61 lines
2.2 KiB
C
61 lines
2.2 KiB
C
#include <stdio.h>
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#include <math.h>
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#include "mbedtls/base64.h"
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/**
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* encode using base64
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* @param input_data the data to be encoded
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* @param input_length the length of the input data
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* @param output_data where the data is to be stored
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* @param max_output_length the max size of the output_data
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* @param bytes_written the number of bytes written to output_data
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* @returns true(1) on success, otherwise false
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*/
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int libp2p_crypto_encoding_base64_encode(const unsigned char* input_data, size_t input_length, unsigned char* output_data, size_t max_output_length, size_t* bytes_written) {
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int retVal = mbedtls_base64_encode(output_data, max_output_length, bytes_written, input_data, input_length);
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return retVal == 0;
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}
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/**
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* decode something that was encoded as base64
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* @param input_data the data to decode
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* @param input_length the length of the input data
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* @param output_data the buffer to store the output
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* @param max_output_length the length of the output buffer
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* @param bytes_written the number of bytes written to output_data
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* @returns true(1) on success, otherwise 0
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*/
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int libp2p_crypto_encoding_base64_decode(const unsigned char* input_data, size_t input_length, unsigned char* output_data, size_t max_output_length, size_t* bytes_written) {
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int retVal = mbedtls_base64_decode(output_data, max_output_length, bytes_written, input_data, input_length);
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return retVal == 0;
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}
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/**
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* calculate the max length in bytes of an encoding of n source bytes
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* @param encoded_size the size of the encoded string
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* @returns the maximum size in bytes had the string been decoded
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*/
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size_t libp2p_crypto_encoding_base64_decode_size(size_t encoded_size) {
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size_t radix = 64;
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double bits_per_digit = log2(radix); // each char represents about 6 bits
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return ceil(encoded_size * bits_per_digit / 8);
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}
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/**
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* calculate the max length in bytes of a decoding of n source bytes
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* @param decoded_size the size of the incoming string to be encoded
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* @returns the maximum size in bytes had the string been encoded
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*/
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size_t libp2p_crypto_encoding_base64_encode_size(size_t decoded_size) {
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/*
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size_t radix = 64;
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double bits_per_digit = log2(radix);
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return ceil( (8 / bits_per_digit * decoded_size) + 1);
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*/
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return (decoded_size / 3 + (decoded_size % 3 != 0)) * 4 + 1;
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}
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