func()

in client/client.go [517:581]
47 lines of code
10 McCabe index (conditional complexity)

func (c *StetClient) Encrypt(ctx context.Context, input io.Reader, output io.Writer, stetConfig *configpb.StetConfig, blobID string) (*StetMetadata, error) {
	config := stetConfig.GetEncryptConfig()
	if config == nil {
		return nil, fmt.Errorf("nil EncryptConfig passed to Encrypt()")
	}

	keyCfg := config.GetKeyConfig()
	dataEncryptionKey := shares.NewDEK()
	shares, err := shares.CreateDEKShares(dataEncryptionKey, keyCfg)
	if err != nil {
		return nil, fmt.Errorf("error creating DEK shares: %v", err)
	}

	// Set blob ID if specified, otherwise generate UUID.
	if blobID == "" {
		blobID = uuid.NewString()
	}

	// Create metadata.
	metadata := &configpb.Metadata{BlobId: blobID, KeyConfig: keyCfg}

	var keyURIs []string
	opts := sharesOpts{
		kekInfos:        keyCfg.GetKekInfos(),
		asymmetricKeys:  stetConfig.GetAsymmetricKeys(),
		confSpaceConfig: c.newConfSpaceConfig(stetConfig),
	}

	metadata.Shares, keyURIs, err = c.wrapShares(ctx, shares, opts)
	if err != nil {
		return nil, fmt.Errorf("error wrapping shares: %v", err)
	}

	// Create AAD from metadata.
	aad, err := MetadataToAAD(metadata)
	if err != nil {
		return nil, fmt.Errorf("error serializing metadata: %v", err)
	}

	// Marshal the metadata into serialized bytes.
	metadataBytes, err := proto.Marshal(metadata)
	if err != nil {
		return nil, fmt.Errorf("failed to serialize metadata: %v", err)
	}

	// Write the header and metadata to `output`.
	if err := WriteSTETHeader(output, len(metadataBytes)); err != nil {
		return nil, fmt.Errorf("failed to write encrypted file header: %v", err)
	}

	if _, err := output.Write(metadataBytes); err != nil {
		return nil, fmt.Errorf("failed to write metadata: %v", err)
	}

	// Pass `output` to the AEAD encryption function to write the ciphertext.
	if err := AeadEncrypt(dataEncryptionKey, input, output, aad); err != nil {
		return nil, fmt.Errorf("error encrypting data: %v", err)
	}

	return &StetMetadata{
		KeyUris: keyURIs,
		BlobID:  metadata.GetBlobId(),
	}, nil

}