[ptxdist] [PATCH] RFC: ptxd_make_world: Extract CPE for packages

[Simon Falsig <sfalsig@verity.net>]

From: Simon Falsig <sfalsig@verity.ch>

If a package specifies a CPE or CPE_VENDOR and CPE_PRODUCT, this is
extracted into the fast report for that package. If no CPE is
specified, or not both of CPE_VENDOR and CPE_PRODUCT, then no value is
added.

By default, the existing VERSION is used, but can be overridden with
CPE_VERSION.

Constructed CPEs are validated against the official CPE regex.

The CPE (Common Platform Enumerator) allows matching CVEs to specific
packages, and see if these apply to a specific deployment.
---
 rules/post/ptxd_make_world_common.make |  4 ++++
 scripts/lib/ptxd_make_world_report.sh  | 29 ++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/rules/post/ptxd_make_world_common.make b/rules/post/ptxd_make_world_common.make
index 08120607a..0804f0b81 100644
--- a/rules/post/ptxd_make_world_common.make
+++ b/rules/post/ptxd_make_world_common.make
@@ -78,6 +78,10 @@ world/env/impl = \
 	pkg_PKG="$(call ptx/escape,$(1))"					\
 	pkg_pkg="$(call ptx/escape,$($(1)))"					\
 	pkg_version="$(call ptx/escape,$($(1)_VERSION))"			\
+	pkg_cpe_vendor="$(call ptx/escape,$($(1)_CPE_VENDOR))"			\
+	pkg_cpe_product="$(call ptx/escape,$($(1)_CPE_PRODUCT))"		\
+	pkg_cpe_version="$(call ptx/escape,$($(1)_CPE_VERSION))"		\
+	pkg_cpe="$(call ptx/escape,$($(1)_CPE))"				\
 	pkg_config="$(call ptx/escape,$($(1)_CONFIG))"				\
 	pkg_ref_config="$(call ptx/escape,$($(1)_REF_CONFIG))"			\
 	pkg_path="$(call ptx/escape,$($(1)_PATH))"				\
diff --git a/scripts/lib/ptxd_make_world_report.sh b/scripts/lib/ptxd_make_world_report.sh
index dbdae5736..11f17b405 100644
--- a/scripts/lib/ptxd_make_world_report.sh
+++ b/scripts/lib/ptxd_make_world_report.sh
@@ -31,6 +31,30 @@ ptxd_make_world_report_yaml() {
 	    awk "BEGIN { RS=\" \" } { if (\$1) print \"- '\" \$1 \"'\" }" <<<"${2}"
 	fi
     }
+    do_build_cpe() {
+        prefix="${1}"
+        cpe="${2}"
+        vendor="${3}"
+        product="${4}"
+        version="${5}"
+        if [ -n "${cpe}" ]; then
+            # If a cpe is fully specified, then use that
+            :
+        elif [ -n "${vendor}" -a -n "${product}" -a -n "${version}" ]; then
+            # Otherwise, if we have vendor, product and version, then build a CPE2.3 string from it
+            cpe="cpe:2.3:a:${vendor}:${product}:${version}:*:*:*:*:*:*:*"
+        fi
+        if [ -n "$cpe" ]; then
+            # Validate the resulting CPE string
+            # Regex taken from: https://csrc.nist.gov/schema/cpe/2.3/cpe-naming_2.3.xsd
+            if echo "$cpe" | grep -Eq 'cpe:2\.3:[aho\*\-](:(((\?*|\*?)([a-zA-Z0-9\-\._]|(\\[\\\*\?!"#$$%&'\''\(\)\+,/:;<=>@\[\]\^`\{\|}~]))+(\?*|\*?))|[\*\-])){5}(:(([a-zA-Z]{2,3}(-([a-zA-Z]{2}|[0-9]{3}))?)|[\*\-]))(:(((\?*|\*?)([a-zA-Z0-9\-\._]|(\\[\\\*\?!"#$$%&''\''\(\)\+,/:;<=>@\[\]\^`\{\|}~]))+(\?*|\*?))|[\*\-])){4}'; then
+                echo "${prefix} ${cpe}"
+            else
+                >&2 echo "Error! $cpe is not valid CPE format string"
+                return 1
+            fi
+        fi
+    }
     do_echo "name:" "${pkg_label}"
     do_echo "rulefile:" "${pkg_makefile}"
     do_list "extra-rulefiles:" "${pkg_extra_makefiles}"
@@ -39,6 +63,11 @@ ptxd_make_world_report_yaml() {
     do_list "rundeps:" "${pkg_run_deps}"
     do_echo "config:" "${pkg_config}"
     do_echo "version:" "${pkg_version}"
+    if [ ! -n "${pkg_cpe_version}" ]; then
+    # Default to using pkg_version for the CPE string, unless _CPE_VERSION is explicitly specified
+    pkg_cpe_version="${pkg_version}";
+    fi
+    do_build_cpe "cpe:" "${pkg_cpe}" "${pkg_cpe_vendor}" "${pkg_cpe_product}" "${pkg_cpe_version}"
     do_list "url:" "${pkg_url}"
     do_echo "md5:" "${pkg_md5}"
     do_echo "source:" "${pkg_src}"
-- 
2.25.1