X-Git-Url: https://git.distorted.org.uk/~mdw/ezmlm/blobdiff_plain/5b62e993b0af39700031c2875d7f6654e6a02850..f8beb284087c279acfb30506f5bb32baa4949b44:/decodeB.c

diff --git a/decodeB.c b/decodeB.c
new file mode 100644
index 0000000..78406bc
--- /dev/null
+++ b/decodeB.c
@@ -0,0 +1,71 @@
+#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;
+    }
+  }
+}
+