1 files changed, 174 insertions, 0 deletions
diff --git a/verify/cmd/verify.go b/verify/cmd/verify.go
new file mode 100644
index 0000000..d0360f6
--- /dev/null
+++ b/verify/cmd/verify.go
@@ -0,0 +1,174 @@
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"os"
+	"sync"
+
+	"github.com/axtloss/fsverify/config"
+	"github.com/axtloss/fsverify/core"
+	"github.com/spf13/cobra"
+)
+
+var validateFailed bool
+
+func NewVerifyCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:          "verify",
+		Short:        "Verify the root filesystem based on the given verification",
+		RunE:         ValidateCommand,
+		SilenceUsage: true,
+	}
+
+	return cmd
+}
+
+// validateThread validates a chain of nodes against a given byte slice
+func validateThread(blockStart int, blockEnd int, bundleSize int, diskBytes []byte, n int, dbfile string, waitGroup *sync.WaitGroup, errChan chan error) {
+	defer waitGroup.Done()
+	defer close(errChan)
+	var reader *bytes.Reader
+	blockCount := math.Floor(float64(bundleSize / 2000))
+	totalReadBlocks := 0
+
+	db, err := core.OpenDB(dbfile, true)
+	if err != nil {
+		errChan <- err
+	}
+
+	reader = bytes.NewReader(diskBytes)
+
+	node, err := core.GetNode(fmt.Sprintf("Entrypoint%d", n), db)
+	if err != nil {
+		errChan <- err
+	}
+	block, i, err := core.ReadBlock(node, reader, totalReadBlocks)
+	totalReadBlocks = i
+
+	err = core.VerifyBlock(block, node)
+	if err != nil {
+		errChan <- err
+	}
+
+	for int64(totalReadBlocks) < int64(blockCount) {
+		if validateFailed {
+			return
+		}
+		nodeSum, err := node.GetHash()
+		if err != nil {
+			fmt.Println("Using node ", nodeSum)
+			errChan <- err
+		}
+		node, err = core.GetNode(nodeSum, db)
+		if err != nil {
+			fmt.Println("Failed to get next node")
+			errChan <- err
+		}
+		part, i, err := core.ReadBlock(node, reader, totalReadBlocks)
+		totalReadBlocks = i
+		if err != nil {
+			errChan <- err
+			validateFailed = true
+			return
+		}
+		err = core.VerifyBlock(part, node)
+		if err != nil {
+			errChan <- err
+			validateFailed = true
+			return
+		}
+
+	}
+
+}
+
+func ValidateCommand(_ *cobra.Command, args []string) error {
+	if len(args) != 1 {
+		return fmt.Errorf("Usage: fsverify verify [disk]")
+	}
+	header, err := core.ReadHeader(config.FsVerifyPart)
+	if err != nil {
+		return err
+	}
+
+	// Check if the partition is even correct
+	// this does not check if the partition has been tampered with
+	// it only checks if the specified partition is even an fsverify partition
+	if header.MagicNumber != 0xACAB {
+		return fmt.Errorf("sanity bit does not match. Expected %d, got %d", 0xACAB, header.MagicNumber)
+	}
+
+	fmt.Println("Reading DB")
+	dbfile, err := core.ReadDB(config.FsVerifyPart)
+	if err != nil {
+		return err
+	}
+	key, err := core.ReadKey()
+	if err != nil {
+		return err
+	}
+	fmt.Println("Key: " + key)
+	verified, err := core.VerifySignature(key, header.Signature, dbfile)
+	if err != nil {
+		return err
+	} else if !verified {
+		return fmt.Errorf("Signature verification failed\n")
+	} else {
+		fmt.Println("Signature verification success!")
+	}
+
+	fmt.Println("----")
+	disk, err := os.Open(args[0])
+	if err != nil {
+		return err
+	}
+	defer disk.Close()
+	diskInfo, err := disk.Stat()
+	if err != nil {
+		return err
+	}
+	diskSize := diskInfo.Size()
+
+	// If the filesystem size has increased ever since the fsverify partition was created
+	// it would mean that fsverify is not able to verify the entire partition, making it useless
+	if header.FilesystemSize*header.FilesystemUnit != int(diskSize) {
+		return fmt.Errorf("disk size does not match disk size specified in header. Expected %d, got %d", header.FilesystemSize*header.FilesystemUnit, diskSize)
+	}
+
+	bundleSize := math.Floor(float64(diskSize / int64(config.ProcCount)))
+	diskBytes := make([]byte, diskSize)
+	_, err = disk.Read(diskBytes)
+	if err != nil {
+		return err
+	}
+	reader := bytes.NewReader(diskBytes)
+	var waitGroup sync.WaitGroup
+	errChan := make(chan error)
+	validateFailed = false
+	for i := 0; i < config.ProcCount; i++ {
+		// To ensure that each thread only uses the byte area it is meant to use, a copy of the
+		// area is made
+		diskBytes, err := core.CopyByteArea(i*(int(bundleSize)), (i+1)*(int(bundleSize)), reader)
+		if err != nil {
+			fmt.Println("Failed to copy byte area ", i*int(bundleSize), " ", (i+1)+int(bundleSize))
+			return err
+		}
+		waitGroup.Add(1)
+		go validateThread(i*int(bundleSize), (i+1)*int(bundleSize), int(bundleSize), diskBytes, i, dbfile, &waitGroup, errChan)
+	}
+
+	go func() {
+		waitGroup.Wait()
+		close(errChan)
+	}()
+
+	for err := range errChan {
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}