New class implementing the multipart/encrypted content type. Contains

2002-06-26  Jeffrey Stedfast  <fejj@ximian.com>

	* camel-multipart-encrypted.[c,h]: New class implementing the
	multipart/encrypted content type. Contains methods for encrypting
	and decrypting a multipart/encrypted MIME object.

svn path=/trunk/; revision=17296

1 files changed, 329 insertions, 0 deletions

diff --git a/camel/camel-multipart-encrypted.c b/camel/camel-multipart-encrypted.c
new file mode 100644
index 0000000000..0d77d20e19
--- /dev/null
+++ b/camel/camel-multipart-encrypted.c
@@ -0,0 +1,329 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/*
+ *  Authors: Jeffrey Stedfast <fejj@ximian.com>
+ *
+ *  Copyright 2002 Ximian, Inc. (www.ximian.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+
+#include "camel-multipart-encrypted.h"
+#include "camel-mime-filter-crlf.h"
+#include "camel-stream-filter.h"
+#include "camel-stream-mem.h"
+#include "camel-mime-utils.h"
+#include "camel-mime-part.h"
+
+static void camel_multipart_encrypted_class_init (CamelMultipartEncryptedClass *klass);
+static void camel_multipart_encrypted_init (gpointer object, gpointer klass);
+static void camel_multipart_encrypted_finalize (CamelObject *object);
+
+static void set_mime_type_field (CamelDataWrapper *data_wrapper, CamelContentType *mime_type);
+
+
+static CamelMultipartClass *parent_class = NULL;
+
+
+CamelType
+camel_multipart_encrypted_get_type (void)
+{
+	static CamelType type = CAMEL_INVALID_TYPE;
+	
+	if (type == CAMEL_INVALID_TYPE) {
+		type = camel_type_register (camel_multipart_get_type (),
+					    "CamelMultipartEncrypted",
+					    sizeof (CamelMultipartEncrypted),
+					    sizeof (CamelMultipartEncryptedClass),
+					    (CamelObjectClassInitFunc) camel_multipart_encrypted_class_init,
+					    NULL,
+					    (CamelObjectInitFunc) camel_multipart_encrypted_init,
+					    (CamelObjectFinalizeFunc) camel_multipart_encrypted_finalize);
+	}
+	
+	return type;
+}
+
+
+static void
+camel_multipart_encrypted_class_init (CamelMultipartEncryptedClass *klass)
+{
+	CamelDataWrapperClass *camel_data_wrapper_class = CAMEL_DATA_WRAPPER_CLASS (klass);
+	
+	parent_class = (CamelMultipartClass *) camel_multipart_get_type ();
+	
+	/* virtual method overload */
+	camel_data_wrapper_class->set_mime_type_field = set_mime_type_field;
+}
+
+static void
+camel_multipart_encrypted_init (gpointer object, gpointer klass)
+{
+	CamelMultipartEncrypted *multipart = (CamelMultipartEncrypted *) object;
+	
+	camel_data_wrapper_set_mime_type (CAMEL_DATA_WRAPPER (multipart), "multipart/encrypted");
+	
+	multipart->decrypted = NULL;
+}
+
+static void
+camel_multipart_encrypted_finalize (CamelObject *object)
+{
+	CamelMultipartEncrypted *mpe = (CamelMultipartEncrypted *) object;
+	
+	g_free (mpe->protocol);
+	
+	if (mpe->decrypted)
+		camel_object_unref (mpe->decrypted);
+}
+
+/* we snoop the mime type to get the protocol */
+static void
+set_mime_type_field (CamelDataWrapper *data_wrapper, CamelContentType *mime_type)
+{
+	CamelMultipartEncrypted *mpe = (CamelMultipartEncrypted *) data_wrapper;
+	
+	if (mime_type) {
+		const char *protocol;
+		
+		protocol = header_content_type_param (mime_type, "protocol");
+		g_free (mpe->protocol);
+		mpe->protocol = g_strdup (protocol);
+	}
+	
+	((CamelDataWrapperClass *) parent_class)->set_mime_type_field (data_wrapper, mime_type);
+}
+
+
+/**
+ * camel_multipart_encrypted_new:
+ *
+ * Create a new CamelMultipartEncrypted object.
+ *
+ * A MultipartEncrypted should be used to store and create parts of
+ * type "multipart/encrypted".
+ *
+ * Returns a new CamelMultipartEncrypted
+ **/
+CamelMultipartEncrypted *
+camel_multipart_encrypted_new (void)
+{
+	CamelMultipartEncrypted *multipart;
+	
+	multipart = (CamelMultipartEncrypted *) camel_object_new (CAMEL_MULTIPART_ENCRYPTED_TYPE);
+	
+	return multipart;
+}
+
+
+int
+camel_multipart_encrypted_encrypt (CamelMultipartEncrypted *mpe, CamelMimePart *content,
+				   CamelCipherContext *cipher, GPtrArray *recipients,
+				   CamelException *ex)
+{
+	CamelMimePart *version_part, *encrypted_part;
+	CamelContentType *mime_type;
+	CamelDataWrapper *wrapper;
+	CamelStream *filtered_stream;
+	CamelStream *stream, *ciphertext;
+	CamelMimeFilter *crlf_filter;
+	
+	g_return_val_if_fail (CAMEL_IS_MULTIPART_ENCRYPTED (mpe), -1);
+	g_return_val_if_fail (CAMEL_IS_CIPHER_CONTEXT (cipher), -1);
+	g_return_val_if_fail (cipher->encrypt_protocol != NULL, -1);
+	g_return_val_if_fail (CAMEL_IS_MIME_PART (content), -1);
+	
+	/* get the cleartext */
+	stream = camel_stream_mem_new ();
+	filtered_stream = (CamelStream *) camel_stream_filter_new_with_stream (stream);
+	
+	crlf_filter = camel_mime_filter_crlf_new (CAMEL_MIME_FILTER_CRLF_ENCODE,
+						  CAMEL_MIME_FILTER_CRLF_MODE_CRLF_ONLY);
+	camel_stream_filter_add (CAMEL_STREAM_FILTER (filtered_stream), crlf_filter);
+	camel_object_unref (crlf_filter);
+	
+	camel_data_wrapper_write_to_stream ((CamelDataWrapper *) content, filtered_stream);
+	camel_stream_flush (filtered_stream);
+	camel_object_unref (filtered_stream);
+	
+	/* reset the content stream */
+	camel_stream_reset (stream);
+	
+	/* encrypt the content stream */
+	ciphertext = camel_stream_mem_new ();
+	if (camel_cipher_encrypt (cipher, FALSE, NULL, recipients, stream, ciphertext, ex) == -1) {
+		camel_object_unref (ciphertext);
+		camel_object_unref (stream);
+		return -1;
+	}
+	
+	camel_object_unref (stream);
+	camel_stream_reset (ciphertext);
+	
+	/* construct the version part */
+	stream = camel_stream_mem_new ();
+	camel_stream_write_string (stream, "Version: 1");
+	camel_stream_reset (stream);
+	
+	version_part = camel_mime_part_new ();
+	wrapper = camel_data_wrapper_new ();
+	camel_data_wrapper_set_mime_type (wrapper, cipher->encrypt_protocol);
+	camel_data_wrapper_construct_from_stream (wrapper, stream);
+	camel_object_unref (stream);
+	camel_medium_set_content_object ((CamelMedium *) version_part, wrapper);
+	camel_object_unref (wrapper);
+	
+	/* construct the encrypted mime part */
+	encrypted_part = camel_mime_part_new ();
+	wrapper = camel_data_wrapper_new ();
+	camel_data_wrapper_set_mime_type (wrapper, "application/octet-stream; name=encrypted.asc");
+	camel_data_wrapper_construct_from_stream (wrapper, ciphertext);
+	camel_object_unref (ciphertext);
+	camel_medium_set_content_object ((CamelMedium *) encrypted_part, wrapper);
+	camel_object_unref (wrapper);
+	
+	/* save the version and encrypted parts */
+	/* FIXME: make sure there aren't any other parts?? */
+	camel_multipart_add_part (CAMEL_MULTIPART (mpe), version_part);
+	camel_object_unref (version_part);
+	camel_multipart_add_part (CAMEL_MULTIPART (mpe), encrypted_part);
+	camel_object_unref (encrypted_part);
+	
+	/* cache the decrypted content */
+	camel_object_ref (content);
+	mpe->decrypted = content;
+	
+	/* set the content-type params for this multipart/encrypted part */
+	mime_type = header_content_type_new ("multipart", "encrypted");
+	header_content_type_set_param (mime_type, "protocol", cipher->encrypt_protocol);
+	camel_data_wrapper_set_mime_type_field (CAMEL_DATA_WRAPPER (mpe), mime_type);
+	header_content_type_unref (mime_type);
+	camel_multipart_set_boundary ((CamelMultipart *) mpe, NULL);
+	
+	return 0;
+}
+
+
+CamelMimePart *
+camel_multipart_encrypted_decrypt (CamelMultipartEncrypted *mpe,
+				   CamelCipherContext *cipher,
+				   CamelException *ex)
+{
+	CamelMimePart *version_part, *encrypted_part, *decrypted_part;
+	CamelContentType *mime_type;
+	CamelDataWrapper *wrapper;
+	CamelStream *filtered_stream;
+	CamelMimeFilter *crlf_filter;
+	CamelStream *ciphertext;
+	CamelStream *stream;
+	const char *protocol;
+	char *content_type;
+	
+	g_return_val_if_fail (CAMEL_IS_MULTIPART_ENCRYPTED (mpe), NULL);
+	g_return_val_if_fail (CAMEL_IS_CIPHER_CONTEXT (cipher), NULL);
+	g_return_val_if_fail (cipher->encrypt_protocol != NULL, NULL);
+	
+	if (mpe->decrypted) {
+		/* we seem to have already decrypted the part */
+		camel_object_ref (mpe->decrypted);
+		return mpe->decrypted;
+	}
+	
+	protocol = mpe->protocol;
+	
+	if (protocol) {
+		/* make sure the protocol matches the cipher encrypt protocol */
+		if (strcasecmp (cipher->encrypt_protocol, protocol) != 0) {
+			camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
+					     _("Failed to decrypt MIME part: protocol error"));
+			
+			return NULL;
+		}
+	} else {
+		/* *shrug* - I guess just go on as if they match? */
+		protocol = cipher->encrypt_protocol;
+	}
+	
+	version_part = camel_multipart_get_part (CAMEL_MULTIPART (mpe), CAMEL_MULTIPART_ENCRYPTED_VERSION);
+	
+	/* make sure the protocol matches the version part's content-type */
+	content_type = camel_data_wrapper_get_mime_type ((CamelDataWrapper *) version_part);
+	if (strcasecmp (content_type, protocol) != 0) {
+		camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
+				     _("Failed to decrypt MIME part: protocol error"));
+		
+		camel_object_unref (version_part);
+		g_free (content_type);
+		
+		return NULL;
+	}
+	g_free (content_type);
+	
+	/* get the encrypted part (second part) */
+	encrypted_part = camel_multipart_get_part (CAMEL_MULTIPART (mpe), CAMEL_MULTIPART_ENCRYPTED_CONTENT);
+	mime_type = camel_mime_part_get_content_type (encrypted_part);
+	if (!header_content_type_is (mime_type, "application", "octet-stream")) {
+		camel_object_unref (encrypted_part);
+		camel_object_unref (version_part);
+		return NULL;
+	}
+	
+	/* get the ciphertext stream */
+	ciphertext = camel_stream_mem_new ();
+	wrapper = camel_medium_get_content_object ((CamelMedium *) encrypted_part);
+	camel_data_wrapper_write_to_stream (wrapper, ciphertext);
+	camel_stream_reset (ciphertext);
+	
+	stream = camel_stream_mem_new ();
+	filtered_stream = (CamelStream *) camel_stream_filter_new_with_stream (stream);
+	crlf_filter = camel_mime_filter_crlf_new (CAMEL_MIME_FILTER_CRLF_DECODE,
+						  CAMEL_MIME_FILTER_CRLF_MODE_CRLF_ONLY);
+	camel_stream_filter_add (CAMEL_STREAM_FILTER (filtered_stream), crlf_filter);
+	camel_object_unref (crlf_filter);
+	
+	/* get the cleartext */
+	if (camel_cipher_decrypt (cipher, ciphertext, filtered_stream, ex) == -1) {
+		camel_object_unref (filtered_stream);
+		camel_object_unref (ciphertext);
+		camel_object_unref (stream);
+		
+		return NULL;
+	}
+	
+	camel_stream_flush (filtered_stream);
+	camel_object_unref (filtered_stream);
+	camel_object_unref (ciphertext);
+	
+	decrypted_part = camel_mime_part_new ();
+	camel_data_wrapper_construct_from_stream (CAMEL_DATA_WRAPPER (decrypted_part), stream);
+	
+	if (decrypted_part) {
+		/* cache the decrypted part */
+		camel_object_ref (decrypted_part);
+		mpe->decrypted = decrypted_part;
+	} else {
+		camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
+				     _("Failed to decrypt MIME part: parse error"));
+	}
+	
+	return decrypted_part;
+}