initial commit

libpcp/pad.c

@@ -0,0 +1,53 @@
+#include "pad.h"
+
+void pcp_pad_prepend(unsigned char **padded, unsigned char *unpadded,
+		 size_t padlen, size_t unpadlen) {
+  *padded = ucmalloc(unpadlen + padlen);
+  unsigned char *tmp = ucmalloc(unpadlen + padlen);
+
+  // pcp_append orig
+  int i;
+  for(i=0; i<unpadlen; ++i) {
+    tmp[i + padlen] = unpadded[i];
+  }
+
+  memcpy(*padded, tmp, unpadlen + padlen);
+  free(tmp);
+}
+
+void pcp_pad_remove(unsigned char **unpadded, unsigned char *padded,
+		size_t padlen, size_t unpadlen) {
+  *unpadded = ucmalloc(unpadlen * sizeof(unsigned char));
+  unsigned char *tmp = ucmalloc(unpadlen);
+
+  int i;
+  for(i=0; i<unpadlen; ++i) {
+    tmp[i] = padded[padlen + i];
+  }
+  
+  memcpy(*unpadded, tmp, unpadlen);
+  free(tmp);
+}
+
+#ifdef _MK_ZPAD_MAIN
+int main(int argc, char **argv) {
+  if(argc >= 2) {
+    size_t unpadlen;
+    int padlen = strtol(argv[2], NULL, 0);
+    unpadlen = strlen(argv[1]);
+    unsigned char *dst;
+    
+    pcp_pad_prepend(&dst, argv[1], padlen, unpadlen);
+    //printf("   prev: %s\n  after: %s\n", argv[1], dst);
+    
+    unsigned char *reverse;
+    pcp_pad_remove(&reverse, dst, padlen, unpadlen);
+    //printf("reverse: %s\n", reverse);
+    
+    return 0;
+  }
+  //fprintf(stderr, "Usage: pad <string> <padlen>\n");
+  return -1;
+}
+#endif
+