Merge tag 'modsign-pkcs7-20150812-3' of...

Merge tag 'modsign-pkcs7-20150812-3' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next

.gitignore

@@ -97,6 +97,7 @@ GTAGS
 # Leavings from module signing
 #
 extra_certificates
+signing_key.pem
 signing_key.priv
 signing_key.x509
 x509.genkey

Documentation/kbuild/kbuild.txt

@@ -174,6 +174,11 @@ The output directory is often set using "O=..." on the commandline.
 
 The value can be overridden in which case the default value is ignored.
 
+KBUILD_SIGN_PIN
+--------------------------------------------------
+This variable allows a passphrase or PIN to be passed to the sign-file
+utility when signing kernel modules, if the private key requires such.
+
 KBUILD_MODPOST_WARN
 --------------------------------------------------
 KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined

Documentation/module-signing.txt

@@ -89,6 +89,32 @@ This has a number of options available:
      their signatures checked without causing a dependency loop.
 
 
+ (4) "File name or PKCS#11 URI of module signing key" (CONFIG_MODULE_SIG_KEY)
+
+     Setting this option to something other than its default of
+     "signing_key.pem" will disable the autogeneration of signing keys and
+     allow the kernel modules to be signed with a key of your choosing.
+     The string provided should identify a file containing both a private
+     key and its corresponding X.509 certificate in PEM form, or — on
+     systems where the OpenSSL ENGINE_pkcs11 is functional — a PKCS#11 URI
+     as defined by RFC7512. In the latter case, the PKCS#11 URI should
+     reference both a certificate and a private key.
+
+     If the PEM file containing the private key is encrypted, or if the
+     PKCS#11 token requries a PIN, this can be provided at build time by
+     means of the KBUILD_SIGN_PIN variable.
+
+
+ (5) "Additional X.509 keys for default system keyring" (CONFIG_SYSTEM_TRUSTED_KEYS)
+
+     This option can be set to the filename of a PEM-encoded file containing
+     additional certificates which will be included in the system keyring by
+     default.
+
+Note that enabling module signing adds a dependency on the OpenSSL devel
+packages to the kernel build processes for the tool that does the signing.
+
+
 =======================
 GENERATING SIGNING KEYS
 =======================
@@ -100,11 +126,11 @@ it can be deleted or stored securely.  The public key gets built into the
 kernel so that it can be used to check the signatures as the modules are
 loaded.
 
-Under normal conditions, the kernel build will automatically generate a new
-keypair using openssl if one does not exist in the files:
+Under normal conditions, when CONFIG_MODULE_SIG_KEY is unchanged from its
+default, the kernel build will automatically generate a new keypair using
+openssl if one does not exist in the file:
 
-	signing_key.priv
-	signing_key.x509
+	signing_key.pem
 
 during the building of vmlinux (the public part of the key needs to be built
 into vmlinux) using parameters in the:
@@ -135,8 +161,12 @@ kernel sources tree and the openssl command.  The following is an example to
 generate the public/private key files:
 
 	openssl req -new -nodes -utf8 -sha256 -days 36500 -batch -x509 \
-	   -config x509.genkey -outform DER -out signing_key.x509 \
-	   -keyout signing_key.priv
+	   -config x509.genkey -outform PEM -out kernel_key.pem \
+	   -keyout kernel_key.pem
+
+The full pathname for the resulting kernel_key.pem file can then be specified
+in the CONFIG_MODULE_SIG_KEY option, and the certificate and key therein will
+be used instead of an autogenerated keypair.
 
 
 =========================
@@ -152,10 +182,9 @@ in a keyring called ".system_keyring" that can be seen by:
 	302d2d52 I------     1 perm 1f010000     0     0 asymmetri Fedora kernel signing key: d69a84e6bce3d216b979e9505b3e3ef9a7118079: X509.RSA a7118079 []
 	...
 
-Beyond the public key generated specifically for module signing, any file
-placed in the kernel source root directory or the kernel build root directory
-whose name is suffixed with ".x509" will be assumed to be an X.509 public key
-and will be added to the keyring.
+Beyond the public key generated specifically for module signing, additional
+trusted certificates can be provided in a PEM-encoded file referenced by the
+CONFIG_SYSTEM_TRUSTED_KEYS configuration option.
 
 Further, the architecture code may take public keys from a hardware store and
 add those in also (e.g. from the UEFI key database).
@@ -181,7 +210,7 @@ To manually sign a module, use the scripts/sign-file tool available in
 the Linux kernel source tree.  The script requires 4 arguments:
 
 	1.  The hash algorithm (e.g., sha256)
-	2.  The private key filename
+	2.  The private key filename or PKCS#11 URI
 	3.  The public key filename
 	4.  The kernel module to be signed
 
@@ -194,6 +223,9 @@ The hash algorithm used does not have to match the one configured, but if it
 doesn't, you should make sure that hash algorithm is either built into the
 kernel or can be loaded without requiring itself.
 
+If the private key requires a passphrase or PIN, it can be provided in the
+$KBUILD_SIGN_PIN environment variable.
+
 
 ============================
 SIGNED MODULES AND STRIPPING

Makefile

@@ -870,10 +870,10 @@ INITRD_COMPRESS-$(CONFIG_RD_LZ4)   := lz4
 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
 
 ifdef CONFIG_MODULE_SIG_ALL
-MODSECKEY = ./signing_key.priv
+MODSECKEY = $(CONFIG_MODULE_SIG_KEY)
 MODPUBKEY = ./signing_key.x509
 export MODPUBKEY
-mod_sign_cmd = perl $(srctree)/scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODSECKEY) $(MODPUBKEY)
+mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODSECKEY) $(MODPUBKEY)
 else
 mod_sign_cmd = true
 endif
@@ -1173,8 +1173,8 @@ MRPROPER_DIRS  += include/config usr/include include/generated          \
 		  arch/*/include/generated .tmp_objdiff
 MRPROPER_FILES += .config .config.old .version .old_version \
 		  Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
-		  signing_key.priv signing_key.x509 x509.genkey		\
-		  extra_certificates signing_key.x509.keyid		\
+		  signing_key.pem signing_key.priv signing_key.x509	\
+		  x509.genkey extra_certificates signing_key.x509.keyid	\
 		  signing_key.x509.signer vmlinux-gdb.py
 
 # clean - Delete most, but leave enough to build external modules

arch/x86/kernel/kexec-bzimage64.c

@@ -536,7 +536,9 @@ static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
 	int ret;
 
 	ret = verify_pefile_signature(kernel, kernel_len,
-				      system_trusted_keyring, &trusted);
+				      system_trusted_keyring,
+				      VERIFYING_KEXEC_PE_SIGNATURE,
+				      &trusted);
 	if (ret < 0)
 		return ret;
 	if (!trusted)

crypto/asymmetric_keys/Makefile

@@ -15,15 +15,21 @@ obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o
 obj-$(CONFIG_X509_CERTIFICATE_PARSER) += x509_key_parser.o
 x509_key_parser-y := \
 	x509-asn1.o \
+	x509_akid-asn1.o \
 	x509_rsakey-asn1.o \
 	x509_cert_parser.o \
 	x509_public_key.o
 
-$(obj)/x509_cert_parser.o: $(obj)/x509-asn1.h $(obj)/x509_rsakey-asn1.h
+$(obj)/x509_cert_parser.o: \
+	$(obj)/x509-asn1.h \
+	$(obj)/x509_akid-asn1.h \
+	$(obj)/x509_rsakey-asn1.h
 $(obj)/x509-asn1.o: $(obj)/x509-asn1.c $(obj)/x509-asn1.h
+$(obj)/x509_akid-asn1.o: $(obj)/x509_akid-asn1.c $(obj)/x509_akid-asn1.h
 $(obj)/x509_rsakey-asn1.o: $(obj)/x509_rsakey-asn1.c $(obj)/x509_rsakey-asn1.h
 
 clean-files	+= x509-asn1.c x509-asn1.h
+clean-files	+= x509_akid-asn1.c x509_akid-asn1.h
 clean-files	+= x509_rsakey-asn1.c x509_rsakey-asn1.h
 
 #

crypto/asymmetric_keys/asymmetric_type.c

@@ -12,6 +12,7 @@
  */
 #include <keys/asymmetric-subtype.h>
 #include <keys/asymmetric-parser.h>
+#include <crypto/public_key.h>
 #include <linux/seq_file.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -20,6 +21,16 @@
 
 MODULE_LICENSE("GPL");
 
+const char *const key_being_used_for[NR__KEY_BEING_USED_FOR] = {
+	[VERIFYING_MODULE_SIGNATURE]		= "mod sig",
+	[VERIFYING_FIRMWARE_SIGNATURE]		= "firmware sig",
+	[VERIFYING_KEXEC_PE_SIGNATURE]		= "kexec PE sig",
+	[VERIFYING_KEY_SIGNATURE]		= "key sig",
+	[VERIFYING_KEY_SELF_SIGNATURE]		= "key self sig",
+	[VERIFYING_UNSPECIFIED_SIGNATURE]	= "unspec sig",
+};
+EXPORT_SYMBOL_GPL(key_being_used_for);
+
 static LIST_HEAD(asymmetric_key_parsers);
 static DECLARE_RWSEM(asymmetric_key_parsers_sem);
 

crypto/asymmetric_keys/pkcs7.asn1

 PKCS7ContentInfo ::= SEQUENCE {
-	contentType	ContentType,
+	contentType	ContentType ({ pkcs7_check_content_type }),
 	content		[0] EXPLICIT SignedData OPTIONAL
 }
 
 ContentType ::= OBJECT IDENTIFIER ({ pkcs7_note_OID })
 
 SignedData ::= SEQUENCE {
-	version			INTEGER,
+	version			INTEGER ({ pkcs7_note_signeddata_version }),
 	digestAlgorithms	DigestAlgorithmIdentifiers,
-	contentInfo		ContentInfo,
+	contentInfo		ContentInfo ({ pkcs7_note_content }),
 	certificates		CHOICE {
 		certSet		[0] IMPLICIT ExtendedCertificatesAndCertificates,
 		certSequence	[2] IMPLICIT Certificates
@@ -21,7 +21,7 @@ SignedData ::= SEQUENCE {
 }
 
 ContentInfo ::= SEQUENCE {
-	contentType	ContentType,
+	contentType	ContentType ({ pkcs7_note_OID }),
 	content		[0] EXPLICIT Data OPTIONAL
 }
 
@@ -68,8 +68,8 @@ SignerInfos ::= CHOICE {
 }
 
 SignerInfo ::= SEQUENCE {
-	version			INTEGER,
-	issuerAndSerialNumber	IssuerAndSerialNumber,
+	version			INTEGER ({ pkcs7_note_signerinfo_version }),
+	sid			SignerIdentifier, -- CMS variant, not PKCS#7
 	digestAlgorithm		DigestAlgorithmIdentifier ({ pkcs7_sig_note_digest_algo }),
 	authenticatedAttributes	CHOICE {
 		aaSet		[0] IMPLICIT SetOfAuthenticatedAttribute
@@ -88,6 +88,12 @@ SignerInfo ::= SEQUENCE {
 	} OPTIONAL
 } ({ pkcs7_note_signed_info })
 
+SignerIdentifier ::= CHOICE {
+	-- RFC5652 sec 5.3
+	issuerAndSerialNumber IssuerAndSerialNumber,
+        subjectKeyIdentifier [0] IMPLICIT SubjectKeyIdentifier
+}
+
 IssuerAndSerialNumber ::= SEQUENCE {
 	issuer			Name ({ pkcs7_sig_note_issuer }),
 	serialNumber		CertificateSerialNumber ({ pkcs7_sig_note_serial })
@@ -95,6 +101,8 @@ IssuerAndSerialNumber ::= SEQUENCE {
 
 CertificateSerialNumber ::= INTEGER
 
+SubjectKeyIdentifier ::= OCTET STRING ({ pkcs7_sig_note_skid })
+
 SetOfAuthenticatedAttribute ::= SET OF AuthenticatedAttribute
 
 AuthenticatedAttribute ::= SEQUENCE {
@@ -103,7 +111,7 @@ AuthenticatedAttribute ::= SEQUENCE {
 }
 
 UnauthenticatedAttribute ::= SEQUENCE {
-	type			OBJECT IDENTIFIER ({ pkcs7_note_OID }),
+	type			OBJECT IDENTIFIER,
 	values			SET OF ANY
 }
 

crypto/asymmetric_keys/pkcs7_key_type.c

@@ -14,16 +14,26 @@
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/key-type.h>
+#include <keys/asymmetric-type.h>
 #include <crypto/pkcs7.h>
 #include <keys/user-type.h>
 #include <keys/system_keyring.h>
 #include "pkcs7_parser.h"
 
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("PKCS#7 testing key type");
+
+static unsigned pkcs7_usage;
+module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO);
+MODULE_PARM_DESC(pkcs7_usage,
+		 "Usage to specify when verifying the PKCS#7 message");
+
 /*
  * Preparse a PKCS#7 wrapped and validated data blob.
  */
 static int pkcs7_preparse(struct key_preparsed_payload *prep)
 {
+	enum key_being_used_for usage = pkcs7_usage;
 	struct pkcs7_message *pkcs7;
 	const void *data, *saved_prep_data;
 	size_t datalen, saved_prep_datalen;
@@ -32,6 +42,11 @@ static int pkcs7_preparse(struct key_preparsed_payload *prep)
 
 	kenter("");
 
+	if (usage >= NR__KEY_BEING_USED_FOR) {
+		pr_err("Invalid usage type %d\n", usage);
+		return -EINVAL;
+	}
+
 	saved_prep_data = prep->data;
 	saved_prep_datalen = prep->datalen;
 	pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
@@ -40,7 +55,7 @@ static int pkcs7_preparse(struct key_preparsed_payload *prep)
 		goto error;
 	}
 
-	ret = pkcs7_verify(pkcs7);
+	ret = pkcs7_verify(pkcs7, usage);
 	if (ret < 0)
 		goto error_free;
 

crypto/asymmetric_keys/pkcs7_parser.c

@@ -33,6 +33,9 @@ struct pkcs7_parse_context {
 	unsigned	raw_serial_size;
 	unsigned	raw_issuer_size;
 	const void	*raw_issuer;
+	const void	*raw_skid;
+	unsigned	raw_skid_size;
+	bool		expect_skid;
 };
 
 /*
@@ -78,6 +81,30 @@ void pkcs7_free_message(struct pkcs7_message *pkcs7)
 }
 EXPORT_SYMBOL_GPL(pkcs7_free_message);
 
+/*
+ * Check authenticatedAttributes are provided or not provided consistently.
+ */
+static int pkcs7_check_authattrs(struct pkcs7_message *msg)
+{
+	struct pkcs7_signed_info *sinfo;
+	bool want;
+
+	sinfo = msg->signed_infos;
+	if (sinfo->authattrs) {
+		want = true;
+		msg->have_authattrs = true;
+	}
+
+	for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
+		if (!!sinfo->authattrs != want)
+			goto inconsistent;
+	return 0;
+
+inconsistent:
+	pr_warn("Inconsistently supplied authAttrs\n");
+	return -EINVAL;
+}
+
 /**
  * pkcs7_parse_message - Parse a PKCS#7 message
  * @data: The raw binary ASN.1 encoded message to be parsed
@@ -110,6 +137,10 @@ struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
 		goto out;
 	}
 
+	ret = pkcs7_check_authattrs(ctx->msg);
+	if (ret < 0)
+		goto out;
+
 	msg = ctx->msg;
 	ctx->msg = NULL;
 
@@ -225,6 +256,100 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
 	return 0;
 }
 
+/*
+ * We only support signed data [RFC2315 sec 9].
+ */
+int pkcs7_check_content_type(void *context, size_t hdrlen,
+			     unsigned char tag,
+			     const void *value, size_t vlen)
+{
+	struct pkcs7_parse_context *ctx = context;
+
+	if (ctx->last_oid != OID_signed_data) {
+		pr_warn("Only support pkcs7_signedData type\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Note the SignedData version
+ */
+int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
+				  unsigned char tag,
+				  const void *value, size_t vlen)
+{
+	struct pkcs7_parse_context *ctx = context;
+	unsigned version;
+
+	if (vlen != 1)
+		goto unsupported;
+
+	ctx->msg->version = version = *(const u8 *)value;
+	switch (version) {
+	case 1:
+		/* PKCS#7 SignedData [RFC2315 sec 9.1]
+		 * CMS ver 1 SignedData [RFC5652 sec 5.1]
+		 */
+		break;
+	case 3:
+		/* CMS ver 3 SignedData [RFC2315 sec 5.1] */
+		break;
+	default:
+		goto unsupported;
+	}
+
+	return 0;
+
+unsupported:
+	pr_warn("Unsupported SignedData version\n");
+	return -EINVAL;
+}
+
+/*
+ * Note the SignerInfo version
+ */
+int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
+				  unsigned char tag,
+				  const void *value, size_t vlen)
+{
+	struct pkcs7_parse_context *ctx = context;
+	unsigned version;
+
+	if (vlen != 1)
+		goto unsupported;
+
+	version = *(const u8 *)value;
+	switch (version) {
+	case 1:
+		/* PKCS#7 SignerInfo [RFC2315 sec 9.2]
+		 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
+		 */
+		if (ctx->msg->version != 1)
+			goto version_mismatch;
+		ctx->expect_skid = false;
+		break;
+	case 3:
+		/* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
+		if (ctx->msg->version == 1)
+			goto version_mismatch;
+		ctx->expect_skid = true;
+		break;
+	default:
+		goto unsupported;
+	}
+
+	return 0;
+
+unsupported:
+	pr_warn("Unsupported SignerInfo version\n");
+	return -EINVAL;
+version_mismatch:
+	pr_warn("SignedData-SignerInfo version mismatch\n");
+	return -EBADMSG;
+}
+
 /*
  * Extract a certificate and store it in the context.
  */
@@ -283,6 +408,25 @@ int pkcs7_note_certificate_list(void *context, size_t hdrlen,
 	return 0;
 }
 
+/*
+ * Note the content type.
+ */
+int pkcs7_note_content(void *context, size_t hdrlen,
+		       unsigned char tag,
+		       const void *value, size_t vlen)
+{
+	struct pkcs7_parse_context *ctx = context;
+
+	if (ctx->last_oid != OID_data &&
+	    ctx->last_oid != OID_msIndirectData) {
+		pr_warn("Unsupported data type %d\n", ctx->last_oid);
+		return -EINVAL;
+	}
+
+	ctx->msg->data_type = ctx->last_oid;
+	return 0;
+}
+
 /*
  * Extract the data from the message and store that and its content type OID in
  * the context.
@@ -298,45 +442,119 @@ int pkcs7_note_data(void *context, size_t hdrlen,
 	ctx->msg->data = value;
 	ctx->msg->data_len = vlen;
 	ctx->msg->data_hdrlen = hdrlen;
-	ctx->msg->data_type = ctx->last_oid;
 	return 0;
 }
 
 /*
- * Parse authenticated attributes
+ * Parse authenticated attributes.
  */
 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
 				      unsigned char tag,
 				      const void *value, size_t vlen)
 {
 	struct pkcs7_parse_context *ctx = context;
+	struct pkcs7_signed_info *sinfo = ctx->sinfo;
+	enum OID content_type;
 
 	pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
 
 	switch (ctx->last_oid) {
+	case OID_contentType:
+		if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
+			goto repeated;
+		content_type = look_up_OID(value, vlen);
+		if (content_type != ctx->msg->data_type) {
+			pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
+				ctx->msg->data_type, sinfo->index,
+				content_type);
+			return -EBADMSG;
+		}
+		return 0;
+
+	case OID_signingTime:
+		if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
+			goto repeated;
+		/* Should we check that the signing time is consistent
+		 * with the signer's X.509 cert?
+		 */
+		return x509_decode_time(&sinfo->signing_time,
+					hdrlen, tag, value, vlen);
+
 	case OID_messageDigest:
+		if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
+			goto repeated;
 		if (tag != ASN1_OTS)
 			return -EBADMSG;
-		ctx->sinfo->msgdigest = value;
-		ctx->sinfo->msgdigest_len = vlen;
+		sinfo->msgdigest = value;
+		sinfo->msgdigest_len = vlen;
+		return 0;
+
+	case OID_smimeCapabilites:
+		if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
+			goto repeated;
+		if (ctx->msg->data_type != OID_msIndirectData) {
+			pr_warn("S/MIME Caps only allowed with Authenticode\n");
+			return -EKEYREJECTED;
+		}
+		return 0;
+
+		/* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
+		 * char URLs and cont[1] 8-bit char URLs.
+		 *
+		 * Microsoft StatementType seems to contain a list of OIDs that
+		 * are also used as extendedKeyUsage types in X.509 certs.
+		 */
+	case OID_msSpOpusInfo:
+		if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
+			goto repeated;
+		goto authenticode_check;
+	case OID_msStatementType:
+		if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
+			goto repeated;
+	authenticode_check:
+		if (ctx->msg->data_type != OID_msIndirectData) {
+			pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
+			return -EKEYREJECTED;
+		}
+		/* I'm not sure how to validate these */
 		return 0;
 	default:
 		return 0;
 	}
+
+repeated:
+	/* We permit max one item per AuthenticatedAttribute and no repeats */
+	pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
+	return -EKEYREJECTED;
 }
 
 /*
- * Note the set of auth attributes for digestion purposes [RFC2315 9.3]
+ * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
  */
 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
 				    unsigned char tag,
 				    const void *value, size_t vlen)
 {
 	struct pkcs7_parse_context *ctx = context;
+	struct pkcs7_signed_info *sinfo = ctx->sinfo;
+
+	if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
+	    !test_bit(sinfo_has_message_digest, &sinfo->aa_set) ||
+	    (ctx->msg->data_type == OID_msIndirectData &&
+	     !test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))) {
+		pr_warn("Missing required AuthAttr\n");
+		return -EBADMSG;
+	}
+
+	if (ctx->msg->data_type != OID_msIndirectData &&
+	    test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
+		pr_warn("Unexpected Authenticode AuthAttr\n");
+		return -EBADMSG;
+	}
 
 	/* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
-	ctx->sinfo->authattrs = value - (hdrlen - 1);
-	ctx->sinfo->authattrs_len = vlen + (hdrlen - 1);
+	sinfo->authattrs = value - (hdrlen - 1);
+	sinfo->authattrs_len = vlen + (hdrlen - 1);
 	return 0;
 }
 
@@ -366,6 +584,22 @@ int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
 	return 0;
 }
 
+/*
+ * Note the issuing cert's subjectKeyIdentifier
+ */
+int pkcs7_sig_note_skid(void *context, size_t hdrlen,
+			unsigned char tag,
+			const void *value, size_t vlen)
+{
+	struct pkcs7_parse_context *ctx = context;
+
+	pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
+
+	ctx->raw_skid = value;
+	ctx->raw_skid_size = vlen;
+	return 0;
+}
+
 /*
  * Note the signature data
  */
@@ -398,14 +632,27 @@ int pkcs7_note_signed_info(void *context, size_t hdrlen,
 	struct pkcs7_signed_info *sinfo = ctx->sinfo;
 	struct asymmetric_key_id *kid;
 
+	if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
+		pr_warn("Authenticode requires AuthAttrs\n");
+		return -EBADMSG;
+	}
+
 	/* Generate cert issuer + serial number key ID */
-	kid = asymmetric_key_generate_id(ctx->raw_serial,
-					 ctx->raw_serial_size,
-					 ctx->raw_issuer,
-					 ctx->raw_issuer_size);
+	if (!ctx->expect_skid) {
+		kid = asymmetric_key_generate_id(ctx->raw_serial,
+						 ctx->raw_serial_size,
+						 ctx->raw_issuer,
+						 ctx->raw_issuer_size);
+	} else {
+		kid = asymmetric_key_generate_id(ctx->raw_skid,
+						 ctx->raw_skid_size,
+						 "", 0);
+	}
 	if (IS_ERR(kid))
 		return PTR_ERR(kid);
 
+	pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
+
 	sinfo->signing_cert_id = kid;
 	sinfo->index = ++ctx->sinfo_index;
 	*ctx->ppsinfo = sinfo;

crypto/asymmetric_keys/pkcs7_parser.h

@@ -21,9 +21,9 @@
 struct pkcs7_signed_info {
 	struct pkcs7_signed_info *next;
 	struct x509_certificate *signer; /* Signing certificate (in msg->certs) */
-	unsigned index;
-	bool trusted;
-	bool unsupported_crypto;	/* T if not usable due to missing crypto */
+	unsigned	index;
+	bool		trusted;
+	bool		unsupported_crypto;	/* T if not usable due to missing crypto */
 
 	/* Message digest - the digest of the Content Data (or NULL) */
 	const void	*msgdigest;
@@ -32,8 +32,18 @@ struct pkcs7_signed_info {
 	/* Authenticated Attribute data (or NULL) */
 	unsigned	authattrs_len;
 	const void	*authattrs;
+	unsigned long	aa_set;
+#define	sinfo_has_content_type		0
+#define	sinfo_has_signing_time		1
+#define	sinfo_has_message_digest	2
+#define sinfo_has_smime_caps		3
+#define	sinfo_has_ms_opus_info		4
+#define	sinfo_has_ms_statement_type	5
+	time64_t	signing_time;
 
-	/* Issuing cert serial number and issuer's name */
+	/* Issuing cert serial number and issuer's name [PKCS#7 or CMS ver 1]
+	 * or issuing cert's SKID [CMS ver 3].
+	 */
 	struct asymmetric_key_id *signing_cert_id;
 
 	/* Message signature.
@@ -50,6 +60,8 @@ struct pkcs7_message {
 	struct x509_certificate *certs;	/* Certificate list */
 	struct x509_certificate *crl;	/* Revocation list */
 	struct pkcs7_signed_info *signed_infos;
+	u8		version;	/* Version of cert (1 -> PKCS#7 or CMS; 3 -> CMS) */
+	bool		have_authattrs;	/* T if have authattrs */
 
 	/* Content Data (or NULL) */
 	enum OID	data_type;	/* Type of Data */

crypto/asymmetric_keys/pkcs7_trust.c

@@ -54,7 +54,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
 		/* Look to see if this certificate is present in the trusted
 		 * keys.
 		 */
-		key = x509_request_asymmetric_key(trust_keyring, x509->id,
+		key = x509_request_asymmetric_key(trust_keyring,
+						  x509->id, x509->skid,
 						  false);
 		if (!IS_ERR(key)) {
 			/* One of the X.509 certificates in the PKCS#7 message
@@ -85,8 +86,10 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
 	/* No match - see if the root certificate has a signer amongst the
 	 * trusted keys.
 	 */
-	if (last && last->authority) {
-		key = x509_request_asymmetric_key(trust_keyring, last->authority,
+	if (last && (last->akid_id || last->akid_skid)) {
+		key = x509_request_asymmetric_key(trust_keyring,
+						  last->akid_id,
+						  last->akid_skid,
 						  false);
 		if (!IS_ERR(key)) {
 			x509 = last;
@@ -103,6 +106,7 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
 	 */
 	key = x509_request_asymmetric_key(trust_keyring,
 					  sinfo->signing_cert_id,
+					  NULL,
 					  false);
 	if (!IS_ERR(key)) {
 		pr_devel("sinfo %u: Direct signer is key %x\n",

crypto/asymmetric_keys/pkcs7_verify.c

@@ -70,9 +70,15 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
 	 * message digest attribute amongst them which corresponds to the
 	 * digest we just calculated.
 	 */
-	if (sinfo->msgdigest) {
+	if (sinfo->authattrs) {
 		u8 tag;
 
+		if (!sinfo->msgdigest) {
+			pr_warn("Sig %u: No messageDigest\n", sinfo->index);
+			ret = -EKEYREJECTED;
+			goto error;
+		}
+
 		if (sinfo->msgdigest_len != sinfo->sig.digest_size) {
 			pr_debug("Sig %u: Invalid digest size (%u)\n",
 				 sinfo->index, sinfo->msgdigest_len);
@@ -170,6 +176,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
 				  struct pkcs7_signed_info *sinfo)
 {
 	struct x509_certificate *x509 = sinfo->signer, *p;
+	struct asymmetric_key_id *auth;
 	int ret;
 
 	kenter("");
@@ -187,11 +194,14 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
 			goto maybe_missing_crypto_in_x509;
 
 		pr_debug("- issuer %s\n", x509->issuer);
-		if (x509->authority)
-			pr_debug("- authkeyid %*phN\n",
-				 x509->authority->len, x509->authority->data);
-
-		if (!x509->authority ||
+		if (x509->akid_id)
+			pr_debug("- authkeyid.id %*phN\n",
+				 x509->akid_id->len, x509->akid_id->data);
+		if (x509->akid_skid)
+			pr_debug("- authkeyid.skid %*phN\n",
+				 x509->akid_skid->len, x509->akid_skid->data);
+
+		if ((!x509->akid_id && !x509->akid_skid) ||
 		    strcmp(x509->subject, x509->issuer) == 0) {
 			/* If there's no authority certificate specified, then
 			 * the certificate must be self-signed and is the root
@@ -215,21 +225,42 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
 		/* Look through the X.509 certificates in the PKCS#7 message's
 		 * list to see if the next one is there.
 		 */
-		pr_debug("- want %*phN\n",
-			 x509->authority->len, x509->authority->data);
-		for (p = pkcs7->certs; p; p = p->next) {
-			if (!p->skid)
-				continue;
-			pr_debug("- cmp [%u] %*phN\n",
-				 p->index, p->skid->len, p->skid->data);
-			if (asymmetric_key_id_same(p->skid, x509->authority))
-				goto found_issuer;
+		auth = x509->akid_id;
+		if (auth) {
+			pr_debug("- want %*phN\n", auth->len, auth->data);
+			for (p = pkcs7->certs; p; p = p->next) {
+				pr_debug("- cmp [%u] %*phN\n",
+					 p->index, p->id->len, p->id->data);
+				if (asymmetric_key_id_same(p->id, auth))
+					goto found_issuer_check_skid;
+			}
+		} else {
+			auth = x509->akid_skid;
+			pr_debug("- want %*phN\n", auth->len, auth->data);
+			for (p = pkcs7->certs; p; p = p->next) {
+				if (!p->skid)
+					continue;
+				pr_debug("- cmp [%u] %*phN\n",
+					 p->index, p->skid->len, p->skid->data);
+				if (asymmetric_key_id_same(p->skid, auth))
+					goto found_issuer;
+			}
 		}
 
 		/* We didn't find the root of this chain */
 		pr_debug("- top\n");
 		return 0;
 
+	found_issuer_check_skid:
+		/* We matched issuer + serialNumber, but if there's an
+		 * authKeyId.keyId, that must match the CA subjKeyId also.
+		 */
+		if (x509->akid_skid &&
+		    !asymmetric_key_id_same(p->skid, x509->akid_skid)) {
+			pr_warn("Sig %u: X.509 chain contains auth-skid nonmatch (%u->%u)\n",
+				sinfo->index, x509->index, p->index);
+			return -EKEYREJECTED;
+		}
 	found_issuer:
 		pr_debug("- subject %s\n", p->subject);
 		if (p->seen) {
@@ -289,6 +320,18 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
 	pr_devel("Using X.509[%u] for sig %u\n",
 		 sinfo->signer->index, sinfo->index);
 
+	/* Check that the PKCS#7 signing time is valid according to the X.509
+	 * certificate.  We can't, however, check against the system clock
+	 * since that may not have been set yet and may be wrong.
+	 */
+	if (test_bit(sinfo_has_signing_time, &sinfo->aa_set)) {
+		if (sinfo->signing_time < sinfo->signer->valid_from ||
+		    sinfo->signing_time > sinfo->signer->valid_to) {
+			pr_warn("Message signed outside of X.509 validity window\n");
+			return -EKEYREJECTED;
+		}
+	}
+
 	/* Verify the PKCS#7 binary against the key */
 	ret = public_key_verify_signature(sinfo->signer->pub, &sinfo->sig);
 	if (ret < 0)
@@ -303,6 +346,7 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
 /**
  * pkcs7_verify - Verify a PKCS#7 message
  * @pkcs7: The PKCS#7 message to be verified
+ * @usage: The use to which the key is being put
  *
  * Verify a PKCS#7 message is internally consistent - that is, the data digest
  * matches the digest in the AuthAttrs and any signature in the message or one
@@ -314,6 +358,9 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
  *
  * Returns, in order of descending priority:
  *
+ *  (*) -EKEYREJECTED if a key was selected that had a usage restriction at
+ *      odds with the specified usage, or:
+ *
  *  (*) -EKEYREJECTED if a signature failed to match for which we found an
  *	appropriate X.509 certificate, or:
  *
@@ -325,7 +372,8 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
  *  (*) 0 if all the signature chains that don't incur -ENOPKG can be verified
  *	(note that a signature chain may be of zero length), or:
  */
-int pkcs7_verify(struct pkcs7_message *pkcs7)
+int pkcs7_verify(struct pkcs7_message *pkcs7,
+		 enum key_being_used_for usage)
 {
 	struct pkcs7_signed_info *sinfo;
 	struct x509_certificate *x509;
@@ -334,12 +382,48 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
 
 	kenter("");
 
+	switch (usage) {
+	case VERIFYING_MODULE_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid module sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		if (pkcs7->have_authattrs) {
+			pr_warn("Invalid module sig (has authattrs)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	case VERIFYING_FIRMWARE_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid firmware sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		if (!pkcs7->have_authattrs) {
+			pr_warn("Invalid firmware sig (missing authattrs)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	case VERIFYING_KEXEC_PE_SIGNATURE:
+		if (pkcs7->data_type != OID_msIndirectData) {
+			pr_warn("Invalid kexec sig (not Authenticode)\n");
+			return -EKEYREJECTED;
+		}
+		/* Authattr presence checked in parser */
+		break;
+	case VERIFYING_UNSPECIFIED_SIGNATURE:
+		if (pkcs7->data_type != OID_data) {
+			pr_warn("Invalid unspecified sig (not pkcs7-data)\n");
+			return -EKEYREJECTED;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	for (n = 0, x509 = pkcs7->certs; x509; x509 = x509->next, n++) {
 		ret = x509_get_sig_params(x509);
 		if (ret < 0)
 			return ret;
-		pr_debug("X.509[%u] %*phN\n",
-			 n, x509->authority->len, x509->authority->data);
 	}
 
 	for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
@@ -359,3 +443,28 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
 	return enopkg;
 }
 EXPORT_SYMBOL_GPL(pkcs7_verify);
+
+/**
+ * pkcs7_supply_detached_data - Supply the data needed to verify a PKCS#7 message
+ * @pkcs7: The PKCS#7 message
+ * @data: The data to be verified
+ * @datalen: The amount of data
+ *
+ * Supply the detached data needed to verify a PKCS#7 message.  Note that no
+ * attempt to retain/pin the data is made.  That is left to the caller.  The
+ * data will not be modified by pkcs7_verify() and will not be freed when the
+ * PKCS#7 message is freed.
+ *
+ * Returns -EINVAL if data is already supplied in the message, 0 otherwise.
+ */
+int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7,
+			       const void *data, size_t datalen)
+{
+	if (pkcs7->data) {
+		pr_debug("Data already supplied\n");
+		return -EINVAL;
+	}
+	pkcs7->data = data;
+	pkcs7->data_len = datalen;
+	return 0;
+}

crypto/asymmetric_keys/public_key.c

@@ -39,6 +39,7 @@ EXPORT_SYMBOL_GPL(pkey_algo);
 const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
 	[PKEY_ID_PGP]		= "PGP",
 	[PKEY_ID_X509]		= "X509",
+	[PKEY_ID_PKCS7]		= "PKCS#7",
 };
 EXPORT_SYMBOL_GPL(pkey_id_type_name);
 

crypto/asymmetric_keys/verify_pefile.c

@@ -393,6 +393,7 @@ static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
  * @pebuf: Buffer containing the PE binary image
  * @pelen: Length of the binary image
  * @trust_keyring: Signing certificates to use as starting points
+ * @usage: The use to which the key is being put.
  * @_trusted: Set to true if trustworth, false otherwise
  *
  * Validate that the certificate chain inside the PKCS#7 message inside the PE
@@ -417,7 +418,9 @@ static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
  * May also return -ENOMEM.
  */
 int verify_pefile_signature(const void *pebuf, unsigned pelen,
-			    struct key *trusted_keyring, bool *_trusted)
+			    struct key *trusted_keyring,
+			    enum key_being_used_for usage,
+			    bool *_trusted)
 {
 	struct pkcs7_message *pkcs7;
 	struct pefile_context ctx;
@@ -462,7 +465,7 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
 	if (ret < 0)
 		goto error;
 
-	ret = pkcs7_verify(pkcs7);
+	ret = pkcs7_verify(pkcs7, usage);
 	if (ret < 0)
 		goto error;
 

crypto/asymmetric_keys/x509_akid.asn1

+-- X.509 AuthorityKeyIdentifier
+-- rfc5280 section 4.2.1.1
+
+AuthorityKeyIdentifier ::= SEQUENCE {
+	keyIdentifier			[0] IMPLICIT KeyIdentifier		OPTIONAL,
+	authorityCertIssuer		[1] IMPLICIT GeneralNames		OPTIONAL,
+	authorityCertSerialNumber	[2] IMPLICIT CertificateSerialNumber	OPTIONAL
+	}
+
+KeyIdentifier ::= OCTET STRING ({ x509_akid_note_kid })
+
+CertificateSerialNumber ::= INTEGER ({ x509_akid_note_serial })
+
+GeneralNames ::= SEQUENCE OF GeneralName
+
+GeneralName ::= CHOICE {
+	otherName			[0] ANY,
+	rfc822Name			[1] IA5String,
+	dNSName				[2] IA5String,
+	x400Address			[3] ANY,
+	directoryName			[4] Name ({ x509_akid_note_name }),
+	ediPartyName			[5] ANY,
+	uniformResourceIdentifier	[6] IA5String,
+	iPAddress			[7] OCTET STRING,
+	registeredID			[8] OBJECT IDENTIFIER
+	}
+
+Name ::= SEQUENCE OF RelativeDistinguishedName
+
+RelativeDistinguishedName ::= SET OF AttributeValueAssertion
+
+AttributeValueAssertion ::= SEQUENCE {
+	attributeType		OBJECT IDENTIFIER ({ x509_note_OID }),
+	attributeValue		ANY ({ x509_extract_name_segment })
+	}

crypto/asymmetric_keys/x509_cert_parser.c

@@ -18,6 +18,7 @@
 #include "public_key.h"
 #include "x509_parser.h"
 #include "x509-asn1.h"
+#include "x509_akid-asn1.h"
 #include "x509_rsakey-asn1.h"
 
 struct x509_parse_context {
@@ -35,6 +36,10 @@ struct x509_parse_context {
 	u16		o_offset;		/* Offset of organizationName (O) */
 	u16		cn_offset;		/* Offset of commonName (CN) */
 	u16		email_offset;		/* Offset of emailAddress */
+	unsigned	raw_akid_size;
+	const void	*raw_akid;		/* Raw authorityKeyId in ASN.1 */
+	const void	*akid_raw_issuer;	/* Raw directoryName in authorityKeyId */
+	unsigned	akid_raw_issuer_size;
 };
 
 /*
@@ -48,7 +53,8 @@ void x509_free_certificate(struct x509_certificate *cert)
 		kfree(cert->subject);
 		kfree(cert->id);
 		kfree(cert->skid);
-		kfree(cert->authority);
+		kfree(cert->akid_id);
+		kfree(cert->akid_skid);
 		kfree(cert->sig.digest);
 		mpi_free(cert->sig.rsa.s);
 		kfree(cert);
@@ -85,6 +91,18 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
 	if (ret < 0)
 		goto error_decode;
 
+	/* Decode the AuthorityKeyIdentifier */
+	if (ctx->raw_akid) {
+		pr_devel("AKID: %u %*phN\n",
+			 ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
+		ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
+				       ctx->raw_akid, ctx->raw_akid_size);
+		if (ret < 0) {
+			pr_warn("Couldn't decode AuthKeyIdentifier\n");
+			goto error_decode;
+		}
+	}
+
 	/* Decode the public key */
 	ret = asn1_ber_decoder(&x509_rsakey_decoder, ctx,
 			       ctx->key, ctx->key_size);
@@ -422,7 +440,6 @@ int x509_process_extension(void *context, size_t hdrlen,
 	struct x509_parse_context *ctx = context;
 	struct asymmetric_key_id *kid;
 	const unsigned char *v = value;
-	int i;
 
 	pr_debug("Extension: %u\n", ctx->last_oid);
 
@@ -437,9 +454,7 @@ int x509_process_extension(void *context, size_t hdrlen,
 
 		ctx->cert->raw_skid_size = vlen;
 		ctx->cert->raw_skid = v;
-		kid = asymmetric_key_generate_id(ctx->cert->raw_subject,
-						 ctx->cert->raw_subject_size,
-						 v, vlen);
+		kid = asymmetric_key_generate_id(v, vlen, "", 0);
 		if (IS_ERR(kid))
 			return PTR_ERR(kid);
 		ctx->cert->skid = kid;
@@ -449,117 +464,113 @@ int x509_process_extension(void *context, size_t hdrlen,
 
 	if (ctx->last_oid == OID_authorityKeyIdentifier) {
 		/* Get hold of the CA key fingerprint */
-		if (ctx->cert->authority || vlen < 5)
-			return -EBADMSG;
-
-		/* Authority Key Identifier must be a Constructed SEQUENCE */
-		if (v[0] != (ASN1_SEQ | (ASN1_CONS << 5)))
-			return -EBADMSG;
-
-		/* Authority Key Identifier is not indefinite length */
-		if (unlikely(vlen == ASN1_INDEFINITE_LENGTH))
-			return -EBADMSG;
-
-		if (vlen < ASN1_INDEFINITE_LENGTH) {
-			/* Short Form length */
-			if (v[1] != vlen - 2 ||
-			    v[2] != SEQ_TAG_KEYID ||
-			    v[3] > vlen - 4)
-				return -EBADMSG;
-
-			vlen = v[3];
-			v += 4;
-		} else {
-			/* Long Form length */
-			size_t seq_len = 0;
-			size_t sub = v[1] - ASN1_INDEFINITE_LENGTH;
-
-			if (sub > 2)
-				return -EBADMSG;
-
-			/* calculate the length from subsequent octets */
-			v += 2;
-			for (i = 0; i < sub; i++) {
-				seq_len <<= 8;
-				seq_len |= v[i];
-			}
-
-			if (seq_len != vlen - 2 - sub ||
-			    v[sub] != SEQ_TAG_KEYID ||
-			    v[sub + 1] > vlen - 4 - sub)
-				return -EBADMSG;
-
-			vlen = v[sub + 1];
-			v += (sub + 2);
-		}
-
-		kid = asymmetric_key_generate_id(ctx->cert->raw_issuer,
-						 ctx->cert->raw_issuer_size,
-						 v, vlen);
-		if (IS_ERR(kid))
-			return PTR_ERR(kid);
-		pr_debug("authkeyid %*phN\n", kid->len, kid->data);
-		ctx->cert->authority = kid;
+		ctx->raw_akid = v;
+		ctx->raw_akid_size = vlen;
 		return 0;
 	}
 
 	return 0;
 }
 
-/*
- * Record a certificate time.
+/**
+ * x509_decode_time - Decode an X.509 time ASN.1 object
+ * @_t: The time to fill in
+ * @hdrlen: The length of the object header
+ * @tag: The object tag
+ * @value: The object value
+ * @vlen: The size of the object value
+ *
+ * Decode an ASN.1 universal time or generalised time field into a struct the
+ * kernel can handle and check it for validity.  The time is decoded thus:
+ *
+ *	[RFC5280 §4.1.2.5]
+ *	CAs conforming to this profile MUST always encode certificate validity
+ *	dates through the year 2049 as UTCTime; certificate validity dates in
+ *	2050 or later MUST be encoded as GeneralizedTime.  Conforming
+ *	applications MUST be able to process validity dates that are encoded in
+ *	either UTCTime or GeneralizedTime.
  */
-static int x509_note_time(struct tm *tm,  size_t hdrlen,
-			  unsigned char tag,
-			  const unsigned char *value, size_t vlen)
+int x509_decode_time(time64_t *_t,  size_t hdrlen,
+		     unsigned char tag,
+		     const unsigned char *value, size_t vlen)
 {
+	static const unsigned char month_lengths[] = { 31, 29, 31, 30, 31, 30,
+						       31, 31, 30, 31, 30, 31 };
 	const unsigned char *p = value;
+	unsigned year, mon, day, hour, min, sec, mon_len;
 
-#define dec2bin(X) ((X) - '0')
+#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
 #define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
 
 	if (tag == ASN1_UNITIM) {
 		/* UTCTime: YYMMDDHHMMSSZ */
 		if (vlen != 13)
 			goto unsupported_time;
-		tm->tm_year = DD2bin(p);
-		if (tm->tm_year >= 50)
-			tm->tm_year += 1900;
+		year = DD2bin(p);
+		if (year >= 50)
+			year += 1900;
 		else
-			tm->tm_year += 2000;
+			year += 2000;
 	} else if (tag == ASN1_GENTIM) {
 		/* GenTime: YYYYMMDDHHMMSSZ */
 		if (vlen != 15)
 			goto unsupported_time;
-		tm->tm_year = DD2bin(p) * 100 + DD2bin(p);
+		year = DD2bin(p) * 100 + DD2bin(p);
+		if (year >= 1950 && year <= 2049)
+			goto invalid_time;
 	} else {
 		goto unsupported_time;
 	}
 
-	tm->tm_year -= 1900;
-	tm->tm_mon  = DD2bin(p) - 1;
-	tm->tm_mday = DD2bin(p);
-	tm->tm_hour = DD2bin(p);
-	tm->tm_min  = DD2bin(p);
-	tm->tm_sec  = DD2bin(p);
+	mon  = DD2bin(p);
+	day = DD2bin(p);
+	hour = DD2bin(p);
+	min  = DD2bin(p);
+	sec  = DD2bin(p);
 
 	if (*p != 'Z')
 		goto unsupported_time;
 
+	mon_len = month_lengths[mon];
+	if (mon == 2) {
+		if (year % 4 == 0) {
+			mon_len = 29;
+			if (year % 100 == 0) {
+				year /= 100;
+				if (year % 4 != 0)
+					mon_len = 28;
+			}
+		}
+	}
+
+	if (year < 1970 ||
+	    mon < 1 || mon > 12 ||
+	    day < 1 || day > mon_len ||
+	    hour < 0 || hour > 23 ||
+	    min < 0 || min > 59 ||
+	    sec < 0 || sec > 59)
+		goto invalid_time;
+	
+	*_t = mktime64(year, mon, day, hour, min, sec);
 	return 0;
 
 unsupported_time:
-	pr_debug("Got unsupported time [tag %02x]: '%*.*s'\n",
-		 tag, (int)vlen, (int)vlen, value);
+	pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
+		 tag, (int)vlen, value);
+	return -EBADMSG;
+invalid_time:
+	pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
+		 tag, (int)vlen, value);
 	return -EBADMSG;
 }
+EXPORT_SYMBOL_GPL(x509_decode_time);
 
 int x509_note_not_before(void *context, size_t hdrlen,
 			 unsigned char tag,
 			 const void *value, size_t vlen)
 {
 	struct x509_parse_context *ctx = context;
-	return x509_note_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
+	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
 }
 
 int x509_note_not_after(void *context, size_t hdrlen,
@@ -567,5 +578,71 @@ int x509_note_not_after(void *context, size_t hdrlen,
 			const void *value, size_t vlen)
 {
 	struct x509_parse_context *ctx = context;
-	return x509_note_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
+	return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
+}
+
+/*
+ * Note a key identifier-based AuthorityKeyIdentifier
+ */
+int x509_akid_note_kid(void *context, size_t hdrlen,
+		       unsigned char tag,
+		       const void *value, size_t vlen)
+{
+	struct x509_parse_context *ctx = context;
+	struct asymmetric_key_id *kid;
+
+	pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
+
+	if (ctx->cert->akid_skid)
+		return 0;
+
+	kid = asymmetric_key_generate_id(value, vlen, "", 0);
+	if (IS_ERR(kid))
+		return PTR_ERR(kid);
+	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+	ctx->cert->akid_skid = kid;
+	return 0;
+}
+
+/*
+ * Note a directoryName in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_name(void *context, size_t hdrlen,
+			unsigned char tag,
+			const void *value, size_t vlen)
+{
+	struct x509_parse_context *ctx = context;
+
+	pr_debug("AKID: name: %*phN\n", (int)vlen, value);
+
+	ctx->akid_raw_issuer = value;
+	ctx->akid_raw_issuer_size = vlen;
+	return 0;
+}
+
+/*
+ * Note a serial number in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_serial(void *context, size_t hdrlen,
+			  unsigned char tag,
+			  const void *value, size_t vlen)
+{
+	struct x509_parse_context *ctx = context;
+	struct asymmetric_key_id *kid;
+
+	pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
+
+	if (!ctx->akid_raw_issuer || ctx->cert->akid_id)
+		return 0;
+
+	kid = asymmetric_key_generate_id(value,
+					 vlen,
+					 ctx->akid_raw_issuer,
+					 ctx->akid_raw_issuer_size);
+	if (IS_ERR(kid))
+		return PTR_ERR(kid);
+
+	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+	ctx->cert->akid_id = kid;
+	return 0;
 }

crypto/asymmetric_keys/x509_parser.h

@@ -19,11 +19,12 @@ struct x509_certificate {
 	struct public_key_signature sig;	/* Signature parameters */
 	char		*issuer;		/* Name of certificate issuer */
 	char		*subject;		/* Name of certificate subject */
-	struct asymmetric_key_id *id;		/* Serial number + issuer */
+	struct asymmetric_key_id *id;		/* Issuer + Serial number */
 	struct asymmetric_key_id *skid;		/* Subject + subjectKeyId (optional) */
-	struct asymmetric_key_id *authority;	/* Authority key identifier (optional) */
-	struct tm	valid_from;
-	struct tm	valid_to;
+	struct asymmetric_key_id *akid_id;	/* CA AuthKeyId matching ->id (optional) */
+	struct asymmetric_key_id *akid_skid;	/* CA AuthKeyId matching ->skid (optional) */
+	time64_t	valid_from;
+	time64_t	valid_to;
 	const void	*tbs;			/* Signed data */
 	unsigned	tbs_size;		/* Size of signed data */
 	unsigned	raw_sig_size;		/* Size of sigature */
@@ -48,6 +49,9 @@ struct x509_certificate {
  */
 extern void x509_free_certificate(struct x509_certificate *cert);
 extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen);
+extern int x509_decode_time(time64_t *_t,  size_t hdrlen,
+			    unsigned char tag,
+			    const unsigned char *value, size_t vlen);
 
 /*
  * x509_public_key.c

crypto/asymmetric_keys/x509_public_key.c

@@ -65,23 +65,37 @@ __setup("ca_keys=", ca_keys_setup);
 /**
  * x509_request_asymmetric_key - Request a key by X.509 certificate params.
  * @keyring: The keys to search.
- * @kid: The key ID.
+ * @id: The issuer & serialNumber to look for or NULL.
+ * @skid: The subjectKeyIdentifier to look for or NULL.
  * @partial: Use partial match if true, exact if false.
  *
- * Find a key in the given keyring by subject name and key ID.  These might,
- * for instance, be the issuer name and the authority key ID of an X.509
- * certificate that needs to be verified.
+ * Find a key in the given keyring by identifier.  The preferred identifier is
+ * the issuer + serialNumber and the fallback identifier is the
+ * subjectKeyIdentifier.  If both are given, the lookup is by the former, but
+ * the latter must also match.
  */
 struct key *x509_request_asymmetric_key(struct key *keyring,
-					const struct asymmetric_key_id *kid,
+					const struct asymmetric_key_id *id,
+					const struct asymmetric_key_id *skid,
 					bool partial)
 {
-	key_ref_t key;
-	char *id, *p;
-
+	struct key *key;
+	key_ref_t ref;
+	const char *lookup;
+	char *req, *p;
+	int len;
+
+	if (id) {
+		lookup = id->data;
+		len = id->len;
+	} else {
+		lookup = skid->data;
+		len = skid->len;
+	}
+	
 	/* Construct an identifier "id:<keyid>". */
-	p = id = kmalloc(2 + 1 + kid->len * 2 + 1, GFP_KERNEL);
-	if (!id)
+	p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL);
+	if (!req)
 		return ERR_PTR(-ENOMEM);
 
 	if (partial) {
@@ -92,32 +106,48 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
 		*p++ = 'x';
 	}
 	*p++ = ':';
-	p = bin2hex(p, kid->data, kid->len);
+	p = bin2hex(p, lookup, len);
 	*p = 0;
 
-	pr_debug("Look up: \"%s\"\n", id);
+	pr_debug("Look up: \"%s\"\n", req);
 
-	key = keyring_search(make_key_ref(keyring, 1),
-			     &key_type_asymmetric, id);
-	if (IS_ERR(key))
-		pr_debug("Request for key '%s' err %ld\n", id, PTR_ERR(key));
-	kfree(id);
+	ref = keyring_search(make_key_ref(keyring, 1),
+			     &key_type_asymmetric, req);
+	if (IS_ERR(ref))
+		pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref));
+	kfree(req);
 
-	if (IS_ERR(key)) {
-		switch (PTR_ERR(key)) {
+	if (IS_ERR(ref)) {
+		switch (PTR_ERR(ref)) {
 			/* Hide some search errors */
 		case -EACCES:
 		case -ENOTDIR:
 		case -EAGAIN:
 			return ERR_PTR(-ENOKEY);
 		default:
-			return ERR_CAST(key);
+			return ERR_CAST(ref);
+		}
+	}
+
+	key = key_ref_to_ptr(ref);
+	if (id && skid) {
+		const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
+		if (!kids->id[1]) {
+			pr_debug("issuer+serial match, but expected SKID missing\n");
+			goto reject;
+		}
+		if (!asymmetric_key_id_same(skid, kids->id[1])) {
+			pr_debug("issuer+serial match, but SKID does not\n");
+			goto reject;
 		}
 	}
+	
+	pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key));
+	return key;
 
-	pr_devel("<==%s() = 0 [%x]\n", __func__,
-		 key_serial(key_ref_to_ptr(key)));
-	return key_ref_to_ptr(key);
+reject:
+	key_put(key);
+	return ERR_PTR(-EKEYREJECTED);
 }
 EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
 
@@ -227,10 +257,11 @@ static int x509_validate_trust(struct x509_certificate *cert,
 	if (!trust_keyring)
 		return -EOPNOTSUPP;
 
-	if (ca_keyid && !asymmetric_key_id_partial(cert->authority, ca_keyid))
+	if (ca_keyid && !asymmetric_key_id_partial(cert->akid_skid, ca_keyid))
 		return -EPERM;
 
-	key = x509_request_asymmetric_key(trust_keyring, cert->authority,
+	key = x509_request_asymmetric_key(trust_keyring,
+					  cert->akid_id, cert->akid_skid,
 					  false);
 	if (!IS_ERR(key))  {
 		if (!use_builtin_keys
@@ -271,14 +302,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	}
 
 	pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]);
-	pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n",
-		 cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1,
-		 cert->valid_from.tm_mday, cert->valid_from.tm_hour,
-		 cert->valid_from.tm_min,  cert->valid_from.tm_sec);
-	pr_devel("Cert Valid To: %04ld-%02d-%02d %02d:%02d:%02d\n",
-		 cert->valid_to.tm_year + 1900, cert->valid_to.tm_mon + 1,
-		 cert->valid_to.tm_mday, cert->valid_to.tm_hour,
-		 cert->valid_to.tm_min,  cert->valid_to.tm_sec);
+	pr_devel("Cert Valid period: %lld-%lld\n", cert->valid_from, cert->valid_to);
 	pr_devel("Cert Signature: %s + %s\n",
 		 pkey_algo_name[cert->sig.pkey_algo],
 		 hash_algo_name[cert->sig.pkey_hash_algo]);
@@ -287,8 +311,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	cert->pub->id_type = PKEY_ID_X509;
 
 	/* Check the signature on the key if it appears to be self-signed */
-	if (!cert->authority ||
-	    asymmetric_key_id_same(cert->skid, cert->authority)) {
+	if ((!cert->akid_skid && !cert->akid_id) ||
+	    asymmetric_key_id_same(cert->skid, cert->akid_skid) ||
+	    asymmetric_key_id_same(cert->id, cert->akid_id)) {
 		ret = x509_check_signature(cert->pub, cert); /* self-signed */
 		if (ret < 0)
 			goto error_free_cert;

include/crypto/pkcs7.h

@@ -9,6 +9,11 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
+#ifndef _CRYPTO_PKCS7_H
+#define _CRYPTO_PKCS7_H
+
+#include <crypto/public_key.h>
+
 struct key;
 struct pkcs7_message;
 
@@ -33,4 +38,10 @@ extern int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
 /*
  * pkcs7_verify.c
  */
-extern int pkcs7_verify(struct pkcs7_message *pkcs7);
+extern int pkcs7_verify(struct pkcs7_message *pkcs7,
+			enum key_being_used_for usage);
+
+extern int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7,
+				      const void *data, size_t datalen);
+
+#endif /* _CRYPTO_PKCS7_H */

include/crypto/public_key.h

@@ -33,11 +33,26 @@ extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
 enum pkey_id_type {
 	PKEY_ID_PGP,		/* OpenPGP generated key ID */
 	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
+	PKEY_ID_PKCS7,		/* Signature in PKCS#7 message */
 	PKEY_ID_TYPE__LAST
 };
 
 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
 
+/*
+ * The use to which an asymmetric key is being put.
+ */
+enum key_being_used_for {
+	VERIFYING_MODULE_SIGNATURE,
+	VERIFYING_FIRMWARE_SIGNATURE,
+	VERIFYING_KEXEC_PE_SIGNATURE,
+	VERIFYING_KEY_SIGNATURE,
+	VERIFYING_KEY_SELF_SIGNATURE,
+	VERIFYING_UNSPECIFIED_SIGNATURE,
+	NR__KEY_BEING_USED_FOR
+};
+extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
+
 /*
  * Cryptographic data for the public-key subtype of the asymmetric key type.
  *
@@ -101,7 +116,8 @@ extern int verify_signature(const struct key *key,
 
 struct asymmetric_key_id;
 extern struct key *x509_request_asymmetric_key(struct key *keyring,
-					       const struct asymmetric_key_id *kid,
+					       const struct asymmetric_key_id *id,
+					       const struct asymmetric_key_id *skid,
 					       bool partial);
 
 #endif /* _LINUX_PUBLIC_KEY_H */

include/keys/system_keyring.h

@@ -15,6 +15,7 @@
 #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING
 
 #include <linux/key.h>
+#include <crypto/public_key.h>
 
 extern struct key *system_trusted_keyring;
 static inline struct key *get_system_trusted_keyring(void)
@@ -28,4 +29,10 @@ static inline struct key *get_system_trusted_keyring(void)
 }
 #endif
 
+#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+extern int system_verify_data(const void *data, unsigned long len,
+			      const void *raw_pkcs7, size_t pkcs7_len,
+			      enum key_being_used_for usage);
+#endif
+
 #endif /* _KEYS_SYSTEM_KEYRING_H */

include/linux/oid_registry.h

@@ -41,7 +41,7 @@ enum OID {
 	OID_signed_data,		/* 1.2.840.113549.1.7.2 */
 	/* PKCS#9 {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)} */
 	OID_email_address,		/* 1.2.840.113549.1.9.1 */
-	OID_content_type,		/* 1.2.840.113549.1.9.3 */
+	OID_contentType,		/* 1.2.840.113549.1.9.3 */
 	OID_messageDigest,		/* 1.2.840.113549.1.9.4 */
 	OID_signingTime,		/* 1.2.840.113549.1.9.5 */
 	OID_smimeCapabilites,		/* 1.2.840.113549.1.9.15 */
@@ -54,6 +54,8 @@ enum OID {
 
 	/* Microsoft Authenticode & Software Publishing */
 	OID_msIndirectData,		/* 1.3.6.1.4.1.311.2.1.4 */
+	OID_msStatementType,		/* 1.3.6.1.4.1.311.2.1.11 */
+	OID_msSpOpusInfo,		/* 1.3.6.1.4.1.311.2.1.12 */
 	OID_msPeImageDataObjId,		/* 1.3.6.1.4.1.311.2.1.15 */
 	OID_msIndividualSPKeyPurpose,	/* 1.3.6.1.4.1.311.2.1.21 */
 	OID_msOutlookExpress,		/* 1.3.6.1.4.1.311.16.4 */

include/linux/verify_pefile.h

@@ -12,7 +12,11 @@
 #ifndef _LINUX_VERIFY_PEFILE_H
 #define _LINUX_VERIFY_PEFILE_H
 
+#include <crypto/public_key.h>
+
 extern int verify_pefile_signature(const void *pebuf, unsigned pelen,
-				   struct key *trusted_keyring, bool *_trusted);
+				   struct key *trusted_keyring,
+				   enum key_being_used_for usage,
+				   bool *_trusted);
 
 #endif /* _LINUX_VERIFY_PEFILE_H */

init/Kconfig

@@ -1752,6 +1752,37 @@ config SYSTEM_TRUSTED_KEYRING
 
 	  Keys in this keyring are used by module signature checking.
 
+config SYSTEM_TRUSTED_KEYS
+	string "Additional X.509 keys for default system keyring"
+	depends on SYSTEM_TRUSTED_KEYRING
+	help
+	  If set, this option should be the filename of a PEM-formatted file
+	  containing trusted X.509 certificates to be included in the default
+	  system keyring. Any certificate used for module signing is implicitly
+	  also trusted.
+
+	  NOTE: If you previously provided keys for the system keyring in the
+	  form of DER-encoded *.x509 files in the top-level build directory,
+	  those are no longer used. You will need to set this option instead.
+
+config SYSTEM_DATA_VERIFICATION
+	def_bool n
+	select SYSTEM_TRUSTED_KEYRING
+	select KEYS
+	select CRYPTO
+	select ASYMMETRIC_KEY_TYPE
+	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	select PUBLIC_KEY_ALGO_RSA
+	select ASN1
+	select OID_REGISTRY
+	select X509_CERTIFICATE_PARSER
+	select PKCS7_MESSAGE_PARSER
+	help
+	  Provide PKCS#7 message verification using the contents of the system
+	  trusted keyring to provide public keys.  This then can be used for
+	  module verification, kexec image verification and firmware blob
+	  verification.
+
 config PROFILING
 	bool "Profiling support"
 	help
@@ -1860,20 +1891,16 @@ config MODULE_SRCVERSION_ALL
 config MODULE_SIG
 	bool "Module signature verification"
 	depends on MODULES
-	select SYSTEM_TRUSTED_KEYRING
-	select KEYS
-	select CRYPTO
-	select ASYMMETRIC_KEY_TYPE
-	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
-	select PUBLIC_KEY_ALGO_RSA
-	select ASN1
-	select OID_REGISTRY
-	select X509_CERTIFICATE_PARSER
+	select SYSTEM_DATA_VERIFICATION
 	help
 	  Check modules for valid signatures upon load: the signature
 	  is simply appended to the module. For more information see
 	  Documentation/module-signing.txt.
 
+	  Note that this option adds the OpenSSL development packages as a
+	  kernel build dependency so that the signing tool can use its crypto
+	  library.
+
 	  !!!WARNING!!!  If you enable this option, you MUST make sure that the
 	  module DOES NOT get stripped after being signed.  This includes the
 	  debuginfo strip done by some packagers (such as rpmbuild) and
@@ -1938,6 +1965,20 @@ config MODULE_SIG_HASH
 	default "sha384" if MODULE_SIG_SHA384
 	default "sha512" if MODULE_SIG_SHA512
 
+config MODULE_SIG_KEY
+	string "File name or PKCS#11 URI of module signing key"
+	default "signing_key.pem"
+	depends on MODULE_SIG
+	help
+         Provide the file name of a private key/certificate in PEM format,
+         or a PKCS#11 URI according to RFC7512. The file should contain, or
+         the URI should identify, both the certificate and its corresponding
+         private key.
+
+         If this option is unchanged from its default "signing_key.pem",
+         then the kernel will automatically generate the private key and
+         certificate as described in Documentation/module-signing.txt
+
 config MODULE_COMPRESS
 	bool "Compress modules on installation"
 	depends on MODULES

kernel/Makefile

@@ -114,46 +114,74 @@ $(obj)/config_data.h: $(obj)/config_data.gz FORCE
 
 ###############################################################################
 #
-# Roll all the X.509 certificates that we can find together and pull them into
-# the kernel so that they get loaded into the system trusted keyring during
-# boot.
+# When a Kconfig string contains a filename, it is suitable for
+# passing to shell commands. It is surrounded by double-quotes, and
+# any double-quotes or backslashes within it are escaped by
+# backslashes.
 #
-# We look in the source root and the build root for all files whose name ends
-# in ".x509".  Unfortunately, this will generate duplicate filenames, so we
-# have make canonicalise the pathnames and then sort them to discard the
-# duplicates.
+# This is no use for dependencies or $(wildcard). We need to strip the
+# surrounding quotes and the escaping from quotes and backslashes, and
+# we *do* need to escape any spaces in the string. So, for example:
+#
+# Usage: $(eval $(call config_filename,FOO))
+#
+# Defines FOO_FILENAME based on the contents of the CONFIG_FOO option,
+# transformed as described above to be suitable for use within the
+# makefile.
+#
+# Also, if the filename is a relative filename and exists in the source
+# tree but not the build tree, define FOO_SRCPREFIX as $(srctree)/ to
+# be prefixed to *both* command invocation and dependencies.
+#
+# Note: We also print the filenames in the quiet_cmd_foo text, and
+# perhaps ought to have a version specially escaped for that purpose.
+# But it's only cosmetic, and $(patsubst "%",%,$(CONFIG_FOO)) is good
+# enough.  It'll strip the quotes in the common case where there's no
+# space and it's a simple filename, and it'll retain the quotes when
+# there's a space. There are some esoteric cases in which it'll print
+# the wrong thing, but we don't really care. The actual dependencies
+# and commands *do* get it right, with various combinations of single
+# and double quotes, backslashes and spaces in the filenames.
 #
 ###############################################################################
-ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
-X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509)
-X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += $(objtree)/signing_key.x509
-X509_CERTIFICATES-raw := $(sort $(foreach CERT,$(X509_CERTIFICATES-y), \
-				$(or $(realpath $(CERT)),$(CERT))))
-X509_CERTIFICATES := $(subst $(realpath $(objtree))/,,$(X509_CERTIFICATES-raw))
-
-ifeq ($(X509_CERTIFICATES),)
-$(warning *** No X.509 certificates found ***)
+#
+quote := $(firstword " ")
+space :=
+space +=
+space_escape := %%%SPACE%%%
+#
+define config_filename
+ifneq ($$(CONFIG_$(1)),"")
+$(1)_FILENAME := $$(subst \\,\,$$(subst \$$(quote),$$(quote),$$(subst $$(space_escape),\$$(space),$$(patsubst "%",%,$$(subst $$(space),$$(space_escape),$$(CONFIG_$(1)))))))
+ifneq ($$(patsubst /%,%,$$(firstword $$($(1)_FILENAME))),$$(firstword $$($(1)_FILENAME)))
+else
+ifeq ($$(wildcard $$($(1)_FILENAME)),)
+ifneq ($$(wildcard $$(srctree)/$$($(1)_FILENAME)),)
+$(1)_SRCPREFIX := $(srctree)/
 endif
-
-ifneq ($(wildcard $(obj)/.x509.list),)
-ifneq ($(shell cat $(obj)/.x509.list),$(X509_CERTIFICATES))
-$(warning X.509 certificate list changed to "$(X509_CERTIFICATES)" from "$(shell cat $(obj)/.x509.list)")
-$(shell rm $(obj)/.x509.list)
 endif
 endif
+endif
+endef
+#
+###############################################################################
+
+ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
 
-kernel/system_certificates.o: $(obj)/x509_certificate_list
+$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
 
-quiet_cmd_x509certs  = CERTS   $@
-      cmd_x509certs  = cat $(X509_CERTIFICATES) /dev/null >$@ $(foreach X509,$(X509_CERTIFICATES),; $(kecho) "  - Including cert $(X509)")
+# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
+$(obj)/system_certificates.o: $(obj)/x509_certificate_list
 
-targets += $(obj)/x509_certificate_list
-$(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list
-	$(call if_changed,x509certs)
+# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
+AFLAGS_system_certificates.o := -I$(srctree)
 
-targets += $(obj)/.x509.list
-$(obj)/.x509.list:
-	@echo $(X509_CERTIFICATES) >$@
+quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
+      cmd_extract_certs  = scripts/extract-cert $(2) $@ || ( rm $@; exit 1)
+
+targets += x509_certificate_list
+$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
+	$(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
 endif
 
 clean-files := x509_certificate_list .x509.list
@@ -170,7 +198,11 @@ ifndef CONFIG_MODULE_SIG_HASH
 $(error Could not determine digest type to use from kernel config)
 endif
 
-signing_key.priv signing_key.x509: x509.genkey
+# We do it this way rather than having a boolean option for enabling an
+# external private key, because 'make randconfig' might enable such a
+# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
+ifeq ($(CONFIG_MODULE_SIG_KEY),"signing_key.pem")
+signing_key.pem: x509.genkey
 	@echo "###"
 	@echo "### Now generating an X.509 key pair to be used for signing modules."
 	@echo "###"
@@ -181,8 +213,8 @@ signing_key.priv signing_key.x509: x509.genkey
 	@echo "###"
 	openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
 		-batch -x509 -config x509.genkey \
-		-outform DER -out signing_key.x509 \
-		-keyout signing_key.priv 2>&1
+		-outform PEM -out signing_key.pem \
+		-keyout signing_key.pem 2>&1
 	@echo "###"
 	@echo "### Key pair generated."
 	@echo "###"
@@ -207,3 +239,17 @@ x509.genkey:
 	@echo >>x509.genkey "subjectKeyIdentifier=hash"
 	@echo >>x509.genkey "authorityKeyIdentifier=keyid"
 endif
+
+$(eval $(call config_filename,MODULE_SIG_KEY))
+
+# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
+ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
+X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
+endif
+
+# GCC PR#66871 again.
+$(obj)/system_certificates.o: signing_key.x509
+
+signing_key.x509: scripts/extract-cert include/config/module/sig/key.h $(X509_DEP)
+	$(call cmd,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
+endif

kernel/module_signing.c

@@ -10,11 +10,8 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/err.h>
-#include <crypto/public_key.h>
-#include <crypto/hash.h>
-#include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
+#include <crypto/public_key.h>
 #include "module-internal.h"
 
 /*
@@ -28,170 +25,22 @@
  *	- Information block
  */
 struct module_signature {
-	u8	algo;		/* Public-key crypto algorithm [enum pkey_algo] */
-	u8	hash;		/* Digest algorithm [enum hash_algo] */
-	u8	id_type;	/* Key identifier type [enum pkey_id_type] */
-	u8	signer_len;	/* Length of signer's name */
-	u8	key_id_len;	/* Length of key identifier */
+	u8	algo;		/* Public-key crypto algorithm [0] */
+	u8	hash;		/* Digest algorithm [0] */
+	u8	id_type;	/* Key identifier type [PKEY_ID_PKCS7] */
+	u8	signer_len;	/* Length of signer's name [0] */
+	u8	key_id_len;	/* Length of key identifier [0] */
 	u8	__pad[3];
 	__be32	sig_len;	/* Length of signature data */
 };
 
-/*
- * Digest the module contents.
- */
-static struct public_key_signature *mod_make_digest(enum hash_algo hash,
-						    const void *mod,
-						    unsigned long modlen)
-{
-	struct public_key_signature *pks;
-	struct crypto_shash *tfm;
-	struct shash_desc *desc;
-	size_t digest_size, desc_size;
-	int ret;
-
-	pr_devel("==>%s()\n", __func__);
-	
-	/* Allocate the hashing algorithm we're going to need and find out how
-	 * big the hash operational data will be.
-	 */
-	tfm = crypto_alloc_shash(hash_algo_name[hash], 0, 0);
-	if (IS_ERR(tfm))
-		return (PTR_ERR(tfm) == -ENOENT) ? ERR_PTR(-ENOPKG) : ERR_CAST(tfm);
-
-	desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
-	digest_size = crypto_shash_digestsize(tfm);
-
-	/* We allocate the hash operational data storage on the end of our
-	 * context data and the digest output buffer on the end of that.
-	 */
-	ret = -ENOMEM;
-	pks = kzalloc(digest_size + sizeof(*pks) + desc_size, GFP_KERNEL);
-	if (!pks)
-		goto error_no_pks;
-
-	pks->pkey_hash_algo	= hash;
-	pks->digest		= (u8 *)pks + sizeof(*pks) + desc_size;
-	pks->digest_size	= digest_size;
-
-	desc = (void *)pks + sizeof(*pks);
-	desc->tfm   = tfm;
-	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
-
-	ret = crypto_shash_init(desc);
-	if (ret < 0)
-		goto error;
-
-	ret = crypto_shash_finup(desc, mod, modlen, pks->digest);
-	if (ret < 0)
-		goto error;
-
-	crypto_free_shash(tfm);
-	pr_devel("<==%s() = ok\n", __func__);
-	return pks;
-
-error:
-	kfree(pks);
-error_no_pks:
-	crypto_free_shash(tfm);
-	pr_devel("<==%s() = %d\n", __func__, ret);
-	return ERR_PTR(ret);
-}
-
-/*
- * Extract an MPI array from the signature data.  This represents the actual
- * signature.  Each raw MPI is prefaced by a BE 2-byte value indicating the
- * size of the MPI in bytes.
- *
- * RSA signatures only have one MPI, so currently we only read one.
- */
-static int mod_extract_mpi_array(struct public_key_signature *pks,
-				 const void *data, size_t len)
-{
-	size_t nbytes;
-	MPI mpi;
-
-	if (len < 3)
-		return -EBADMSG;
-	nbytes = ((const u8 *)data)[0] << 8 | ((const u8 *)data)[1];
-	data += 2;
-	len -= 2;
-	if (len != nbytes)
-		return -EBADMSG;
-
-	mpi = mpi_read_raw_data(data, nbytes);
-	if (!mpi)
-		return -ENOMEM;
-	pks->mpi[0] = mpi;
-	pks->nr_mpi = 1;
-	return 0;
-}
-
-/*
- * Request an asymmetric key.
- */
-static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
-					  const u8 *key_id, size_t key_id_len)
-{
-	key_ref_t key;
-	size_t i;
-	char *id, *q;
-
-	pr_devel("==>%s(,%zu,,%zu)\n", __func__, signer_len, key_id_len);
-
-	/* Construct an identifier. */
-	id = kmalloc(signer_len + 2 + key_id_len * 2 + 1, GFP_KERNEL);
-	if (!id)
-		return ERR_PTR(-ENOKEY);
-
-	memcpy(id, signer, signer_len);
-
-	q = id + signer_len;
-	*q++ = ':';
-	*q++ = ' ';
-	for (i = 0; i < key_id_len; i++) {
-		*q++ = hex_asc[*key_id >> 4];
-		*q++ = hex_asc[*key_id++ & 0x0f];
-	}
-
-	*q = 0;
-
-	pr_debug("Look up: \"%s\"\n", id);
-
-	key = keyring_search(make_key_ref(system_trusted_keyring, 1),
-			     &key_type_asymmetric, id);
-	if (IS_ERR(key))
-		pr_warn("Request for unknown module key '%s' err %ld\n",
-			id, PTR_ERR(key));
-	kfree(id);
-
-	if (IS_ERR(key)) {
-		switch (PTR_ERR(key)) {
-			/* Hide some search errors */
-		case -EACCES:
-		case -ENOTDIR:
-		case -EAGAIN:
-			return ERR_PTR(-ENOKEY);
-		default:
-			return ERR_CAST(key);
-		}
-	}
-
-	pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key_ref_to_ptr(key)));
-	return key_ref_to_ptr(key);
-}
-
 /*
  * Verify the signature on a module.
  */
 int mod_verify_sig(const void *mod, unsigned long *_modlen)
 {
-	struct public_key_signature *pks;
 	struct module_signature ms;
-	struct key *key;
-	const void *sig;
 	size_t modlen = *_modlen, sig_len;
-	int ret;
 
 	pr_devel("==>%s(,%zu)\n", __func__, modlen);
 
@@ -205,46 +54,24 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen)
 	if (sig_len >= modlen)
 		return -EBADMSG;
 	modlen -= sig_len;
-	if ((size_t)ms.signer_len + ms.key_id_len >= modlen)
-		return -EBADMSG;
-	modlen -= (size_t)ms.signer_len + ms.key_id_len;
-
 	*_modlen = modlen;
-	sig = mod + modlen;
-
-	/* For the moment, only support RSA and X.509 identifiers */
-	if (ms.algo != PKEY_ALGO_RSA ||
-	    ms.id_type != PKEY_ID_X509)
-		return -ENOPKG;
 
-	if (ms.hash >= PKEY_HASH__LAST ||
-	    !hash_algo_name[ms.hash])
+	if (ms.id_type != PKEY_ID_PKCS7) {
+		pr_err("Module is not signed with expected PKCS#7 message\n");
 		return -ENOPKG;
-
-	key = request_asymmetric_key(sig, ms.signer_len,
-				     sig + ms.signer_len, ms.key_id_len);
-	if (IS_ERR(key))
-		return PTR_ERR(key);
-
-	pks = mod_make_digest(ms.hash, mod, modlen);
-	if (IS_ERR(pks)) {
-		ret = PTR_ERR(pks);
-		goto error_put_key;
 	}
 
-	ret = mod_extract_mpi_array(pks, sig + ms.signer_len + ms.key_id_len,
-				    sig_len);
-	if (ret < 0)
-		goto error_free_pks;
-
-	ret = verify_signature(key, pks);
-	pr_devel("verify_signature() = %d\n", ret);
+	if (ms.algo != 0 ||
+	    ms.hash != 0 ||
+	    ms.signer_len != 0 ||
+	    ms.key_id_len != 0 ||
+	    ms.__pad[0] != 0 ||
+	    ms.__pad[1] != 0 ||
+	    ms.__pad[2] != 0) {
+		pr_err("PKCS#7 signature info has unexpected non-zero params\n");
+		return -EBADMSG;
+	}
 
-error_free_pks:
-	mpi_free(pks->rsa.s);
-	kfree(pks);
-error_put_key:
-	key_put(key);
-	pr_devel("<==%s() = %d\n", __func__, ret);
-	return ret;	
+	return system_verify_data(mod, modlen, mod + modlen, sig_len,
+				  VERIFYING_MODULE_SIGNATURE);
 }

kernel/system_certificates.S

@@ -7,6 +7,9 @@
 	.globl VMLINUX_SYMBOL(system_certificate_list)
 VMLINUX_SYMBOL(system_certificate_list):
 __cert_list_start:
+#ifdef CONFIG_MODULE_SIG
+	.incbin "signing_key.x509"
+#endif
 	.incbin "kernel/x509_certificate_list"
 __cert_list_end:
 

kernel/system_keyring.c

@@ -16,7 +16,7 @@
 #include <linux/err.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
-#include "module-internal.h"
+#include <crypto/pkcs7.h>
 
 struct key *system_trusted_keyring;
 EXPORT_SYMBOL_GPL(system_trusted_keyring);
@@ -104,3 +104,54 @@ static __init int load_system_certificate_list(void)
 	return 0;
 }
 late_initcall(load_system_certificate_list);
+
+#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+
+/**
+ * Verify a PKCS#7-based signature on system data.
+ * @data: The data to be verified.
+ * @len: Size of @data.
+ * @raw_pkcs7: The PKCS#7 message that is the signature.
+ * @pkcs7_len: The size of @raw_pkcs7.
+ * @usage: The use to which the key is being put.
+ */
+int system_verify_data(const void *data, unsigned long len,
+		       const void *raw_pkcs7, size_t pkcs7_len,
+		       enum key_being_used_for usage)
+{
+	struct pkcs7_message *pkcs7;
+	bool trusted;
+	int ret;
+
+	pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
+	if (IS_ERR(pkcs7))
+		return PTR_ERR(pkcs7);
+
+	/* The data should be detached - so we need to supply it. */
+	if (pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
+		pr_err("PKCS#7 signature with non-detached data\n");
+		ret = -EBADMSG;
+		goto error;
+	}
+
+	ret = pkcs7_verify(pkcs7, usage);
+	if (ret < 0)
+		goto error;
+
+	ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
+	if (ret < 0)
+		goto error;
+
+	if (!trusted) {
+		pr_err("PKCS#7 signature not signed with a trusted key\n");
+		ret = -ENOKEY;
+	}
+
+error:
+	pkcs7_free_message(pkcs7);
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(system_verify_data);
+
+#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */

scripts/Makefile

@@ -16,9 +16,13 @@ hostprogs-$(CONFIG_VT)           += conmakehash
 hostprogs-$(BUILD_C_RECORDMCOUNT) += recordmcount
 hostprogs-$(CONFIG_BUILDTIME_EXTABLE_SORT) += sortextable
 hostprogs-$(CONFIG_ASN1)	 += asn1_compiler
+hostprogs-$(CONFIG_MODULE_SIG)	 += sign-file
+hostprogs-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += extract-cert
 
 HOSTCFLAGS_sortextable.o = -I$(srctree)/tools/include
 HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
+HOSTLOADLIBES_sign-file = -lcrypto
+HOSTLOADLIBES_extract-cert = -lcrypto
 
 always		:= $(hostprogs-y) $(hostprogs-m)
 

scripts/Makefile.modinst

@@ -22,7 +22,7 @@ quiet_cmd_modules_install = INSTALL $@
     mkdir -p $(2) ; \
     cp $@ $(2) ; \
     $(mod_strip_cmd) $(2)/$(notdir $@) ; \
-    $(mod_sign_cmd) $(2)/$(notdir $@) $(patsubst %,|| true,$(KBUILD_EXTMOD)) ; \
+    $(mod_sign_cmd) $(2)/$(notdir $@) $(patsubst %,|| true,$(KBUILD_EXTMOD)) && \
     $(mod_compress_cmd) $(2)/$(notdir $@)
 
 # Modules built outside the kernel source tree go into extra by default

scripts/extract-cert.c

+/* Extract X.509 certificate in DER form from PKCS#11 or PEM.
+ *
+ * Copyright © 2014 Red Hat, Inc. All Rights Reserved.
+ * Copyright © 2015 Intel Corporation.
+ *
+ * Authors: David Howells <dhowells@redhat.com>
+ *          David Woodhouse <dwmw2@infradead.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <err.h>
+#include <arpa/inet.h>
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+#include <openssl/pkcs7.h>
+#include <openssl/err.h>
+#include <openssl/engine.h>
+
+#define PKEY_ID_PKCS7 2
+
+static __attribute__((noreturn))
+void format(void)
+{
+	fprintf(stderr,
+		"Usage: scripts/extract-cert <source> <dest>\n");
+	exit(2);
+}
+
+static void display_openssl_errors(int l)
+{
+	const char *file;
+	char buf[120];
+	int e, line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	fprintf(stderr, "At main.c:%d:\n", l);
+
+	while ((e = ERR_get_error_line(&file, &line))) {
+		ERR_error_string(e, buf);
+		fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
+	}
+}
+
+static void drain_openssl_errors(void)
+{
+	const char *file;
+	int line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	while (ERR_get_error_line(&file, &line)) {}
+}
+
+#define ERR(cond, fmt, ...)				\
+	do {						\
+		bool __cond = (cond);			\
+		display_openssl_errors(__LINE__);	\
+		if (__cond) {				\
+			err(1, fmt, ## __VA_ARGS__);	\
+		}					\
+	} while(0)
+
+static const char *key_pass;
+static BIO *wb;
+static char *cert_dst;
+int kbuild_verbose;
+
+static void write_cert(X509 *x509)
+{
+	char buf[200];
+
+	if (!wb) {
+		wb = BIO_new_file(cert_dst, "wb");
+		ERR(!wb, "%s", cert_dst);
+	}
+	X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
+	ERR(!i2d_X509_bio(wb, x509), cert_dst);
+	if (kbuild_verbose)
+		fprintf(stderr, "Extracted cert: %s\n", buf);
+}
+
+int main(int argc, char **argv)
+{
+	char *cert_src;
+
+	OpenSSL_add_all_algorithms();
+	ERR_load_crypto_strings();
+	ERR_clear_error();
+
+	kbuild_verbose = atoi(getenv("KBUILD_VERBOSE")?:"0");
+
+        key_pass = getenv("KBUILD_SIGN_PIN");
+
+	if (argc != 3)
+		format();
+
+	cert_src = argv[1];
+	cert_dst = argv[2];
+
+	if (!cert_src[0]) {
+		/* Invoked with no input; create empty file */
+		FILE *f = fopen(cert_dst, "wb");
+		ERR(!f, "%s", cert_dst);
+		fclose(f);
+		exit(0);
+	} else if (!strncmp(cert_src, "pkcs11:", 7)) {
+		ENGINE *e;
+		struct {
+			const char *cert_id;
+			X509 *cert;
+		} parms;
+
+		parms.cert_id = cert_src;
+		parms.cert = NULL;
+
+		ENGINE_load_builtin_engines();
+		drain_openssl_errors();
+		e = ENGINE_by_id("pkcs11");
+		ERR(!e, "Load PKCS#11 ENGINE");
+		if (ENGINE_init(e))
+			drain_openssl_errors();
+		else
+			ERR(1, "ENGINE_init");
+		if (key_pass)
+			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
+		ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
+		ERR(!parms.cert, "Get X.509 from PKCS#11");
+		write_cert(parms.cert);
+	} else {
+		BIO *b;
+		X509 *x509;
+
+		b = BIO_new_file(cert_src, "rb");
+		ERR(!b, "%s", cert_src);
+
+		while (1) {
+			x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
+			if (wb && !x509) {
+				unsigned long err = ERR_peek_last_error();
+				if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
+				    ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
+					ERR_clear_error();
+					break;
+				}
+			}
+			ERR(!x509, "%s", cert_src);
+			write_cert(x509);
+		}
+	}
+
+	BIO_free(wb);
+
+	return 0;
+}

scripts/sign-file.c

+/* Sign a module file using the given key.
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <getopt.h>
+#include <err.h>
+#include <arpa/inet.h>
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+#include <openssl/cms.h>
+#include <openssl/err.h>
+#include <openssl/engine.h>
+
+struct module_signature {
+	uint8_t		algo;		/* Public-key crypto algorithm [0] */
+	uint8_t		hash;		/* Digest algorithm [0] */
+	uint8_t		id_type;	/* Key identifier type [PKEY_ID_PKCS7] */
+	uint8_t		signer_len;	/* Length of signer's name [0] */
+	uint8_t		key_id_len;	/* Length of key identifier [0] */
+	uint8_t		__pad[3];
+	uint32_t	sig_len;	/* Length of signature data */
+};
+
+#define PKEY_ID_PKCS7 2
+
+static char magic_number[] = "~Module signature appended~\n";
+
+static __attribute__((noreturn))
+void format(void)
+{
+	fprintf(stderr,
+		"Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n");
+	exit(2);
+}
+
+static void display_openssl_errors(int l)
+{
+	const char *file;
+	char buf[120];
+	int e, line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	fprintf(stderr, "At main.c:%d:\n", l);
+
+	while ((e = ERR_get_error_line(&file, &line))) {
+		ERR_error_string(e, buf);
+		fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
+	}
+}
+
+static void drain_openssl_errors(void)
+{
+	const char *file;
+	int line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	while (ERR_get_error_line(&file, &line)) {}
+}
+
+#define ERR(cond, fmt, ...)				\
+	do {						\
+		bool __cond = (cond);			\
+		display_openssl_errors(__LINE__);	\
+		if (__cond) {				\
+			err(1, fmt, ## __VA_ARGS__);	\
+		}					\
+	} while(0)
+
+static const char *key_pass;
+
+static int pem_pw_cb(char *buf, int len, int w, void *v)
+{
+	int pwlen;
+
+	if (!key_pass)
+		return -1;
+
+	pwlen = strlen(key_pass);
+	if (pwlen >= len)
+		return -1;
+
+	strcpy(buf, key_pass);
+
+	/* If it's wrong, don't keep trying it. */
+	key_pass = NULL;
+
+	return pwlen;
+}
+
+int main(int argc, char **argv)
+{
+	struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 };
+	char *hash_algo = NULL;
+	char *private_key_name, *x509_name, *module_name, *dest_name;
+	bool save_cms = false, replace_orig;
+	bool sign_only = false;
+	unsigned char buf[4096];
+	unsigned long module_size, cms_size;
+	unsigned int use_keyid = 0, use_signed_attrs = CMS_NOATTR;
+	const EVP_MD *digest_algo;
+	EVP_PKEY *private_key;
+	CMS_ContentInfo *cms;
+	X509 *x509;
+	BIO *b, *bd = NULL, *bm;
+	int opt, n;
+
+	OpenSSL_add_all_algorithms();
+	ERR_load_crypto_strings();
+	ERR_clear_error();
+
+	key_pass = getenv("KBUILD_SIGN_PIN");
+
+	do {
+		opt = getopt(argc, argv, "dpk");
+		switch (opt) {
+		case 'p': save_cms = true; break;
+		case 'd': sign_only = true; save_cms = true; break;
+		case 'k': use_keyid = CMS_USE_KEYID; break;
+		case -1: break;
+		default: format();
+		}
+	} while (opt != -1);
+
+	argc -= optind;
+	argv += optind;
+	if (argc < 4 || argc > 5)
+		format();
+
+	hash_algo = argv[0];
+	private_key_name = argv[1];
+	x509_name = argv[2];
+	module_name = argv[3];
+	if (argc == 5) {
+		dest_name = argv[4];
+		replace_orig = false;
+	} else {
+		ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0,
+		    "asprintf");
+		replace_orig = true;
+	}
+
+	/* Read the private key and the X.509 cert the PKCS#7 message
+	 * will point to.
+	 */
+	if (!strncmp(private_key_name, "pkcs11:", 7)) {
+		ENGINE *e;
+
+		ENGINE_load_builtin_engines();
+		drain_openssl_errors();
+		e = ENGINE_by_id("pkcs11");
+		ERR(!e, "Load PKCS#11 ENGINE");
+		if (ENGINE_init(e))
+			drain_openssl_errors();
+		else
+			ERR(1, "ENGINE_init");
+		if (key_pass)
+			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
+		private_key = ENGINE_load_private_key(e, private_key_name, NULL,
+						      NULL);
+		ERR(!private_key, "%s", private_key_name);
+	} else {
+		b = BIO_new_file(private_key_name, "rb");
+		ERR(!b, "%s", private_key_name);
+		private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb, NULL);
+		ERR(!private_key, "%s", private_key_name);
+		BIO_free(b);
+	}
+
+	b = BIO_new_file(x509_name, "rb");
+	ERR(!b, "%s", x509_name);
+	x509 = d2i_X509_bio(b, NULL); /* Binary encoded X.509 */
+	if (!x509) {
+		ERR(BIO_reset(b) != 1, "%s", x509_name);
+		x509 = PEM_read_bio_X509(b, NULL, NULL, NULL); /* PEM encoded X.509 */
+		if (x509)
+			drain_openssl_errors();
+	}
+	BIO_free(b);
+	ERR(!x509, "%s", x509_name);
+
+	/* Open the destination file now so that we can shovel the module data
+	 * across as we read it.
+	 */
+	if (!sign_only) {
+		bd = BIO_new_file(dest_name, "wb");
+		ERR(!bd, "%s", dest_name);
+	}
+
+	/* Digest the module data. */
+	OpenSSL_add_all_digests();
+	display_openssl_errors(__LINE__);
+	digest_algo = EVP_get_digestbyname(hash_algo);
+	ERR(!digest_algo, "EVP_get_digestbyname");
+
+	bm = BIO_new_file(module_name, "rb");
+	ERR(!bm, "%s", module_name);
+
+	/* Load the CMS message from the digest buffer. */
+	cms = CMS_sign(NULL, NULL, NULL, NULL,
+		       CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | CMS_DETACHED | CMS_STREAM);
+	ERR(!cms, "CMS_sign");
+
+	ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo,
+			     CMS_NOCERTS | CMS_BINARY | CMS_NOSMIMECAP |
+			     use_keyid | use_signed_attrs),
+	    "CMS_sign_add_signer");
+	ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,
+	    "CMS_final");
+
+	if (save_cms) {
+		char *cms_name;
+
+		ERR(asprintf(&cms_name, "%s.p7s", module_name) < 0, "asprintf");
+		b = BIO_new_file(cms_name, "wb");
+		ERR(!b, "%s", cms_name);
+		ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0, "%s", cms_name);
+		BIO_free(b);
+	}
+
+	if (sign_only)
+		return 0;
+
+	/* Append the marker and the PKCS#7 message to the destination file */
+	ERR(BIO_reset(bm) < 0, "%s", module_name);
+	while ((n = BIO_read(bm, buf, sizeof(buf))),
+	       n > 0) {
+		ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);
+	}
+	ERR(n < 0, "%s", module_name);
+	module_size = BIO_number_written(bd);
+
+	ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
+	cms_size = BIO_number_written(bd) - module_size;
+	sig_info.sig_len = htonl(cms_size);
+	ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name);
+	ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name);
+
+	ERR(BIO_free(bd) < 0, "%s", dest_name);
+
+	/* Finally, if we're signing in place, replace the original. */
+	if (replace_orig)
+		ERR(rename(dest_name, module_name) < 0, "%s", dest_name);
+
+	return 0;
+}