| Message ID | 20210628214304.4165769-3-stefanb@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for ECDSA-signed kernel modules | expand |
On Mon, Jun 28, 2021 at 05:43:04PM -0400, Stefan Berger wrote: > From: Stefan Berger <stefanb@linux.ibm.com> > > 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. > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> > Cc: David Howells <dhowells@redhat.com> > Cc: David Woodhouse <dwmw2@infradead.org> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> > --- When you change the patches, you should remove all reviewed-by etc. tags. Also, move Cc-tags before your sob. /Jarkko > certs/Kconfig | 26 ++++++++++++++++++++++++++ > certs/Makefile | 13 +++++++++++++ > crypto/asymmetric_keys/pkcs7_parser.c | 8 ++++++++ > 3 files changed, 47 insertions(+) > > diff --git a/certs/Kconfig b/certs/Kconfig > index f4e61116f94e..916cbb1af928 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 5.11 and older kernels. > + > +endchoice > + > config SYSTEM_TRUSTED_KEYRING > bool "Provide system-wide ring of trusted keys" > depends on KEYS > diff --git a/certs/Makefile b/certs/Makefile > index f9344e52ecda..279433783b10 100644 > --- a/certs/Makefile > +++ b/certs/Makefile > @@ -66,9 +66,21 @@ ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") > > ifeq ($(openssl_available),yes) > X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null) > +endif > > +# Support user changing key type > +ifdef CONFIG_MODULE_SIG_KEY_TYPE_ECDSA > +keytype_openssl = -newkey ec -pkeyopt ec_paramgen_curve:secp384r1 > +ifeq ($(openssl_available),yes) > +$(if $(findstring id-ecPublicKey,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem")) > +endif > +endif # CONFIG_MODULE_SIG_KEY_TYPE_ECDSA > + > +ifdef CONFIG_MODULE_SIG_KEY_TYPE_RSA > +ifeq ($(openssl_available),yes) > $(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem")) > endif > +endif # CONFIG_MODULE_SIG_KEY_TYPE_RSA > > $(obj)/signing_key.pem: $(obj)/x509.genkey > @$(kecho) "###" > @@ -83,6 +95,7 @@ $(obj)/signing_key.pem: $(obj)/x509.genkey > -batch -x509 -config $(obj)/x509.genkey \ > -outform PEM -out $(obj)/signing_key.pem \ > -keyout $(obj)/signing_key.pem \ > + $(keytype_openssl) \ > $($(quiet)redirect_openssl) > @$(kecho) "###" > @$(kecho) "### Key pair generated." > diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c > index 967329e0a07b..6592279d839a 100644 > --- a/crypto/asymmetric_keys/pkcs7_parser.c > +++ b/crypto/asymmetric_keys/pkcs7_parser.c > @@ -269,6 +269,14 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen, > ctx->sinfo->sig->pkey_algo = "rsa"; > ctx->sinfo->sig->encoding = "pkcs1"; > break; > + case OID_id_ecdsa_with_sha1: > + case OID_id_ecdsa_with_sha224: > + case OID_id_ecdsa_with_sha256: > + case OID_id_ecdsa_with_sha384: > + case OID_id_ecdsa_with_sha512: > + ctx->sinfo->sig->pkey_algo = "ecdsa"; > + ctx->sinfo->sig->encoding = "x962"; > + break; > default: > printk("Unsupported pkey algo: %u\n", ctx->last_oid); > return -ENOPKG; > -- > 2.31.1 > >
diff --git a/certs/Kconfig b/certs/Kconfig index f4e61116f94e..916cbb1af928 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 5.11 and older kernels. + +endchoice + config SYSTEM_TRUSTED_KEYRING bool "Provide system-wide ring of trusted keys" depends on KEYS diff --git a/certs/Makefile b/certs/Makefile index f9344e52ecda..279433783b10 100644 --- a/certs/Makefile +++ b/certs/Makefile @@ -66,9 +66,21 @@ ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") ifeq ($(openssl_available),yes) X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null) +endif +# Support user changing key type +ifdef CONFIG_MODULE_SIG_KEY_TYPE_ECDSA +keytype_openssl = -newkey ec -pkeyopt ec_paramgen_curve:secp384r1 +ifeq ($(openssl_available),yes) +$(if $(findstring id-ecPublicKey,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem")) +endif +endif # CONFIG_MODULE_SIG_KEY_TYPE_ECDSA + +ifdef CONFIG_MODULE_SIG_KEY_TYPE_RSA +ifeq ($(openssl_available),yes) $(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem")) endif +endif # CONFIG_MODULE_SIG_KEY_TYPE_RSA $(obj)/signing_key.pem: $(obj)/x509.genkey @$(kecho) "###" @@ -83,6 +95,7 @@ $(obj)/signing_key.pem: $(obj)/x509.genkey -batch -x509 -config $(obj)/x509.genkey \ -outform PEM -out $(obj)/signing_key.pem \ -keyout $(obj)/signing_key.pem \ + $(keytype_openssl) \ $($(quiet)redirect_openssl) @$(kecho) "###" @$(kecho) "### Key pair generated." diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c index 967329e0a07b..6592279d839a 100644 --- a/crypto/asymmetric_keys/pkcs7_parser.c +++ b/crypto/asymmetric_keys/pkcs7_parser.c @@ -269,6 +269,14 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen, ctx->sinfo->sig->pkey_algo = "rsa"; ctx->sinfo->sig->encoding = "pkcs1"; break; + case OID_id_ecdsa_with_sha1: + case OID_id_ecdsa_with_sha224: + case OID_id_ecdsa_with_sha256: + case OID_id_ecdsa_with_sha384: + case OID_id_ecdsa_with_sha512: + ctx->sinfo->sig->pkey_algo = "ecdsa"; + ctx->sinfo->sig->encoding = "x962"; + break; default: printk("Unsupported pkey algo: %u\n", ctx->last_oid); return -ENOPKG;