/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2009, Daniel Stenberg, , 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 http://curl.haxx.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. * * $Id: base64.c,v 1.53 2009-06-04 23:55:56 yangtse Exp $ ***************************************************************************/ /* Base64 encoding/decoding * * Test harnesses down the bottom - compile with -DTEST_ENCODE for * a program that will read in raw data from stdin and write out * a base64-encoded version to stdout, and the length returned by the * encoding function to stderr. Compile with -DTEST_DECODE for a program that * will go the other way. * * This code will break if int is smaller than 32 bits */ #include "setup.h" #include #include #define _MPRINTF_REPLACE /* use our functions only */ #include #include "urldata.h" /* for the SessionHandle definition */ #include "easyif.h" /* for Curl_convert_... prototypes */ #include "curl_base64.h" #include "curl_memory.h" /* include memdebug.h last */ #include "memdebug.h" /* ---- Base64 Encoding/Decoding Table --- */ static const char table64[]= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static void decodeQuantum(unsigned char *dest, const char *src) { unsigned int x = 0; int i; char *found; for(i = 0; i < 4; i++) { if((found = strchr(table64, src[i])) != NULL) x = (x << 6) + (unsigned int)(found - table64); else if(src[i] == '=') x = (x << 6); } dest[2] = (unsigned char)(x & 255); x >>= 8; dest[1] = (unsigned char)(x & 255); x >>= 8; dest[0] = (unsigned char)(x & 255); } /* * Curl_base64_decode() * * Given a base64 string at src, decode it and return an allocated memory in * the *outptr. Returns the length of the decoded data. */ size_t Curl_base64_decode(const char *src, unsigned char **outptr) { int length = 0; int equalsTerm = 0; int i; int numQuantums; unsigned char lastQuantum[3]; size_t rawlen=0; unsigned char *newstr; *outptr = NULL; while((src[length] != '=') && src[length]) length++; /* A maximum of two = padding characters is allowed */ if(src[length] == '=') { equalsTerm++; if(src[length+equalsTerm] == '=') equalsTerm++; } numQuantums = (length + equalsTerm) / 4; /* Don't allocate a buffer if the decoded length is 0 */ if(numQuantums <= 0) return 0; rawlen = (numQuantums * 3) - equalsTerm; /* The buffer must be large enough to make room for the last quantum (which may be partially thrown out) and the zero terminator. */ newstr = malloc(rawlen+4); if(!newstr) return 0; *outptr = newstr; /* Decode all but the last quantum (which may not decode to a multiple of 3 bytes) */ for(i = 0; i < numQuantums - 1; i++) { decodeQuantum(newstr, src); newstr += 3; src += 4; } /* This final decode may actually read slightly past the end of the buffer if the input string is missing pad bytes. This will almost always be harmless. */ decodeQuantum(lastQuantum, src); for(i = 0; i < 3 - equalsTerm; i++) newstr[i] = lastQuantum[i]; newstr[i] = 0; /* zero terminate */ return rawlen; } /* * Curl_base64_encode() * * Returns the length of the newly created base64 string. The third argument * is a pointer to an allocated area holding the base64 data. If something * went wrong, 0 is returned. * */ size_t Curl_base64_encode(struct SessionHandle *data, const char *inputbuff, size_t insize, char **outptr) { unsigned char ibuf[3]; unsigned char obuf[4]; int i; int inputparts; char *output; char *base64data; #ifdef CURL_DOES_CONVERSIONS char *convbuf = NULL; #endif const char *indata = inputbuff; *outptr = NULL; /* set to NULL in case of failure before we reach the end */ if(0 == insize) insize = strlen(indata); base64data = output = malloc(insize*4/3+4); if(NULL == output) return 0; #ifdef CURL_DOES_CONVERSIONS /* * The base64 data needs to be created using the network encoding * not the host encoding. And we can't change the actual input * so we copy it to a buffer, translate it, and use that instead. */ if(data) { convbuf = malloc(insize); if(!convbuf) { free(output); return 0; } memcpy(convbuf, indata, insize); if(CURLE_OK != Curl_convert_to_network(data, convbuf, insize)) { free(convbuf); free(output); return 0; } indata = convbuf; /* switch to the converted buffer */ } #else (void)data; #endif while(insize > 0) { for (i = inputparts = 0; i < 3; i++) { if(insize > 0) { inputparts++; ibuf[i] = *indata; indata++; insize--; } else ibuf[i] = 0; } obuf[0] = (unsigned char) ((ibuf[0] & 0xFC) >> 2); obuf[1] = (unsigned char) (((ibuf[0] & 0x03) << 4) | \ ((ibuf[1] & 0xF0) >> 4)); obuf[2] = (unsigned char) (((ibuf[1] & 0x0F) << 2) | \ ((ibuf[2] & 0xC0) >> 6)); obuf[3] = (unsigned char) (ibuf[2] & 0x3F); switch(inputparts) { case 1: /* only one byte read */ snprintf(output, 5, "%c%c==", table64[obuf[0]], table64[obuf[1]]); break; case 2: /* two bytes read */ snprintf(output, 5, "%c%c%c=", table64[obuf[0]], table64[obuf[1]], table64[obuf[2]]); break; default: snprintf(output, 5, "%c%c%c%c", table64[obuf[0]], table64[obuf[1]], table64[obuf[2]], table64[obuf[3]] ); break; } output += 4; } *output=0; *outptr = base64data; /* make it return the actual data memory */ #ifdef CURL_DOES_CONVERSIONS if(data) free(convbuf); #endif return strlen(base64data); /* return the length of the new data */ } /* ---- End of Base64 Encoding ---- */