Function cryptCheck

cmd/cryptcheck/cryptcheck.go:67–117

cryptCheck checks the integrity of an encrypted remote

(ctx context.Context, fdst, fsrc fs.Fs)

// cryptCheck checks the integrity of an encrypted remote
func cryptCheck(ctx context.Context, fdst, fsrc fs.Fs) error {
	// Check to see fcrypt is a crypt
	fcrypt, ok := fdst.(*crypt.Fs)
	if !ok {
		return fmt.Errorf("%s:%s is not a crypt remote", fdst.Name(), fdst.Root())
	}
	// Find a hash to use
	funderlying := fcrypt.UnWrap()
	hashType := funderlying.Hashes().GetOne()
	if hashType == hash.None {
		return fmt.Errorf("%s:%s does not support any hashes", funderlying.Name(), funderlying.Root())
	}
	fs.Infof(nil, "Using %v for hash comparisons", hashType)

	opt, close, err := check.GetCheckOpt(fsrc, fcrypt)
	if err != nil {
		return err
	}
	defer close()

	// checkIdentical checks to see if dst and src are identical
	//
	// it returns true if differences were found
	// it also returns whether it couldn't be hashed
	opt.Check = func(ctx context.Context, dst, src fs.Object) (differ bool, noHash bool, err error) {
		cryptDst := dst.(*crypt.Object)
		underlyingDst := cryptDst.UnWrap()
		underlyingHash, err := underlyingDst.Hash(ctx, hashType)
		if err != nil {
			return true, false, fmt.Errorf("error reading hash from underlying %v: %w", underlyingDst, err)
		}
		if underlyingHash == "" {
			return false, true, nil
		}
		cryptHash, err := fcrypt.ComputeHash(ctx, cryptDst, src, hashType)
		if err != nil {
			return true, false, fmt.Errorf("error computing hash: %w", err)
		}
		if cryptHash == "" {
			return false, true, nil
		}
		if cryptHash != underlyingHash {
			err = fmt.Errorf("hashes differ (%s:%s) %q vs (%s:%s) %q", fdst.Name(), fdst.Root(), cryptHash, fsrc.Name(), fsrc.Root(), underlyingHash)
			fs.Errorf(src, "%s", err.Error())
			return true, false, nil
		}
		return false, false, nil
	}

	return operations.CheckFn(ctx, opt)
}