diff --git a/.golangci.yml b/.golangci.yml
index cf8696e..79a2e91 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -12,8 +12,6 @@ linters-settings:
   goconst:
     min-len: 2
     min-occurrences: 4
-  lll:
-    line-length: 140
   nolintlint:
     allow-leading-space: true # don't require machine-readable nolint directives (i.e. with no leading space)
     allow-unused: false # report any unused nolint directives
@@ -29,37 +27,36 @@ linters:
     - depguard
     - dogsled
     - dupl
-    # - errcheck
+    - errcheck
     - exhaustive
     - exportloopref
     # - funlen
-    # - gci
+    - gci
     # - gochecknoglobals
     - gochecknoinits
-    # - gocognit
+    - gocognit
     - goconst
-    # - gocritic
-    # - gocyclo
+    - gocritic
+    - gocyclo
     # - godox
     - gofmt
     - gofumpt
     - goheader
     - goimports
     - golint
-    # - gomnd
+    - gomnd
     - gomodguard
     - goprintffuncname
-    # - gosec
+    - gosec
     - gosimple
-    # - govet
+    - govet
     - ineffassign
-    # - interfacer
-    # - lll
+    - interfacer
     - maligned
     - misspell
     - nakedret
-    # - nestif
-    # - nlreturn
+    - nestif
+    - nlreturn
     - noctx
     - nolintlint
     - prealloc
@@ -71,7 +68,7 @@ linters:
     - stylecheck
     - typecheck
     - unconvert
-    # - unparam
+    - unparam
     - unused
     - varcheck
     - whitespace
diff --git a/README.md b/README.md
index dbe46df..3e849e7 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,9 @@
 
 # go-onerng
 
-This is a Go port of the OneRNG tools distributed at https://onerng.info/. Much credit is due to the OneRNG creators - all I'm doing here is porting a bunch of Bash and Python code to Go.
+This is an unofficial Go version of the OneRNG tools distributed at https://onerng.info/. Much credit is due to the OneRNG creators - this all started as a port of a bunch of Bash and Python code to Go.
+
+The different commands available were discovered by reading [the firmware source code](https://github.com/OneRNG/firmware/blob/master/cdc_app.c#L346).
 
 ## Roadmap
 
diff --git a/cmd/onerng/commands.go b/cmd/onerng/commands.go
new file mode 100644
index 0000000..44ac9f5
--- /dev/null
+++ b/cmd/onerng/commands.go
@@ -0,0 +1,204 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"os"
+	"time"
+
+	"github.com/hairyhenderson/go-onerng"
+	"github.com/spf13/cobra"
+)
+
+func createORNG(cmd *cobra.Command) *onerng.OneRNG {
+	return &onerng.OneRNG{Path: cmd.Flag("device").Value.String()}
+}
+
+func idCmd(cmd *cobra.Command, args []string) error {
+	o := createORNG(cmd)
+	id, err := o.Identify(cmd.Context())
+	if err != nil {
+		return err
+	}
+	fmt.Printf("OneRNG Hardware ID: %s\n", id)
+
+	return nil
+}
+
+func versionCmd(cmd *cobra.Command, args []string) error {
+	o := createORNG(cmd)
+	version, err := o.Version(cmd.Context())
+	if err != nil {
+		return err
+	}
+	fmt.Printf("OneRNG Hardware Version: %d\n", version)
+
+	return nil
+}
+
+func flushCmd(cmd *cobra.Command, args []string) error {
+	o := createORNG(cmd)
+
+	return o.Flush(cmd.Context())
+}
+
+func initCmd(cmd *cobra.Command, args []string) error {
+	o := createORNG(cmd)
+
+	return o.Init(cmd.Context())
+}
+
+func verifyCmd(cmd *cobra.Command, args []string) error {
+	ctx := cmd.Context()
+	o := createORNG(cmd)
+	err := o.Init(ctx)
+	if err != nil {
+		return fmt.Errorf("init failed before image verification: %w", err)
+	}
+	image, err := o.Image(ctx)
+	if err != nil {
+		return fmt.Errorf("image extraction failed before verification: %w", err)
+	}
+	err = onerng.Verify(ctx, bytes.NewBuffer(image), publicKey)
+
+	return err
+}
+
+func imageCmd(cmd *cobra.Command, args []string) error {
+	ctx := cmd.Context()
+	o := createORNG(cmd)
+
+	err := o.Init(ctx)
+	if err != nil {
+		return fmt.Errorf("init failed before image extraction: %w", err)
+	}
+	image, err := o.Image(ctx)
+	if err != nil {
+		return err
+	}
+
+	out := os.Stdout
+	imgOut := cmd.Flag("out").Value.String()
+	if imgOut != "-" {
+		out, err = os.OpenFile(imgOut, os.O_RDWR|os.O_CREATE, 0o644)
+		if err != nil {
+			return err
+		}
+	}
+	n, err := out.Write(image)
+	fmt.Fprintf(os.Stderr, "Wrote %db to %s\n", n, imgOut)
+
+	return err
+}
+
+func readFlags(cmd *cobra.Command) (onerng.NoiseMode, error) {
+	disableAvalanche, err := cmd.Flags().GetBool("disable-avalanche")
+	if err != nil {
+		return 0, err
+	}
+
+	enableRF, err := cmd.Flags().GetBool("enable-rf")
+	if err != nil {
+		return 0, err
+	}
+
+	disableWhitener, err := cmd.Flags().GetBool("disable-whitener")
+	if err != nil {
+		return 0, err
+	}
+
+	// set flags based on commandline options
+	flags := onerng.Default
+	if disableAvalanche {
+		flags |= onerng.DisableAvalanche
+	}
+	if enableRF {
+		flags |= onerng.EnableRF
+	}
+	if disableWhitener {
+		flags |= onerng.DisableWhitener
+	}
+
+	return flags, nil
+}
+
+//nolint:gocyclo
+func readCmd(cmd *cobra.Command, args []string) error {
+	ctx := cmd.Context()
+	o := createORNG(cmd)
+	err := o.Init(ctx)
+	if err != nil {
+		return fmt.Errorf("init failed before read: %w", err)
+	}
+
+	enableAESWhiten, err := cmd.Flags().GetBool("aes-whitener")
+	if err != nil {
+		return err
+	}
+	count, err := cmd.Flags().GetInt64("count")
+	if err != nil {
+		return err
+	}
+	flags, err := readFlags(cmd)
+	if err != nil {
+		return err
+	}
+
+	// waste some entropy...
+	devNull, err := os.OpenFile("/dev/null", os.O_WRONLY, 0o200)
+	if err != nil {
+		return err
+	}
+	wasteAmount := 10240
+	_, err = o.Read(ctx, devNull, int64(wasteAmount), flags)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "warning: entropy wasteage failed or incomplete, continuing anyway\n")
+	}
+
+	out := io.WriteCloser(os.Stdout)
+	readOut := cmd.Flag("out").Value.String()
+	if readOut != "-" {
+		out, err = os.OpenFile(readOut, os.O_RDWR|os.O_CREATE, 0o644)
+		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", humanizeBytes(float64(written)), delta, humanizeBytes(rate))
+
+	return err
+}
+
+// humanizeBytes produces a human readable representation of an IEC size.
+// Taken from github.com/dustin/go-humanize
+//nolint:gomnd
+func humanizeBytes(s float64) string {
+	base := 1024.0
+	sizes := []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
+	if s < 10 {
+		return fmt.Sprintf("%f B", s)
+	}
+
+	e := math.Floor(math.Log(s) / math.Log(base))
+	suffix := sizes[int(e)]
+	val := math.Floor(s/math.Pow(base, e)*10+0.5) / 10
+	f := "%.0f %s"
+	if val < 10 {
+		f = "%.1f %s"
+	}
+
+	return fmt.Sprintf(f, val, suffix)
+}
diff --git a/cmd/onerng/flush.go b/cmd/onerng/flush.go
deleted file mode 100644
index 38ff207..0000000
--- a/cmd/onerng/flush.go
+++ /dev/null
@@ -1,20 +0,0 @@
-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)
-		},
-	}
-}
diff --git a/cmd/onerng/id.go b/cmd/onerng/id.go
deleted file mode 100644
index 61a46e6..0000000
--- a/cmd/onerng/id.go
+++ /dev/null
@@ -1,26 +0,0 @@
-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
-		},
-	}
-}
diff --git a/cmd/onerng/image.go b/cmd/onerng/image.go
deleted file mode 100644
index edbc730..0000000
--- a/cmd/onerng/image.go
+++ /dev/null
@@ -1,46 +0,0 @@
-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
-}
diff --git a/cmd/onerng/init.go b/cmd/onerng/init.go
deleted file mode 100644
index 1604bf2..0000000
--- a/cmd/onerng/init.go
+++ /dev/null
@@ -1,21 +0,0 @@
-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
-		},
-	}
-}
diff --git a/cmd/onerng/main.go b/cmd/onerng/main.go
index 5042c66..0356967 100644
--- a/cmd/onerng/main.go
+++ b/cmd/onerng/main.go
@@ -7,18 +7,89 @@ import (
 	"fmt"
 	"os"
 	"os/signal"
+
+	"github.com/hairyhenderson/go-onerng/version"
+	"github.com/spf13/cobra"
 )
 
-func main() {
-	ctx := context.Background()
+func commands() *cobra.Command {
+	cmd := &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.`,
+		Version: version.Version,
+		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			cmd.SilenceErrors = true
+			cmd.SilenceUsage = true
+
+			return nil
+		},
+	}
+	cmd.PersistentFlags().StringP("device", "d", "/dev/ttyACM0", "the OneRNG device")
+
+	flush := &cobra.Command{
+		Use:   "flush",
+		Short: "Flush the OneRNG's entropy pool",
+		RunE:  flushCmd,
+	}
+	id := &cobra.Command{
+		Use:   "id",
+		Short: "Display the OneRNG's hardware id",
+		RunE:  idCmd,
+	}
+	init := &cobra.Command{
+		Use:   "init",
+		Short: "Initialize the RNG",
+		RunE:  initCmd,
+	}
+	verify := &cobra.Command{
+		Use:   "verify",
+		Short: "Verify that OneRNG's firmware has not been tampered with.",
+		RunE:  verifyCmd,
+	}
+	version := &cobra.Command{
+		Use:   "version",
+		Short: "Display the OneRNG's hardware version",
+		RunE:  versionCmd,
+	}
+	image := &cobra.Command{
+		Use:   "image",
+		Short: "Dump the OneRNG's firmware image",
+		RunE:  imageCmd,
+	}
+	image.Flags().StringP("out", "o", "onerng.img", "output file for image (use - for stdout)")
+
+	read := &cobra.Command{
+		Use:   "read",
+		Short: "read some random data from the OneRNG",
+		RunE:  readCmd,
+	}
+	read.Flags().StringP("out", "o", "-", "output file for data (use - for stdout)")
+	read.Flags().Bool("disable-avalanche", false, "Disable noise generation from the Avalanche Diode")
+	read.Flags().Bool("enable-rf", false, "Enable noise generation from RF")
+	read.Flags().Bool("disable-whitener", false, "Disable the on-board CRC16 generator")
+	read.Flags().Int64P("count", "n", -1, "Read only N bytes (use -1 for unlimited)")
+	read.Flags().Bool("aes-whitener", true, "encrypt with AES-128 to 'whiten' the input stream with a random key obtained from the OneRNG")
+
+	cmd.AddCommand(flush, id, init, image, read, verify, version)
+
+	return cmd
+}
+
+func main() {
+	returncode := 0
+	defer func() { os.Exit(returncode) }()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
 
-	ctx, cancel := context.WithCancel(ctx)
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt)
-	defer func() {
-		signal.Stop(c)
-		cancel()
-	}()
+	defer signal.Stop(c)
+
 	go func() {
 		select {
 		case <-c:
@@ -27,10 +98,9 @@ func main() {
 		}
 	}()
 
-	cmd := rootCmd(ctx)
-	initConfig(ctx, cmd)
-	if err := cmd.Execute(); err != nil {
+	cmd := commands()
+	if err := cmd.ExecuteContext(ctx); err != nil {
 		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
+		returncode = 1
 	}
 }
diff --git a/cmd/onerng/verify.go b/cmd/onerng/public_key.go
similarity index 83%
rename from cmd/onerng/verify.go
rename to cmd/onerng/public_key.go
index 95a1219..d64462d 100644
--- a/cmd/onerng/verify.go
+++ b/cmd/onerng/public_key.go
@@ -1,17 +1,9 @@
 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-----
+// extracted from onerng_verify.py bundled in
+// https://github.com/OneRNG/onerng.github.io/raw/master/sw/onerng_3.6-1_all.deb
+// SHA256: a9ccf7b04ee317dbfc91518542301e2d60ebe205d38e80563f29aac7cd845ccb
+const publicKey = `-----BEGIN PGP PUBLIC KEY BLOCK-----
 Version: GnuPG v1
 
 mQINBFPXhxIBEADHeR56yhuF77hOErNk6LXTvbNIViVBG/Ss6cHJcnarnLjaGZ5y
@@ -75,24 +67,3 @@ W2KHfJBcr1Ag0zZ5q1SoyMiqFmhgo0i+D58QIjtNw7JVyOYZPw==
 =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
-		},
-	}
-}
diff --git a/cmd/onerng/read.go b/cmd/onerng/read.go
deleted file mode 100644
index 6b02049..0000000
--- a/cmd/onerng/read.go
+++ /dev/null
@@ -1,89 +0,0 @@
-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
-}
diff --git a/cmd/onerng/root.go b/cmd/onerng/root.go
deleted file mode 100644
index ba9f424..0000000
--- a/cmd/onerng/root.go
+++ /dev/null
@@ -1,64 +0,0 @@
-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
-}
diff --git a/cmd/onerng/version.go b/cmd/onerng/version.go
deleted file mode 100644
index 5b3b0cc..0000000
--- a/cmd/onerng/version.go
+++ /dev/null
@@ -1,26 +0,0 @@
-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
-		},
-	}
-}
diff --git a/go.mod b/go.mod
index 9f141ab..f65e894 100644
--- a/go.mod
+++ b/go.mod
@@ -3,10 +3,7 @@ module github.com/hairyhenderson/go-onerng
 go 1.15
 
 require (
-	github.com/dustin/go-humanize v1.0.0
-	github.com/pkg/errors v0.9.1
 	github.com/spf13/cobra v1.1.1
-	github.com/spf13/viper v1.7.1
 	github.com/stretchr/testify v1.6.1
 	golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897
 )
diff --git a/go.sum b/go.sum
index 4220796..092b288 100644
--- a/go.sum
+++ b/go.sum
@@ -11,7 +11,6 @@ cloud.google.com/go/firestore v1.1.0/go.mod h1:ulACoGHTpvq5r8rxGJ4ddJZBZqakUQqCl
 cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
 cloud.google.com/go/storage v1.0.0/go.mod h1:IhtSnM/ZTZV8YYJWCY8RULGVqBDmpoyjwiyrjsg+URw=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
@@ -37,10 +36,7 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
-github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
-github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
-github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
@@ -68,7 +64,6 @@ github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OI
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
-github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
@@ -89,7 +84,6 @@ github.com/hashicorp/go-uuid v1.0.1/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/b
 github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
-github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=
 github.com/hashicorp/mdns v1.0.0/go.mod h1:tL+uN++7HEJ6SQLQ2/p+z2pH24WQKWjBPkE0mNTz8vQ=
@@ -100,7 +94,6 @@ github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANyt
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
-github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
@@ -112,7 +105,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/magiconair/properties v1.8.1 h1:ZC2Vc7/ZFkGmsVC9KvOjumD+G5lXy2RtTKyzRKO2BQ4=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
@@ -125,19 +117,15 @@ github.com/mitchellh/go-testing-interface v1.0.0/go.mod h1:kRemZodwjscx+RGhAo8eI
 github.com/mitchellh/gox v0.4.0/go.mod h1:Sd9lOJ0+aimLBi73mGofS1ycjY8lL3uZM3JPS42BGNg=
 github.com/mitchellh/iochan v1.0.0/go.mod h1:JwYml1nuB7xOzsp52dPpHFffvOCDupsG0QubkSMEySY=
 github.com/mitchellh/mapstructure v0.0.0-20160808181253-ca63d7c062ee/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
-github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
-github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/posener/complete v1.1.1/go.mod h1:em0nMJCgc9GFtwrmVmEMR/ZL6WyhyjMBndrE9hABlRI=
@@ -157,33 +145,25 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
-github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
-github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
-github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
-github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
 github.com/spf13/cobra v1.1.1 h1:KfztREH0tPxJJ+geloSLaAkaPkr4ki2Er5quFV1TDo4=
 github.com/spf13/cobra v1.1.1/go.mod h1:WnodtKOvamDL/PwE2M4iKs8aMDBZ5Q5klgD3qfVJQMI=
-github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/spf13/viper v1.7.0/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
-github.com/spf13/viper v1.7.1 h1:pM5oEahlgWv/WnHXpgbKz7iLIxRf65tye2Ci+XFK5sk=
-github.com/spf13/viper v1.7.1/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/subosito/gotenv v1.2.0 h1:Slr1R9HxAlEKefgq5jn9U+DnETlIUa6HfgEzj0g5d7s=
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
@@ -252,11 +232,9 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190507160741-ecd444e8653b/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190606165138-5da285871e9c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0 h1:HyfiK1WMnHj5FXFXatD+Qs1A/xC2Run6RzeW1SyHxpc=
 golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
@@ -304,13 +282,11 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
-gopkg.in/ini.v1 v1.51.0 h1:AQvPpx3LzTDM0AjnIRlVFwFFGC+npRopjZxLJj6gdno=
 gopkg.in/ini.v1 v1.51.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/onerng.go b/onerng.go
index f654ce1..996307b 100644
--- a/onerng.go
+++ b/onerng.go
@@ -35,14 +35,13 @@ import (
 	"context"
 	"crypto/aes"
 	"crypto/cipher"
+	"fmt"
 	"io"
 	mrand "math/rand"
 	"os"
 	"strconv"
 	"strings"
 	"time"
-
-	"github.com/pkg/errors"
 )
 
 // OneRNG - a OneRNG device
@@ -51,6 +50,8 @@ type OneRNG struct {
 	device io.ReadWriteCloser
 }
 
+const copyReadTimeout = 500 * time.Millisecond
+
 // cmd sends one or more commands to the OneRNG. The device is not closed on
 // completion, as it's usually being read from simultaneously.
 func (o *OneRNG) cmd(ctx context.Context, c ...string) error {
@@ -61,7 +62,7 @@ func (o *OneRNG) cmd(ctx context.Context, c ...string) error {
 	for _, v := range c {
 		_, err = o.device.Write([]byte(v))
 		if err != nil {
-			return errors.Wrapf(err, "Errored on command %q", v)
+			return fmt.Errorf("errored on command %q: %w", v, err)
 		}
 		select {
 		case <-ctx.Done():
@@ -69,6 +70,7 @@ func (o *OneRNG) cmd(ctx context.Context, c ...string) error {
 		default:
 		}
 	}
+
 	return nil
 }
 
@@ -79,6 +81,7 @@ func (o *OneRNG) open() (err error) {
 		return nil
 	}
 	o.device, err = os.OpenFile(o.Path, os.O_RDWR, 0600)
+
 	return err
 }
 
@@ -89,6 +92,7 @@ func (o *OneRNG) close() error {
 	}
 	err := o.device.Close()
 	o.device = nil
+
 	return err
 }
 
@@ -105,7 +109,7 @@ func (o *OneRNG) Version(ctx context.Context) (int, error) {
 		return 0, err
 	}
 
-	_, cancel := context.WithCancel(ctx)
+	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	buf := make(chan string)
 	errc := make(chan error, 1)
@@ -127,9 +131,10 @@ loop:
 			if strings.HasPrefix(b, "Version ") {
 				verString = b
 				cancel()
+
 				break loop
 			}
-		case err := <-errc:
+		case err = <-errc:
 			return 0, err
 		}
 	}
@@ -141,6 +146,7 @@ loop:
 
 	n := strings.Replace(verString, "Version ", "", 1)
 	version, err := strconv.Atoi(n)
+
 	return version, err
 }
 
@@ -174,9 +180,10 @@ loop:
 			if strings.HasPrefix(b, "___") {
 				idString = b
 				cancel()
+
 				break loop
 			}
-		case err := <-errc:
+		case err = <-errc:
 			return "", err
 		}
 	}
@@ -199,14 +206,15 @@ func (o *OneRNG) Flush(ctx context.Context) error {
 
 	_, cancel := context.WithCancel(ctx)
 	defer cancel()
-	err = o.cmd(ctx, cmdFlush)
-	return err
+
+	return o.cmd(ctx, cmdFlush)
 }
 
 // Image extracts the firmware image. This image is padded with random data to
 // either 128Kb or 256Kb (depending on hardware), and signed.
 //
 // See also the Verify function.
+//nolint:gocyclo
 func (o *OneRNG) Image(ctx context.Context) ([]byte, error) {
 	err := o.open()
 	if err != nil {
@@ -219,9 +227,7 @@ func (o *OneRNG) Image(ctx context.Context) ([]byte, error) {
 		return nil, err
 	}
 
-	time.Sleep(2 * time.Second)
-
-	_, cancel := context.WithCancel(ctx)
+	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	buf := make(chan []byte)
 	errc := make(chan error, 1)
@@ -234,25 +240,24 @@ func (o *OneRNG) Image(ctx context.Context) ([]byte, error) {
 
 	image := []byte{}
 	zeros := 0
-loop:
-	for {
+	// stream data until we're done, or until we have 200+ consecutive zeroes
+	//nolint:gomnd
+	for zeros <= 200 {
 		var b []byte
 		select {
 		case <-ctx.Done():
 			return nil, ctx.Err()
 		case b = <-buf:
 			image = append(image, b...)
+			// count consecutive zeroes - if we hit non-zero, reset
 			for _, v := range b {
 				if v == 0 {
 					zeros++
 				} else {
 					zeros = 0
 				}
-				if zeros > 200 {
-					break loop
-				}
 			}
-		case err := <-errc:
+		case err = <-errc:
 			return nil, err
 		}
 	}
@@ -278,6 +283,7 @@ func (o *OneRNG) Init(ctx context.Context) error {
 		}
 	}
 	// fmt.Fprintf(os.Stderr, "Initialized after %d loops\n", i)
+
 	return nil
 }
 
@@ -298,13 +304,15 @@ func (o *OneRNG) Read(ctx context.Context, out io.Writer, n int64, flags NoiseMo
 		return 0, err
 	}
 
+	//nolint:errcheck
 	defer o.cmd(ctx, cmdPause)
 
 	written, err = copyWithContext(ctx, out, o.device, n)
+
 	return written, err
 }
 
-// readData - try to read some data from the RNG
+// readData - try to read some data from the RNG (during initialization)
 func (o *OneRNG) readData(ctx context.Context) (int, error) {
 	err := o.open()
 	if err != nil {
@@ -312,7 +320,8 @@ func (o *OneRNG) readData(ctx context.Context) (int, error) {
 	}
 	defer o.close()
 
-	_, cancel := context.WithTimeout(ctx, 50*time.Millisecond)
+	const readTimeout = 50 * time.Millisecond
+	_, cancel := context.WithTimeout(ctx, readTimeout)
 	defer cancel()
 
 	buf := make(chan []byte)
@@ -325,6 +334,7 @@ func (o *OneRNG) readData(ctx context.Context) (int, error) {
 	}
 
 	// make sure we always end with a pause/silence/flush
+	//nolint:errcheck
 	defer o.cmd(ctx, cmdPause, noiseCommand(Silent), cmdFlush)
 
 	// blocking read from the channel, with a timeout (from context)
@@ -344,6 +354,7 @@ func (o *OneRNG) stream(ctx context.Context, bs int, buf chan []byte, errc chan
 	err := o.open()
 	if err != nil {
 		errc <- err
+
 		return
 	}
 
@@ -354,10 +365,12 @@ func (o *OneRNG) stream(ctx context.Context, bs int, buf chan []byte, errc chan
 		n, err := io.ReadAtLeast(o.device, b, len(b))
 		if err != nil {
 			errc <- err
+
 			return
 		}
 		if n < len(b) {
-			errc <- errors.Errorf("unexpected short read - wanted %db, read %db", len(b), n)
+			errc <- fmt.Errorf("unexpected short read: wanted %db, read %db", len(b), n)
+
 			return
 		}
 
@@ -373,6 +386,7 @@ func (o *OneRNG) scan(ctx context.Context, buf chan string, errc chan error) {
 	err := o.open()
 	if err != nil {
 		errc <- err
+
 		return
 	}
 	defer close(buf)
@@ -408,7 +422,7 @@ const (
 // predictable ways.
 //
 // This uses AES-128.
-func (o *OneRNG) AESWhitener(ctx context.Context, out io.WriteCloser) (io.WriteCloser, error) {
+func (o *OneRNG) AESWhitener(ctx context.Context, out io.Writer) (io.WriteCloser, error) {
 	k, err := o.key(ctx)
 	if err != nil {
 		return nil, err
@@ -418,8 +432,10 @@ func (o *OneRNG) AESWhitener(ctx context.Context, out io.WriteCloser) (io.WriteC
 		return nil, err
 	}
 
-	// create a random IV with math/rand - doesn't need to be cryptographically-random
+	// create a random IV with math/rand - doesn't need to be cryptographically-random,
+	// and we don't want to consume entropy while trying to generate entropy...
 	iv := make([]byte, aes.BlockSize)
+	//nolint:gosec
 	_, err = mrand.Read(iv)
 	if err != nil {
 		return nil, err
@@ -427,6 +443,7 @@ func (o *OneRNG) AESWhitener(ctx context.Context, out io.WriteCloser) (io.WriteC
 
 	stream := cipher.NewCFBEncrypter(block, iv)
 	s := &cipher.StreamWriter{S: stream, W: out}
+
 	return s, nil
 }
 
@@ -442,7 +459,10 @@ func (o *OneRNG) key(ctx context.Context) ([]byte, error) {
 	if err != nil {
 		return []byte{}, err
 	}
+
+	//nolint:errcheck
 	defer o.cmd(ctx, cmdPause)
+
 	// 16 bytes == AES-128
 	_, err = copyWithContext(ctx, buf, o.device, 16)
 	k := buf.Bytes()
@@ -464,12 +484,13 @@ const (
 	// Default mode - Avalanche enabled, RF disabled, Whitener enabled.
 	Default NoiseMode = 0
 	// Silent - a convenience - everything disabled
-	Silent NoiseMode = 4
+	Silent NoiseMode = DisableAvalanche
 )
 
 // noiseCommand converts the given mode to the appropriate command to send to the OneRNG
 func noiseCommand(flags NoiseMode) string {
 	num := strconv.Itoa(int(flags))
+
 	return "cmd" + num + "\n"
 }
 
@@ -485,7 +506,7 @@ func copyWithContext(ctx context.Context, dst io.Writer, src io.Reader, n int64)
 	rf := func(p []byte) (int, error) {
 		if f, ok := src.(*os.File); ok {
 			// I don't want reads to block forever, but I also don't want to time out immediately
-			err := f.SetReadDeadline(time.Now().Add(500 * time.Millisecond))
+			err := f.SetReadDeadline(time.Now().Add(copyReadTimeout))
 			if err != nil {
 				return 0, err
 			}
@@ -499,9 +520,11 @@ func copyWithContext(ctx context.Context, dst io.Writer, src io.Reader, n int64)
 			if allowedTimeouts > 0 {
 				if err != nil && os.IsTimeout(err) {
 					allowedTimeouts--
+
 					return n, nil
 				}
 			}
+
 			return n, err
 		}
 	}
@@ -509,5 +532,6 @@ func copyWithContext(ctx context.Context, dst io.Writer, src io.Reader, n int64)
 	if n < 0 {
 		return io.Copy(dst, readerFunc(rf))
 	}
+
 	return io.CopyN(dst, readerFunc(rf), n)
 }
diff --git a/onerng_test.go b/onerng_test.go
index cf36a16..9087dee 100644
--- a/onerng_test.go
+++ b/onerng_test.go
@@ -8,31 +8,25 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-// func TestNoiseCommand(t *testing.T) {
-// 	fmt.Println(DisableWhitener)
-// 	fmt.Println(EnableRF)
-// 	fmt.Println(DisableAvalanche)
-
-// 	fmt.Println(Default)
-// 	fmt.Println(Silent)
-
-// 	testdata := []struct {
-// 		flags NoiseMode
-// 		cmd   string
-// 	}{
-// 		{Default, "cmd0\n"},
-// 		{DisableWhitener, "cmd1\n"},
-// 		{EnableRF, "cmd2\n"},
-// 		{EnableRF | DisableWhitener, "cmd3\n"},
-// 		{DisableAvalanche, "cmd4\n"},
-// 		{DisableAvalanche | DisableWhitener, "cmd5\n"},
-// 		{DisableAvalanche | EnableRF, "cmd6\n"},
-// 		{DisableAvalanche | EnableRF | DisableWhitener, "cmd7\n"},
-// 	}
-// 	for _, d := range testdata {
-// 		assert.Equal(t, d.cmd, noiseCommand(d.flags), d.cmd, d.flags)
-// 	}
-// }
+func TestNoiseCommand(t *testing.T) {
+	testdata := []struct {
+		flags NoiseMode
+		cmd   string
+	}{
+		{Default, "cmd0\n"},
+		{DisableWhitener, "cmd1\n"},
+		{EnableRF, "cmd2\n"},
+		{EnableRF | DisableWhitener, "cmd3\n"},
+		{Silent, "cmd4\n"},
+		{DisableAvalanche, "cmd4\n"},
+		{DisableAvalanche | DisableWhitener, "cmd5\n"},
+		{DisableAvalanche | EnableRF, "cmd6\n"},
+		{DisableAvalanche | EnableRF | DisableWhitener, "cmd7\n"},
+	}
+	for _, d := range testdata {
+		assert.Equal(t, d.cmd, noiseCommand(d.flags), d.cmd, d.flags)
+	}
+}
 
 type fakeDev struct {
 	closed bool
@@ -48,6 +42,7 @@ func (d *fakeDev) reset() {
 
 func (d *fakeDev) Close() error {
 	d.closed = true
+
 	return nil
 }
 
@@ -101,3 +96,19 @@ func TestVersion(t *testing.T) {
 	assert.Equal(t, "cmdo\ncmd4\ncmdv\ncmdO\ncmdo\n", d.wbuf.String())
 	assert.Equal(t, 3, v)
 }
+
+func TestIdentify(t *testing.T) {
+	d := &fakeDev{
+		wbuf: &bytes.Buffer{},
+		rbuf: bytes.NewBufferString("dfoawiuhf98h9inf2oifoi2jr\n" +
+			"dfkjawflihjwfoiuh2rliu13he487631487645t98y23rtoqu3rbno9q34htgfv\n" +
+			"\r\nVersion 3\r\nas;dlfjaw;oihf2ih2o3iuf2ofnlo2jnlfuhf2iou\n\n" +
+			"dlfkhadslfihwaflkhjw\n___lskdjfalsdkjflsd___\n\n"),
+	}
+	o := &OneRNG{Path: "/dev/null", device: d}
+	ctx := context.Background()
+	id, err := o.Identify(ctx)
+	assert.NoError(t, err)
+	assert.Equal(t, "cmd4\ncmdI\ncmdO\ncmdo\n", d.wbuf.String())
+	assert.Equal(t, "___lskdjfalsdkjflsd___", id)
+}
diff --git a/verify.go b/verify.go
index 40be3a0..8984a5c 100644
--- a/verify.go
+++ b/verify.go
@@ -7,7 +7,6 @@ import (
 	"io"
 	"os"
 
-	"github.com/pkg/errors"
 	"golang.org/x/crypto/openpgp"
 )
 
@@ -16,110 +15,154 @@ import (
 //
 // Details are printed to Stderr on success, otherwise an error is returned.
 //
-// This is a more-or-less straight port from the official onerng_verify.py
-// script distributed alongside the OneRNG package.
+// The general logic is ported from the official onerng_verify.py script
+// distributed alongside the OneRNG package.
 func Verify(ctx context.Context, image io.Reader, pubkey string) error {
-	var x byte
-	length := 0
-	version := 0
-	state := int8(0)
-	for {
-		c := make([]byte, 1)
-		n, err := io.ReadAtLeast(image, c, len(c))
-		if err != nil {
-			return err
-		}
-		if n == 0 {
-			return errors.Errorf("Short image")
-		}
-		x = c[0]
-
-		// 1. read magic (6 bytes)
-		if state == 0 && x == 0xfe {
-			state++
-		} else if state == 1 && x == 0xed {
-			state++
-		} else if state == 2 && x == 0xbe {
-			state++
-		} else if state == 3 && x == 0xef {
-			state++
-		} else if state == 4 && x == 0x20 {
-			state++
-		} else if state == 5 && x == 0x14 {
-			state++
-			// 2. read length (3 bytes)
-		} else if state == 6 {
-			length = int(x)
-			state++
-		} else if state == 7 {
-			length = length | (int(x) << 8)
-			state++
-		} else if state == 8 {
-			length = length | (int(x) << 16)
-			state++
-			// 3. read version (2 bytes)
-		} else if state == 9 {
-			version = int(x)
-			state++
-		} else if state == 10 {
-			version = version | (int(x) << 8)
-			state++
-		} else if state == 11 {
-			// skip a padding byte I guess...
-			state++
-		} else if state == 12 {
-			// 4. read image
-			c := make([]byte, length)
-			n, err := io.ReadAtLeast(image, c, length)
-			if err != nil {
-				return err
-			}
-			if n != length {
-				return errors.Errorf("Bad image")
-			}
-
-			// determine end offset
-			endOff := 0
-			if version >= 3 {
-				endOff = 680
-			} else {
-				endOff = 600
-			}
-
-			// read length of signature - 2 bytes between image and signature
-			x = c[length-endOff]
-			klen := int(x)
-			x = c[length-endOff+1]
-			klen = klen | (int(x) << 8)
-
-			// split last part into image (signed part) & signature
-			signature := bytes.NewBuffer(c[length-endOff+2 : length-endOff+2+klen])
-			signed := bytes.NewBuffer(c[0 : length-endOff])
-
-			// read public key
-			keyring, err := openpgp.ReadArmoredKeyRing(bytes.NewBufferString(pubkey))
-			if err != nil {
-				return err
-			}
-
-			// verify
-			signer, err := openpgp.CheckDetachedSignature(keyring, signed, signature)
-			if err != nil {
-				return errors.Wrapf(err, "failed to verify firmware signature")
-			}
-
-			fmt.Fprintf(os.Stderr, "firmware verification passed OK - version=%d\n", version)
-			for _, id := range signer.Identities {
-				fmt.Fprintf(os.Stderr, "signed by: %#v\n", id.Name)
-				fmt.Fprintf(os.Stderr, "\tcreated: %q\n", id.SelfSignature.CreationTime)
-				fmt.Fprintf(os.Stderr, "\tfingerprint: %X\n", signer.PrimaryKey.Fingerprint)
-			}
-
-			break
-		} else {
-			// something didn't line up, so we need to begin again...
-			state = 0
-		}
+	if err := readMagic(image); err != nil {
+		return fmt.Errorf("failed to find magic number: %w", err)
 	}
+	length, version, err := readHeader(image)
+	if err != nil {
+		return fmt.Errorf("failed to read header: %w", err)
+	}
+
+	return readAndVerify(image, version, length, pubkey)
+}
+
+func read(r io.Reader, p []byte) error {
+	n, err := r.Read(p)
+	if err != nil {
+		return fmt.Errorf("read failed: %w", err)
+	}
+	if n == 0 {
+		return fmt.Errorf("short read")
+	}
+
 	return nil
 }
+
+// readHeader reads the header and returns the length and the version
+//nolint:gomnd
+func readHeader(r io.Reader) (length, version int, err error) {
+	// read the length
+	l := make([]byte, 3)
+	if err := read(r, l); err != nil {
+		return 0, 0, fmt.Errorf("failed reading length: %w", err)
+	}
+	length = int(l[0])
+	length |= int(l[1]) << 8
+	length |= int(l[2]) << 16
+
+	// read the version
+	l = make([]byte, 2)
+	if err := read(r, l); err != nil {
+		return 0, 0, fmt.Errorf("failed reading version: %w", err)
+	}
+	version = int(l[0])
+	version |= int(l[1]) << 8
+
+	// read the actual code size - we don't use it yet
+	if err := read(r, make([]byte, 2)); err != nil {
+		return 0, 0, fmt.Errorf("failed reading actual code size: %w", err)
+	}
+
+	return length, version, nil
+}
+
+// readMagic reads the input until the magic sequence 0xfeedbeef2014 is found
+//nolint:gomnd, gocyclo
+func readMagic(r io.Reader) error {
+	for i := int8(0); i < 6; i++ {
+		c := make([]byte, 1)
+		if err := read(r, c); err != nil {
+			return fmt.Errorf("couldn't read header: %w", err)
+		}
+		x := c[0]
+
+		switch {
+		case i == 0 && x == 0xfe,
+			i == 1 && x == 0xed,
+			i == 2 && x == 0xbe,
+			i == 3 && x == 0xef,
+			i == 4 && x == 0x20,
+			i == 5 && x == 0x14:
+			// as long as this looks like the magic number, keep going!
+			continue
+		default:
+			i = 0
+		}
+	}
+
+	return nil
+}
+
+func readAndVerify(image io.Reader, version, length int, pubkey string) error {
+	signed, signature, err := parseImage(image, version, length)
+	if err != nil {
+		return err
+	}
+
+	signer, err := verifyImage(signed, signature, pubkey)
+	if err != nil {
+		return err
+	}
+
+	fmt.Fprintf(os.Stderr, "firmware verification passed OK - version=%d\n", version)
+	for _, id := range signer.Identities {
+		fmt.Fprintf(os.Stderr, "signed by: %#v\n", id.Name)
+		fmt.Fprintf(os.Stderr, "\tcreated: %q\n", id.SelfSignature.CreationTime)
+		fmt.Fprintf(os.Stderr, "\tfingerprint: %X\n", signer.PrimaryKey.Fingerprint)
+	}
+
+	return nil
+}
+
+func verifyImage(signed, sig []byte, pubkey string) (signer *openpgp.Entity, err error) {
+	// read public key
+	keyring, err := openpgp.ReadArmoredKeyRing(bytes.NewBufferString(pubkey))
+	if err != nil {
+		return nil, err
+	}
+
+	// verify
+	signer, err = openpgp.CheckDetachedSignature(
+		keyring,
+		bytes.NewBuffer(signed),
+		bytes.NewBuffer(sig),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to verify firmware signature: %w", err)
+	}
+
+	return signer, nil
+}
+
+//nolint:gomnd
+func parseImage(image io.Reader, version, length int) (signed, sig []byte, err error) {
+	c := make([]byte, length)
+	n, err := io.ReadAtLeast(image, c, length)
+	if err != nil {
+		return nil, nil, err
+	}
+	if n != length {
+		return nil, nil, fmt.Errorf("bad image: wrong length: was %d, expected %d", n, length)
+	}
+
+	// determine end offset
+	endOff := 0
+	if version >= 3 {
+		endOff = 680
+	} else {
+		endOff = 600
+	}
+
+	// signature length - 2 bytes between image and signature
+	slen := int(c[length-endOff])
+	slen |= int(c[length-endOff+1]) << 8
+
+	// split last part into image (signed part) & signature
+	signed = c[0 : length-endOff]
+	sig = c[length-endOff+2 : length-endOff+2+slen]
+
+	return signed, sig, nil
+}
diff --git a/verify_test.go b/verify_test.go
new file mode 100644
index 0000000..2bb023e
--- /dev/null
+++ b/verify_test.go
@@ -0,0 +1,52 @@
+package onerng
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestReadMagic(t *testing.T) {
+	r := &bytes.Buffer{}
+	err := readMagic(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBufferString("abcdefg")
+	err = readMagic(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBuffer([]byte{0x00, 0x01, 0x02, 0xfe, 0xed, 0xbe, 0xee, 0xff})
+	err = readMagic(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBuffer([]byte{0x00, 0x01, 0x02, 0xfe, 0xed, 0xbe, 0xef, 0x20, 0x14})
+	err = readMagic(r)
+	assert.NoError(t, err)
+}
+
+func TestReadHeader(t *testing.T) {
+	r := &bytes.Buffer{}
+	_, _, err := readHeader(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBuffer([]byte{0x00, 0x00, 0x00})
+	_, _, err = readHeader(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBuffer([]byte{0x00, 0x00, 0x00, 0x00})
+	_, _, err = readHeader(r)
+	assert.Error(t, err)
+
+	r = bytes.NewBuffer([]byte{0x0f, 0x00, 0x00, 0x07, 0x00, 0xff, 0xee})
+	l, v, err := readHeader(r)
+	assert.NoError(t, err)
+	assert.Equal(t, 15, l)
+	assert.Equal(t, 7, v)
+
+	r = bytes.NewBuffer([]byte{0x0f, 0xf0, 0x01, 0x07, 0x70, 0xff, 0xee, 0x11, 0x42})
+	l, v, err = readHeader(r)
+	assert.NoError(t, err)
+	assert.Equal(t, 0x01f00f, l)
+	assert.Equal(t, 0x7007, v)
+}