| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) Daniel Stenberg, <[email protected]>, et al. |
| * |
| * This software is licensed as described in the file COPYING, which |
| * you should have received as part of this distribution. The terms |
| * are also available at https://curl.se/docs/copyright.html. |
| * |
| * You may opt to use, copy, modify, merge, publish, distribute and/or sell |
| * copies of the Software, and permit persons to whom the Software is |
| * furnished to do so, under the terms of the COPYING file. |
| * |
| * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
| * KIND, either express or implied. |
| * |
| * SPDX-License-Identifier: curl |
| * |
| ***************************************************************************/ |
| |
| /* Base64 encoding/decoding */ |
| |
| #include "curl_setup.h" |
| |
| #if !defined(CURL_DISABLE_HTTP_AUTH) || defined(USE_SSH) || \ |
| !defined(CURL_DISABLE_LDAP) || \ |
| !defined(CURL_DISABLE_SMTP) || \ |
| !defined(CURL_DISABLE_POP3) || \ |
| !defined(CURL_DISABLE_IMAP) || \ |
| !defined(CURL_DISABLE_DOH) || defined(USE_SSL) || defined(BUILDING_CURL) |
| #include "curl/curl.h" |
| #include "warnless.h" |
| #include "curl_base64.h" |
| |
| /* The last 2 #include files should be in this order */ |
| #ifdef BUILDING_LIBCURL |
| #include "curl_memory.h" |
| #endif |
| #include "memdebug.h" |
| |
| /* ---- Base64 Encoding/Decoding Table --- */ |
| /* Padding character string starts at offset 64. */ |
| static const char base64encdec[]= |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; |
| |
| /* The Base 64 encoding with a URL and filename safe alphabet, RFC 4648 |
| section 5 */ |
| static const char base64url[]= |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; |
| |
| static const unsigned char decodetable[] = |
| { 62, 255, 255, 255, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, |
| 255, 255, 255, 255, 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, 255, 255, 255, 255, 255, 255, 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 }; |
| /* |
| * Curl_base64_decode() |
| * |
| * Given a base64 NUL-terminated string at src, decode it and return a |
| * pointer in *outptr to a newly allocated memory area holding decoded |
| * data. Size of decoded data is returned in variable pointed by outlen. |
| * |
| * Returns CURLE_OK on success, otherwise specific error code. Function |
| * output shall not be considered valid unless CURLE_OK is returned. |
| * |
| * When decoded data length is 0, returns NULL in *outptr. |
| * |
| * @unittest: 1302 |
| */ |
| CURLcode Curl_base64_decode(const char *src, |
| unsigned char **outptr, size_t *outlen) |
| { |
| size_t srclen = 0; |
| size_t padding = 0; |
| size_t i; |
| size_t numQuantums; |
| size_t fullQuantums; |
| size_t rawlen = 0; |
| unsigned char *pos; |
| unsigned char *newstr; |
| unsigned char lookup[256]; |
| |
| *outptr = NULL; |
| *outlen = 0; |
| srclen = strlen(src); |
| |
| /* Check the length of the input string is valid */ |
| if(!srclen || srclen % 4) |
| return CURLE_BAD_CONTENT_ENCODING; |
| |
| /* srclen is at least 4 here */ |
| while(src[srclen - 1 - padding] == '=') { |
| /* count padding characters */ |
| padding++; |
| /* A maximum of two = padding characters is allowed */ |
| if(padding > 2) |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Calculate the number of quantums */ |
| numQuantums = srclen / 4; |
| fullQuantums = numQuantums - (padding ? 1 : 0); |
| |
| /* Calculate the size of the decoded string */ |
| rawlen = (numQuantums * 3) - padding; |
| |
| /* Allocate our buffer including room for a null-terminator */ |
| newstr = malloc(rawlen + 1); |
| if(!newstr) |
| return CURLE_OUT_OF_MEMORY; |
| |
| pos = newstr; |
| |
| memset(lookup, 0xff, sizeof(lookup)); |
| memcpy(&lookup['+'], decodetable, sizeof(decodetable)); |
| /* replaces |
| { |
| unsigned char c; |
| const unsigned char *p = (const unsigned char *)base64encdec; |
| for(c = 0; *p; c++, p++) |
| lookup[*p] = c; |
| } |
| */ |
| |
| /* Decode the complete quantums first */ |
| for(i = 0; i < fullQuantums; i++) { |
| unsigned char val; |
| unsigned int x = 0; |
| int j; |
| |
| for(j = 0; j < 4; j++) { |
| val = lookup[(unsigned char)*src++]; |
| if(val == 0xff) /* bad symbol */ |
| goto bad; |
| x = (x << 6) | val; |
| } |
| pos[2] = x & 0xff; |
| pos[1] = (x >> 8) & 0xff; |
| pos[0] = (x >> 16) & 0xff; |
| pos += 3; |
| } |
| if(padding) { |
| /* this means either 8 or 16 bits output */ |
| unsigned char val; |
| unsigned int x = 0; |
| int j; |
| size_t padc = 0; |
| for(j = 0; j < 4; j++) { |
| if(*src == '=') { |
| x <<= 6; |
| src++; |
| if(++padc > padding) |
| /* this is a badly placed '=' symbol! */ |
| goto bad; |
| } |
| else { |
| val = lookup[(unsigned char)*src++]; |
| if(val == 0xff) /* bad symbol */ |
| goto bad; |
| x = (x << 6) | val; |
| } |
| } |
| if(padding == 1) |
| pos[1] = (x >> 8) & 0xff; |
| pos[0] = (x >> 16) & 0xff; |
| pos += 3 - padding; |
| } |
| |
| /* Zero terminate */ |
| *pos = '\0'; |
| |
| /* Return the decoded data */ |
| *outptr = newstr; |
| *outlen = rawlen; |
| |
| return CURLE_OK; |
| bad: |
| free(newstr); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| static CURLcode base64_encode(const char *table64, |
| const char *inputbuff, size_t insize, |
| char **outptr, size_t *outlen) |
| { |
| char *output; |
| char *base64data; |
| const unsigned char *in = (unsigned char *)inputbuff; |
| const char *padstr = &table64[64]; /* Point to padding string. */ |
| |
| *outptr = NULL; |
| *outlen = 0; |
| |
| if(!insize) |
| insize = strlen(inputbuff); |
| |
| #if SIZEOF_SIZE_T == 4 |
| if(insize > UINT_MAX/4) |
| return CURLE_OUT_OF_MEMORY; |
| #endif |
| |
| base64data = output = malloc((insize + 2) / 3 * 4 + 1); |
| if(!output) |
| return CURLE_OUT_OF_MEMORY; |
| |
| while(insize >= 3) { |
| *output++ = table64[ in[0] >> 2 ]; |
| *output++ = table64[ ((in[0] & 0x03) << 4) | (in[1] >> 4) ]; |
| *output++ = table64[ ((in[1] & 0x0F) << 2) | ((in[2] & 0xC0) >> 6) ]; |
| *output++ = table64[ in[2] & 0x3F ]; |
| insize -= 3; |
| in += 3; |
| } |
| if(insize) { |
| /* this is only one or two bytes now */ |
| *output++ = table64[ in[0] >> 2 ]; |
| if(insize == 1) { |
| *output++ = table64[ ((in[0] & 0x03) << 4) ]; |
| if(*padstr) { |
| *output++ = *padstr; |
| *output++ = *padstr; |
| } |
| } |
| else { |
| /* insize == 2 */ |
| *output++ = table64[ ((in[0] & 0x03) << 4) | ((in[1] & 0xF0) >> 4) ]; |
| *output++ = table64[ ((in[1] & 0x0F) << 2) ]; |
| if(*padstr) |
| *output++ = *padstr; |
| } |
| } |
| |
| /* Zero terminate */ |
| *output = '\0'; |
| |
| /* Return the pointer to the new data (allocated memory) */ |
| *outptr = base64data; |
| |
| /* Return the length of the new data */ |
| *outlen = output - base64data; |
| |
| return CURLE_OK; |
| } |
| |
| /* |
| * Curl_base64_encode() |
| * |
| * Given a pointer to an input buffer and an input size, encode it and |
| * return a pointer in *outptr to a newly allocated memory area holding |
| * encoded data. Size of encoded data is returned in variable pointed by |
| * outlen. |
| * |
| * Input length of 0 indicates input buffer holds a NUL-terminated string. |
| * |
| * Returns CURLE_OK on success, otherwise specific error code. Function |
| * output shall not be considered valid unless CURLE_OK is returned. |
| * |
| * @unittest: 1302 |
| */ |
| CURLcode Curl_base64_encode(const char *inputbuff, size_t insize, |
| char **outptr, size_t *outlen) |
| { |
| return base64_encode(base64encdec, inputbuff, insize, outptr, outlen); |
| } |
| |
| /* |
| * Curl_base64url_encode() |
| * |
| * Given a pointer to an input buffer and an input size, encode it and |
| * return a pointer in *outptr to a newly allocated memory area holding |
| * encoded data. Size of encoded data is returned in variable pointed by |
| * outlen. |
| * |
| * Input length of 0 indicates input buffer holds a NUL-terminated string. |
| * |
| * Returns CURLE_OK on success, otherwise specific error code. Function |
| * output shall not be considered valid unless CURLE_OK is returned. |
| * |
| * @unittest: 1302 |
| */ |
| CURLcode Curl_base64url_encode(const char *inputbuff, size_t insize, |
| char **outptr, size_t *outlen) |
| { |
| return base64_encode(base64url, inputbuff, insize, outptr, outlen); |
| } |
| |
| #endif /* no users so disabled */ |
