Move Base32_encode from packet-fc00.c to wsutil (as ws_base32_decode)

There could be some reuse out of it, so but it with the rest of the
general utilities.

Change-Id: I404c135b933660a82678510b9ca2701985c5632a
Reviewed-on: https://code.wireshark.org/review/18589
Reviewed-by: Michael Mann <mmann78@netscape.net>
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/wsutil/base32.c b/wsutil/base32.c
new file mode 100644
index 0000000000..6bb1b610b1
--- /dev/null
+++ b/wsutil/base32.c
@@ -0,0 +1,82 @@
+/* base32.c
+ * Base-32 conversion
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include <string.h>
+#include "base32.h"
+
+/*
+ * Cjdns style base32 encoding
+ */
+
+/** Returned by ws_base32_encode() if the input is not valid base32. */
+#define Base32_BAD_INPUT -1
+/** Returned by ws_base32_encode() if the output buffer is too small. */
+#define Base32_TOO_BIG -2
+
+int ws_base32_decode(guint8* output, const guint32 outputLength,
+						const guint8* in, const guint32 inputLength)
+{
+	guint32 outIndex = 0;
+	guint32 inIndex = 0;
+	guint32 work = 0;
+	guint32 bits = 0;
+	static const guint8* kChars = (guint8*) "0123456789bcdfghjklmnpqrstuvwxyz";
+	while (inIndex < inputLength) {
+		work |= ((unsigned) in[inIndex++]) << bits;
+		bits += 8;
+		while (bits >= 5) {
+			if (outIndex >= outputLength) {
+				return Base32_TOO_BIG;
+			}
+			output[outIndex++] = kChars[work & 31];
+			bits -= 5;
+			work >>= 5;
+		}
+	}
+	if (bits) {
+		if (outIndex >= outputLength) {
+			return Base32_TOO_BIG;
+		}
+		output[outIndex++] = kChars[work & 31];
+	}
+	if (outIndex < outputLength) {
+		output[outIndex] = '\0';
+	}
+	return outIndex;
+}
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */