nuclei/pkg/templates/compile.go

415 lines
13 KiB
Go

package templates
import (
"encoding/json"
"fmt"
"io"
"reflect"
"sync"
"sync/atomic"
"github.com/logrusorgru/aurora"
"github.com/pkg/errors"
"gopkg.in/yaml.v2"
"github.com/projectdiscovery/gologger"
"github.com/projectdiscovery/nuclei/v3/pkg/catalog/config"
"github.com/projectdiscovery/nuclei/v3/pkg/js/compiler"
"github.com/projectdiscovery/nuclei/v3/pkg/operators"
"github.com/projectdiscovery/nuclei/v3/pkg/protocols"
"github.com/projectdiscovery/nuclei/v3/pkg/protocols/offlinehttp"
"github.com/projectdiscovery/nuclei/v3/pkg/templates/cache"
"github.com/projectdiscovery/nuclei/v3/pkg/templates/signer"
"github.com/projectdiscovery/nuclei/v3/pkg/tmplexec"
"github.com/projectdiscovery/nuclei/v3/pkg/utils"
"github.com/projectdiscovery/retryablehttp-go"
errorutil "github.com/projectdiscovery/utils/errors"
stringsutil "github.com/projectdiscovery/utils/strings"
)
var (
ErrCreateTemplateExecutor = errors.New("cannot create template executer")
ErrIncompatibleWithOfflineMatching = errors.New("template can't be used for offline matching")
parsedTemplatesCache *cache.Templates
// track how many templates are verfied and by which signer
SignatureStats = map[string]*atomic.Uint64{}
)
const (
Unsigned = "unsigned"
)
func init() {
parsedTemplatesCache = cache.New()
for _, verifier := range signer.DefaultTemplateVerifiers {
SignatureStats[verifier.Identifier()] = &atomic.Uint64{}
}
SignatureStats[Unsigned] = &atomic.Uint64{}
}
// Parse parses a yaml request template file
// TODO make sure reading from the disk the template parsing happens once: see parsers.ParseTemplate vs templates.Parse
//
//nolint:gocritic // this cannot be passed by pointer
func Parse(filePath string, preprocessor Preprocessor, options protocols.ExecutorOptions) (*Template, error) {
if !options.DoNotCache {
if value, err := parsedTemplatesCache.Has(filePath); value != nil {
return value.(*Template), err
}
}
var reader io.ReadCloser
if utils.IsURL(filePath) {
// use retryablehttp (tls verification is enabled by default in the standard library)
resp, err := retryablehttp.DefaultClient().Get(filePath)
if err != nil {
return nil, err
}
reader = resp.Body
} else {
var err error
reader, err = options.Catalog.OpenFile(filePath)
if err != nil {
return nil, err
}
}
defer reader.Close()
options.TemplatePath = filePath
template, err := ParseTemplateFromReader(reader, preprocessor, options.Copy())
if err != nil {
return nil, err
}
// Compile the workflow request
if len(template.Workflows) > 0 {
compiled := &template.Workflow
compileWorkflow(filePath, preprocessor, &options, compiled, options.WorkflowLoader)
template.CompiledWorkflow = compiled
template.CompiledWorkflow.Options = &options
}
template.Path = filePath
if !options.DoNotCache {
parsedTemplatesCache.Store(filePath, template, err)
}
return template, nil
}
// parseSelfContainedRequests parses the self contained template requests.
func (template *Template) parseSelfContainedRequests() {
if template.Signature.Value.String() != "" {
for _, request := range template.RequestsHTTP {
request.Signature = template.Signature
}
}
if !template.SelfContained {
return
}
for _, request := range template.RequestsHTTP {
request.SelfContained = true
}
for _, request := range template.RequestsNetwork {
request.SelfContained = true
}
for _, request := range template.RequestsHeadless {
request.SelfContained = true
}
}
// Requests returns the total request count for the template
func (template *Template) Requests() int {
return len(template.RequestsDNS) +
len(template.RequestsHTTP) +
len(template.RequestsFile) +
len(template.RequestsNetwork) +
len(template.RequestsHeadless) +
len(template.Workflows) +
len(template.RequestsSSL) +
len(template.RequestsWebsocket) +
len(template.RequestsWHOIS) +
len(template.RequestsCode) +
len(template.RequestsJavascript)
}
// compileProtocolRequests compiles all the protocol requests for the template
func (template *Template) compileProtocolRequests(options *protocols.ExecutorOptions) error {
templateRequests := template.Requests()
if templateRequests == 0 {
return fmt.Errorf("no requests defined for %s", template.ID)
}
if options.Options.OfflineHTTP {
return template.compileOfflineHTTPRequest(options)
}
var requests []protocols.Request
if template.hasMultipleRequests() {
// when multiple requests are present preserve the order of requests and protocols
// which is already done during unmarshalling
requests = template.RequestsQueue
if options.Flow == "" {
options.IsMultiProtocol = true
}
} else {
if len(template.RequestsDNS) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsDNS)...)
}
if len(template.RequestsFile) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsFile)...)
}
if len(template.RequestsNetwork) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsNetwork)...)
}
if len(template.RequestsHTTP) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsHTTP)...)
}
if len(template.RequestsHeadless) > 0 && options.Options.Headless {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsHeadless)...)
}
if len(template.RequestsSSL) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsSSL)...)
}
if len(template.RequestsWebsocket) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsWebsocket)...)
}
if len(template.RequestsWHOIS) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsWHOIS)...)
}
if len(template.RequestsCode) > 0 && options.Options.EnableCodeTemplates {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsCode)...)
}
if len(template.RequestsJavascript) > 0 {
requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsJavascript)...)
}
}
var err error
template.Executer, err = tmplexec.NewTemplateExecuter(requests, options)
return err
}
// convertRequestToProtocolsRequest is a convenience wrapper to convert
// arbitrary interfaces which are slices of requests from the template to a
// slice of protocols.Request interface items.
func (template *Template) convertRequestToProtocolsRequest(requests interface{}) []protocols.Request {
switch reflect.TypeOf(requests).Kind() {
case reflect.Slice:
s := reflect.ValueOf(requests)
requestSlice := make([]protocols.Request, s.Len())
for i := 0; i < s.Len(); i++ {
value := s.Index(i)
valueInterface := value.Interface()
requestSlice[i] = valueInterface.(protocols.Request)
}
return requestSlice
}
return nil
}
// compileOfflineHTTPRequest iterates all requests if offline http mode is
// specified and collects all matchers for all the base request templates
// (those with URL {{BaseURL}} and it's slash variation.)
func (template *Template) compileOfflineHTTPRequest(options *protocols.ExecutorOptions) error {
operatorsList := []*operators.Operators{}
mainLoop:
for _, req := range template.RequestsHTTP {
hasPaths := len(req.Path) > 0
if !hasPaths {
break mainLoop
}
for _, path := range req.Path {
pathIsBaseURL := stringsutil.EqualFoldAny(path, "{{BaseURL}}", "{{BaseURL}}/", "/")
if !pathIsBaseURL {
break mainLoop
}
}
operatorsList = append(operatorsList, &req.Operators)
}
if len(operatorsList) > 0 {
options.Operators = operatorsList
var err error
template.Executer, err = tmplexec.NewTemplateExecuter([]protocols.Request{&offlinehttp.Request{}}, options)
if err != nil {
// it seems like flow executor cannot be used for offline http matching (ex:http(1) && http(2))
return ErrIncompatibleWithOfflineMatching
}
return err
}
return ErrIncompatibleWithOfflineMatching
}
// ParseTemplateFromReader reads the template from reader
// returns the parsed template
func ParseTemplateFromReader(reader io.Reader, preprocessor Preprocessor, options protocols.ExecutorOptions) (*Template, error) {
data, err := io.ReadAll(reader)
if err != nil {
return nil, err
}
// a preprocessor is a variable like
// {{randstr}} which is replaced before unmarshalling
// as it is known to be a random static value per template
hasPreprocessor := false
allPreprocessors := getPreprocessors(preprocessor)
for _, preprocessor := range allPreprocessors {
if preprocessor.Exists(data) {
hasPreprocessor = true
break
}
}
if !hasPreprocessor {
// if no preprocessors exists parse template and exit
template, err := parseTemplate(data, options)
if err != nil {
return nil, err
}
if !template.Verified && len(template.Workflows) == 0 {
if config.DefaultConfig.LogAllEvents {
gologger.DefaultLogger.Print().Msgf("[%v] Template %s is not signed or tampered\n", aurora.Yellow("WRN").String(), template.ID)
}
SignatureStats[Unsigned].Add(1)
}
return template, nil
}
// if preprocessor is required / exists in this template
// first unmarshal it and check if its verified
// persist verified status value and then
// expand all preprocessor and reparse template
// === signature verification before preprocessors ===
template, err := parseTemplate(data, options)
if err != nil {
return nil, err
}
isVerified := template.Verified
if !template.Verified && len(template.Workflows) == 0 {
// workflows are not signed by default
if config.DefaultConfig.LogAllEvents {
gologger.DefaultLogger.Print().Msgf("[%v] Template %s is not signed or tampered\n", aurora.Yellow("WRN").String(), template.ID)
}
SignatureStats[Unsigned].Add(1)
}
// ==== execute preprocessors ======
for _, v := range allPreprocessors {
data = v.Process(data)
}
reParsed, err := parseTemplate(data, options)
if err != nil {
return nil, err
}
reParsed.Verified = isVerified
return reParsed, nil
}
// this method does not include any kind of preprocessing
func parseTemplate(data []byte, options protocols.ExecutorOptions) (*Template, error) {
template := &Template{}
var err error
switch config.GetTemplateFormatFromExt(template.Path) {
case config.JSON:
err = json.Unmarshal(data, template)
case config.YAML:
err = yaml.Unmarshal(data, template)
default:
// assume its yaml
if err = yaml.Unmarshal(data, template); err != nil {
return nil, err
}
}
if err != nil {
return nil, errorutil.NewWithErr(err).Msgf("failed to parse %s", template.Path)
}
if utils.IsBlank(template.Info.Name) {
return nil, errors.New("no template name field provided")
}
if template.Info.Authors.IsEmpty() {
return nil, errors.New("no template author field provided")
}
// Setting up variables regarding template metadata
options.TemplateID = template.ID
options.TemplateInfo = template.Info
options.StopAtFirstMatch = template.StopAtFirstMatch
if template.Variables.Len() > 0 {
options.Variables = template.Variables
}
// if more than 1 request per protocol exist we add request id to protocol request
// since in template context we have proto_prefix for each protocol it is overwritten
// if request id is not present
template.validateAllRequestIDs()
// create empty context args for template scope
options.CreateTemplateCtxStore()
options.ProtocolType = template.Type()
options.Constants = template.Constants
// initialize the js compiler if missing
if options.JsCompiler == nil {
options.JsCompiler = GetJsCompiler()
}
template.Options = &options
// If no requests, and it is also not a workflow, return error.
if template.Requests() == 0 {
return nil, fmt.Errorf("no requests defined for %s", template.ID)
}
// load `flow` and `source` in code protocol from file
// if file is referenced instead of actual source code
if err := template.ImportFileRefs(template.Options); err != nil {
return nil, errorutil.NewWithErr(err).Msgf("failed to load file refs for %s", template.ID)
}
if err := template.compileProtocolRequests(template.Options); err != nil {
return nil, err
}
if template.Executer != nil {
if err := template.Executer.Compile(); err != nil {
return nil, errors.Wrap(err, "could not compile request")
}
template.TotalRequests = template.Executer.Requests()
}
if template.Executer == nil && template.CompiledWorkflow == nil {
return nil, ErrCreateTemplateExecutor
}
template.parseSelfContainedRequests()
// check if the template is verified
// only valid templates can be verified or signed
var verifier *signer.TemplateSigner
for _, verifier = range signer.DefaultTemplateVerifiers {
template.Verified, _ = verifier.Verify(data, template)
if template.Verified {
SignatureStats[verifier.Identifier()].Add(1)
break
}
}
if !(template.Verified && verifier.Identifier() == "projectdiscovery/nuclei-templates") {
template.Options.RawTemplate = data
}
return template, nil
}
var (
jsCompiler *compiler.Compiler
jsCompilerOnce = sync.OnceFunc(func() {
jsCompiler = compiler.New()
})
)
func GetJsCompiler() *compiler.Compiler {
jsCompilerOnce()
return jsCompiler
}