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- /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 4 -*- */
- /* vi: set expandtab shiftwidth=4 tabstop=4: */
- /**
- * \file
- * <PRE>
- * MODP_B64 - High performance base64 encoder/decoder
- * Version 1.3 -- 17-Mar-2006
- * http://modp.com/release/base64
- *
- * Copyright © 2005, 2006 Nick Galbreath -- nickg [at] modp [dot] com
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * Neither the name of the modp.com nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * This is the standard "new" BSD license:
- * http://www.opensource.org/licenses/bsd-license.php
- * </PRE>
- */
- /* public header */
- #include "modp_b64.h"
- /*
- * If you are ripping this out of the library, comment out the next
- * line and uncomment the next lines as approrpiate
- */
- //#include "config.h"
- /* if on motoral, sun, ibm; uncomment this */
- /* #define WORDS_BIGENDIAN 1 */
- /* else for Intel, Amd; uncomment this */
- /* #undef WORDS_BIGENDIAN */
- #include "modp_b64_data.h"
- #define BADCHAR 0x01FFFFFF
- /**
- * you can control if we use padding by commenting out this
- * next line. However, I highly recommend you use padding and not
- * using it should only be for compatability with a 3rd party.
- * Also, 'no padding' is not tested!
- */
- #define DOPAD 1
- /*
- * if we aren't doing padding
- * set the pad character to NULL
- */
- #ifndef DOPAD
- #undef CHARPAD
- #define CHARPAD '\0'
- #endif
- size_t modp_b64_encode(char* dest, const char* str, size_t len)
- {
- size_t i = 0;
- uint8_t* p = (uint8_t*) dest;
- /* unsigned here is important! */
- uint8_t t1, t2, t3;
- if (len > 2) {
- for (; i < len - 2; i += 3) {
- t1 = str[i]; t2 = str[i+1]; t3 = str[i+2];
- *p++ = e0[t1];
- *p++ = e1[((t1 & 0x03) << 4) | ((t2 >> 4) & 0x0F)];
- *p++ = e1[((t2 & 0x0F) << 2) | ((t3 >> 6) & 0x03)];
- *p++ = e2[t3];
- }
- }
- switch (len - i) {
- case 0:
- break;
- case 1:
- t1 = str[i];
- *p++ = e0[t1];
- *p++ = e1[(t1 & 0x03) << 4];
- *p++ = CHARPAD;
- *p++ = CHARPAD;
- break;
- default: /* case 2 */
- t1 = str[i]; t2 = str[i+1];
- *p++ = e0[t1];
- *p++ = e1[((t1 & 0x03) << 4) | ((t2 >> 4) & 0x0F)];
- *p++ = e2[(t2 & 0x0F) << 2];
- *p++ = CHARPAD;
- }
- *p = '\0';
- return p - (uint8_t*)dest;
- }
- #ifdef WORDS_BIGENDIAN /* BIG ENDIAN -- SUN / IBM / MOTOROLA */
- int modp_b64_decode(char* dest, const char* src, int len)
- {
- if (len == 0) return 0;
- #ifdef DOPAD
- /* if padding is used, then the message must be at least
- 4 chars and be a multiple of 4.
- there can be at most 2 pad chars at the end */
- if (len < 4 || (len % 4 != 0)) return MODP_B64_ERROR;
- if (src[len-1] == CHARPAD) {
- len--;
- if (src[len -1] == CHARPAD) {
- len--;
- }
- }
- #endif /* DOPAD */
- size_t i;
- int leftover = len % 4;
- size_t chunks = (leftover == 0) ? len / 4 - 1 : len /4;
- uint8_t* p = (uint8_t*) dest;
- uint32_t x = 0;
- uint32_t* destInt = (uint32_t*) p;
- uint32_t* srcInt = (uint32_t*) src;
- uint32_t y = *srcInt++;
- for (i = 0; i < chunks; ++i) {
- x = d0[y >> 24 & 0xff] | d1[y >> 16 & 0xff] |
- d2[y >> 8 & 0xff] | d3[y & 0xff];
- if (x >= BADCHAR) return MODP_B64_ERROR;
- *destInt = x << 8;
- p += 3;
- destInt = (uint32_t*)p;
- y = *srcInt++;
- }
- switch (leftover) {
- case 0:
- x = d0[y >> 24 & 0xff] | d1[y >> 16 & 0xff] |
- d2[y >> 8 & 0xff] | d3[y & 0xff];
- if (x >= BADCHAR) return MODP_B64_ERROR;
- *p++ = ((uint8_t*)&x)[1];
- *p++ = ((uint8_t*)&x)[2];
- *p = ((uint8_t*)&x)[3];
- return (chunks+1)*3;
- case 1:
- x = d3[y >> 24];
- *p = (uint8_t)x;
- break;
- case 2:
- x = d3[y >> 24] *64 + d3[(y >> 16) & 0xff];
- *p = (uint8_t)(x >> 4);
- break;
- default: /* case 3 */
- x = (d3[y >> 24] *64 + d3[(y >> 16) & 0xff])*64 +
- d3[(y >> 8) & 0xff];
- *p++ = (uint8_t) (x >> 10);
- *p = (uint8_t) (x >> 2);
- break;
- }
- if (x >= BADCHAR) return MODP_B64_ERROR;
- return 3*chunks + (6*leftover)/8;
- }
- #else /* LITTLE ENDIAN -- INTEL AND FRIENDS */
- size_t modp_b64_decode(char* dest, const char* src, size_t len)
- {
- if (len == 0) return 0;
- #ifdef DOPAD
- /*
- * if padding is used, then the message must be at least
- * 4 chars and be a multiple of 4
- */
- if (len < 4 || (len % 4 != 0)) return MODP_B64_ERROR; /* error */
- /* there can be at most 2 pad chars at the end */
- if (src[len-1] == CHARPAD) {
- len--;
- if (src[len -1] == CHARPAD) {
- len--;
- }
- }
- #endif
- size_t i;
- int leftover = len % 4;
- size_t chunks = (leftover == 0) ? len / 4 - 1 : len /4;
- uint8_t* p = (uint8_t*)dest;
- uint32_t x = 0;
- const uint8_t* y = (uint8_t*)src;
- for (i = 0; i < chunks; ++i, y += 4) {
- x = d0[y[0]] | d1[y[1]] | d2[y[2]] | d3[y[3]];
- if (x >= BADCHAR) return MODP_B64_ERROR;
- *p++ = ((uint8_t*)(&x))[0];
- *p++ = ((uint8_t*)(&x))[1];
- *p++ = ((uint8_t*)(&x))[2];
- }
- switch (leftover) {
- case 0:
- x = d0[y[0]] | d1[y[1]] | d2[y[2]] | d3[y[3]];
- if (x >= BADCHAR) return MODP_B64_ERROR;
- *p++ = ((uint8_t*)(&x))[0];
- *p++ = ((uint8_t*)(&x))[1];
- *p = ((uint8_t*)(&x))[2];
- return (chunks+1)*3;
- case 1: /* with padding this is an impossible case */
- x = d0[y[0]];
- *p = *((uint8_t*)(&x)); // i.e. first char/byte in int
- break;
- case 2: // * case 2, 1 output byte */
- x = d0[y[0]] | d1[y[1]];
- *p = *((uint8_t*)(&x)); // i.e. first char
- break;
- default: /* case 3, 2 output bytes */
- x = d0[y[0]] | d1[y[1]] | d2[y[2]]; /* 0x3c */
- *p++ = ((uint8_t*)(&x))[0];
- *p = ((uint8_t*)(&x))[1];
- break;
- }
- if (x >= BADCHAR) return MODP_B64_ERROR;
- return 3*chunks + (6*leftover)/8;
- }
- #endif /* if bigendian / else / endif */
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