diff -ur --new-file popa3d-0.4.orig/Makefile popa3d-0.4/Makefile
--- popa3d-0.4.orig/Makefile	Tue Aug 29 03:59:09 2000
+++ popa3d-0.4/Makefile	Tue Aug 29 03:58:00 2000
@@ -1,10 +1,35 @@
 CC = gcc
 LD = gcc
 RM = rm -f
-CFLAGS = -c -Wall -O2 -fomit-frame-pointer
+
+CFLAGS = $(FLAGDB) $(FLAGCR) -c -Wall -O2 -pedantic -fomit-frame-pointer
 LDFLAGS = -s
 #LDFLAGS = -s -lcrypt
 
+#Uncomment to use db1
+#Needed under my linux
+#LIBDB = -ldb1
+#Nothing needed under my freebsd
+
+#_or_ uncomment to use gdbm
+#FLAGDB = -DGDBM
+#Needed under my linux
+#LIBDB = -lgdbm
+#Needed under my freebsd
+#LIBDB = -L/usr/local/lib -lgdbm
+
+#Uncomment to use OpenSSL
+#Needed under my linux
+#FLAGCR = -DUSEOPENSSL -I/usr/local/ssl/include
+#LIBCR = -L/usr/local/ssl/lib -lcrypto
+#Needed under my freebsd
+#FLAGCR = -DUSEOPENSSL -I/usr/local/include
+#LIBCR = -L/usr/local/lib -lcrypto
+
+#_or_ uncomment to use system md5
+#Needed under my freebsd
+LIBCR = -lmd
+
 PROJ = popa3d
 OBJS = md5/md5.o \
 	standalone.o \
@@ -12,13 +37,16 @@
 	protocol.o database.o mailbox.o \
 	misc.o
 
-all: popauth popa3d
+all: popauth popa3d apop
+
+apop: apop.o
+	$(LD) $(LDFLAGS) -o $@ apop.o $(LIBCR)
 
 popauth: popauth.o
-	$(LD) $(LDFLAGS) -o $@ popauth.o
+	$(LD) $(LDFLAGS) -o $@ popauth.o $(LIBDB)
 
 popa3d: $(OBJS)
-	$(LD) $(LDFLAGS) $(OBJS) -o popa3d
+	$(LD) $(LDFLAGS) $(OBJS) -o popa3d $(LIBDB) $(LIBCR)
 
 md5/md5.o: md5/md5.c md5/md5.h
 	$(CC) $(CFLAGS) -D_LIBC md5/md5.c -o md5/md5.o
@@ -27,4 +55,4 @@
 	$(CC) $(CFLAGS) $*.c
 
 clean:
-	$(RM) $(PROJ) $(OBJS) *.o popauth *~
+	$(RM) $(PROJ) $(OBJS) *.o popauth apop *~
diff -ur --new-file popa3d-0.4.orig/apop.c popa3d-0.4/apop.c
--- popa3d-0.4.orig/apop.c	Thu Jan  1 01:00:00 1970
+++ popa3d-0.4/apop.c	Tue Aug 29 04:02:08 2000
@@ -0,0 +1,39 @@
+#include <stdio.h>
+#ifdef USEOPENSSL
+#include <openssl/md5.h>
+#else
+#include <sys/types.h>
+#include <md5.h>
+#endif
+
+int main (int argc, char *argv[])
+{
+  int i;
+  MD5_CTX ctx;
+  unsigned char hash[16];
+  static char hache[33];
+
+  if(argc != 3) {
+    fprintf(stderr, "%s <challenge> clear_text_password\n", argv[0]);
+    return -1;
+  }
+
+#ifdef USEOPENSSL
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, argv[1], strlen(argv[1]));
+	MD5_Update(&ctx, argv[2], strlen(argv[2]));
+	MD5_Final(hash, &ctx);
+	for (i = 0;  i < 16;  i++) 
+	  sprintf(hache+2*i, "%02x", hash[i]);
+	hache[32]=0;
+	printf("%s\n",hache);
+#else
+	MD5Init(&ctx);
+	MD5Update(&ctx, argv[1], strlen(argv[1]));
+	MD5Update(&ctx, argv[2], strlen(argv[2]));
+	MD5End(&ctx, hash);
+	printf("%s\n",hash);
+#endif
+
+  return 0;
+}
diff -ur --new-file popa3d-0.4.orig/pop_auth.c popa3d-0.4/pop_auth.c
--- popa3d-0.4.orig/pop_auth.c	Tue Aug 29 03:59:09 2000
+++ popa3d-0.4/pop_auth.c	Tue Aug 29 03:25:19 2000
@@ -6,6 +6,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <syslog.h>
+#include <time.h>
 
 #include "misc.h"
 #include "params.h"
diff -ur --new-file popa3d-0.4.orig/pop_root.c popa3d-0.4/pop_root.c
--- popa3d-0.4.orig/pop_root.c	Tue Aug 29 03:59:09 2000
+++ popa3d-0.4/pop_root.c	Tue Aug 29 03:25:19 2000
@@ -23,9 +23,15 @@
 
 #if AUTH_APOP
 #include <fcntl.h>
+#ifdef USEOPENSSL
+#include <openssl/md5.h>
+#else
 #include <md5.h>
+#endif
 #if GDBM
 # include <gdbm.h>
+#elif __linux__
+#include <db1/ndbm.h>
 #else
 # include <ndbm.h>
 #endif
@@ -38,7 +44,7 @@
 
 /* *DBM compatibility nonsense. */
 #if GDBM
-#define DBM			GDBM_FILE
+#define DB			GDBM_FILE
 #define F_RDONLY		GDBM_READER
 #define dbm_open(x, y, z)	gdbm_open(x, 512, y, z, 0)
 #define dbm_fetch		gdbm_fetch
@@ -102,7 +108,8 @@
 	DB *db;
 	datum key, value;
 	MD5_CTX ctx;
-	char hash[33];
+	unsigned char hash[33];
+	char hache[33];
 	int i;
 	
 	pw = getpwnam(user);
@@ -126,13 +133,39 @@
 	for (i = 0; i < value.dsize - 1; i++)
 		value.dptr[i] ^= 0xff;
 
+#ifdef USEOPENSSL
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, challenge, strlen(challenge));
+	MD5_Update(&ctx, value.dptr, strlen(value.dptr));
+	MD5_Final(hash, &ctx);
+	for (i = 0;  i < 16;  i++) 
+	  sprintf(hache+2*i, "%02x", hash[i]);
+	hache[32]=0;
+#else
 	MD5Init(&ctx);
 	MD5Update(&ctx, challenge, strlen(challenge));
 	MD5Update(&ctx, value.dptr, strlen(value.dptr));
 	MD5End(&ctx, hash);
+#endif
 	dbm_close(db);
-	
+
+/*
+syslog(LOG_AUTH, " challenge: %s", challenge);
+syslog(LOG_AUTH, "value.dptr: %s", value.dptr);
+*//* Please use this for debuging purposes only *//*
+syslog(LOG_AUTH, "      pass: %s", pass);
+#ifdef USEOPENSSL
+syslog(LOG_AUTH, "     hache: %s", hache);
+#else
+syslog(LOG_AUTH, "      hash: %s", hash);
+#endif
+*/
+
+#ifdef USEOPENSSL
+	if (strcmp(pass, hache)) pw = NULL;
+#else
 	if (strcmp(pass, hash)) pw = NULL;
+#endif
 	
 	return (pw);
 }
diff -ur --new-file popa3d-0.4.orig/popauth.c popa3d-0.4/popauth.c
--- popa3d-0.4.orig/popauth.c	Tue Aug 29 03:59:09 2000
+++ popa3d-0.4/popauth.c	Tue Aug 29 03:25:19 2000
@@ -41,6 +41,8 @@
 #include <grp.h>
 #if GDBM
 # include <gdbm.h>
+#elif __linux__
+#include <db1/ndbm.h>
 #else
 # include <ndbm.h>
 #endif
@@ -49,7 +51,7 @@
 
 /* *DBM compatibility nonsense. */
 #if GDBM
-#define DBM			GDBM_FILE
+#define DB			GDBM_FILE
 #define F_WRCREAT		GDBM_WRCREAT
 #define F_RDONLY		GDBM_READER
 #define F_RDWR			GDBM_WRITER
@@ -59,6 +61,8 @@
 #define dbm_fetch		gdbm_fetch
 #define dbm_delete		gdbm_delete
 #define dbm_close		gdbm_close
+#define dbm_nextkey		gdbm_nextkey
+#define DBM_REPLACE		GDBM_REPLACE
 #else
 #define F_WRCREAT		O_RDWR|O_CREAT
 #define F_RDONLY		O_RDONLY
@@ -201,7 +205,11 @@
 	}
 	else {
 		for (key = dbm_firstkey(db); key.dptr != NULL;
+#ifdef GDBM
+		     key = dbm_nextkey(db, key)) {
+#else
 		     key = dbm_nextkey(db)) {
+#endif
 			value = dbm_fetch(db, key);
 
 			if (value.dptr != NULL)