clair/ext/vulnsrc/oracle/oracle.go
Sida Chen fb32dcfa58 Clair Logic, Extensions: updated mock tests, extensions, basic logic
Main Clair logic is changed in worker, updater, notifier for better adapting
ancestry schema. Extensions are updated with the new model and feature lister
 and namespace detector drivers are able to specify the specific listers and
detectors used to process layer's content. InRange and GetFixedIn interfaces
are added to Version format for adapting ranged affected features and next
available fixed in in the future. Tests for worker, updater and extensions
are fixed.
2017-08-10 11:24:40 -04:00

409 lines
11 KiB
Go

// Copyright 2017 clair authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package oracle implements a vulnerability source updater using the
// Oracle Linux OVAL Database.
package oracle
import (
"bufio"
"encoding/xml"
"io"
"net/http"
"regexp"
"strconv"
"strings"
log "github.com/sirupsen/logrus"
"fmt"
"github.com/coreos/clair/database"
"github.com/coreos/clair/ext/versionfmt"
"github.com/coreos/clair/ext/versionfmt/rpm"
"github.com/coreos/clair/ext/vulnsrc"
"github.com/coreos/clair/pkg/commonerr"
)
const (
firstOracle5ELSA = 20070057
ovalURI = "https://linux.oracle.com/oval/"
elsaFilePrefix = "com.oracle.elsa-"
updaterFlag = "oracleUpdater"
)
var (
ignoredCriterions = []string{
" is signed with the Oracle Linux",
".ksplice1.",
}
elsaRegexp = regexp.MustCompile(`com.oracle.elsa-(\d+).xml`)
)
type oval struct {
Definitions []definition `xml:"definitions>definition"`
}
type definition struct {
Title string `xml:"metadata>title"`
Description string `xml:"metadata>description"`
References []reference `xml:"metadata>reference"`
Criteria criteria `xml:"criteria"`
Severity string `xml:"metadata>advisory>severity"`
}
type reference struct {
Source string `xml:"source,attr"`
URI string `xml:"ref_url,attr"`
}
type criteria struct {
Operator string `xml:"operator,attr"`
Criterias []*criteria `xml:"criteria"`
Criterions []criterion `xml:"criterion"`
}
type criterion struct {
Comment string `xml:"comment,attr"`
}
type updater struct{}
func init() {
vulnsrc.RegisterUpdater("oracle", &updater{})
}
func compareELSA(left, right int) int {
// Fast path equals.
if right == left {
return 0
}
lstr := strconv.Itoa(left)
rstr := strconv.Itoa(right)
for i := range lstr {
// If right is too short to be indexed, left is greater.
if i >= len(rstr) {
return 1
}
ldigit, _ := strconv.Atoi(string(lstr[i]))
rdigit, _ := strconv.Atoi(string(rstr[i]))
if ldigit > rdigit {
return 1
} else if ldigit < rdigit {
return -1
}
continue
}
// Everything the length of left is the same.
return len(lstr) - len(rstr)
}
func (u *updater) Update(datastore database.Datastore) (resp vulnsrc.UpdateResponse, err error) {
log.WithField("package", "Oracle Linux").Info("Start fetching vulnerabilities")
// Get the first ELSA we have to manage.
tx, err := datastore.Begin()
if err != nil {
return resp, err
}
defer tx.Rollback()
flagValue, ok, err := tx.FindKeyValue(updaterFlag)
if err != nil {
return resp, err
}
if !ok {
flagValue = ""
}
firstELSA, err := strconv.Atoi(flagValue)
if firstELSA == 0 || err != nil {
firstELSA = firstOracle5ELSA
}
// Fetch the update list.
r, err := http.Get(ovalURI)
if err != nil {
log.WithError(err).Error("could not download Oracle's update list")
return resp, commonerr.ErrCouldNotDownload
}
defer r.Body.Close()
// Get the list of ELSAs that we have to process.
var elsaList []int
scanner := bufio.NewScanner(r.Body)
for scanner.Scan() {
line := scanner.Text()
r := elsaRegexp.FindStringSubmatch(line)
if len(r) == 2 {
elsaNo, _ := strconv.Atoi(r[1])
if compareELSA(elsaNo, firstELSA) > 0 {
elsaList = append(elsaList, elsaNo)
}
}
}
for _, elsa := range elsaList {
// Download the ELSA's XML file.
r, err := http.Get(ovalURI + elsaFilePrefix + strconv.Itoa(elsa) + ".xml")
if err != nil {
log.WithError(err).Error("could not download Oracle's update list")
return resp, commonerr.ErrCouldNotDownload
}
// Parse the XML.
vs, err := parseELSA(r.Body)
if err != nil {
return resp, err
}
// Collect vulnerabilities.
for _, v := range vs {
resp.Vulnerabilities = append(resp.Vulnerabilities, v)
}
}
// Set the flag if we found anything.
if len(elsaList) > 0 {
resp.FlagName = updaterFlag
resp.FlagValue = strconv.Itoa(largest(elsaList))
} else {
log.WithField("package", "Oracle Linux").Debug("no update")
}
return resp, nil
}
func largest(list []int) (largest int) {
for _, element := range list {
if element > largest {
largest = element
}
}
return
}
func (u *updater) Clean() {}
func parseELSA(ovalReader io.Reader) (vulnerabilities []database.VulnerabilityWithAffected, err error) {
// Decode the XML.
var ov oval
err = xml.NewDecoder(ovalReader).Decode(&ov)
if err != nil {
log.WithError(err).Error("could not decode Oracle's XML")
err = commonerr.ErrCouldNotParse
return
}
// Iterate over the definitions and collect any vulnerabilities that affect
// at least one package.
for _, definition := range ov.Definitions {
pkgs := toFeatures(definition.Criteria)
if len(pkgs) > 0 {
vulnerability := database.VulnerabilityWithAffected{
Vulnerability: database.Vulnerability{
Name: name(definition),
Link: link(definition),
Severity: severity(definition),
Description: description(definition),
},
}
for _, p := range pkgs {
vulnerability.Affected = append(vulnerability.Affected, p)
}
vulnerabilities = append(vulnerabilities, vulnerability)
}
}
return
}
func getCriterions(node criteria) [][]criterion {
// Filter useless criterions.
var criterions []criterion
for _, c := range node.Criterions {
ignored := false
for _, ignoredItem := range ignoredCriterions {
if strings.Contains(c.Comment, ignoredItem) {
ignored = true
break
}
}
if !ignored {
criterions = append(criterions, c)
}
}
if node.Operator == "AND" {
return [][]criterion{criterions}
} else if node.Operator == "OR" {
var possibilities [][]criterion
for _, c := range criterions {
possibilities = append(possibilities, []criterion{c})
}
return possibilities
}
return [][]criterion{}
}
func getPossibilities(node criteria) [][]criterion {
if len(node.Criterias) == 0 {
return getCriterions(node)
}
var possibilitiesToCompose [][][]criterion
for _, criteria := range node.Criterias {
possibilitiesToCompose = append(possibilitiesToCompose, getPossibilities(*criteria))
}
if len(node.Criterions) > 0 {
possibilitiesToCompose = append(possibilitiesToCompose, getCriterions(node))
}
var possibilities [][]criterion
if node.Operator == "AND" {
for _, possibility := range possibilitiesToCompose[0] {
possibilities = append(possibilities, possibility)
}
for _, possibilityGroup := range possibilitiesToCompose[1:] {
var newPossibilities [][]criterion
for _, possibility := range possibilities {
for _, possibilityInGroup := range possibilityGroup {
var p []criterion
p = append(p, possibility...)
p = append(p, possibilityInGroup...)
newPossibilities = append(newPossibilities, p)
}
}
possibilities = newPossibilities
}
} else if node.Operator == "OR" {
for _, possibilityGroup := range possibilitiesToCompose {
for _, possibility := range possibilityGroup {
possibilities = append(possibilities, possibility)
}
}
}
return possibilities
}
func toFeatures(criteria criteria) []database.AffectedFeature {
// There are duplicates in Oracle .xml files.
// This map is for deduplication.
featureVersionParameters := make(map[string]database.AffectedFeature)
possibilities := getPossibilities(criteria)
for _, criterions := range possibilities {
var (
featureVersion database.AffectedFeature
osVersion int
err error
)
// Attempt to parse package data from trees of criterions.
for _, c := range criterions {
if strings.Contains(c.Comment, " is installed") {
const prefixLen = len("Oracle Linux ")
osVersion, err = strconv.Atoi(strings.TrimSpace(c.Comment[prefixLen : prefixLen+strings.Index(c.Comment[prefixLen:], " ")]))
if err != nil {
log.WithError(err).WithField("comment", c.Comment).Warning("could not parse Oracle Linux release version from comment")
}
} else if strings.Contains(c.Comment, " is earlier than ") {
const prefixLen = len(" is earlier than ")
featureVersion.FeatureName = strings.TrimSpace(c.Comment[:strings.Index(c.Comment, " is earlier than ")])
version := c.Comment[strings.Index(c.Comment, " is earlier than ")+prefixLen:]
err := versionfmt.Valid(rpm.ParserName, version)
if err != nil {
log.WithError(err).WithField("version", version).Warning("could not parse package version. skipping")
} else {
featureVersion.AffectedVersion = version
if version != versionfmt.MaxVersion {
featureVersion.FixedInVersion = version
}
}
}
}
featureVersion.Namespace.Name = "oracle" + ":" + strconv.Itoa(osVersion)
featureVersion.Namespace.VersionFormat = rpm.ParserName
if featureVersion.Namespace.Name != "" && featureVersion.FeatureName != "" && featureVersion.AffectedVersion != "" && featureVersion.FixedInVersion != "" {
featureVersionParameters[featureVersion.Namespace.Name+":"+featureVersion.FeatureName] = featureVersion
} else {
log.WithField("criterions", fmt.Sprintf("%v", criterions)).Warning("could not determine a valid package from criterions")
}
}
// Convert the map to slice.
var featureVersionParametersArray []database.AffectedFeature
for _, fv := range featureVersionParameters {
featureVersionParametersArray = append(featureVersionParametersArray, fv)
}
return featureVersionParametersArray
}
func description(def definition) (desc string) {
// It is much more faster to proceed like this than using a Replacer.
desc = strings.Replace(def.Description, "\n\n\n", " ", -1)
desc = strings.Replace(desc, "\n\n", " ", -1)
desc = strings.Replace(desc, "\n", " ", -1)
return
}
func name(def definition) string {
return strings.TrimSpace(def.Title[:strings.Index(def.Title, ": ")])
}
func link(def definition) (link string) {
for _, reference := range def.References {
if reference.Source == "elsa" {
link = reference.URI
break
}
}
return
}
func severity(def definition) database.Severity {
switch strings.ToLower(def.Severity) {
case "n/a":
return database.NegligibleSeverity
case "low":
return database.LowSeverity
case "moderate":
return database.MediumSeverity
case "important":
return database.HighSeverity
case "critical":
return database.CriticalSeverity
default:
log.WithField("severity", def.Severity).Warning("could not determine vulnerability severity")
return database.UnknownSeverity
}
}