+/*
+ * This file is part of DisOrder
+ * Copyright (C) 2005, 2007 Richard Kettlewell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+/** @file lib/base64.c
+ * @brief Support for MIME base64
+ */
+
+#include <config.h>
+#include "types.h"
+
+#include <string.h>
+
+#include <stdio.h>
+
+#include "mem.h"
+#include "base64.h"
+#include "vector.h"
+
+static const char mime_base64_table[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+/** @brief Convert MIME base64
+ * @param s base64 data
+ * @return Decoded data
+ */
+char *mime_base64(const char *s, size_t *nsp) {
+ struct dynstr d;
+ const char *t;
+ int b[4], n, c;
+
+ dynstr_init(&d);
+ n = 0;
+ while((c = (unsigned char)*s++)) {
+ if((t = strchr(mime_base64_table, c))) {
+ b[n++] = t - mime_base64_table;
+ if(n == 4) {
+ dynstr_append(&d, (b[0] << 2) + (b[1] >> 4));
+ dynstr_append(&d, (b[1] << 4) + (b[2] >> 2));
+ dynstr_append(&d, (b[2] << 6) + b[3]);
+ n = 0;
+ }
+ } else if(c == '=') {
+ if(n >= 2) {
+ dynstr_append(&d, (b[0] << 2) + (b[1] >> 4));
+ if(n == 3)
+ dynstr_append(&d, (b[1] << 4) + (b[2] >> 2));
+ }
+ break;
+ }
+ }
+ if(nsp)
+ *nsp = d.nvec;
+ dynstr_terminate(&d);
+ return d.vec;
+}
+
+/** @brief Convert a binary string to base64
+ * @param s Bytes to convert
+ * @param ns Number of bytes to convert
+ * @return Encoded data
+ *
+ * This function does not attempt to split up lines.
+ */
+char *mime_to_base64(const uint8_t *s, size_t ns) {
+ struct dynstr d[1];
+
+ dynstr_init(d);
+ while(ns >= 3) {
+ /* Input bytes with output bits: AAAAAABB BBBBCCCC CCDDDDDD */
+ /* Output bytes with input bits: 000000 001111 111122 222222 */
+ dynstr_append(d, mime_base64_table[s[0] >> 2]);
+ dynstr_append(d, mime_base64_table[((s[0] & 3) << 4)
+ + (s[1] >> 4)]);
+ dynstr_append(d, mime_base64_table[((s[1] & 15) << 2)
+ + (s[2] >> 6)]);
+ dynstr_append(d, mime_base64_table[s[2] & 63]);
+ ns -= 3;
+ s += 3;
+ }
+ if(ns > 0) {
+ dynstr_append(d, mime_base64_table[s[0] >> 2]);
+ switch(ns) {
+ case 1:
+ dynstr_append(d, mime_base64_table[(s[0] & 3) << 4]);
+ dynstr_append(d, '=');
+ dynstr_append(d, '=');
+ break;
+ case 2:
+ dynstr_append(d, mime_base64_table[((s[0] & 3) << 4)
+ + (s[1] >> 4)]);
+ dynstr_append(d, mime_base64_table[(s[1] & 15) << 2]);
+ dynstr_append(d, '=');
+ break;
+ }
+ }
+ dynstr_terminate(d);
+ return d->vec;
+}
+
+/*
+Local Variables:
+c-basic-offset:2
+comment-column:40
+fill-column:79
+End:
+*/