diff --git a/src/hash/crc16.c b/src/hash/crc16.c
new file mode 100644
index 0000000000000000000000000000000000000000..8bfc456baebc897adc54e5e6edc88277e6656a80
--- /dev/null
+++ b/src/hash/crc16.c
@@ -0,0 +1,88 @@
+/* crc16.c */
+
+/* CCITT 16-bit CRC table and calculation function */
+
+/* $Id$ */
+
+/****************************************************************************
+ * @format.tab-size 4 (Plain Text/Source Code File Header) *
+ * @format.use-tabs true (see http://www.synchro.net/ptsc_hdr.html) *
+ * *
+ * Copyright 2003 Rob Swindell - http://www.synchro.net/copyright.html *
+ * *
+ * This program is free software; you can redistribute it and/or *
+ * modify it under the terms of the GNU General Public License *
+ * as published by the Free Software Foundation; either version 2 *
+ * of the License, or (at your option) any later version. *
+ * See the GNU General Public License for more details: gpl.txt or *
+ * http://www.fsf.org/copyleft/gpl.html *
+ * *
+ * Anonymous FTP access to the most recent released source is available at *
+ * ftp://vert.synchro.net, ftp://cvs.synchro.net and ftp://ftp.synchro.net *
+ * *
+ * Anonymous CVS access to the development source and modification history *
+ * is available at cvs.synchro.net:/cvsroot/sbbs, example: *
+ * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs login *
+ * (just hit return, no password is necessary) *
+ * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs checkout src *
+ * *
+ * For Synchronet coding style and modification guidelines, see *
+ * http://www.synchro.net/source.html *
+ * *
+ * You are encouraged to submit any modifications (preferably in Unix diff *
+ * format) via e-mail to mods@synchro.net *
+ * *
+ * Note: If this box doesn't appear square, then you need to fix your tabs. *
+ ****************************************************************************/
+
+#include <string.h> /* strlen */
+#include "crc16.h"
+
+unsigned short crc16tbl[] = {
+0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
+0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
+0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
+0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
+0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
+0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
+0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
+0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
+0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
+0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
+0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
+0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
+0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
+0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
+0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
+0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
+0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
+0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
+0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
+0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
+0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
+0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
+0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
+0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
+0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
+0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
+0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
+0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
+0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
+0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
+};
+
+unsigned short crc16(char* data, unsigned long len)
+{
+ unsigned short crc = 0;
+ unsigned long l;
+
+ if(len==0)
+ len=strlen(data);
+ for(l=0;l<len;l++)
+ crc = ucrc16(data[l],crc);
+
+ return(crc);
+}
+
diff --git a/src/hash/crc16.h b/src/hash/crc16.h
new file mode 100644
index 0000000000000000000000000000000000000000..1cd9ff5db964d606b3f07761b7e175de88879463
--- /dev/null
+++ b/src/hash/crc16.h
@@ -0,0 +1,50 @@
+/* crc16.h */
+
+/* CCITT 16-bit CRC table and calculation macro */
+
+/* $Id$ */
+
+/****************************************************************************
+ * @format.tab-size 4 (Plain Text/Source Code File Header) *
+ * @format.use-tabs true (see http://www.synchro.net/ptsc_hdr.html) *
+ * *
+ * Copyright 2003 Rob Swindell - http://www.synchro.net/copyright.html *
+ * *
+ * This program is free software; you can redistribute it and/or *
+ * modify it under the terms of the GNU General Public License *
+ * as published by the Free Software Foundation; either version 2 *
+ * of the License, or (at your option) any later version. *
+ * See the GNU General Public License for more details: gpl.txt or *
+ * http://www.fsf.org/copyleft/gpl.html *
+ * *
+ * Anonymous FTP access to the most recent released source is available at *
+ * ftp://vert.synchro.net, ftp://cvs.synchro.net and ftp://ftp.synchro.net *
+ * *
+ * Anonymous CVS access to the development source and modification history *
+ * is available at cvs.synchro.net:/cvsroot/sbbs, example: *
+ * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs login *
+ * (just hit return, no password is necessary) *
+ * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs checkout src *
+ * *
+ * For Synchronet coding style and modification guidelines, see *
+ * http://www.synchro.net/source.html *
+ * *
+ * You are encouraged to submit any modifications (preferably in Unix diff *
+ * format) via e-mail to mods@synchro.net *
+ * *
+ * Note: If this box doesn't appear square, then you need to fix your tabs. *
+ ****************************************************************************/
+
+#ifndef _CRC16_H_
+#define _CRC16_H_
+
+extern unsigned short crc16tbl[];
+
+#define ucrc16(ch,crc) (crc16tbl[((crc>>8)&0xff)^(unsigned char)ch]^(crc << 8))
+
+#ifdef __cplusplus
+extern "C"
+#endif
+unsigned short crc16(char *data, unsigned long len);
+
+#endif
diff --git a/src/sbbs3/objects.mk b/src/sbbs3/objects.mk
index 9f24c4cf57c83085bd564496c3d98f049724ed4c..b02858c2bd63448bb41883456f09c3e9933d20a3 100644
--- a/src/sbbs3/objects.mk
+++ b/src/sbbs3/objects.mk
@@ -17,6 +17,7 @@ OBJS = $(LIBODIR)$(SLASH)ansiterm.$(OFILE)\
$(LIBODIR)$(SLASH)chk_ar.$(OFILE)\
$(LIBODIR)$(SLASH)con_hi.$(OFILE)\
$(LIBODIR)$(SLASH)con_out.$(OFILE)\
+ $(LIBODIR)$(SLASH)crc16.$(OFILE)\
$(LIBODIR)$(SLASH)crc32.$(OFILE)\
$(LIBODIR)$(SLASH)dat_rec.$(OFILE)\
$(LIBODIR)$(SLASH)data.$(OFILE)\