go-onerng/cmd/onerng/read.go
Dave Henderson a1879b1eb0
A bunch of changes
Signed-off-by: Dave Henderson <dhenderson@gmail.com>
2018-08-20 20:06:33 -04:00

90 lines
2.4 KiB
Go

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
}