1 files changed, 60 insertions, 0 deletions
diff --git a/lib/base32.h b/lib/base32.h
new file mode 100644
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--- /dev/null
+++ b/lib/base32.h
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+/* base32.h -- Encode binary data using printable characters.
+   Copyright (C) 2004-2006, 2009-2022 Free Software Foundation, Inc.
+   Adapted from Simon Josefsson's base64 code by Gijs van Tulder.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef BASE32_H
+# define BASE32_H
+
+/* Get idx_t. */
+# include <idx.h>
+
+/* Get bool. */
+# include <stdbool.h>
+
+/* This uses that the expression (n+(k-1))/k means the smallest
+   integer >= n/k, i.e., the ceiling of n/k.  */
+# define BASE32_LENGTH(inlen) ((((inlen) + 4) / 5) * 8)
+
+struct base32_decode_context
+{
+  int i;
+  char buf[8];
+};
+
+extern bool isbase32 (char ch) _GL_ATTRIBUTE_CONST;
+
+extern void base32_encode (const char *restrict in, idx_t inlen,
+                           char *restrict out, idx_t outlen);
+
+extern idx_t base32_encode_alloc (const char *in, idx_t inlen, char **out);
+
+extern void base32_decode_ctx_init (struct base32_decode_context *ctx);
+
+extern bool base32_decode_ctx (struct base32_decode_context *ctx,
+                               const char *restrict in, idx_t inlen,
+                               char *restrict out, idx_t *outlen);
+
+extern bool base32_decode_alloc_ctx (struct base32_decode_context *ctx,
+                                     const char *in, idx_t inlen,
+                                     char **out, idx_t *outlen);
+
+#define base32_decode(in, inlen, out, outlen) \
+        base32_decode_ctx (NULL, in, inlen, out, outlen)
+
+#define base32_decode_alloc(in, inlen, out, outlen) \
+        base32_decode_alloc_ctx (NULL, in, inlen, out, outlen)
+
+#endif /* BASE32_H */