package_rpm: support signing of rpm packages

This patch adds a new bbclass for generating rpm packages that are
signed with a user defined key. The packages are signed as part of the
"package_write_rpm" task.

In order to enable the feature you need to
1. 'INHERIT += " sign_rpm"' in bitbake config (e.g. local or
   distro)
2. Create a file that contains the passphrase to your gpg secret key
3. 'RPM_GPG_PASSPHRASE_FILE = "<path_to_file>" in bitbake config,
   pointing to the passphrase file created in 2.
4. Define GPG key name to use by either defining
   'RPM_GPG_NAME = "<key_id>" in bitbake config OR by defining
   %_gpg_name <key_id> in your ~/.oerpmmacros file
5. 'RPM_GPG_PUBKEY = "<path_to_pubkey>" in bitbake config pointing to
   the public key (in "armor" format)

The user may optionally define "GPG_BIN" variable in the bitbake
configuration in order to specify a specific gpg binary/wrapper to use.

The sign_rpm.bbclass implements a simple scenario of locally signing the
packages. It could be replaced by a more advanced class that would
utilize a separate signing server for signing the packages, for example.

[YOCTO #8134]

(From OE-Core rev: 75f5f11b19ba1bf8743caf9ee7c99a3c67f4b266)

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/package_manager.py

@@ -108,6 +108,7 @@ class RpmIndexer(Indexer):
         archs = archs.union(set(sdk_pkg_archs))
 
         rpm_createrepo = bb.utils.which(os.getenv('PATH'), "createrepo")
+
         index_cmds = []
         rpm_dirs_found = False
         for arch in archs:
@@ -127,9 +128,16 @@ class RpmIndexer(Indexer):
             bb.note("There are no packages in %s" % self.deploy_dir)
             return
 
+        # Create repodata
         result = oe.utils.multiprocess_exec(index_cmds, create_index)
         if result:
             bb.fatal('%s' % ('\n'.join(result)))
+        # Copy pubkey to repo
+        distro_version = self.d.getVar('DISTRO_VERSION', True) or "oe.0"
+        if self.d.getVar('RPM_SIGN_PACKAGES', True) == '1':
+            shutil.copy2(self.d.getVar('RPM_GPG_PUBKEY', True),
+                         os.path.join(self.deploy_dir,
+                                      'RPM-GPG-KEY-%s' % distro_version))
 
 
 class OpkgIndexer(Indexer):
@@ -352,6 +360,9 @@ class RpmPkgsList(PkgsList):
             pkg = line.split()[0]
             arch = line.split()[1]
             ver = line.split()[2]
+            # Skip GPG keys
+            if pkg == 'gpg-pubkey':
+                continue
             if self.rpm_version == 4:
                 pkgorigin = "unknown"
             else:
@@ -864,6 +875,12 @@ class RpmPM(PackageManager):
         except subprocess.CalledProcessError as e:
             bb.fatal("Create rpm database failed. Command '%s' "
                      "returned %d:\n%s" % (cmd, e.returncode, e.output))
+        # Import GPG key to RPM database of the target system
+        if self.d.getVar('RPM_SIGN_PACKAGES', True) == '1':
+            pubkey_path = self.d.getVar('RPM_GPG_PUBKEY', True)
+            cmd = "%s --root %s --dbpath /var/lib/rpm --import %s > /dev/null" % (
+                  self.rpm_cmd, self.target_rootfs, pubkey_path)
+            subprocess.check_output(cmd, stderr=subprocess.STDOUT, shell=True)
 
         # Configure smart
         bb.note("configuring Smart settings")