/*********************************************************************** * _ _ __ _ _ * __ _ _ __ ___| |_ | |__ __ _ ___ ___ / /_ | || | * / _` | '_ \ / _ \ __| | '_ \ / _` / __|/ _ \ '_ \| || |_ * | (_| | | | | __/ |_ | |_) | (_| \__ \ __/ (_) |__ _| * \__, |_| |_|\___|\__| |_.__/ \__,_|___/\___|\___/ |_| * |___/ * * created by Alfred Reibenschuh , * under the ``GNU Library General Public License´´ (see below). * *********************************************************************** * * Copyright (C) 2003 Free Software Foundation * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * ***********************************************************************/ #include "base64.h" #include #include static gchar gnet_Base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; #define gnet_Pad64 '=' static guchar gnet_Base64_rank[256] = { 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0x00-0x0f */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0x10-0x1f */ 255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63, /* 0x20-0x2f */ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,255,255,255, /* 0x30-0x3f */ 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40-0x4f */ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255, /* 0x50-0x5f */ 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60-0x6f */ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255, /* 0x70-0x7f */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0x80-0x8f */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0x90-0x9f */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xa0-0xaf */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xb0-0xbf */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xc0-0xcf */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xd0-0xdf */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xe0-0xef */ 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0xf0-0xff */ }; /** * gnet_base64_encode * @src: source buffer * @srclen: length of the source buffer * @dstlenp: length of the buffer returned (including the terminating \0) * @strict: insert new lines as required by RFC 2045 * * Convert a buffer from binary to base64 representation. Set * @strict to TRUE to insert a newline every 72th character. This is * required by RFC 2045, but some applications don't require this. * * Returns: caller-owned buffer. * **/ gchar* gnet_base64_encode (gchar* src, gint srclen, gint* dstlenp, gboolean strict) { gchar* dst; gint dstpos; guchar input[3]; guchar output[4]; gint ocnt; gint i; if (srclen == 0) return NULL; /* FIX: Or return ""? */ /* Calculate required length of dst. 4 bytes of dst are needed for every 3 bytes of src. */ *dstlenp = (((srclen + 2) / 3) * 4)+5; if (strict) *dstlenp += (*dstlenp / 72); /* Handle trailing \n */ dst = g_new(gchar, *dstlenp ); /* bulk encoding */ dstpos = 0; ocnt = 0; while (srclen >= 3) { /* Convert 3 bytes of src to 4 bytes of output output[0] = input[0] 7:2 output[1] = input[0] 1:0 input[1] 7:4 output[2] = input[1] 3:0 input[2] 7:6 output[3] = input[1] 5:0 */ input[0] = *src++; input[1] = *src++; input[2] = *src++; srclen -= 3; output[0] = (input[0] >> 2); output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); output[3] = (input[2] & 0x3f); g_assert ((dstpos + 4) < *dstlenp); /* Map output to the Base64 alphabet */ dst[dstpos++] = gnet_Base64[(guint) output[0]]; dst[dstpos++] = gnet_Base64[(guint) output[1]]; dst[dstpos++] = gnet_Base64[(guint) output[2]]; dst[dstpos++] = gnet_Base64[(guint) output[3]]; /* Add a newline if strict and */ if (strict) if ((++ocnt % (72/4)) == 0) dst[dstpos++] = '\n'; } /* Now worry about padding with remaining 1 or 2 bytes */ if (srclen != 0) { input[0] = input[1] = input[2] = '\0'; for (i = 0; i < srclen; i++) input[i] = *src++; output[0] = (input[0] >> 2); output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); g_assert ((dstpos + 4) < *dstlenp); dst[dstpos++] = gnet_Base64[(guint) output[0]]; dst[dstpos++] = gnet_Base64[(guint) output[1]]; if (srclen == 1) dst[dstpos++] = gnet_Pad64; else dst[dstpos++] = gnet_Base64[(guint) output[2]]; dst[dstpos++] = gnet_Pad64; } g_assert (dstpos <= *dstlenp); dst[dstpos] = '\0'; *dstlenp = dstpos + 1; return dst; } /** * gnet_base64_decode * @src: the source buffer * @srclen: the length of the source buffer * @dstlenp: pointer to length of the destination buffer * * Convert a buffer from base64 to binary representation. This * function is liberal in what it will accept. It ignores non-base64 * symbols. * * Returns: caller-owned buffer. The integer pointed to by @dstlenp * is set to the length of that buffer. * **/ gchar* gnet_base64_decode (gchar* src, gint srclen, gint* dstlenp) { gchar* dst; gint dstidx, state, ch = 0; gchar res; guchar pos; if (srclen == 0) srclen = strlen(src); state = 0; dstidx = 0; res = 0; dst = g_new(gchar, srclen+1); *dstlenp = srclen+1; while (srclen-- > 0) { ch = *src++; if (gnet_Base64_rank[ch]==255) /* Skip any non-base64 anywhere */ continue; if (ch == gnet_Pad64) break; pos = gnet_Base64_rank[ch]; switch (state) { case 0: if (dst != NULL) { dst[dstidx] = (pos << 2); } state = 1; break; case 1: if (dst != NULL) { dst[dstidx] |= (pos >> 4); res = ((pos & 0x0f) << 4); } dstidx++; state = 2; break; case 2: if (dst != NULL) { dst[dstidx] = res | (pos >> 2); res = (pos & 0x03) << 6; } dstidx++; state = 3; break; case 3: if (dst != NULL) { dst[dstidx] = res | pos; } dstidx++; state = 0; break; default: break; } } /* * We are done decoding Base-64 chars. Let's see if we ended * on a byte boundary, and/or with erroneous trailing characters. */ if (ch == gnet_Pad64) /* We got a pad char. */ { switch (state) { case 0: /* Invalid = in first position */ case 1: /* Invalid = in second position */ return NULL; case 2: /* Valid, means one byte of info */ /* Skip any number of spaces. */ while (srclen-- > 0) { ch = *src++; if (gnet_Base64_rank[ch] != 255) break; } /* Make sure there is another trailing = sign. */ if (ch != gnet_Pad64) { g_free(dst); *dstlenp = 0; return NULL; } /* FALLTHROUGH */ case 3: /* Valid, means two bytes of info */ /* * We know this char is an =. Is there anything but * whitespace after it? */ while (srclen-- > 0) { ch = *src++; if (gnet_Base64_rank[ch] != 255) { g_free(dst); *dstlenp = 0; return NULL; } } /* * Now make sure for cases 2 and 3 that the "extra" * bits that slopped past the last full byte were * zeros. If we don't check them, they become a * subliminal channel. */ if (dst != NULL && res != 0) { g_free(dst); *dstlenp = 0; return NULL; } default: break; } } else { /* * We ended by seeing the end of the string. Make sure we * have no partial bytes lying around. */ if (state != 0) { g_free(dst); *dstlenp = 0; return NULL; } } dst[dstidx]=0; *dstlenp = dstidx; return dst; }