MODSIGN: Use the same digest for the autogen key sig as for the module sig (5e8cb1e4) · Commits · 戴 / test

Use the same digest type for the autogenerated key signature as for the module signature so that the hash algorithm is guaranteed to be present in the kernel. Without this, the X.509 certificate loader may reject the X.509 certificate so generated because it was self-signed and the signature will be checked against itself - but this won't work if the digest algorithm must be loaded as a module. The symptom is that the key fails to load with the following message emitted into the kernel log: MODSIGN: Problem loading in-kernel X.509 certificate (-65) the error in brackets being -ENOPKG. What you should see is something like: MODSIGN: Loaded cert 'Magarathea: Glacier signing key: 9588321144239a119d3406d4c4cf1fbae1836fa0' Note that this doesn't apply to certificates that are not self-signed as we don't check those currently as they require the parent CA certificate to be available. Reported-by:

Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:

David Howells <dhowells@redhat.com> Signed-off-by:

Rusty Russell <rusty@rustcorp.com.au>

kernel/Makefile

+21 −1

Original line number	Diff line number	Diff line
		@@ -149,6 +149,26 @@ kernel/modsign_pubkey.o: signing_key.x509 extra_certificates
		# fail and that the kernel may be used afterwards.
		#
		###############################################################################
		sign_key_with_hash :=
		ifeq ($(CONFIG_MODULE_SIG_SHA1),y)
		sign_key_with_hash := -sha1
		endif
		ifeq ($(CONFIG_MODULE_SIG_SHA224),y)
		sign_key_with_hash := -sha224
		endif
		ifeq ($(CONFIG_MODULE_SIG_SHA256),y)
		sign_key_with_hash := -sha256
		endif
		ifeq ($(CONFIG_MODULE_SIG_SHA384),y)
		sign_key_with_hash := -sha384
		endif
		ifeq ($(CONFIG_MODULE_SIG_SHA512),y)
		sign_key_with_hash := -sha512
		endif
		ifeq ($(sign_key_with_hash),)
		$(error Could not determine digest type to use from kernel config)
		endif

		signing_key.priv signing_key.x509: x509.genkey
		@echo "###"
		@echo "### Now generating an X.509 key pair to be used for signing modules."
		@@ -160,7 +180,7 @@ signing_key.priv signing_key.x509: x509.genkey
		@echo "###"
		@echo "### rngd -r /dev/hwrandom"
		@echo "###"
		openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
		openssl req -new -nodes -utf8 $(sign_key_with_hash) -days 36500 -batch \
		-x509 -config x509.genkey \
		-outform DER -out signing_key.x509 \
		-keyout signing_key.priv

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