func GenerateImage()

in image/create.go [342:416]
62 lines of code
14 McCabe index (conditional complexity)

func GenerateImage(opts ImageCreateOpts) (Image, error) {
	ic := NewImageCreator()

	srcBin, err := ioutil.ReadFile(opts.SrcBinFilename)
	if err != nil {
		return Image{}, errors.Wrapf(err, "Can't read app binary")
	}

	ic.Body = srcBin
	ic.Version = opts.Version
	ic.SigKeys = opts.SigKeys
	ic.HWKeyIndex = opts.SrcEncKeyIndex
	ic.Sections = opts.Sections
	ic.UseLegacyTLV = opts.UseLegacyTLV

	if opts.LoaderHash != nil {
		ic.InitialHash = opts.LoaderHash
		ic.Bootable = false
	} else {
		ic.Bootable = true
	}

	if opts.HdrPad > 0 {
		ic.HeaderSize = opts.HdrPad
	}

	if opts.ImagePad > 0 {
		tail_pad := opts.ImagePad - (len(ic.Body) % opts.ImagePad)
		ic.Body = append(ic.Body, bytes.Repeat([]byte{byte(0xff)}, tail_pad)...)
	}

	if ic.HWKeyIndex >= 0 {
		hash := sha256.Sum256(ic.Body)
		ic.Nonce = hash[:8]
	}

	if opts.SrcEncKeyFilename != "" {
		plainSecret, err := GeneratePlainSecret()
		if err != nil {
			return Image{}, err
		}

		pubKeBytes, err := ioutil.ReadFile(opts.SrcEncKeyFilename)
		if err != nil {
			return Image{}, errors.Wrapf(err, "error reading pubkey file")
		}

		if ic.HWKeyIndex < 0 {
			pubKe, err := sec.ParsePubEncKey(pubKeBytes)
			if err != nil {
				return Image{}, err
			}

			cipherSecret, err := pubKe.Encrypt(plainSecret)
			if err != nil {
				return Image{}, err
			}

			ic.CipherSecret = cipherSecret
			ic.PlainSecret = plainSecret
		} else {
			ic.PlainSecret, err = base64.StdEncoding.DecodeString(string(pubKeBytes))
			if err != nil {
				return Image{}, err
			}
		}
	}

	ri, err := ic.Create()
	if err != nil {
		return Image{}, err
	}

	return ri, nil
}