1 files changed, 68 insertions, 0 deletions
diff --git a/wsutil/base32.c b/wsutil/base32.c
new file mode 100644
index 00000000..ad8b800c
--- /dev/null
+++ b/wsutil/base32.c
@@ -0,0 +1,68 @@
+/* base32.c
+ * Base-32 conversion
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+#include "base32.h"
+
+#include <string.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(uint8_t* output, const uint32_t outputLength,
+						const uint8_t* in, const uint32_t inputLength)
+{
+	uint32_t outIndex = 0;
+	uint32_t inIndex = 0;
+	uint32_t work = 0;
+	uint32_t bits = 0;
+	static const uint8_t* kChars = (uint8_t*) "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  -  https://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:
+ */