+/**
+ * Feed data into an MD4 accumulator, md. The results may be
+ * retrieved using sum_end(). md is used for different purposes at
+ * different points during execution.
+ *
+ * @todo Perhaps get rid of md and just pass in the address each time.
+ * Very slightly clearer and slower.
+ **/
+void sum_update(char *p, int32 len)
+{
+ if (len + sumresidue < CSUM_CHUNK) {
+ memcpy(sumrbuf + sumresidue, p, len);
+ sumresidue += len;
+ return;
+ }
+
+ if (sumresidue) {
+ int32 i = CSUM_CHUNK - sumresidue;
+ memcpy(sumrbuf + sumresidue, p, i);
+ mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
+ len -= i;
+ p += i;
+ }
+
+ while (len >= CSUM_CHUNK) {
+ mdfour_update(&md, (uchar *)p, CSUM_CHUNK);
+ len -= CSUM_CHUNK;
+ p += CSUM_CHUNK;
+ }
+
+ sumresidue = len;
+ if (sumresidue)
+ memcpy(sumrbuf, p, sumresidue);
+}