+/**
+ * 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, int len)
+{
+ int i;
+ if (len + sumresidue < CSUM_CHUNK) {
+ memcpy(sumrbuf+sumresidue, p, len);
+ sumresidue += len;
+ return;
+ }
+
+ if (sumresidue) {
+ i = MIN(CSUM_CHUNK-sumresidue,len);
+ memcpy(sumrbuf+sumresidue,p,i);
+ mdfour_update(&md, (uchar *)sumrbuf, (i+sumresidue));
+ len -= i;
+ p += i;
+ }
+
+ for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
+ memcpy(sumrbuf,p+i,CSUM_CHUNK);
+ mdfour_update(&md, (uchar *)sumrbuf, CSUM_CHUNK);
+ }
+
+ if (len - i > 0) {
+ sumresidue = len-i;
+ memcpy(sumrbuf,p+i,sumresidue);
+ } else {
+ sumresidue = 0;
+ }
+}