A bunch of changes

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

cmd/onerng/doc.go

@@ -0,0 +1,10 @@
+/*
+
+onerng is a OneRNG hardware random number generation utility.
+
+Usage
+
+TODO...
+
+*/
+package main

cmd/onerng/flush.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"context"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+// flushCmd represents the flush command
+func flushCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "flush",
+		Short: "Flush the OneRNG's entropy pool",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := onerng.OneRNG{Path: opts.Device}
+			return o.Flush(ctx)
+		},
+	}
+}

cmd/onerng/id.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+// idCmd represents the id command
+func idCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "id",
+		Short: "Display the OneRNG's hardware id",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := onerng.OneRNG{Path: opts.Device}
+			id, err := o.Identify(ctx)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("OneRNG Hardware ID: %s\n", id)
+			return nil
+		},
+	}
+}

cmd/onerng/image.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/pkg/errors"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+// imageCmd represents the image command
+func imageCmd(ctx context.Context) *cobra.Command {
+	var imgOut string
+	cmd := &cobra.Command{
+		Use:   "image",
+		Short: "Dump the OneRNG's firmware image",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := onerng.OneRNG{Path: opts.Device}
+			err := o.Init(ctx)
+			if err != nil {
+				return errors.Wrapf(err, "init failed before image extraction")
+			}
+			image, err := o.Image(ctx)
+			if err != nil {
+				return err
+			}
+			var out *os.File
+			if imgOut == "-" {
+				out = os.Stdout
+			} else {
+				out, err = os.OpenFile(imgOut, os.O_RDWR|os.O_CREATE, 0644)
+				if err != nil {
+					return err
+				}
+			}
+			n, err := out.Write(image)
+			fmt.Fprintf(os.Stderr, "Wrote %db to %s\n", n, imgOut)
+			return err
+		},
+	}
+	cmd.Flags().StringVarP(&imgOut, "out", "o", "onerng.img", "output file for image (use - for stdout)")
+	return cmd
+}

cmd/onerng/init.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"context"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+// initCmd represents the init command
+func initCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "init",
+		Short: "Initialize the RNG",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := onerng.OneRNG{Path: opts.Device}
+			err := o.Init(ctx)
+			return err
+		},
+	}
+}

cmd/onerng/main.go

@@ -1,11 +1,12 @@
+// onerng: OneRNG hardware random number generation utility
+
 package main
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"os/signal"
-
-	"github.com/hairyhenderson/go-onerng/cmd"
 )
 
 func main() {
@@ -26,5 +27,10 @@ func main() {
 		}
 	}()
 
-	cmd.Execute(ctx)
+	cmd := rootCmd(ctx)
+	initConfig(ctx, cmd)
+	if err := cmd.Execute(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
 }

cmd/onerng/read.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"github.com/pkg/errors"
+
+	"github.com/dustin/go-humanize"
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+func readCmd(ctx context.Context) *cobra.Command {
+	readOut := ""
+	disableAvalanche := false
+	enableRF := false
+	disableWhitener := false
+	enableAESWhiten := true
+
+	count := int64(-1)
+	cmd := &cobra.Command{
+		Use:   "read",
+		Short: "read some random data from the OneRNG",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := &onerng.OneRNG{Path: opts.Device}
+			err := o.Init(ctx)
+			if err != nil {
+				return errors.Wrapf(err, "init failed")
+			}
+
+			// set flags based on commandline options
+			flags := onerng.Default
+			if disableAvalanche {
+				flags |= onerng.DisableAvalanche
+			}
+			if enableRF {
+				flags |= onerng.EnableRF
+			}
+			if disableWhitener {
+				flags |= onerng.DisableWhitener
+			}
+
+			// waste some entropy...
+			devNull, err := os.OpenFile("/dev/null", os.O_WRONLY, 0200)
+			if err != nil {
+				return err
+			}
+			_, err = o.Read(ctx, devNull, 10*1024, flags)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "warning: entropy wasteage failed or incomplete, continuing anyway\n")
+			}
+
+			var out io.WriteCloser
+			if readOut == "-" {
+				out = os.Stdout
+			} else {
+				out, err = os.OpenFile(readOut, os.O_RDWR|os.O_CREATE, 0644)
+				if err != nil {
+					return err
+				}
+			}
+
+			if enableAESWhiten {
+				out, err = o.AESWhitener(ctx, out)
+				if err != nil {
+					return err
+				}
+			}
+
+			start := time.Now()
+			written, err := o.Read(ctx, out, count, flags)
+			delta := time.Since(start)
+			rate := float64(written) / delta.Seconds()
+			fmt.Fprintf(os.Stderr, "%s written in %s (%s/s)\n", humanize.Bytes(uint64(written)), delta, humanize.Bytes(uint64(rate)))
+			return err
+		},
+	}
+	cmd.Flags().StringVarP(&readOut, "out", "o", "-", "output file for data (use - for stdout)")
+	cmd.Flags().BoolVar(&disableAvalanche, "disable-avalanche", false, "Disable noise generation from the Avalanche Diode")
+	cmd.Flags().BoolVar(&enableRF, "enable-rf", false, "Enable noise generation from RF")
+	cmd.Flags().BoolVar(&disableWhitener, "disable-whitener", false, "Disable the on-board CRC16 generator")
+	cmd.Flags().Int64VarP(&count, "count", "n", -1, "Read only N bytes (use -1 for unlimited)")
+	cmd.Flags().BoolVar(&enableAESWhiten, "aes-whitener", true, "encrypt with AES-128 to 'whiten' the input stream with a random key obtained from the OneRNG")
+	return cmd
+}

cmd/onerng/root.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var (
+	cfgFile string
+	opts    config
+)
+
+func rootCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "onerng [opts] COMMAND",
+		Short: "Tool for the OneRNG open source hardware entropy generator",
+		Long: `OneRNG is an open source hardware entropy generator in a USB dongle.
+
+This tool can be used to verify that the OneRNG device operates
+correctly, and that the firmware has not been tampered with.`,
+		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			cmd.SilenceErrors = true
+			cmd.SilenceUsage = true
+			return nil
+		},
+	}
+}
+
+func initConfig(ctx context.Context, cmd *cobra.Command) {
+	cmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.go-onerng.yaml)")
+	opts = config{}
+	cmd.PersistentFlags().StringVarP(&opts.Device, "device", "d", "/dev/ttyACM0", "the OneRNG device")
+
+	cmd.AddCommand(
+		verifyCmd(ctx),
+		versionCmd(ctx),
+		idCmd(ctx),
+		flushCmd(ctx),
+		imageCmd(ctx),
+		initCmd(ctx),
+		readCmd(ctx),
+	)
+
+	if cfgFile != "" { // enable ability to specify config file via flag
+		viper.SetConfigFile(cfgFile)
+	}
+
+	viper.SetConfigName(".go-onerng")      // name of config file (without extension)
+	viper.AddConfigPath(os.Getenv("HOME")) // adding home directory as first search path
+	viper.AutomaticEnv()                   // read in environment variables that match
+
+	// If a config file is found, read it in.
+	if err := viper.ReadInConfig(); err == nil {
+		fmt.Fprintln(os.Stderr, "Using config file:", viper.ConfigFileUsed())
+	}
+}
+
+type config struct {
+	Device string
+}

cmd/onerng/verify.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"bytes"
+	"context"
+
+	"github.com/pkg/errors"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+const (
+	publicKey = `-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: GnuPG v1
+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+=IjnI
+-----END PGP PUBLIC KEY BLOCK-----
+`
+)
+
+func verifyCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "verify",
+		Short: "Verify that OneRNG's firmware has not been tampered with.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := onerng.OneRNG{Path: opts.Device}
+			err := o.Init(ctx)
+			if err != nil {
+				return errors.Wrapf(err, "init failed before image verification")
+			}
+			image, err := o.Image(ctx)
+			if err != nil {
+				return errors.Wrapf(err, "image extraction failed before verification")
+			}
+			err = onerng.Verify(ctx, bytes.NewBuffer(image), publicKey)
+			return err
+		},
+	}
+}

cmd/onerng/version.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+// versionCmd represents the version command
+func versionCmd(ctx context.Context) *cobra.Command {
+	return &cobra.Command{
+		Use:   "version",
+		Short: "Display the OneRNG's hardware version",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			o := &onerng.OneRNG{Path: opts.Device}
+			version, err := o.Version(ctx)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("OneRNG Hardware Version: %d\n", version)
+			return nil
+		},
+	}
+}