unleashed-firmware/applications/external/totp/lib/base32/base32.h

40 lines
1.4 KiB
C

// Base32 implementation
//
// Copyright 2010 Google Inc.
// Author: Markus Gutschke
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Encode and decode from base32 encoding using the following alphabet:
// ABCDEFGHIJKLMNOPQRSTUVWXYZ234567
// This alphabet is documented in RFC 4648/3548
//
// We allow white-space and hyphens, but all other characters are considered
// invalid.
//
// All functions return the number of output bytes or -1 on error. If the
// output buffer is too small, the result will silently be truncated.
#pragma once
#include <stddef.h>
#include <stdint.h>
/**
* @brief Decodes Base-32 encoded bytes into plain bytes.
* @param encoded Base-32 encoded bytes
* @param[out] result result output buffer
* @param bufSize result output buffer size
* @return Decoded result length in bytes if successfully decoded; \c 0 otherwise
*/
size_t base32_decode(const uint8_t* encoded, uint8_t* result, size_t bufSize);