--- /dev/null
+#include "stralloc.h"
+#include "strerr.h"
+#include "uint32.h"
+#include "errtxt.h"
+
+ /* Characters and translation as per rfc2047. */
+static char char64table[128] = {
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
+ -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
+ 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
+ -1, 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,-1, -1,-1,-1,-1,
+ -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
+ 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
+};
+
+#define char64enc(c) (((c) & 0x80) ? -1 : char64table[(c)])
+
+static void die_nomem(fatal)
+ char *fatal;
+{
+ strerr_die2x(111,fatal,ERR_NOMEM);
+}
+
+void decodeB(cpfrom,n,outdata,fatal)
+char *cpfrom;
+unsigned int n;
+stralloc *outdata;
+char *fatal;
+/* does B decoding of the string pointed to by cpfrom up to the character */
+/* before the one pointed to by cpnext, and appends the results to mimeline*/
+{
+ uint32 hold32;
+ char holdch[4] = "???";
+ int i,j;
+ char c; /* needs to be signed */
+ char *cp, *cpnext;
+
+ cp = cpfrom;
+ cpnext = cp + n;
+ i = 0;
+ hold32 = 0L;
+ if (!stralloc_readyplus(outdata,n)) die_nomem(fatal);
+ for (;;) {
+ if (i == 4) {
+ for (j = 2; j >= 0; --j) {
+ holdch[j] = hold32 & 0xff;
+ hold32 = hold32 >> 8;
+ }
+ if (!stralloc_cats(outdata,holdch)) die_nomem(fatal);
+ if (cp >= cpnext)
+ break;
+ hold32 = 0L;
+ i = 0;
+ }
+ if (cp >= cpnext) { /* pad */
+ c = 0;
+ } else {
+ c = char64enc(*cp);
+ ++cp;
+ }
+ if (c < 0) /* ignore illegal characters */
+ continue;
+ else {
+ hold32 = (hold32 << 6) | (c & 0x7f);
+ ++i;
+ }
+ }
+}
+