Add support for decrypting raw data, see issue #5

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: gpg
 Type: Package
 Title: GNU Privacy Guard for R
-Version: 0.5
+Version: 0.5.9000
 Authors@R: person("Jeroen", "Ooms", email = "jeroen@berkeley.edu", role = c("aut", "cre"))
 Description: Bindings to GnuPG for working with OpenGPG (RFC4880) cryptographic methods.
     Includes utilities for public key encryption, creating and verifying digital signatures,
@@ -11,7 +11,7 @@ Description: Bindings to GnuPG for working with OpenGPG (RFC4880) cryptographic
 License: MIT + file LICENSE
 SystemRequirements: GPGME: libgpgme11-dev (deb), gpgme-devel (rpm) gpgme (brew). 
     On Linux 'haveged' is recommended for generating entropy when using the GPG key generator.
-RoxygenNote: 6.0.1
+RoxygenNote: 6.1.1
 Roxygen: list(markdown = TRUE)
 Imports:
     curl

NEWS

@@ -1,3 +1,6 @@
+0.6
+  - Add as_text parameter to decrypt to support raw output
+
 0.5
   - Extract autobrew script to separate repository
 

R/encrypt.R

@@ -26,13 +26,14 @@ gpg_encrypt <- function(data, receiver, signer = NULL){
 #' @rdname gpg_encrypt
 #' @param verify automatically checks that all signatures (if any) can be verified and
 #' raises an error otherwise
+#' @param as_text convert output to text. Set to FALSE if you expect binary data.
 #' @useDynLib gpg R_gpgme_decrypt R_gpgme_signed_decrypt
-gpg_decrypt <- function(data, verify = TRUE){
+gpg_decrypt <- function(data, verify = TRUE, as_text = TRUE){
   data <- file_or_raw(data)
   if(isTRUE(verify)){
-    .Call(R_gpgme_signed_decrypt, data)
+    .Call(R_gpgme_signed_decrypt, data, as_text)
   } else {
-    .Call(R_gpgme_decrypt, data)
+    .Call(R_gpgme_decrypt, data, as_text)
   }
 }
 

src/common.h

@@ -10,6 +10,7 @@
 gpgme_ctx_t ctx;
 gpgme_error_t pwprompt(void *hook, const char *uid_hint, const char *passphrase_info, int prev_was_bad, int fd);
 SEXP data_to_string(gpgme_data_t buf);
+SEXP data_to_raw(gpgme_data_t buf);
 
 struct keylist {
   gpgme_key_t key;

src/encrypt.c

@@ -18,12 +18,12 @@ SEXP R_gpgme_encrypt(SEXP data, SEXP id) {
   return data_to_string(output);
 }
 
-SEXP R_gpgme_decrypt(SEXP data) {
+SEXP R_gpgme_decrypt(SEXP data, SEXP as_text) {
   gpgme_data_t output, input;
   bail(gpgme_data_new_from_mem(&input, (const char*) RAW(data), LENGTH(data), 0), "creating input buffer");
   bail(gpgme_data_new(&output), "creating output buffer");
   bail(gpgme_op_decrypt(ctx, input, output), "decrypt message");
-  return data_to_string(output);
+  return Rf_asLogical(as_text) ? data_to_string(output) : data_to_raw(output);
 }
 
 SEXP R_gpgme_signed_encrypt(SEXP data, SEXP receiver, SEXP sender) {
@@ -51,12 +51,13 @@ SEXP R_gpgme_signed_encrypt(SEXP data, SEXP receiver, SEXP sender) {
   return data_to_string(output);
 }
 
-SEXP R_gpgme_signed_decrypt(SEXP data) {
+SEXP R_gpgme_signed_decrypt(SEXP data, SEXP as_text) {
   gpgme_data_t output, input;
   bail(gpgme_data_new_from_mem(&input, (const char*) RAW(data), LENGTH(data), 0), "creating input buffer");
   bail(gpgme_data_new(&output), "creating output buffer");
   bail(gpgme_op_decrypt_verify(ctx, input, output), "verify signatures and decrypt message");
-  SEXP out = PROTECT(data_to_string(output));
+  SEXP out = Rf_asLogical(as_text) ? data_to_string(output) : data_to_raw(output);
+  PROTECT(out);
 
   //check signatures
   gpgme_verify_result_t result = gpgme_op_verify_result(ctx);
@@ -81,3 +82,11 @@ SEXP data_to_string(gpgme_data_t buf){
   return out;
 }
 
+SEXP data_to_raw(gpgme_data_t buf){
+  size_t len;
+  char * sig = gpgme_data_release_and_get_mem(buf, &len);
+  SEXP out = allocVector(RAWSXP, len);
+  memcpy(RAW(out), sig, len);
+  gpgme_free(sig);
+  return out;
+}