[gmime] Added partial implementation of application/pkcs7-mime compressed-data support

[Rico Tzschichholz <ricotz src gnome org>]

commit c46ee83921d88e9d52bbf11df13835604472b970
Author: Jeffrey Stedfast <jestedfa microsoft com>
Date:   Mon Dec 2 14:58:17 2019 -0500

    Added partial implementation of application/pkcs7-mime compressed-data support

 gmime/gmime-application-pkcs7-mime.c | 111 ++++++++++++++++++++++++++++++++++-
 gmime/gmime-crypto-context.h         |   8 +++
 2 files changed, 117 insertions(+), 2 deletions(-)
---
diff --git a/gmime/gmime-application-pkcs7-mime.c b/gmime/gmime-application-pkcs7-mime.c
index d7eb2f64..312de66b 100644
--- a/gmime/gmime-application-pkcs7-mime.c
+++ b/gmime/gmime-application-pkcs7-mime.c
@@ -203,14 +203,121 @@ g_mime_application_pkcs7_mime_get_smime_type (GMimeApplicationPkcs7Mime *pkcs7_m
 
 #if 0
 GMimeApplicationPkcs7Mime *
-g_mime_application_pkcs7_mime_compress (GMimePkcs7Context *ctx, GMimeObject *entity, GError **err)
+g_mime_application_pkcs7_mime_compress (GMimeObject *entity, GError **err)
 {
+       GMimeApplicationPkcs7Mime *pkcs7_mime;
+       GMimeStream *compressed, *stream;
+       GMimeFormatOptions *options;
+       GMimeDataWrapper *content;
+       GMimeCryptoContext *ctx;
+       
+       g_return_val_if_fail (GMIME_IS_OBJECT (entity), NULL);
+       
+       if (!(ctx = g_mime_crypto_context_new ("application/pkcs7-mime"))) {
+               g_set_error (err, GMIME_ERROR, GMIME_ERROR_PROTOCOL_ERROR,
+                            _("Cannot compress application/pkcs7-mime part: no crypto context registered for 
this type."));
+               
+               return NULL;
+       }
+       
+       options = _g_mime_format_options_clone (NULL, FALSE);
+       g_mime_format_options_set_newline_format (options, GMIME_NEWLINE_FORMAT_DOS);
+       
+       /* get the cleartext */
+       stream = g_mime_stream_mem_new ();
+       g_mime_object_write_to_stream (entity, options, stream);
+       g_mime_format_options_free (options);
+       
+       /* reset the content stream */
+       g_mime_stream_reset (stream);
+       
+       /* compress the content stream */
+       compressed = g_mime_stream_mem_new ();
+       if (g_mime_crypto_context_compress (ctx, stream, compressed, err) == -1) {
+               g_object_unref (compressed);
+               g_object_unref (stream);
+               g_object_unref (ctx);
+               return NULL;
+       }
+       
+       g_object_unref (stream);
+       g_mime_stream_reset (compressed);
+       g_object_unref (ctx);
+       
+       /* construct the application/pkcs7-mime part */
+       pkcs7_mime = g_mime_application_pkcs7_mime_new (GMIME_SECURE_MIME_TYPE_COMPRESSED_DATA);
+       content = g_mime_data_wrapper_new_with_stream (compressed, GMIME_CONTENT_ENCODING_DEFAULT);
+       g_mime_part_set_content ((GMimePart *) pkcs7_mime, content);
+       g_object_unref (compressed);
+       g_object_unref (content);
+       
+       return pkcs7_mime;
 }
 
 
 GMimeObject *
-g_mime_application_pkcs7_mime_decompress (GMimeApplicationPkcs7Mime *pkcs7_mime, GMimePkcs7Context *ctx)
+g_mime_application_pkcs7_mime_decompress (GMimeApplicationPkcs7Mime *pkcs7_mime)
 {
+       GMimeStream *filtered, *compressed, *stream;
+       GMimeObject *decompressed;
+       GMimeDataWrapper *content;
+       GMimeCryptoContext *ctx;
+       GMimeDecryptResult *res;
+       GMimeFilter *filter;
+       GMimeParser *parser;
+       
+       g_return_val_if_fail (GMIME_IS_APPLICATION_PKCS7_MIME (pkcs7_mime), NULL);
+       
+       if (!(ctx = g_mime_crypto_context_new ("application/pkcs7-mime"))) {
+               g_set_error (err, GMIME_ERROR, GMIME_ERROR_PROTOCOL_ERROR,
+                            _("Cannot decompress application/pkcs7-mime part: no crypto context registered 
for this type."));
+               
+               return NULL;
+       }
+       
+       /* get the compressed stream */
+       content = g_mime_part_get_content ((GMimePart *) pkcs7_mime);
+       compressed = g_mime_stream_mem_new ();
+       g_mime_data_wrapper_write_to_stream (content, compressed);
+       g_mime_stream_reset (compressed);
+       
+       stream = g_mime_stream_mem_new ();
+       filtered = g_mime_stream_filter_new (stream);
+       filter = g_mime_filter_dos2unix_new (FALSE);
+       g_mime_stream_filter_add ((GMimeStreamFilter *) filtered, filter);
+       g_object_unref (filter);
+       
+       /* decompress the content stream */
+       if (g_mime_crypto_context_decompress (ctx, compressed, stream, err) == -1) {
+               g_object_unref (compressed);
+               g_object_unref (filtered);
+               g_object_unref (stream);
+               g_object_unref (ctx);
+               
+               return NULL;
+       }
+       
+       g_mime_stream_flush (filtered);
+       g_object_unref (compressed);
+       g_object_unref (filtered);
+       g_object_unref (ctx);
+       
+       g_mime_stream_reset (stream);
+       parser = g_mime_parser_new ();
+       g_mime_parser_init_with_stream (parser, stream);
+       g_object_unref (stream);
+       
+       decompressed = g_mime_parser_construct_part (parser, NULL);
+       g_object_unref (parser);
+       
+       if (!decompressed) {
+               g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_PARSE_ERROR,
+                                    _("Cannot decompress application/pkcs7-mime part: failed to parse 
decompressed content."));
+               
+               return NULL;
+       }
+       
+       return decompressed;
 }
 #endif
 
diff --git a/gmime/gmime-crypto-context.h b/gmime/gmime-crypto-context.h
index 8b83d300..0bf0474f 100644
--- a/gmime/gmime-crypto-context.h
+++ b/gmime/gmime-crypto-context.h
@@ -176,6 +176,14 @@ struct _GMimeCryptoContextClass {
        
        int                      (* export_keys) (GMimeCryptoContext *ctx, const char *keys[],
                                                  GMimeStream *ostream, GError **err);
+
+#if 0
+       int                      (* compress)    (GMimeCryptoContext *ctx, GMimeStream *istream,
+                                                 GMimeStream *ostream, GError **err);
+
+       int                      (* decompress)  (GMimeCryptoContext *ctx, GMimeStream *istream,
+                                                 GMimeStream *ostream, GError **err);
+#endif
 };