summary refs log tree commit diff
path: root/certs/Kconfig
diff options
context:
space:
mode:
authorStefan Berger <stefanb@linux.ibm.com>2021-06-29 17:34:21 -0400
committerJarkko Sakkinen <jarkko@kernel.org>2021-08-23 19:55:42 +0300
commita4aed36ed5924a05ecfadc470584188bfba2b928 (patch)
treefa716ef69d3f3ff29aeae2019b6c74164eac5557 /certs/Kconfig
parentea35e0d5df6c92fa2e124bb1b91d09b2240715ba (diff)
downloadlinux-a4aed36ed5924a05ecfadc470584188bfba2b928.tar.gz
certs: Add support for using elliptic curve keys for signing modules
Add support for using elliptic curve keys for signing modules. It uses
a NIST P384 (secp384r1) key if the user chooses an elliptic curve key
and will have ECDSA support built into the kernel.

Note: A developer choosing an ECDSA key for signing modules should still
delete the signing key (rm certs/signing_key.*) when building an older
version of a kernel that only supports RSA keys. Unless kbuild automati-
cally detects and generates a new kernel module key, ECDSA-signed kernel
modules will fail signature verification.

Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'certs/Kconfig')
-rw-r--r--certs/Kconfig26
1 files changed, 26 insertions, 0 deletions
diff --git a/certs/Kconfig b/certs/Kconfig
index f4e61116f94e..ae7f2e876a31 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -15,6 +15,32 @@ config MODULE_SIG_KEY
          then the kernel will automatically generate the private key and
          certificate as described in Documentation/admin-guide/module-signing.rst
 
+choice
+	prompt "Type of module signing key to be generated"
+	default MODULE_SIG_KEY_TYPE_RSA
+	help
+	 The type of module signing key type to generate. This option
+	 does not apply if a #PKCS11 URI is used.
+
+config MODULE_SIG_KEY_TYPE_RSA
+	bool "RSA"
+	depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
+	help
+	 Use an RSA key for module signing.
+
+config MODULE_SIG_KEY_TYPE_ECDSA
+	bool "ECDSA"
+	select CRYPTO_ECDSA
+	depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
+	help
+	 Use an elliptic curve key (NIST P384) for module signing. Consider
+	 using a strong hash like sha256 or sha384 for hashing modules.
+
+	 Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
+	 when falling back to building Linux 5.14 and older kernels.
+
+endchoice
+
 config SYSTEM_TRUSTED_KEYRING
 	bool "Provide system-wide ring of trusted keys"
 	depends on KEYS