meta-integrity: port over from meta-intel-iot-security

Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-integrity/recipes-kernel/linux/linux-%.bbappend

@@ -0,0 +1,116 @@
+IMA_ENABLED_HERE := "${@'yes' if bb.data.inherits_class('kernel', d) and 'ima' in d.getVar('DISTRO_FEATURES', True).split() else 'no'}"
+
+IMA_FILESEXTRAPATHS_yes := "${THISDIR}/linux:"
+IMA_FILESEXTRAPATHS_no := ""
+FILESEXTRAPATHS_prepend := "${IMA_FILESEXTRAPATHS_${IMA_ENABLED_HERE}}"
+
+# These two patches are necessary to unpack archives with security.ima xattr
+# such that security.ima is taken from the archive. If the policy
+# allows hashing, unpatched kernels (at least up to 4.3) will replace
+# a signed hash in security.ima with a locally computed hash.
+#
+# Note that only bsdtar/libarchive are known to work; GNU tar sets
+# the security.ima on an empty file and the tries re-opening it for
+# writing its content, which then fails due to the IMA hash mismatch.
+#
+# Kernels >= 4.7 have the patches, while older kernels are likely to
+# need the patches. So apply them by default. To avoid that,
+# set IMA_EVM_SETATTR_PATCH_x.y.z (where x.y.z == linux kernel version)
+# to an empty string (to avoid patching) or some other patch files
+# suitable for that kernel.
+def ima_evm_setattr_patch(d):
+    result = []
+    linux_version = d.getVar('LINUX_VERSION', True) or ''
+    # These two patches are known to be included upstream.
+    if bb.utils.vercmp_string_op(linux_version, '4.7', '<'):
+        patches = d.getVar('IMA_EVM_SETATTR_PATCH_' + linux_version, True)
+        if patches != None:
+            # Patches explicitly chosen, may be empty.
+            result.append(patches)
+        else:
+            # Enabled by default.
+            result.append('file://0001-ima-fix-ima_inode_post_setattr.patch file://0002-ima-add-support-for-creating-files-using-the-mknodat.patch')
+    # This one addresses a problem added in 4.2. The upstream revert will land
+    # in some future kernel. We need to extend version check once we know
+    # which kernels have the patch.
+    if bb.utils.vercmp_string_op(linux_version, '4.2', '>='):
+        patches = d.getVar('IMA_EVM_SETATTR_REVERT_PATCH_' + linux_version, True)
+        if patches != None:
+            # Patches explicitly chosen, may be empty.
+            result.append(patches)
+        else:
+            # Enabled by default.
+            result.append('file://Revert-ima-limit-file-hash-setting-by-user-to-fix-an.patch')
+    return ' '.join(result)
+
+# Edison kernel too old, patch not applicable -> swupd is broken in Ostro OS for Edison.
+IMA_EVM_SETATTR_PATCH_3.10.98 = ""
+
+# Kernel config fragment enabling IMA/EVM and (where necessary and possible)
+# also patching the kernel.
+IMA_EVM_CFG_yes = " file://ima.cfg \
+                    ${@ ima_evm_setattr_patch(d)} \
+                  "
+IMA_EVM_CFG_no = ""
+SRC_URI_append = "${IMA_EVM_CFG_${IMA_ENABLED_HERE}}"
+
+# IMA_EVM_ROOT_CA, if set, is the absolute path to a der-encoded
+# x509 CA certificate which will get compiled into the kernel.
+# The kernel will then use it to validate additional certificates,
+# like the one loaded dynamically for IMA.
+#
+# Depending on the kernel version, there are two ways to add the
+# CA certificate:
+# - For Linux < 4.3, we put the x509 file into the source directory
+#   where the kernel compilation will find it automatically
+#   (http://lxr.free-electrons.com/source/kernel/Makefile?v=4.2#L115).
+# - For Linux >= 4.3, we set SYSTEM_TRUSTED_KEYS
+#   (http://lxr.free-electrons.com/source/certs/Kconfig?v=4.3#L29).
+#   The ima_evm_root_ca.cfg only contains a blank file name.
+#   The actual file name gets patched in after the file was used
+#   to configure the kernel (see do_kernel_configme_append).
+#   This has to point to a single file, i.e. using it for IMA has to
+#   be coordinated with other usages.
+#
+# The IMA_EVM_ROOT_CA default is set globally in ima-evm-rootfs.bbclass.
+# Need weaker default here in case that ima-evm-rootfs.bbclass is not
+# inherited.
+IMA_EVM_ROOT_CA ??= ""
+
+# Add CONFIG_SYSTEM_TRUSTED_KEYS (for recent kernels) and
+# copy the root certificate into the build directory. By using
+# the normal fetcher mechanism for the certificate we ensure that
+# a rebuild is triggered when the file name or content change.
+#
+# Recompiling on name change is a bit too aggressive and causes
+# unnecessary rebuilds when only the location of the file, but not its
+# content change. This may need further work, should it become a problem
+# in practice. For example, IMA_EVM_ROOT_CA could be redefined as
+# an URL that then gets found via the normal file lookup.
+#
+# The fetcher does not expand SRC_URI. We have to enforce that here.
+IMA_EVM_ROOT_CA_CFG_yes = "${@ \
+ ((' file://ima_evm_root_ca.cfg' if bb.utils.vercmp_string_op('${LINUX_VERSION}', '4.3', '>=') else '') + \
+   ' file://${IMA_EVM_ROOT_CA}') \
+ if '${IMA_EVM_ROOT_CA}' else ''}"
+IMA_EVM_ROOT_CA_CFG_no = ""
+
+SRC_URI_append = "${IMA_EVM_ROOT_CA_CFG_${IMA_ENABLED_HERE}}"
+
+do_kernel_configme_append () {
+    if [ '${IMA_EVM_ROOT_CA}' ] && grep -q '^CONFIG_SYSTEM_TRUSTED_KEYS=' ${B}/.config; then
+        # We can replace a blank value from ima_evm_root_ca.cfg,
+        # but when we find some other value, then we have to abort
+        # because we can't set more than one value.
+        eval `grep '^CONFIG_SYSTEM_TRUSTED_KEYS='`
+        if [ "$CONFIG_SYSTEM_TRUSTED_KEYS" ] && [ "$CONFIG_SYSTEM_TRUSTED_KEYS" != "${IMA_EVM_ROOT_CA}" ]; then
+            bbfatal "CONFIG_SYSTEM_TRUSTED_KEYS already set to $CONFIG_SYSTEM_TRUSTED_KEYS, cannot replace with IMA_EVM_ROOT_CA = ${IMA_EVM_ROOT_CA}"
+            exit 1
+        fi
+        pemcert=${B}/`basename ${IMA_EVM_ROOT_CA}`.pem
+        openssl x509 -inform der -in ${IMA_EVM_ROOT_CA} -out $pemcert
+        sed -i -e "s;^CONFIG_SYSTEM_TRUSTED_KEYS=.*;CONFIG_SYSTEM_TRUSTED_KEYS=\"$pemcert\";" ${B}/.config
+    fi
+}
+
+do_kernel_configme[depends] += "${@ 'openssl-native:do_populate_sysroot' if '${IMA_ENABLED_HERE}' == 'yes' and '${IMA_EVM_ROOT_CA}' else '' }"

meta-integrity/recipes-kernel/linux/linux/0001-ima-fix-ima_inode_post_setattr.patch

@@ -0,0 +1,51 @@
+From 45ea681ebc0dd44aaec5d3cc4143b9722070d3ac Mon Sep 17 00:00:00 2001
+From: Mimi Zohar <zohar@linux.vnet.ibm.com>
+Date: Tue, 8 Mar 2016 16:43:55 -0500
+Subject: [PATCH] ima: fix ima_inode_post_setattr
+
+Changing file metadata (eg. uid, guid) could result in having to
+re-appraise a file's integrity, but does not change the "new file"
+status nor the security.ima xattr.  The IMA_PERMIT_DIRECTIO and
+IMA_DIGSIG_REQUIRED flags are policy rule specific.  This patch
+only resets these flags, not the IMA_NEW_FILE or IMA_DIGSIG flags.
+
+With this patch, changing the file timestamp will not remove the
+file signature on new files.
+
+Upstream-Status: Accepted [https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/security/integrity/ima/ima_appraise.c?id=42a4c603198f0d45b7aa936d3ac6ba1b8bd14a1b]
+
+Reported-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
+Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
+---
+ security/integrity/ima/ima_appraise.c | 2 +-
+ security/integrity/integrity.h        | 1 +
+ 2 files changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
+index 4df493e..a384ba1 100644
+--- a/security/integrity/ima/ima_appraise.c
++++ b/security/integrity/ima/ima_appraise.c
+@@ -327,7 +327,7 @@ void ima_inode_post_setattr(struct dentry *dentry)
+ 	if (iint) {
+ 		iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
+ 				 IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
+-				 IMA_ACTION_FLAGS);
++				 IMA_ACTION_RULE_FLAGS);
+ 		if (must_appraise)
+ 			iint->flags |= IMA_APPRAISE;
+ 	}
+diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
+index 0fc9519..f9decae 100644
+--- a/security/integrity/integrity.h
++++ b/security/integrity/integrity.h
+@@ -28,6 +28,7 @@
+ 
+ /* iint cache flags */
+ #define IMA_ACTION_FLAGS	0xff000000
++#define IMA_ACTION_RULE_FLAGS	0x06000000
+ #define IMA_DIGSIG		0x01000000
+ #define IMA_DIGSIG_REQUIRED	0x02000000
+ #define IMA_PERMIT_DIRECTIO	0x04000000
+-- 
+2.5.0
+

meta-integrity/recipes-kernel/linux/linux/0002-ima-add-support-for-creating-files-using-the-mknodat.patch

@@ -0,0 +1,138 @@
+From baaec960e9e7be0b526eaf831b079ddfe5c15124 Mon Sep 17 00:00:00 2001
+From: Mimi Zohar <zohar@linux.vnet.ibm.com>
+Date: Thu, 10 Mar 2016 18:19:20 +0200
+Subject: [PATCH] ima: add support for creating files using the mknodat
+ syscall
+
+Commit 3034a14 "ima: pass 'opened' flag to identify newly created files"
+stopped identifying empty files as new files.  However new empty files
+can be created using the mknodat syscall.  On systems with IMA-appraisal
+enabled, these empty files are not labeled with security.ima extended
+attributes properly, preventing them from subsequently being opened in
+order to write the file data contents.  This patch marks these empty
+files, created using mknodat, as new in order to allow the file data
+contents to be written.
+
+Files with security.ima xattrs containing a file signature are considered
+"immutable" and can not be modified.  The file contents need to be
+written, before signing the file.  This patch relaxes this requirement
+for new files, allowing the file signature to be written before the file
+contents.
+
+Upstream-Status: Accepted [https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/security/integrity/ima/ima_appraise.c?id=05d1a717ec0430c916a749b94eb90ab74bbfa356]
+
+Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
+---
+ fs/namei.c                            |  2 ++
+ include/linux/ima.h                   |  7 ++++++-
+ security/integrity/ima/ima_appraise.c |  3 +++
+ security/integrity/ima/ima_main.c     | 32 +++++++++++++++++++++++++++++++-
+ 4 files changed, 42 insertions(+), 2 deletions(-)
+
+diff --git a/fs/namei.c b/fs/namei.c
+index ccd7f98..19502da 100644
+--- a/fs/namei.c
++++ b/fs/namei.c
+@@ -3526,6 +3526,8 @@ retry:
+ 	switch (mode & S_IFMT) {
+ 		case 0: case S_IFREG:
+ 			error = vfs_create(path.dentry->d_inode,dentry,mode,true);
++			if (!error)
++				ima_post_path_mknod(dentry);
+ 			break;
+ 		case S_IFCHR: case S_IFBLK:
+ 			error = vfs_mknod(path.dentry->d_inode,dentry,mode,
+diff --git a/include/linux/ima.h b/include/linux/ima.h
+index 120ccc5..7f51971 100644
+--- a/include/linux/ima.h
++++ b/include/linux/ima.h
+@@ -20,7 +20,7 @@ extern void ima_file_free(struct file *file);
+ extern int ima_file_mmap(struct file *file, unsigned long prot);
+ extern int ima_module_check(struct file *file);
+ extern int ima_fw_from_file(struct file *file, char *buf, size_t size);
+-
++extern void ima_post_path_mknod(struct dentry *dentry);
+ #else
+ static inline int ima_bprm_check(struct linux_binprm *bprm)
+ {
+@@ -52,6 +52,11 @@ static inline int ima_fw_from_file(struct file *file, char *buf, size_t size)
+ 	return 0;
+ }
+ 
++static inline void ima_post_path_mknod(struct dentry *dentry)
++{
++	return;
++}
++
+ #endif /* CONFIG_IMA */
+ 
+ #ifdef CONFIG_IMA_APPRAISE
+diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
+index 4df493e..20806ea 100644
+--- a/security/integrity/ima/ima_appraise.c
++++ b/security/integrity/ima/ima_appraise.c
+@@ -274,6 +274,11 @@ out:
+ 		     xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
+ 			if (!ima_fix_xattr(dentry, iint))
+ 				status = INTEGRITY_PASS;
++		} else if ((inode->i_size == 0) &&
++			   (iint->flags & IMA_NEW_FILE) &&
++			   (xattr_value &&
++			    xattr_value->type == EVM_IMA_XATTR_DIGSIG)) {
++			status = INTEGRITY_PASS;
+ 		}
+ 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
+ 				    op, cause, rc, 0);
+diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
+index eeee00dc..705bf78 100644
+--- a/security/integrity/ima/ima_main.c
++++ b/security/integrity/ima/ima_main.c
+@@ -242,7 +242,8 @@ static int process_measurement(struct file *file, int mask, int function,
+ 		ima_audit_measurement(iint, pathname);
+ 
+ out_digsig:
+-	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
++	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) &&
++	     !(iint->flags & IMA_NEW_FILE))
+ 		rc = -EACCES;
+ 	kfree(xattr_value);
+ out_free:
+@@ -310,6 +311,35 @@ int ima_file_check(struct file *file, int mask, int opened)
+ EXPORT_SYMBOL_GPL(ima_file_check);
+ 
+ /**
++ * ima_post_path_mknod - mark as a new inode
++ * @dentry: newly created dentry
++ *
++ * Mark files created via the mknodat syscall as new, so that the
++ * file data can be written later.
++ */
++void ima_post_path_mknod(struct dentry *dentry)
++{
++	struct integrity_iint_cache *iint;
++	struct inode *inode;
++	int must_appraise;
++
++	if (!dentry || !dentry->d_inode)
++		return;
++
++	inode = dentry->d_inode;
++	if (inode->i_size != 0)
++		return;
++
++	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
++	if (!must_appraise)
++		return;
++
++	iint = integrity_inode_get(inode);
++	if (iint)
++		iint->flags |= IMA_NEW_FILE;
++}
++
++/**
+  * ima_module_check - based on policy, collect/store/appraise measurement.
+  * @file: pointer to the file to be measured/appraised
+  *
+-- 
+2.5.0
+

meta-integrity/recipes-kernel/linux/linux/Revert-ima-limit-file-hash-setting-by-user-to-fix-an.patch

@@ -0,0 +1,60 @@
+From a34d61850b680c152e1dcc958ee83c3ab3261c3d Mon Sep 17 00:00:00 2001
+From: Patrick Ohly <patrick.ohly@intel.com>
+Date: Tue, 15 Nov 2016 10:10:23 +0100
+Subject: [PATCH] Revert "ima: limit file hash setting by user to fix and log
+ modes"
+
+This reverts commit c68ed80c97d9720f51ef31fe91560fdd1e121533.
+
+The original motivation was security hardening ("File hashes are
+automatically set and updated and should not be manually set.")
+
+However, that hardening ignores and breaks some valid use cases:
+- File hashes might not be set because the file is currently
+  outside of the policy and therefore have to be set by the
+  creator. Examples:
+  - Booting into an initramfs with an IMA-enabled kernel but
+    without setting an IMA policy, then installing
+    the OS onto the target partition by unpacking a rootfs archive
+    which has the file hashes pre-computed.
+  - Unpacking a file into a staging area with meta data (like owner)
+    that leaves the file outside of the current policy, then changing
+    the meta data such that it becomes part of the current policy.
+- "should not be set manually" implies that the creator is aware
+  of IMA semantic, the current system's configuration, and then
+  skips setting file hashes in security.ima if (and only if) the
+  kernel would prevent it. That's not the case for standard, unmodified
+  tools. Example: unpacking an archive with security.ima xattrs with
+  bsdtar or GNU tar.
+
+Upstream-Status: Submitted [https://sourceforge.net/p/linux-ima/mailman/message/35492824/]
+
+Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
+---
+ security/integrity/ima/ima_appraise.c | 8 ++------
+ 1 file changed, 2 insertions(+), 6 deletions(-)
+
+diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
+index 4b9b4a4..b8b2dd9 100644
+--- a/security/integrity/ima/ima_appraise.c
++++ b/security/integrity/ima/ima_appraise.c
+@@ -385,14 +385,10 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
+ 	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
+ 				   xattr_value_len);
+ 	if (result == 1) {
+-		bool digsig;
+-
+ 		if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST))
+ 			return -EINVAL;
+-		digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG);
+-		if (!digsig && (ima_appraise & IMA_APPRAISE_ENFORCE))
+-			return -EPERM;
+-		ima_reset_appraise_flags(d_backing_inode(dentry), digsig);
++		ima_reset_appraise_flags(d_backing_inode(dentry),
++			 (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0);
+ 		result = 0;
+ 	}
+ 	return result;
+-- 
+2.1.4
+

meta-integrity/recipes-kernel/linux/linux/ima.cfg

@@ -0,0 +1,16 @@
+# Enable bare minimum IMA measurement and appraisal as needed by this layer.
+
+CONFIG_SECURITY=y
+CONFIG_INTEGRITY=y
+
+# measurement
+CONFIG_IMA=y
+
+# appraisal
+CONFIG_IMA_APPRAISE=y
+CONFIG_INTEGRITY_SIGNATURE=y
+CONFIG_INTEGRITY_ASYMMETRIC_KEYS=y
+
+# Kernel will get built with embedded X.509 root CA key and all keys
+# need to be signed with that.
+CONFIG_IMA_TRUSTED_KEYRING=y

meta-integrity/recipes-kernel/linux/linux/ima_evm_root_ca.cfg

@@ -0,0 +1,3 @@
+CONFIG_KEYS=y
+CONFIG_SYSTEM_TRUSTED_KEYRING=y
+CONFIG_SYSTEM_TRUSTED_KEYS=""