nuclei/v2/pkg/protocols/file/request.go

package file

import (
	"bufio"
	"encoding/hex"
	"io"
	"os"
	"strings"

	"github.com/docker/go-units"
	"github.com/pkg/errors"
	"github.com/remeh/sizedwaitgroup"

	"github.com/projectdiscovery/gologger"
	"github.com/projectdiscovery/nuclei/v2/pkg/operators"
	"github.com/projectdiscovery/nuclei/v2/pkg/output"
	"github.com/projectdiscovery/nuclei/v2/pkg/protocols"
	"github.com/projectdiscovery/nuclei/v2/pkg/protocols/common/helpers/eventcreator"
	"github.com/projectdiscovery/nuclei/v2/pkg/protocols/common/helpers/responsehighlighter"
	templateTypes "github.com/projectdiscovery/nuclei/v2/pkg/templates/types"
)

var _ protocols.Request = &Request{}

// Type returns the type of the protocol request
func (request *Request) Type() templateTypes.ProtocolType {
	return templateTypes.FileProtocol
}

type FileMatch struct {
	Data      string
	Line      int
	ByteIndex int
	Match     bool
	Extract   bool
	Expr      string
	Raw       string
}

// ExecuteWithResults executes the protocol requests and returns results instead of writing them.
func (request *Request) ExecuteWithResults(input string, metadata, previous output.InternalEvent, callback protocols.OutputEventCallback) error {
	wg := sizedwaitgroup.New(request.options.Options.BulkSize)

	err := request.getInputPaths(input, func(data string) {
		request.options.Progress.AddToTotal(1)
		wg.Add()

		go func(filePath string) {
			defer wg.Done()

			file, err := os.Open(filePath)
			if err != nil {
				gologger.Error().Msgf("Could not open file path %s: %s\n", filePath, err)
				return
			}
			defer file.Close()

			stat, err := file.Stat()
			if err != nil {
				gologger.Error().Msgf("Could not stat file path %s: %s\n", filePath, err)
				return
			}
			if stat.Size() >= request.maxSize {
				gologger.Verbose().Msgf("Limiting %s processed data to %s bytes: exceeded max size\n", filePath, units.HumanSize(float64(request.maxSize)))
			}

			fileReader := io.LimitReader(file, request.maxSize)
			fileMatches, opResult := request.collect(fileReader, input, filePath, units.BytesSize(float64(stat.Size())), previous)

			// build event structure to interface with internal logic
			event := request.buildEvent(input, filePath, fileMatches, opResult, previous)
			dumpResponse(event, request.options, fileMatches, filePath)
			callback(event)
			request.options.Progress.IncrementRequests()
		}(data)
	})
	wg.Wait()
	if err != nil {
		request.options.Output.Request(request.options.TemplatePath, input, request.Type().String(), err)
		request.options.Progress.IncrementFailedRequestsBy(1)
		return errors.Wrap(err, "could not send file request")
	}
	return nil
}

func (request *Request) collect(reader io.Reader, input, filePath, totalBytes string, previous output.InternalEvent) ([]FileMatch, *operators.Result) {
	var bytesCount, linesCount, wordsCount int
	isResponseDebug := request.options.Options.Debug || request.options.Options.DebugResponse
	scanner := bufio.NewScanner(reader)
	buffer := []byte{}
	scanner.Buffer(buffer, int(chunkSize))

	var fileMatches []FileMatch
	var opResult *operators.Result
	for scanner.Scan() {
		lineContent := scanner.Text()
		n := len(lineContent)

		// update counters
		currentBytes := bytesCount + n
		processedBytes := units.BytesSize(float64(currentBytes))

		gologger.Verbose().Msgf("[%s] Processing file %s chunk %s/%s", request.options.TemplateID, filePath, processedBytes, totalBytes)
		dslMap := request.responseToDSLMap(lineContent, input, filePath)
		for k, v := range previous {
			dslMap[k] = v
		}
		discardEvent := eventcreator.CreateEvent(request, dslMap, isResponseDebug)
		newOpResult := discardEvent.OperatorsResult
		if newOpResult != nil {
			if opResult == nil {
				opResult = newOpResult
			} else {
				opResult.Merge(newOpResult)
			}
			if newOpResult.Matched || newOpResult.Extracted {
				if newOpResult.Extracts != nil {
					for expr, extracts := range newOpResult.Extracts {
						for _, extract := range extracts {
							fileMatches = append(fileMatches, FileMatch{
								Data:      extract,
								Extract:   true,
								Line:      linesCount + 1,
								ByteIndex: bytesCount,
								Expr:      expr,
								Raw:       lineContent,
							})
						}
					}
				}
				if newOpResult.Matches != nil {
					for expr, matches := range newOpResult.Matches {
						for _, match := range matches {
							fileMatches = append(fileMatches, FileMatch{
								Data:      match,
								Match:     true,
								Line:      linesCount + 1,
								ByteIndex: bytesCount,
								Expr:      expr,
								Raw:       lineContent,
							})
						}
					}
				}
			}
		}

		currentLinesCount := 1 + strings.Count(lineContent, "\n")
		linesCount += currentLinesCount
		wordsCount += strings.Count(lineContent, " ")
		bytesCount = currentBytes
	}
	return fileMatches, opResult
}

func (request *Request) buildEvent(input, filePath string, fileMatches []FileMatch, operatorResult *operators.Result, previous output.InternalEvent) *output.InternalWrappedEvent {
	exprLines := make(map[string][]int)
	exprBytes := make(map[string][]int)
	internalEvent := request.responseToDSLMap("", input, filePath)
	for k, v := range previous {
		internalEvent[k] = v
	}
	for _, fileMatch := range fileMatches {
		exprLines[fileMatch.Expr] = append(exprLines[fileMatch.Expr], fileMatch.Line)
		exprBytes[fileMatch.Expr] = append(exprBytes[fileMatch.Expr], fileMatch.ByteIndex)
	}

	event := eventcreator.CreateEventWithOperatorResults(request, internalEvent, operatorResult)
	for _, result := range event.Results {
		switch {
		case result.MatcherName != "":
			result.Lines = exprLines[result.MatcherName]
		case result.ExtractorName != "":
			result.Lines = exprLines[result.ExtractorName]
		}
	}
	return event
}

func dumpResponse(event *output.InternalWrappedEvent, requestOptions *protocols.ExecuterOptions, filematches []FileMatch, filePath string) {
	cliOptions := requestOptions.Options
	if cliOptions.Debug || cliOptions.DebugResponse {
		for _, fileMatch := range filematches {
			lineContent := fileMatch.Raw
			hexDump := false
			if responsehighlighter.HasBinaryContent(lineContent) {
				hexDump = true
				lineContent = hex.Dump([]byte(lineContent))
			}
			highlightedResponse := responsehighlighter.Highlight(event.OperatorsResult, lineContent, cliOptions.NoColor, hexDump)
			gologger.Debug().Msgf("[%s] Dumped match/extract file snippet for %s at line %d\n\n%s", requestOptions.TemplateID, filePath, fileMatch.Line, highlightedResponse)
		}
	}
}