/* gbase64.c - Base64 encoding/decoding * * Copyright (C) 2006 Alexander Larsson * Copyright (C) 2000-2003 Ximian Inc. * * 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., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * This is based on code in camel, written by: * Michael Zucchi * Jeffrey Stedfast */ #include "config.h" #include #include "gbase64.h" #include /* #include */ /* #include */ static const char base64_alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; /** * g_base64_encode_step: * @in: the binary data to encode * @len: the length of @in * @break_lines: whether to break long lines * @out: pointer to destination buffer * @state: Saved state between steps, initialize to 0 * @save: Saved state between steps, initialize to 0 * * Incrementally encode a sequence of binary data into it's Base-64 stringified * representation. By calling this function multiple times you can convert * data in chunks to avoid having to have the full encoded data in memory. * * When all of the data has been converted you must call * g_base64_encode_close() to flush the saved state. * * The output buffer must be large enough to fit all the data that will * be written to it. Due to the way base64 encodes you will need * at least: @len * 4 / 3 + 6 bytes. If you enable line-breaking you will * need at least: @len * 4 / 3 + @len * 4 / (3 * 72) + 7 bytes. * * @break_lines is typically used when putting base64-encoded data in emails. * It breaks the lines at 72 columns instead of putting all of the text on * the same line. This avoids problems with long lines in the email system. * * Return value: The number of bytes of output that was written * * Since: 2.12 */ gsize g_base64_encode_step (const guchar *in, gsize len, gboolean break_lines, gchar *out, gint *state, gint *save) { char *outptr; const guchar *inptr; g_return_val_if_fail (in != NULL, 0); g_return_val_if_fail (out != NULL, 0); g_return_val_if_fail (state != NULL, 0); g_return_val_if_fail (save != NULL, 0); if (len <= 0) return 0; inptr = in; outptr = out; if (len + ((char *) save) [0] > 2) { const guchar *inend = in+len-2; int c1, c2, c3; int already; already = *state; switch (((char *) save) [0]) { case 1: c1 = ((unsigned char *) save) [1]; goto skip1; case 2: c1 = ((unsigned char *) save) [1]; c2 = ((unsigned char *) save) [2]; goto skip2; } /* * yes, we jump into the loop, no i'm not going to change it, * it's beautiful! */ while (inptr < inend) { c1 = *inptr++; skip1: c2 = *inptr++; skip2: c3 = *inptr++; *outptr++ = base64_alphabet [ c1 >> 2 ]; *outptr++ = base64_alphabet [ c2 >> 4 | ((c1&0x3) << 4) ]; *outptr++ = base64_alphabet [ ((c2 &0x0f) << 2) | (c3 >> 6) ]; *outptr++ = base64_alphabet [ c3 & 0x3f ]; /* this is a bit ugly ... */ if (break_lines && (++already) >= 19) { *outptr++ = '\n'; already = 0; } } ((char *)save)[0] = 0; len = 2 - (inptr - inend); *state = already; } if (len>0) { char *saveout; /* points to the slot for the next char to save */ saveout = & (((char *)save)[1]) + ((char *)save)[0]; /* len can only be 0 1 or 2 */ switch(len) { case 2: *saveout++ = *inptr++; case 1: *saveout++ = *inptr++; } ((char *)save)[0] += len; } return outptr - out; } /** * g_base64_encode_close: * @break_lines: whether to break long lines * @out: pointer to destination buffer * @state: Saved state from g_base64_encode_step() * @save: Saved state from g_base64_encode_step() * * Flush the status from a sequence of calls to g_base64_encode_step(). * * Return value: The number of bytes of output that was written * * Since: 2.12 */ gsize g_base64_encode_close (gboolean break_lines, gchar *out, gint *state, gint *save) { int c1, c2; char *outptr = out; g_return_val_if_fail (out != NULL, 0); g_return_val_if_fail (state != NULL, 0); g_return_val_if_fail (save != NULL, 0); c1 = ((unsigned char *) save) [1]; c2 = ((unsigned char *) save) [2]; switch (((char *) save) [0]) { case 2: outptr [2] = base64_alphabet[ ( (c2 &0x0f) << 2 ) ]; g_assert (outptr [2] != 0); goto skip; case 1: outptr[2] = '='; skip: outptr [0] = base64_alphabet [ c1 >> 2 ]; outptr [1] = base64_alphabet [ c2 >> 4 | ( (c1&0x3) << 4 )]; outptr [3] = '='; outptr += 4; break; } if (break_lines) *outptr++ = '\n'; *save = 0; *state = 0; return outptr - out; } /** * g_base64_encode: * @data: the binary data to encode * @len: the length of @data * * Encode a sequence of binary data into its Base-64 stringified * representation. * * Return value: a newly allocated, zero-terminated Base-64 encoded * string representing @data. * * Since: 2.12 */ gchar * g_base64_encode (const guchar *data, gsize len) { gchar *out; gint state = 0, outlen; gint save = 0; g_return_val_if_fail (data != NULL, NULL); g_return_val_if_fail (len > 1, NULL); /* We can use a smaller limit here, since we know the saved state is 0 */ out = g_malloc (len * 4 / 3 + 4); outlen = g_base64_encode_step (data, len, FALSE, out, &state, &save); outlen += g_base64_encode_close (FALSE, out + outlen, &state, &save); out[outlen] = '\0'; return (gchar *) out; } static const unsigned char mime_base64_rank[256] = { 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255, 0,255,255, 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, 51,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, }; /** * g_base64_decode_step: * @in: binary input data * @len: max length of @in data to decode * @out: output buffer * @state: Saved state between steps, initialize to 0 * @save: Saved state between steps, initialize to 0 * * Incrementally decode a sequence of binary data from its Base-64 stringified * representation. By calling this function multiple times you can convert * data in chunks to avoid having to have the full encoded data in memory. * * The output buffer must be large enough to fit all the data that will * be written to it. Since base64 encodes 3 bytes in 4 chars you need * at least: @len * 3 / 4 bytes. * * Return value: The number of bytes of output that was written * * Since: 2.12 **/ gsize g_base64_decode_step (const gchar *in, gsize len, guchar *out, gint *state, guint *save) { const guchar *inptr; guchar *outptr; const guchar *inend; guchar c, rank; guchar last[2]; unsigned int v; int i; g_return_val_if_fail (in != NULL, 0); g_return_val_if_fail (out != NULL, 0); g_return_val_if_fail (state != NULL, 0); g_return_val_if_fail (save != NULL, 0); if (len <= 0) return 0; inend = (const guchar *)in+len; outptr = out; /* convert 4 base64 bytes to 3 normal bytes */ v=*save; i=*state; inptr = (const guchar *)in; last[0] = last[1] = 0; while (inptr < inend) { c = *inptr++; rank = mime_base64_rank [c]; if (rank != 0xff) { last[1] = last[0]; last[0] = c; v = (v<<6) | rank; i++; if (i==4) { *outptr++ = v>>16; if (last[1] != '=') *outptr++ = v>>8; if (last[0] != '=') *outptr++ = v; i=0; } } } *save = v; *state = i; return outptr - out; } /** * g_base64_decode: * @text: zero-terminated string with base64 text to decode * @out_len: The length of the decoded data is written here * * Decode a sequence of Base-64 encoded text into binary data * * Return value: a newly allocated buffer containing the binary data * that @text represents * * Since: 2.12 */ guchar * g_base64_decode (const gchar *text, gsize *out_len) { guchar *ret; gint input_length, state = 0; guint save = 0; g_return_val_if_fail (text != NULL, NULL); g_return_val_if_fail (out_len != NULL, NULL); input_length = strlen (text); g_return_val_if_fail (input_length > 1, NULL); ret = g_malloc0 (input_length * 3 / 4); *out_len = g_base64_decode_step (text, input_length, ret, &state, &save); return ret; } #define __G_BASE64_C__ /* #include "galiasdef.c" */