/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* Fluent Bit * ========== * Copyright (C) 2019-2021 The Fluent Bit Authors * * 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. */ /* This code is based on base64.c from the mbedtls-2.25.0 Library distribution, * as originally written by Paul Bakker, et al., and forked by the Fluent Bit * project to provide performant base64 encoding and decoding routines. * The 2.25.0 implementation is included rather than 2.26.0+ implementation due * to performance degradation introduced in 2.26.0. * * Method and variable names are changed by the Fluent Bit authors to maintain * consistency with the Fluent Bit project. * The self test section of the code was removed by the Fluent Bit authors. * Other minor changes are made by the Fluent Bit authors. * * The original source file base64.c is copyright and licensed as follows; * * RFC 1521 base64 encoding/decoding * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * 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. */ #include #include static const unsigned char base64_enc_map[64] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; static const unsigned char base64_dec_map[128] = { 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 127, 62, 127, 127, 127, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 127, 127, 127, 64, 127, 127, 127, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 127, 127, 127, 127, 127, 127, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 127, 127, 127, 127, 127 }; #define BASE64_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */ /* * Encode a buffer into base64 format */ int flb_base64_encode( unsigned char *dst, size_t dlen, size_t *olen, const unsigned char *src, size_t slen ) { size_t i, n; int C1, C2, C3; unsigned char *p; if( slen == 0 ) { *olen = 0; return( 0 ); } n = slen / 3 + ( slen % 3 != 0 ); if( n > ( BASE64_SIZE_T_MAX - 1 ) / 4 ) { *olen = BASE64_SIZE_T_MAX; return( FLB_BASE64_ERR_BUFFER_TOO_SMALL ); } n *= 4; if( ( dlen < n + 1 ) || ( NULL == dst ) ) { *olen = n + 1; return( FLB_BASE64_ERR_BUFFER_TOO_SMALL ); } n = ( slen / 3 ) * 3; for( i = 0, p = dst; i < n; i += 3 ) { C1 = *src++; C2 = *src++; C3 = *src++; *p++ = base64_enc_map[(C1 >> 2) & 0x3F]; *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F]; *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F]; *p++ = base64_enc_map[C3 & 0x3F]; } if( i < slen ) { C1 = *src++; C2 = ( ( i + 1 ) < slen ) ? *src++ : 0; *p++ = base64_enc_map[(C1 >> 2) & 0x3F]; *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F]; if( ( i + 1 ) < slen ) *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F]; else *p++ = '='; *p++ = '='; } *olen = p - dst; *p = 0; return( 0 ); } /* * Decode a base64-formatted buffer */ int flb_base64_decode( unsigned char *dst, size_t dlen, size_t *olen, const unsigned char *src, size_t slen ) { size_t i, n; uint32_t j, x; unsigned char *p; /* First pass: check for validity and get output length */ for( i = n = j = 0; i < slen; i++ ) { /* Skip spaces before checking for EOL */ x = 0; while( i < slen && src[i] == ' ' ) { ++i; ++x; } /* Spaces at end of buffer are OK */ if( i == slen ) break; if( ( slen - i ) >= 2 && src[i] == '\r' && src[i + 1] == '\n' ) continue; if( src[i] == '\n' ) continue; /* Space inside a line is an error */ if( x != 0 ) return( FLB_BASE64_ERR_INVALID_CHARACTER ); if( src[i] == '=' && ++j > 2 ) return( FLB_BASE64_ERR_INVALID_CHARACTER ); if( src[i] > 127 || base64_dec_map[src[i]] == 127 ) return( FLB_BASE64_ERR_INVALID_CHARACTER ); if( base64_dec_map[src[i]] < 64 && j != 0 ) return( FLB_BASE64_ERR_INVALID_CHARACTER ); n++; } if( n == 0 ) { *olen = 0; return( 0 ); } /* The following expression is to calculate the following formula without * risk of integer overflow in n: * n = ( ( n * 6 ) + 7 ) >> 3; */ n = ( 6 * ( n >> 3 ) ) + ( ( 6 * ( n & 0x7 ) + 7 ) >> 3 ); n -= j; if( dst == NULL || dlen < n ) { *olen = n; return( FLB_BASE64_ERR_BUFFER_TOO_SMALL ); } for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ ) { if( *src == '\r' || *src == '\n' || *src == ' ' ) continue; j -= ( base64_dec_map[*src] == 64 ); x = ( x << 6 ) | ( base64_dec_map[*src] & 0x3F ); if( ++n == 4 ) { n = 0; if( j > 0 ) *p++ = (unsigned char)( x >> 16 ); if( j > 1 ) *p++ = (unsigned char)( x >> 8 ); if( j > 2 ) *p++ = (unsigned char)( x ); } } *olen = p - dst; return( 0 ); }