Add image signing framework and open keys

In order to secure the BMC, we need to sign all the images and include a
public key in the package with which to verify future update images.
This commit adds a framework to sign the image files with an open
private key and generates a corresponding public key added to the image.
This isn't secure by itself (since the private key is available), but
additional changes can easily provide their own private key, creating a
secure BMC.

To use a secure private key:
  export BB_ENV_EXTRAWHITE="$BB_ENV_EXTRAWHITE SIGNING_KEY"
  SIGNING_KEY=/path/to/secure/key bitbake obmc-phosphor-image

Resolves openbmc/openbmc#2835
Resolves openbmc/openbmc#2836
Resolves openbmc/openbmc#2837

Change-Id: I28919b7de54e3a32e5efcbb4522fb39731e68384
Signed-off-by: Eddie James <eajames@us.ibm.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>

3 files changed, 60 insertions, 0 deletions

diff --git a/meta-phosphor/common/recipes-phosphor/flash/files/OpenBMC.priv b/meta-phosphor/common/recipes-phosphor/flash/files/OpenBMC.priv
new file mode 100644
index 000000000..223d31809
--- /dev/null
+++ b/meta-phosphor/common/recipes-phosphor/flash/files/OpenBMC.priv
@@ -0,0 +1,16 @@
+-----BEGIN PRIVATE KEY-----
+MIICdwIBADANBgkqhkiG9w0BAQEFAASCAmEwggJdAgEAAoGBAPvSDLu6slkP1gri
+PaeQXL9ysD69J/HjbBCIQ0RPfeWBb75US1tRTjPP0Ub8CtH8ExVf8iF1ulsZA78B
+zIjBYZVp9pyD6LbpZ/hjV7rIH6dTNhoVpdA+F8LzmQ7cyhHG8l2JMvdunwF2uX5k
+D4WDcZt/ITKZNQNavPtmIyD5HprdAgMBAAECgYEAuQkTSi5ZNpAoWz76xtGRFSwU
+zUT4wQi3Mz6tDtjKTYXasiQGa0dHC1M9F8fDu6BZ9W7W4Dc9hArRcdzEighuxoI/
+nZI/0uL89iUEywnDEIHuS6D5JlZaj86/nx9YvQnO8F/seM+MX0EAWVrd5wC7aAF1
+h6Fu7ykZB4ggUjQAWwECQQD+AUiDOEO+8btLJ135dQfSGc5VFcZiequnKWVm6uXt
+rX771hEYjYMjLqWGFg9G4gE3GuABM5chMINuQQUivy8tAkEA/cxfy19XkjtqcMgE
+x/UDt6Nr+Ky/tk+4Y65WxPRDas0uxFOPk/vEjgVmz1k/TAy9G4giisluTvtmltr5
+DCLocQJBAJnRHx9PiD7uVhRJz6/L/iNuOzPtTsi+Loq5F83+O6T15qsM1CeBMsOw
+cM5FN5UeMcwz+yjfHAsePMkcmMaU7jUCQHlg9+N8upXuIo7Dqj2zOU7nMmkgvSNE
+5yuNImRZabC3ZolwaTdd7nf5r1y1Eyec5Ag5yENV6JKPe1Xkbb1XKJECQDngA0h4
+6ATvfP1Vrx4CbP11eKXbCsZ9OGPHSgyvVjn68oY5ZP3uPsIattoN7dE2BRfuJm7m
+F0nIdUAhR0yTfKM=
+-----END PRIVATE KEY-----
diff --git a/meta-phosphor/common/recipes-phosphor/flash/phosphor-image-signing.bb b/meta-phosphor/common/recipes-phosphor/flash/phosphor-image-signing.bb
new file mode 100644
index 000000000..897bfdea4
--- /dev/null
+++ b/meta-phosphor/common/recipes-phosphor/flash/phosphor-image-signing.bb
@@ -0,0 +1,29 @@
+SUMMARY = "OpenBMC image signing public key"
+DESCRIPTION = "Public key information to be included in images for image verification."
+PR = "r1"
+
+inherit allarch
+inherit obmc-phosphor-license
+
+INSECURE_KEY = "${@'${SIGNING_KEY}' == '${STAGING_DIR_NATIVE}${datadir}/OpenBMC.priv'}"
+
+DEPENDS += "openssl-native"
+DEPENDS += "${@oe.utils.conditional('INSECURE_KEY', 'True', 'phosphor-insecure-signing-key-native', '', d)}"
+
+FILES_${PN} += "${sysconfdir}/activationdata/"
+
+SIGNING_KEY ?= "${STAGING_DIR_NATIVE}${datadir}/OpenBMC.priv"
+SIGNING_KEY_TYPE = "${@os.path.splitext(os.path.basename('${SIGNING_KEY}'))[0]}"
+
+do_install() {
+	openssl pkey -in "${SIGNING_KEY}" -pubout -out ${WORKDIR}/publickey
+	echo HashType=RSA-SHA256 > "${WORKDIR}/hashfunc"
+
+	idir="${D}${sysconfdir}/activationdata/${SIGNING_KEY_TYPE}"
+
+	install -d ${idir}
+	install -m 644 ${WORKDIR}/publickey ${idir}
+	install -m 644 ${WORKDIR}/hashfunc ${idir}
+}
+
+SYSROOT_DIRS_append = " ${sysconfdir}"
diff --git a/meta-phosphor/common/recipes-phosphor/flash/phosphor-insecure-signing-key-native.bb b/meta-phosphor/common/recipes-phosphor/flash/phosphor-insecure-signing-key-native.bb
new file mode 100644
index 000000000..55ebe5779
--- /dev/null
+++ b/meta-phosphor/common/recipes-phosphor/flash/phosphor-insecure-signing-key-native.bb
@@ -0,0 +1,15 @@
+SUMMARY = "Insecure private key for testing and development"
+DESCRIPTION = "Do not use this key to sign images."
+PR = "r1"
+
+inherit allarch
+inherit native
+inherit obmc-phosphor-license
+
+SRC_URI += "file://OpenBMC.priv"
+
+do_install() {
+	bbplain "Using an insecure image signing key!"
+	install -d ${D}${datadir}
+	install -m 400 ${WORKDIR}/OpenBMC.priv ${D}${datadir}
+}