERT_CA_CERT ]]				\
+	|| die "GENCERT_CA_CERT is not set"
+	hxtool_ca_opts+=("--ca-private-key=$GENCERT_CA_PRIV")
+	openssl_x509_opts+=("-CAkey" "$GENCERT_CA_PRIV")
+fi
+
 if [[ -z $GENCERT_REALM ]]; then
 	domain=${hostname}
 	while [[ $domain = *.*.* ]]; do
@@ -60,46 +89,112 @@ if [[ -z $GENCERT_REALM ]]; then
 	|| die "Could not determine realm name for $hostname"
 fi
 
-sans=()
-
 ${GENCERT_INCLUDE_SAN_PKINIT}					\
-&& sans+=(--pk-init-principal="host/$hostname@$GENCERT_REALM")
+&& hxtool_ca_opts+=(--pk-init-principal="host/$hostname@$GENCERT_REALM")
 
 ${GENCERT_INCLUDE_SAN_DNSNAME}					\
-&& sans+=(--hostname="$hostname")
+&& hxtool_ca_opts+=(--hostname="$hostname")
 
-ekus=()
 if ((${#GENCERT_EKUS[@]} > 0)); then
 	for eku in "${GENCERT_EKUS[@]}"; do
-		ekus+=(--eku="$eku")
+		hxtool_ca_opts+=(--eku="$eku")
 	done
 fi
 
+cat > cert-extensions <<EOF
+[client_cert]
+basicConstraints=CA:FALSE
+keyUsage=digitalSignature,keyEncipherment,keyAgreement
+extendedKeyUsage=@eku_section
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid,issuer
+issuerAltName=issuer:copy
+subjectAltName=critical,@subject_alt_section
+
+[eku_section]
+extendedKeyUsage.800=1.3.6.1.5.2.3.4
+extendedKeyUsage.801=1.3.6.1.5.5.7.3.2
+$(
+	for i in "${!GENCERT_EKUS[@]}"; do
+		printf 'extendedKeyUsage.%s=%s\n'		\
+			"$i" "${GENCERT_EKUS[1]}"
+	done
+)
+
+[subject_alt_section]
+$(${GENCERT_INCLUDE_SAN_DNSNAME}	\
+	&& printf 'DNS.1=${ENV::HOST_NAME}\n')
+$(${GENCERT_INCLUDE_SAN_PKINIT}		\
+	&& printf 'otherName.2=1.3.6.1.5.2.2;SEQUENCE:princ_name\n')
+
+[princ_name]
+realm=EXP:0,GeneralString:\${ENV::GENCERT_REALM}
+principal_name=EXP:1,SEQUENCE:principal_seq
+
+[principal_seq]
+name_type=EXP:0,INTEGER:1
+name_string=EXP:1,SEQUENCE:principals
+
+[principals]
+princ0=GeneralString:\${ENV::SERVICE}
+princ1=GeneralString:\${ENV::HOST_NAME}
+EOF
+
 # Generate the private key (and a CSR, which is kind of unnecessary, but...)
-trap 'rm -f cert-req.der cert-key.pem' EXIT
-hxtool request-create						\
-	--subject=''						\
-	--generate-key=rsa					\
-	--key-bits="$GENCERT_KEY_BITS"				\
-	--key="PEM-FILE:$PWD/cert-key.pem"			\
-	cert-req.der						\
-|| die "Could not generate RSA key!"
-# Format and sign the end-entity certificate
-hxtool issue-certificate					\
-	--type=pkinit-client					\
-	--ca-certificate="$GENCERT_CRED"			\
-	--subject=						\
-	"${sans[@]}"						\
-	"${ekus[@]}"						\
-	--ku=digitalSignature					\
-	--lifetime=10y						\
-	--req="PKCS10:cert-req.der"				\
-	--certificate=PEM-FILE:cert.pem				\
-|| die "skip: Could not issue PKINIT certificate for impersonation!"
+trap 'rm -f cert-extensions cert-req cert-key.pem' EXIT
+
+# Try Heimdal's hxtool
+case "$GENCERT_X509_TOOLING" in
+Heimdal)
+	hxtool request-create						\
+		--subject=''						\
+		--generate-key=rsa					\
+		--key-bits="$GENCERT_KEY_BITS"				\
+		--key="PEM-FILE:cert-key.pem"				\
+		cert-req 2>/dev/null					\
+	|| die "Could not generate a key and make a CSR"
+	! hxtool issue-certificate					\
+		"${hxtool_ca_opts[@]}"					\
+		--type=pkinit-client					\
+		--subject=						\
+		--ku=digitalSignature					\
+		--lifetime=10y						\
+		--req="PKCS10:cert-req"					\
+		--certificate=PEM-FILE:cert.pem 2>/dev/null		\
+	|| die "Could not issue certificate"
+	;;
+OpenSSL)
+	openssl genrsa							\
+		-out cert-key.pem 2048					\
+	|| die "Could not make an RSA key"
+	openssl req							\
+		-new							\
+		-batch							\
+		-subj '/'						\
+		-key cert-key.pem					\
+		-out cert-req						\
+	|| die "Could not make a CSR"
+
+	export GENCERT_REALM
+	export HOST_NAME="$hostname"
+	export SERVICE="host"
+
+	openssl x509							\
+		-set_serial "0x$(_rand 16 | bin2hex)"			\
+		"${openssl_x509_opts[@]}"				\
+		-req							\
+		-in cert-req						\
+		-extensions client_cert					\
+		-extfile cert-extensions				\
+		-days 365						\
+		-out cert.pem						\
+	|| die "Could not make a certificate"
+esac
+
 
 # Append the issuer certificate and any other certs in that file to the output
 # so that the full chain is included.
-openssl crl2pkcs7 -nocrl -certfile "${GENCERT_CRED#*:}"		\
+openssl crl2pkcs7 -nocrl -certfile "${GENCERT_CA_CERT#*:}"		\
 | openssl pkcs7 -print_certs >> cert.pem
 
 grep -q PRIVATE cert.pem && die "Private key in cert file?!"