diff --git a/applypatch/imgdiff.cpp b/applypatch/imgdiff.cpp
index c59edeb..7c5bb86 100644
--- a/applypatch/imgdiff.cpp
+++ b/applypatch/imgdiff.cpp
@@ -130,10 +130,6 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-#include <algorithm>
-#include <memory>
-#include <vector>
-
 #include <bsdiff.h>
 
 #include "zlib.h"
@@ -171,8 +167,16 @@
   char* filename;
 } ZipFileEntry;
 
-static bool fileentry_compare(const ZipFileEntry& a, const ZipFileEntry& b) {
-  return a.data_offset < b.data_offset;
+static int fileentry_compare(const void* a, const void* b) {
+  int ao = ((ZipFileEntry*)a)->data_offset;
+  int bo = ((ZipFileEntry*)b)->data_offset;
+  if (ao < bo) {
+    return -1;
+  } else if (ao > bo) {
+    return 1;
+  } else {
+    return 0;
+  }
 }
 
 unsigned char* ReadZip(const char* filename,
@@ -185,9 +189,9 @@
   }
 
   size_t sz = static_cast<size_t>(st.st_size);
-  std::unique_ptr<unsigned char[]> img(new unsigned char[sz]);
+  unsigned char* img = reinterpret_cast<unsigned char*>(malloc(sz));
   FILE* f = fopen(filename, "rb");
-  if (fread(img.get(), 1, sz, f) != sz) {
+  if (fread(img, 1, sz, f) != sz) {
     printf("failed to read \"%s\" %s\n", filename, strerror(errno));
     fclose(f);
     return NULL;
@@ -209,13 +213,14 @@
     return NULL;
   }
 
-  int cdcount = Read2(&img[i+8]);
-  int cdoffset = Read4(&img[i+16]);
+  int cdcount = Read2(img+i+8);
+  int cdoffset = Read4(img+i+16);
 
-  std::vector<ZipFileEntry> temp_entries(cdcount);
+  ZipFileEntry* temp_entries = reinterpret_cast<ZipFileEntry*>(malloc(
+      cdcount * sizeof(ZipFileEntry)));
   int entrycount = 0;
 
-  unsigned char* cd = &img[cdoffset];
+  unsigned char* cd = img+cdoffset;
   for (i = 0; i < cdcount; ++i) {
     if (!(cd[0] == 0x50 && cd[1] == 0x4b && cd[2] == 0x01 && cd[3] == 0x02)) {
       printf("bad central directory entry %d\n", i);
@@ -242,7 +247,7 @@
       continue;
     }
 
-    unsigned char* lh = &img[hoffset];
+    unsigned char* lh = img + hoffset;
 
     if (!(lh[0] == 0x50 && lh[1] == 0x4b && lh[2] == 0x03 && lh[3] == 0x04)) {
       printf("bad local file header entry %d\n", i);
@@ -263,7 +268,7 @@
     ++entrycount;
   }
 
-  std::sort(temp_entries.begin(), temp_entries.end(), fileentry_compare);
+  qsort(temp_entries, entrycount, sizeof(ZipFileEntry), fileentry_compare);
 
 #if 0
   printf("found %d deflated entries\n", entrycount);
@@ -285,7 +290,7 @@
     curr->type = CHUNK_NORMAL;
     curr->start = 0;
     curr->len = st.st_size;
-    curr->data = img.get();
+    curr->data = img;
     curr->filename = NULL;
     ++curr;
     ++*num_chunks;
@@ -299,7 +304,7 @@
       curr->type = CHUNK_DEFLATE;
       curr->start = pos;
       curr->deflate_len = temp_entries[nextentry].deflate_len;
-      curr->deflate_data = &img[pos];
+      curr->deflate_data = img + pos;
       curr->filename = temp_entries[nextentry].filename;
 
       curr->len = temp_entries[nextentry].uncomp_len;
@@ -343,7 +348,7 @@
     } else {
       curr->len = st.st_size - pos;
     }
-    curr->data = &img[pos];
+    curr->data = img + pos;
     curr->filename = NULL;
     pos += curr->len;
 
@@ -351,7 +356,8 @@
     ++curr;
   }
 
-  return img.release();
+  free(temp_entries);
+  return img;
 }
 
 /*
@@ -372,9 +378,9 @@
   }
 
   size_t sz = static_cast<size_t>(st.st_size);
-  std::unique_ptr<unsigned char[]> img(new unsigned char[sz+4]);
+  unsigned char* img = reinterpret_cast<unsigned char*>(malloc(sz + 4));
   FILE* f = fopen(filename, "rb");
-  if (fread(img.get(), 1, sz, f) != sz) {
+  if (fread(img, 1, sz, f) != sz) {
     printf("failed to read \"%s\" %s\n", filename, strerror(errno));
     fclose(f);
     return NULL;
@@ -384,7 +390,7 @@
   // append 4 zero bytes to the data so we can always search for the
   // four-byte string 1f8b0800 starting at any point in the actual
   // file data, without special-casing the end of the data.
-  memset(&img[sz], 0, 4);
+  memset(img+sz, 0, 4);
 
   size_t pos = 0;
 
@@ -392,7 +398,7 @@
   *chunks = NULL;
 
   while (pos < sz) {
-    unsigned char* p = &img[pos];
+    unsigned char* p = img+pos;
 
     if (sz - pos >= 4 &&
         p[0] == 0x1f && p[1] == 0x8b &&
@@ -475,7 +481,7 @@
       curr->type = CHUNK_NORMAL;
       curr->start = pos;
       curr->len = GZIP_FOOTER_LEN;
-      curr->data = &img[pos];
+      curr->data = img+pos;
 
       pos += curr->len;
       p += curr->len;
@@ -489,6 +495,7 @@
       if (footer_size != curr[-2].len) {
         printf("Error: footer size %zu != decompressed size %zu\n",
             footer_size, curr[-2].len);
+        free(img);
         return NULL;
       }
     } else {
@@ -516,7 +523,7 @@
     }
   }
 
-  return img.release();
+  return img;
 }
 
 #define BUFFER_SIZE 32768
@@ -638,7 +645,8 @@
   }
 
   size_t sz = static_cast<size_t>(st.st_size);
-  std::unique_ptr<unsigned char[]> data(new unsigned char[sz]);
+  // TODO: Memory leak on error return.
+  unsigned char* data = reinterpret_cast<unsigned char*>(malloc(sz));
 
   if (tgt->type == CHUNK_NORMAL && tgt->len <= sz) {
     unlink(ptemp);
@@ -655,9 +663,8 @@
     printf("failed to open patch %s: %s\n", ptemp, strerror(errno));
     return NULL;
   }
-  if (fread(data.get(), 1, sz, f) != sz) {
+  if (fread(data, 1, sz, f) != sz) {
     printf("failed to read patch %s: %s\n", ptemp, strerror(errno));
-    fclose(f);
     return NULL;
   }
   fclose(f);
@@ -675,7 +682,7 @@
       break;
   }
 
-  return data.release();
+  return data;
 }
 
 /*
@@ -798,7 +805,7 @@
   }
 
   size_t bonus_size = 0;
-  std::vector<unsigned char> bonus_data;
+  unsigned char* bonus_data = NULL;
   if (argc >= 3 && strcmp(argv[1], "-b") == 0) {
     struct stat st;
     if (stat(argv[2], &st) != 0) {
@@ -806,15 +813,14 @@
       return 1;
     }
     bonus_size = st.st_size;
-    bonus_data.resize(bonus_size);
+    bonus_data = reinterpret_cast<unsigned char*>(malloc(bonus_size));
     FILE* f = fopen(argv[2], "rb");
     if (f == NULL) {
       printf("failed to open bonus file %s: %s\n", argv[2], strerror(errno));
       return 1;
     }
-    if (fread(bonus_data.data(), 1, bonus_size, f) != bonus_size) {
+    if (fread(bonus_data, 1, bonus_size, f) != bonus_size) {
       printf("failed to read bonus file %s: %s\n", argv[2], strerror(errno));
-      fclose(f);
       return 1;
     }
     fclose(f);
@@ -967,11 +973,11 @@
         patch_data[i] = MakePatch(src_chunks, tgt_chunks+i, patch_size+i);
       }
     } else {
-      if (i == 1 && !bonus_data.empty()) {
+      if (i == 1 && bonus_data) {
         printf("  using %zu bytes of bonus data for chunk %d\n", bonus_size, i);
         src_chunks[i].data = reinterpret_cast<unsigned char*>(realloc(src_chunks[i].data,
             src_chunks[i].len + bonus_size));
-        memcpy(src_chunks[i].data+src_chunks[i].len, bonus_data.data(), bonus_size);
+        memcpy(src_chunks[i].data+src_chunks[i].len, bonus_data, bonus_size);
         src_chunks[i].len += bonus_size;
      }
 
@@ -1057,10 +1063,6 @@
   }
 
   fclose(f);
-  for (i = 0; i < num_tgt_chunks; ++i) {
-    free(patch_data[i]);
-  }
-  free(patch_data);
 
   return 0;
 }