Chore: final tests and urandom

Implementierung/Makefile

@@ -9,7 +9,7 @@ ifeq ($(DETAILED_BENCHMARK), true)
 	CFLAGS += -DMD2_DETAILED_BENCHMARK
 endif
 LDFLAGS = -pthread
-TESTFILES = t/1 t/2 t/5 t/10 t/20 t/50 t/100 t/1000 t/2000 t/5000 t/10000
+TESTFILES = t/1 t/2 t/5 t/7 t/10 t/25 t/50 t/75 t/100 t/250 t/500 t/750 t/1000 t/1500 t/2000 t/2500 t/3000 t/3500 t/4000 t/4500 t/5000 t/5500 t/6000 t/6500 t/7000 t/7500 t/8000 t/8500 t/9000 t/9500 t/10000
 TESTFILES_SIZES = ${subst t/,,${TESTFILES}}
 BLUE=\033[1;36m
 RED=\033[1;31m
@@ -44,7 +44,7 @@ t/%:
 	@mkdir -p t
 	@echo
 	@echo -e "${BLUE}=== Generating ${subst t/,,$@}MB of random data... ===${NC}"
-	dd if=/dev/random of=$@ bs=1M count=${subst t/,,$@} status=progress
+	dd if=/dev/urandom of=$@ bs=1M count=${subst t/,,$@} status=progress
 	@echo -e "${BLUE}===                done                     ===${NC}"
 	@echo
 
@@ -56,7 +56,7 @@ benchmarks.csv: md2 ${TESTFILES}
 	done
 	@echo "" >> $@
 
-	@for i in 0 1 2 3 4; do \
+	@for i in 4; do \
 		echo ;\
 		echo -e "${BLUE}=== Testing implementation $$i ===${NC}";\
 		echo -n "Implementierung-$$i" >> $@; \

Implementierung/benchmarks.csv

@@ -1,6 +1,2 @@
-Implementierung;1;2;5;10;20;50;100
-Implementierung-0;0.092604;0.172133;0.422083;0.845732;1.687540;4.232703;8.501036
-Implementierung-1;0.084314;0.167799;0.431772;0.843568;1.708024;5.208127;10.147011
-Implementierung-2;0.097700;0.203661;0.567091;1.062895;2.141933;5.440520;10.342529
-Implementierung-3;0.099547;0.206932;0.546978;1.017148;2.077730;5.067994;9.962873
-Implementierung-4;0.117680;0.239349;0.616783;1.200482;2.356915;5.856234;11.647842
+Implementierung;1;2;5;7;10;25;50;75;100;250;500;750;1000;1500;2000;2500;3000;3500;4000;4500;5000;5500
+Implementierung-4;0.179950;0.308132;0.768091;1.077839;1.793499;3.786488;7.788925;11.049307;15.051300;37.564573;74.324851;112.160912;150.740498;225.111342;305.938520;381.063308;463.611798;533.670234;614.535749;63.418839;137.076754;292.555679

Implementierung/lib/md2.h

@@ -10,7 +10,6 @@
 
 typedef void (*md2_hash_func)(size_t len, const uint8_t buf[len],
                               uint8_t out[16]);
-typedef void (*md2_checksum_func)(size_t len, uint8_t* buf);
 
 /**
  * @brief Calculates checksum of buf and stores it in out
@@ -21,15 +20,6 @@ typedef void (*md2_checksum_func)(size_t len, uint8_t* buf);
  */
 extern md2_hash_func md2_hash;
 
-/**
- * @brief Calculates checksum of buf and appends it to buf
- *
- * @param len Length of data which the checksum should be calculated of
- * @param buf Location of the data. Make sure to reserve 16 bytes more so the
- * chechsum fits!
- */
-extern md2_checksum_func md2_checksum;
-
 /**
  * @brief Choose the implementation to use
  *

Implementierung/lib/md2_impls/md2_0.h

@@ -9,6 +9,5 @@
 #include <sys/types.h>
 
 void md2_hash_0(size_t len, const uint8_t buf[len], uint8_t out[16]);
-void md2_checksum_0(size_t len, uint8_t* buf);
 
 #endif  // MD2_0_H

Implementierung/lib/md2_impls/md2_1.h

@@ -9,6 +9,5 @@
 #include <sys/types.h>
 
 void md2_hash_1(size_t len, const uint8_t buf[len], uint8_t out[16]);
-void md2_checksum_1(size_t len, uint8_t* buf);
 
 #endif  // MD2_1_H

Implementierung/lib/md2_impls/md2_common.h

@@ -59,8 +59,73 @@ extern unsigned char MD2_PI_SUBST[256];
  */
 void md2_print_buf(size_t len, uint8_t buf[len]);
 
+/**
+ * @brief Calculates checksum of buf and appends it to buf
+ *
+ * @param len Length of data which the checksum should be calculated of
+ * @param buf Location of the data. Make sure to reserve 16 bytes more so the
+ * chechsum fits!
+ */
+void md2_checksum(size_t len, uint8_t* buf);
+
+/**
+ * @brief Calculates checksum of buf and writes it into a target
+ *
+ * @param len Length of data which the checksum should be calculated of
+ * @param buf Location of the data. Make sure to reserve 16 bytes more so the
+ * chechsum fits!
+ * @param checksum the output checksum
+ */
+void md2_checksum_with_target(size_t len, const uint8_t* buf,
+                              uint8_t checksum[16]);
+
+/**
+ * @brief Process one block of the checksum
+ *
+ * @param block the block to process
+ * @param checksum the output checksum
+ * @param l the current l
+ */
+void md2_process_block_checksum(uint8_t const block[16], uint8_t checksum[16],
+                                uint8_t* l);
+
+/**
+ * @brief Stores the time if start of a step, calculates the duration if end
+ *
+ * @param step the step to process
+ */
 void md2_process_detailed_benchmark_step(enum md2_detailed_benchmark_step step);
 
+/**
+ * @brief Print the detailed benchmark result
+ *
+ */
 void md2_print_detailed_benchmark_result();
 
+/**
+ * @brief Add padding and allocate extra space for the checksum
+ *
+ * @param buf buffer of the whole message
+ * @param len length of buf
+ * @return uint8_t* pointer to the new buffer
+ */
+uint8_t* md2_add_padding_and_space_for_checksum(const uint8_t* buf,
+                                                size_t* len);
+
+/**
+ * @brief The second loop of the md2 algorithm
+ *
+ * @param messageDigestBuf the message digest buffer
+ */
+void md2_second_loop(uint8_t* messageDigestBuf);
+
+/**
+ * @brief The first loop of the md2 algorithm
+ *
+ * @param buf buffer of the whole message
+ * @param messageDigestBuf the message digest buffer
+ * @param i the index of the 16-byte message block
+ */
+void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, int i);
+
 #endif  // MD2_COMMON_H

Implementierung/lib/md2_impls/md2_reference/md2_reference.h

@@ -8,6 +8,15 @@
  * Quelle: https://datatracker.ietf.org/doc/html/rfc1319
  **********************************************************/
 
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "../md2_common.h"
+
 #ifndef PROTOTYPES
 #define PROTOTYPES 0
 #endif
@@ -34,21 +43,14 @@ typedef unsigned long int UINT4;
 typedef struct {
   unsigned char state[16];    /* state */
   unsigned char checksum[16]; /* checksum */
-  unsigned int count;         /* number of bytes, modulo 16 */
+  size_t count;               /* number of bytes, modulo 16 */
   unsigned char buffer[16];   /* input buffer */
 } MD2_CTX;
 
 void MD2Init PROTO_LIST((MD2_CTX *));
-void MD2Update PROTO_LIST((MD2_CTX *, unsigned char *, unsigned int));
+void MD2Update PROTO_LIST((MD2_CTX *, unsigned char *, size_t));
 void MD2Final PROTO_LIST((unsigned char[16], MD2_CTX *));
 
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
-
 void md2_hash_ref(size_t len, const uint8_t buf[len], uint8_t out[16]);
 
-#endif  // MD2_REF_H
+#endif  // MD2_REF_H

Implementierung/src/md2.c

@@ -8,11 +8,13 @@
 #include "../lib/md2_impls/md2_reference/md2_reference.h"
 
 md2_hash_func md2_hash;
-md2_checksum_func md2_checksum;
 
 // The file "testfile" should lead to this hash:
 // fc982e558db259f298b43cd4c1241c66
 
+static md2_hash_func md2_implementations[] = {
+    md2_hash_0, md2_hash_1, md2_hash_2, md2_hash_3, md2_hash_ref};
+
 void md2_encode_hash(uint8_t hash[16], char* string_hash) {
   for (int i = 0; i < 16; i++) {
     sprintf(string_hash + (2 * i), "%02x", hash[i]);
@@ -20,33 +22,7 @@ void md2_encode_hash(uint8_t hash[16], char* string_hash) {
 }
 
 bool md2_choose_implementation(int i) {
-  switch (i) {
-    case 0:
-      md2_hash = md2_hash_0;
-      md2_checksum = md2_checksum_0;
-      return true;
-
-    case 1:
-      md2_hash = md2_hash_1;
-      md2_checksum = md2_checksum_1;
-      return true;
-
-    case 2:
-      md2_hash = md2_hash_2;
-      md2_checksum = NULL;
-      return true;
-
-    case 3:
-      md2_hash = md2_hash_3;
-      md2_checksum = NULL;
-      return true;
-
-    case 4:
-      md2_hash = md2_hash_ref;
-      md2_checksum = NULL;
-      return true;
-
-    default:
-      return false;
-  }
+  if (i < 0 || i > 4) return false;
+  md2_hash = md2_implementations[i];
+  return true;
 }

Implementierung/src/md2_impls/md2_0.c

@@ -2,50 +2,15 @@
 
 #include "../../lib/md2_impls/md2_common.h"
 
-void md2_checksum_0(size_t len, uint8_t* buf) {
-  uint8_t l = 0;
-
-  for (size_t i = 0; i < len / 16; i++) {
-    for (int j = 0; j < 16; j++) {
-      u_int8_t c = buf[i * 16 + j];
-      // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
-      buf[len + j] ^= MD2_PI_SUBST[c ^ l];
-      l = buf[len + j];
-    }
-  }
-}
-
 void md2_hash_0(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   // === step 1 ===
-  int paddingNeeded = 16 - (len % 16);
-  uint8_t originalPadding = paddingNeeded;
-  len += paddingNeeded;
-
-  // printf("len: %d\n", len);
-
-  // +16 for the checksum
-  uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t));
+  uint8_t* newBuf = md2_add_padding_and_space_for_checksum(buf, &len);
   if (newBuf == NULL) {
     return;
   }
-  memcpy(newBuf, buf, len - paddingNeeded);
-
-  // printBuf(len + 16, newBuf);
-
-  while (paddingNeeded > 0) {
-    newBuf[len - paddingNeeded] = originalPadding;
-    paddingNeeded--;
-  }
-  // printf("buf with padding: ");
-  // printBuf(len + 16, newBuf);
 
   // === step 2 ===
-  CHECKSUM_START_MARK
-  md2_checksum_0(len, newBuf);
-  CHECKSUM_END_MARK
-
-  // printf("buf with cecksum: ");
-  // printBuf(len + 16, newBuf);
+  md2_checksum(len, newBuf);
 
   // === step 3 ===
   uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
@@ -54,29 +19,11 @@ void md2_hash_0(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   }
 
   // === step 4 ===
-  // <= because we need to hash the last block too
-  for (size_t i = 0; i <= (len + 16) / 16 - 1; i++) {
-    FIRST_LOOP_START_MARK
-    for (int j = 0; j < 16; j++) {
-      messageDigestBuf[16 + j] = newBuf[i * 16 + j];
-      messageDigestBuf[32 + j] =
-          (messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
-    }
-    FIRST_LOOP_END_MARK
-
-    u_int8_t t = 0;
-
-    SECOND_LOOP_START_MARK
-    for (int j = 0; j < 18; j++) {
-      for (int k = 0; k < 48; k++) {
-        t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
-      }
-      t = (t + j) % 256;
-    }
-    SECOND_LOOP_END_MARK
+  // <= because we need to hash the last block (the checksum) too
+  for (size_t i = 0; i <= (len) / 16; i++) {
+    md2_first_loop(newBuf, messageDigestBuf, i);
+    md2_second_loop(messageDigestBuf);
   }
-  // printf("messageDigestBuf: \n");
-  // printBuf(16, messageDigestBuf);
 
   END_MARK
   memcpy(out, messageDigestBuf, 16);

Implementierung/src/md2_impls/md2_1.c

@@ -4,19 +4,6 @@
 
 #include "../../lib/md2_impls/md2_common.h"
 
-void md2_checksum_1(size_t len, uint8_t *buf) {
-  uint8_t l = 0;
-
-  for (size_t i = 0; i < len / 16; i++) {
-    for (int j = 0; j < 16; j++) {
-      u_int8_t c = buf[i * 16 + j];
-      // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
-      buf[len + j] ^= MD2_PI_SUBST[c ^ l];
-      l = buf[len + j];
-    }
-  }
-}
-
 static uint8_t PADDING[17][16] = {
     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
     {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
@@ -55,9 +42,7 @@ void md2_hash_1(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   memcpy(newBuf + len - paddingNeeded, PADDING + paddingNeeded, paddingNeeded);
 
   // === step 2 ===
-  CHECKSUM_START_MARK
-  md2_checksum_1(len, newBuf);
-  CHECKSUM_END_MARK
+  md2_checksum(len, newBuf);
 
   // === step 3 ===
   uint8_t *messageDigestBuf = aligned_alloc(16, sizeof(uint8_t) * 48);
@@ -81,16 +66,7 @@ void md2_hash_1(size_t len, const uint8_t buf[len], uint8_t out[16]) {
     _mm_store_si128((__m128i *)(messageDigestBuf + 32), vy);
     FIRST_LOOP_END_MARK
 
-    u_int8_t t = 0;
-
-    SECOND_LOOP_START_MARK
-    for (int j = 0; j < 18; j++) {
-      for (int k = 0; k < 48; k++) {
-        t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
-      }
-      t = (t + j) & 255;
-    }
-    SECOND_LOOP_END_MARK
+    md2_second_loop(messageDigestBuf);
   }
 
   END_MARK

Implementierung/src/md2_impls/md2_2.c

@@ -3,32 +3,8 @@
 #include "../../lib/md2_impls/md2_common.h"
 
 void process_block_hash(uint8_t block[16], uint8_t messageDigestBuf[48]) {
-  FIRST_LOOP_START_MARK
-  for (int j = 0; j < 16; j++) {
-    messageDigestBuf[16 + j] = block[j];
-    messageDigestBuf[32 + j] = (messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
-  }
-  FIRST_LOOP_END_MARK
-
-  u_int8_t t = 0;
-
-  SECOND_LOOP_START_MARK
-  for (int j = 0; j < 18; j++) {
-    for (int k = 0; k < 48; k++) {
-      t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
-    }
-    t = (t + j) % 256;
-  }
-  SECOND_LOOP_END_MARK
-}
-
-void process_block_checksum(uint8_t block[16], uint8_t checksum[16],
-                            uint8_t* l) {
-  for (int j = 0; j < 16; j++) {
-    u_int8_t c = block[j];
-    // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
-    (*l) = checksum[j] ^= MD2_PI_SUBST[c ^ (*l)];
-  }
+  md2_first_loop(block, messageDigestBuf, 0);
+  md2_second_loop(messageDigestBuf);
 }
 
 void apply_padding(size_t len, uint8_t buf[16]) {
@@ -79,7 +55,7 @@ void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]) {
     }
 
     CHECKSUM_START_MARK
-    process_block_checksum(data, checksum, &l);
+    md2_process_block_checksum(data, checksum, &l);
     CHECKSUM_END_MARK
     process_block_hash(data, messageDigestBuf);
 
@@ -87,7 +63,7 @@ void md2_hash_2(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   };
 
   apply_padding(bytes_left_to_process % 16, data);
-  process_block_checksum(data, checksum, &l);
+  md2_process_block_checksum(data, checksum, &l);
   process_block_hash(data, messageDigestBuf);
 
   process_block_hash(checksum, messageDigestBuf);

Implementierung/src/md2_impls/md2_3.c

@@ -10,24 +10,8 @@ struct thread_args {
 void process_nothread_hash(size_t len, const uint8_t buf[len],
                            uint8_t messageDigestBuf[48]) {
   for (size_t i = 0; i < (len + 16) / 16 - 1; i++) {
-    FIRST_LOOP_START_MARK
-    for (int j = 0; j < 16; j++) {
-      messageDigestBuf[16 + j] = buf[i * 16 + j];
-      messageDigestBuf[32 + j] =
-          (messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
-    }
-    FIRST_LOOP_END_MARK
-
-    u_int8_t t = 0;
-
-    SECOND_LOOP_START_MARK
-    for (int j = 0; j < 18; j++) {
-      for (int k = 0; k < 48; k++) {
-        t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
-      }
-      t = (t + j) % 256;
-    }
-    SECOND_LOOP_END_MARK
+    md2_first_loop(buf, messageDigestBuf, i);
+    md2_second_loop(messageDigestBuf);
   }
 }
 
@@ -51,36 +35,16 @@ void* process_checksum(void* threasdArgs) {
     return NULL;
   }
 
-  uint8_t l = 0;
-  CHECKSUM_START_MARK
-  for (size_t i = 0; i < args->len / 16; i++) {
-    for (int j = 0; j < 16; j++) {
-      u_int8_t c = args->buf[i * 16 + j];
-      // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
-      l = checksum[j] ^= MD2_PI_SUBST[c ^ l];
-    }
-  }
-  CHECKSUM_END_MARK
+  md2_checksum_with_target(args->len, args->buf, checksum);
   pthread_exit(checksum);
 }
 
 void md2_hash_3(size_t len, const uint8_t buf[len], uint8_t out[16]) {
-  int paddingNeeded = 16 - (len % 16);
-  uint8_t originalPadding = paddingNeeded;
-  len += paddingNeeded;
-
-  uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t));
+  uint8_t* newBuf = md2_add_padding_and_space_for_checksum(buf, &len);
   if (newBuf == NULL) {
     return;
   }
 
-  memcpy(newBuf, buf, len - paddingNeeded);
-
-  while (paddingNeeded > 0) {
-    newBuf[len - paddingNeeded] = originalPadding;
-    paddingNeeded--;
-  }
-
   pthread_t thread_1, thread_2;
 
   struct thread_args thread_args = {len, newBuf};

Implementierung/src/md2_impls/md2_common.c

@@ -57,4 +57,71 @@ void md2_print_detailed_benchmark_result() {
   printf("  First loop: %f\n", detailed_benchmark_times[1]);
   printf("  Second loop: %f\n", detailed_benchmark_times[2]);
   printf("\n");
+}
+
+uint8_t* md2_add_padding_and_space_for_checksum(const uint8_t* buf,
+                                                size_t* len) {
+  int paddingNeeded = 16 - ((*len) % 16);
+  uint8_t originalPadding = paddingNeeded;
+  (*len) += paddingNeeded;
+
+  // +16 for the checksum
+  uint8_t* newBuf = calloc((*len) + 16, sizeof(uint8_t));
+  if (newBuf == NULL) {
+    return NULL;
+  }
+  memcpy(newBuf, buf, (*len) - paddingNeeded);
+
+  while (paddingNeeded > 0) {
+    newBuf[(*len) - paddingNeeded] = originalPadding;
+    paddingNeeded--;
+  }
+
+  return newBuf;
+}
+
+void md2_process_block_checksum(uint8_t const block[16], uint8_t checksum[16],
+                                uint8_t* l) {
+  for (int j = 0; j < 16; j++) {
+    u_int8_t c = block[j];
+    // reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
+    (*l) = checksum[j] ^= MD2_PI_SUBST[c ^ (*l)];
+  }
+}
+
+void md2_checksum(size_t len, uint8_t* buf) {
+  md2_checksum_with_target(len, buf, buf + len);
+}
+
+void md2_checksum_with_target(size_t len, const uint8_t* buf,
+                              uint8_t checksum[16]) {
+  CHECKSUM_START_MARK
+  uint8_t l = 0;
+
+  for (size_t i = 0; i < len / 16; i++) {
+    md2_process_block_checksum(buf + i * 16, checksum, &l);
+  }
+  CHECKSUM_END_MARK
+}
+
+void md2_second_loop(uint8_t* messageDigestBuf) {
+  u_int8_t t = 0;
+
+  SECOND_LOOP_START_MARK
+  for (int j = 0; j < 18; j++) {
+    for (int k = 0; k < 48; k++) {
+      t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
+    }
+    t = (t + j) & 255;
+  }
+  SECOND_LOOP_END_MARK
+}
+
+void md2_first_loop(const uint8_t* buf, uint8_t* messageDigestBuf, int i) {
+  FIRST_LOOP_START_MARK
+  for (int j = 0; j < 16; j++) {
+    messageDigestBuf[16 + j] = buf[i * 16 + j];
+    messageDigestBuf[32 + j] = (messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
+  }
+  FIRST_LOOP_END_MARK
 }

Implementierung/src/md2_impls/md2_reference/md2_reference.c

@@ -30,8 +30,8 @@
 
 static void MD2Transform PROTO_LIST((unsigned char[16], unsigned char[16],
                                      unsigned char[16]));
-static void MD2_memcpy PROTO_LIST((POINTER, POINTER, unsigned int));
-static void MD2_memset PROTO_LIST((POINTER, int, unsigned int));
+static void MD2_memcpy PROTO_LIST((POINTER, POINTER, size_t));
+static void MD2_memset PROTO_LIST((POINTER, int, size_t));
 
 /* Permutation of 0..255 constructed from the digits of pi. It gives a
    "random" nonlinear byte substitution operation.
@@ -83,6 +83,7 @@ void md2_hash_ref(size_t len, const uint8_t buf[len], uint8_t out[16]) {
   MD2Init(&context);
   MD2Update(&context, buf, len);
   MD2Final(out, &context);
+  END_MARK
 }
 
 /* MD2 initialization. Begins an MD2 operation, writing a new context.
@@ -100,9 +101,9 @@ void MD2Init(context) MD2_CTX *context; /* context */
  */
 void MD2Update(context, input, inputLen) MD2_CTX *context; /* context */
 unsigned char *input;                                      /* input block */
-unsigned int inputLen; /* length of input block */
+size_t inputLen; /* length of input block */
 {
-  unsigned int i, index, partLen;
+  size_t i, index, partLen;
 
   /* Update number of bytes mod 16 */
   index = context->count;
@@ -136,7 +137,7 @@ void MD2Final(digest, context)
     unsigned char digest[16]; /* message digest */
 MD2_CTX *context;             /* context */
 {
-  unsigned int index, padLen;
+  size_t index, padLen;
 
   /* Pad out to multiple of 16.
    */
@@ -162,30 +163,36 @@ static void MD2Transform(state, checksum, block) unsigned char state[16];
 unsigned char checksum[16];
 unsigned char block[16];
 {
-  unsigned int i, j, t;
+  size_t i, j, t;
   unsigned char x[48];
 
   /* Form encryption block from state, block, state ^ block.
    */
   MD2_memcpy((POINTER)x, (POINTER)state, 16);
   MD2_memcpy((POINTER)x + 16, (POINTER)block, 16);
+  FIRST_LOOP_START_MARK
   for (i = 0; i < 16; i++) x[i + 32] = state[i] ^ block[i];
+  FIRST_LOOP_END_MARK
 
   /* Encrypt block (18 rounds).
    */
   t = 0;
+  SECOND_LOOP_START_MARK
   for (i = 0; i < 18; i++) {
     for (j = 0; j < 48; j++) t = x[j] ^= PI_SUBST[t];
     t = (t + i) & 0xff;
   }
+  SECOND_LOOP_END_MARK
 
   /* Save new state */
   MD2_memcpy((POINTER)state, (POINTER)x, 16);
 
   /* Update checksum.
    */
+  CHECKSUM_START_MARK
   t = checksum[15];
   for (i = 0; i < 16; i++) t = checksum[i] ^= PI_SUBST[block[i] ^ t];
+  CHECKSUM_END_MARK
 
   /* Zeroize sensitive information.
    */
@@ -196,9 +203,9 @@ unsigned char block[16];
  */
 static void MD2_memcpy(output, input, len) POINTER output;
 POINTER input;
-unsigned int len;
+size_t len;
 {
-  unsigned int i;
+  size_t i;
 
   for (i = 0; i < len; i++) output[i] = input[i];
 }
@@ -207,9 +214,9 @@ unsigned int len;
  */
 static void MD2_memset(output, value, len) POINTER output;
 int value;
-unsigned int len;
+size_t len;
 {
-  unsigned int i;
+  size_t i;
 
   for (i = 0; i < len; i++) ((char *)output)[i] = (char)value;
 }