CSC User`s Manual - MarshallSoft Computing
Contents
1. 19 4 Challenges and Response Authentication The challenge response authentication protocol is designed to prevent unauthorized clients from connecting to your server Passwords are often used for this purpose but can be stolen en route if transmitted without being encrypted With the challenge and response protocol the server presents a question challenge and the client must provide a valid answer response to be authenticated The program logic for the challenge response protocol is as follows SERVER Server accepts connection from client Server generates an 8 byte challenge string by calling cscChallenge Server sends challenge string to client Server calculates the correct response by calling cscResponse Server waits for a response from the client then reads the response Server drops client if response string is not equal to the computed response string G Lh LM LA Re CLIENT 1 Client connects to the server 2 Client reads the challenge string from the server 3 Client calculates the correct response by calling cscResponse 4 Client sends response string to server The correct response is computed from the following 3 parameters by cscResponse 1 Multiplier any 32 bit number 2 Mask any 32 bit number 3 Rotate count from 0 to 31 The same 3 values above must be used by both the client and the server The challenge string is the 8 byte hexadecimal representation of a random 32 bit2. TCP IP network programs can be classified into two types servers and clients 3 1 Servers The server program must always be running before a client can attempt to connect to it The server can be programmed to accept one or more connections concurrently 3 1 1 Server Program Logic The basic program logic for a server is as follows 1 cscAttach attach CSC32 DLL or CSC64 DLL 2 cscServer start server 3 cscAwaitConnect wait for connection attempt from client 4 cscAcceptConnect accept connection from client 5 L cscPutData send greeting message to client OOP 6 cscGetData read command request from client 7 cscPutData send response to command request GO TO LOOP until done cscClose close connection to client 9 cscRelease release CSC32 DLL or CSC64 DLL Note that the above logic accepts just one connection although servers can be written with CSC that can handle multiple connections The cscSendMessage function can also be used to send a Windows message when a connection is ready to be accepted by the server or when data is ready to be read Obviously cseSendMessage can be used only in programs written using a Windows message loop Refer also to the server example programs 3 1 2 Example Server Programs Each CSC product CSC4C CSC4VB CSC4D and CSC4FP contains several server and client programs See the SERVER example program SERVER C SERVER BAS or SRV_PRJ DPR which accepts connecti
3. C programs 2 3 GUI and Console Mode CSC functions can be called from WIN32 WIN64 console mode programs as well as GUI programs A console mode program is a Windows 95 98 Me NT 2000 2003 2012 XP VISTA WIN7 WIN8 Win32 Win64 command line program running in a command window 2 4 Getting Started Using CSC The first Client Server Communications function that should be called is cscAttach which initializes the CSC library and allocates necessary resources The function escAttach is typically called in the initialization section of a CSC application and should be called just once The function cscRelease should be called before exiting the CSC application The best way to get familiar with CSC is to try out one of the example programs The example programs are described in the CSC4C C C the CSC4VB Visual Basic the CSC4FP Visual FoxPro and the CSC4D Delphi Programmer s Manual e csc_4c CSC Programmer s Manual for C C e CSC_4VB CSC Programmer s Manual for Visual Basic e CBC 4D CSC Programmers Manual for Delphi N CSC_4FP CSC Programmer s Manual for Visual FoxPro e CSC_4XB CSC Programmer s Manual for Xbase e CSC_4DB CSC Programmer s Manual for Visual dBASE After installing CSC compile and run the CSCVER example program which should display the CSC version number and registration string Once CSCVER runs compile and run the SERVER and CLIENT example programs which communicate with each other 10 2 5 Development
4. are as follows NAME DESCRIPTION CSC 4C CSC Programmer s Manual for C C CSC 4VB CSC Programmer s Manual for Visual Basic CSC 4D CSC Programmer s Manual for Delphi CSC 4FP CSC Programmer s Manual for Visual FoxPro CSC 4DB CSC Programmer s Manual for Visual dBase CSC 4XB CSC Programmer s Manual for XBase The CSC User s Manual CSC_USR PDF discusses client server programming issues License and purchase information is also provided Read this manual after reading the CSC Programmer s Manual The CSC Reference Manual CSC_REF PDF contains details on each individual CSC function All documentation can also be accessed online at http www marshallsoft com client server communication htm 1 3 Technical Support We want you to be successful in developing applications using the Client Server Communications Library We are committed to providing the best most robust library that we can If you have any suggestions or comments please let us know If you are having a problem using CSC refer to Section 5 0 Resolving Problems If you still cannot resolve your problem email us at support at marshallsoft com To avoid having your email deleted by our Spam scanners begin the subject of your email with CSC4C CSC4VB CSC4D or MSC HELP Zip up any attachments and send plain ASCII text email only Contact us by phone at 1 256 881 4630 between 7 00 AM 7 00 PM CST Monday Thursda
5. installing and using the SOFTWARE you agree to be bound by the terms of this LICENSE If you do not agree to the terms of this LICENSE do not install or use the SOFTWARE MarshallSoft Computing Inc grants a nonexclusive license to use the SOFTWARE to the original purchaser for the purposes of designing testing or developing software applications Copies may be made for back up or archival purposes only This product is licensed for use by only one developer at a time All developers working on a project that includes a MarshallSoft Software SDK even though not working directly with the MarshallSoft SDK are required to purchase a license for that MarshallSoft product The academic registered DLL s may not be distributed under any circumstances nor may they be used for any commercial purpose The professional registered DLL s may be distributed without royalty in object form only as part of the user s compiled application provided the value of the Key Code License Key is not revealed The registered DLL s may NOT be distributed as part of any software development system compiler or interpreter without our express written permission The source code CSC32 C for the library is copyrighted by MarshallSoft Computing and may not be released or modified in whole or in part 7 2 Warranty MARSHALLSOFT COMPUTING INC DISCLAIMS ALL WARRANTIES RELATING TO THIS SOFTWARE WHETHER EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIE
6. is to change the pad buffer after each use One practical method for doing this is to create a random pad buffer also known as the session key The session key is then encrypted with strong encryption such as the Advanced Encryption Standard before transmitting to the other side that recovers the session by decrypting it In this way the encryption key is different for each connection session Using session keys the CSC logic would be CSC CLIENT 1 Create a random session key 2 Encrypt the session key 3 Connect to the server 4 Transmit the encrypted session key to server 5 Use the session key as the CSC encryption pad CSC SERVER 1 Accept connection from CSC client 2 Receive the encrypted session key from the client 3 Decrypt the session key 4 Use the session key as the CSC encryption pad The aesClient and aesServer example programs requires the MarshallSoft AES Encryption module that can be downloaded from http www marshallsoft com aes htm 16 2 13 Direct Device Control Many external devices can be controlled by writing to their assigned IP address Examples of such devices include Relay Controllers Scales GPS Devices and embedded computers For example suppose that you want to be able to turn on and off electrical equipment in your home or office by computer control An internet search will find quite a few relay controllers To control them by using your computer they will have one
7. same time as the Developer s License for 195 for both 2 Source Code can be ordered within one year of purchasing a Developer s License for 100 After one year a Developer s License update 30 55 or 75 must be purchased prior to purchasing the source code 1 5 Updates When a developer license is purchased for the Client Server Communications SDK the developer will receive the registered DLLs plus a license file CSCxxxx LIC that can be used to update the registered DLLs does not include source code for a period of one year from purchase Updates can be downloaded from http www marshallsoft com update htm After one year the developer license must be updated to be able to download updates The developer license can be updated for 30 if ordered within one year from the original purchase or previous update After one year licenses can be updated for 55 75 after 3 years A license update includes an additional year of technical support Source code previously purchased may be updated for 40 in addition to the cost of the update 30 55 or 75 Note that the registered CSC DLL does not expire Also see the file UPDATES TXT 1 6 Customer ID The customer ID is the 4 or 5 digits following the product name CSC in the license file For example customer 12345 would receive license file CSC12345 LIC Provide the Customer ID in the Subject field of an email when contacting us for technical support CSC4C 12
8. 345 1 7 License File A license file CSCxxxxx LIC where xxxxx is the 5 digit customer ID is provided with each developer license The license file is an encrypted binary file used for updating CSC as explained in Section 1 5 Updates The license file is required in order to create or update the registered DLLs The license file can be found in the DLLS directory created after SETUP is run 1 8 Distribution In order to run an application that calls CSC functions on another computer the file CSC32 DLL or CSC64 DLL must be copied to the Windows directory of the other computer The Windows directory is normally WINDOWS for Windows 95 98 ME 2003 2012 XP Vista Windows 7 Windows 8 and WINNT for Windows NT 2000 Do not attempt to register the DLLs 2 CSC Application Notes 2 1 Keycode When a developer license is purchased the developer will receive a new set of DLLs and a keycode for the CSC DLLs Pass this keycode as the argument to escAttach The keycode will be found in the file named KEYCODE The keycode for the evaluation version is 0 The keycode for the registered version will be a unique 9 or 10 digit number Note The keycode is NOT the same as the Customer ID Registration number 2 2 Dynamic Link Library The Client Server Communications Library SDK includes a Win32 CSC32 DLL and Win64 CSC64 DLL dynamic link library DLL The CSC object files CSC32 OBJ and CSC64 OBJ are also included for use with C
9. 9 For example C Example Code cscAttach 2 long CSC_ KEY CODE if Code lt 0 static char Buffer 64 cscErrorText 0 Code Buffer 64 printf Error d s n Code Buffer Dee e Another good idea is to turn on logging by calling cscSetString cscSetString CSC_SET LOG FILE char SERVER LOG C C CSC_SET LOG FILE SERVER LOG VB Sal If you encounter a problem that you cannot resolve email us at info at marshallsoft com To avoid having your email deleted by our Spam scanners begin the Subject with HELP CSC Zip up any attachments and send plain ASCII text email only If you still get the evaluation screen popup window after purchasing a developer license the problem is that Windows is finding the evaluation DLL before the registered DLL The solution is to delete or zip up all evaluation versions of the CSC32 DLL or CSC64 DLL and run the SETUP program again If you get error 74 when calling escAttach the problem is that the keycode passed to cscAttach does not match the keycode in the DLL s This is caused by 1 using the evaluation keycode value 0 with the registered DLL or 2 using the registered keycode with the evaluation DLL Review the CSC Programmer s and Reference Manuals We also suggest reading Section 3 Servers and Clients 21 6 Versions of CSC The Client Server Communications CSC S
10. COBOL that is capable of calling Windows API functions Both Win32 and Win64 DLLs are provided The User s Manual applies to the Client Server Communications Library CSC for all supported programming languages It discusses Client Server TCP IP processing language independent programming issues as well as purchasing and licensing information We have versions of the Client Server Communications SDK for C C CSC4C Visual Basic CSC4VB Visual FoxPro CSC4FP Delphi CSC4D and FoxPro CSC4FP Purchase a developer license for CSC for one software development language and use it with all others All versions of CSC use the same DLLs CSC32 DLL or CSC64 DLL however the examples provided for each version are written and tested for the specified computer development language We also have declaration files and example programs for a few other languages The Client Server Communication DLLs will run under all versions of Windows 95 98 ME Windows 2000 Windows NT Windows 2003 Windows XP Windows Vista Windows 7 Windows 8 and x64 Fully functional evaluation versions of our Client Server Communications software components are provided so that the developer can test the CSC library in their environment The evaluation version as well as a list of the many Client Server Communications library features provided can be found at http www marshallsoft com client server communication htm 1 1 Application Categories for CSC Progra
11. Client Server Communications Users Manual CSC_USR Version 7 0 March 12 2015 This software is provided as is There are no warranties expressed or implied Copyright C 2015 All rights reserved MarshallSoft Computing Inc Post Office Box 4543 Huntsville AL 35815 USA Voice 1 256 881 4630 web www marshallsoft com MARSHALLSOFT is a registered trademark of MarshallSoft Computing TABLE OF CONTENTS 1 Ou WO ntroduction 1 Application Categories for CSC Programs Documentation Set Technical Support How to Purchase Updates Customer ID License File Distribution Application Notes Keycode Dynamic Link Library GUI and Console Mode Getting Started Using CSC Development Languages Supported Converting From CSC Version 3 to Version 4 Example Client Server Protocol Stream Data I O Stream Packet I O 10 File Transfer 11 Encryption 12 Using the AES Module 13 Direct Device Control TCP and UDP Sockets 3 1 Servers 3 2 Clients Challenge and Response Authentication Resolving Problems Versions of CSC 6 1 Evaluation Version 6 2 Academic Version 6 3 Professional Version Legal Issues 7 1 License 7 2 Warranty CSC Function Summary CSC Error Return Code List S MO B gt d OR LH d aH D AANA LH d LA a I 1 1 1 1 d 1 1 1 C 2 2 2 2 2 2 2 2 2 2 2 2 2 Page Page Page Page Page Page Page Page Page Page Page Page Page Page Pa
12. D WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ALL SUCH WARRANTIES ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED NEITHER MARSHALLSOFT COMPUTING INC NOR ANYONE ELSE WHO HAS BEEN INVOLVED IN THE CREATION PRODUCTION OR DELIVERY OF THIS SOFTWARE SHALL BE LIABLE FOR ANY INDIRECT CONSEQUENTIAL OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE SUCH SOFTWARE EVEN IF MARSHALLSOFT COMPUTING INC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES OR CLAIMS IN NO EVENT SHALL MARSHALLSOFT COMPUTING INC S LIABILITY FOR ANY SUCH DAMAGES EVER EXCEED THE PRICE PAID FOR THE LICENSE TO USE THE SOFTWARE REGARDLESS OF THE FORM OF THE CLAIM THE PERSON USING THE SOFTWARE BEARS ALL RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE Some states do not allow the exclusion of the limit of liability for consequential or incidental damages so the above limitation may not apply to you This agreement shall be governed by the laws of the State of Alabama and shall inure to the benefit of MarshallSoft Computing Inc and any successors administrators heirs and assigns Any action or proceeding brought by either party against the other arising out of or related to this agreement shall be brought only ina STATE or FEDERAL COURT of competent jurisdiction located in Madison County Alabama The parties hereby consent to in personam jurisdiction of said courts 23 8 CSC Function Summaries Refer to the Client Server Communi
13. DK library is available in three versions All three versions have identical functionality 6 1 Evaluation Version The evaluation version can be differentiated from the other two versions by 1 The evaluation reminder screen is displayed at startup 2 The evaluation version may not be used for commercial purposes 3 The evaluation version can be tested for 30 days 6 2 Academic Version The academic version can be differentiated from the other two versions by 1 There is no evaluation reminder screen 2 The academic version may not be used for commercial purposes DLLs purchased with the academic discount may not be distributed and must be used for educational purposes only 6 3 Professional Version The professional version can be differentiated from the other two versions by 1 There is no evaluation reminder screen 2 Source code may be purchased for CSC Compiled DLLs may be distributed royalty free with your compiled applications as specified by the software license However neither the License Key nor the source code if purchased to the DLLs may be distributed The Professional version may be used for commercial purposes 22 7 Legal Issues 7 1 License This license agreement LICENSE is a legal agreement between you either an individual or a single entity and MarshallSoft Computing Inc for this software product SOFTWARE This agreement also governs any later releases or updates of the SOFTWARE By
14. Languages Supported We have versions of the Client Server Communications CSC component library for C C and NET CSC4C Borland Codegear Delphi CSC4D Visual FoxPro CSC4FP Xbase CSC4XB dBASE CSC4DB and Visual Basic and VB NET CSC4VB All versions of CSC use the same DLLs CSC32 DLL or CSC64 DLL Evaluation versions for these may be downloaded from our website at http www marshallsoft com client server communication htm The Client Server Communications DLL can also be used with any application written in any language capable of calling the Windows 95 98 Me NT 2000 2003 2012 XP VISTA Win7 Win8 x64 API 2 5 1 Using CSC with Supported Languages Once a developer license is purchased for one programming language version of the Client Server Communication SDK CSC the same developer can use it with all other supported programming languages Supported languages are C C Visual Basic Visual FoxPro Xbase Visual dBASE and Borland Codegear Embarcadero Delphi For example assume that the developer has previously downloaded and installed the registered version of CSC4C and now wants to also call CSC functions from Visual Basic 1 Make a backup copy of CSC32 DLL and CSC64 DLL found in the Windows directory WINDOWS or WINNT 2 Download and install the evaluation version of CSC4VB http www marshallsoft com csc4vb htm into a separate directory from CSC4C 3 Compile and run the Visual Basic CSCVER ex
15. ample program found in the APPS directory created in step 2 above It should display the pop up evaluation screen 4 Restore CSC32 DLL saved in step 1 above 5 Paste the key code value found in the registered version of CSC4C KEYCODE H into KEYCODE BAS and KEYCODE VB 6 Run the Visual Basic CSCVER example program again It should no longer display the pop up screen A quicker and easier way would be to request multiple programming versions of CSC when a developer license is purchased There is no additional charge 2 5 2 Using CSC with Unsupported Languages The Client Server Communications functions can be called from any program written in any computer language capable of calling Windows 95 98 2000 2003 2012 NT XP VISTA Win7 Win8 API functions Declaration files are available for the following languages L LANGUAGE FILE C C amp NET CSC H Visual Basic amp VB NET CSC32 BAS CSC32 VB VB Net VBA Excel Access CSC32 BAS PowerBASIC CSC32 PBI Borland Delphi CSC32 PAS Fujitsu COBOL CSC32 CBI Visual FoxPro CSC32 FOX Visual dBase CSG32 6C Alaska Xbaset CSC32 CH Additional declaration files will be added Give us a call if a declaration file not listed above is needed If you have interfaced CSC to an unusual language email us the declaration file 11 2 6 Converting From CSC Version 3 to Version 4 The following applies ONLY to those running CSC version 3 0 or earlier In orde
16. ata I O functions cscGetData cscPutData cscCryptoGetData cscCryptoPutData are stream oriented This means that all incoming data will not necessarily be available at one time For example cscPutData may be called to write 10 000 bytes but cseGetData may have to be called several times before the entire 10 000 bytes are received The data I O functions return the number of bytes received 2 9 Packet Data I O The CSC packet I O functions cscGetPacket cscPutPacket cscCryptoGetPacket cescCryptoPutPacket send and receive variable length packets varying from 1 to 10 000 bytes per packet Unlike the CSC data T O functions there is a one to one correspondence between packets send and packets received There is no such thing as a partial packet Because there is always one packet received for one packet transmitted packet I O is easier to code than stream oriented data I O The packet I O functions return the number of bytes received Note that CSC packets are not the same as TCP packets 2 10 File Transfer There are two sets of functions that copy files from one computer to another via a TCP connection 1 cscPutFile cscGetFile and 2 cscPutFileExt cscGetFileExt along with their crypto equivalents 2 10 1 cscPutFile cscGetFile Standard File Transfer protocol Files are transmitted from the program calling cscPutFile to the program calling cscGetFile 2 10 2 cscPutFileExt cscGetFileExt Extended File Transfer Pro
17. cation Reference Manual CSC_REF PDF for detailed information on the CSC functions A one line summary of each function follows There are 49 functions in the Client Server Communication Library cscAcceptConnect escAttach cscAwaitConnect cscAwaitData cescByteToShort cscChallenge escClient cscClose Accept a connection from a client Attaches CSC323 DLL or CSC64 DLL Waits for a connection attempt by a client Waits for incoming data Converts from 8 bit ASCII to 16 bit Unicode ASCII Constructs challenge string Attempts to connect to a server Closes an open connection cscConnectMessag Sends message when connection is ready to accept cscCreateUDP Created UDP socket cscCryptoGetData Reads receives encrypted data escCryptoGetFil Reads receives encrypted file escCryptoGetFileExt Reads receives encrypted extended fil escCryptoGetPacket Reads receives encrypted data packet escCryptoPutData Writes transmits encrypted data cescCryptoPutFile Writes transmits encrypted fil escCryptoPutFileExt Writes transmits and encrypted extended fil escCryptoPutPacket Writes transmits encrypted data packet escDataCRC Computes CRC for data buffer cscDataMessage Sends Windows message when data is ready to read cescErrorText Returns text of error code cscFileCRC Computes the CRC of a file cscFillRandom Fills buffer with random bytes cscGetData cscGetFile cscGetFileEx
18. d The message is recovered by applying the same pad 13H 5CH 29H to the received message 52H XOR 13H 41H 1EH XOR 5CH 42H 68H XOR 29H 41H 2 11 2 Protocol Issues The contents of the pad file passed to eseCryptoPutData and cscCryptoGetData must always be the same That is the contents of the pad file cannot be changed between calls to cseCryptoPutData and cscCryptoGetData unless the receiving side has read all of the data sent by the sending side The contents of the pad file passed to cscPutPacket and cscGetPacket can be changed if desired after each packet is sent and received That is the content of the pad buffer can be changed if desired provided that the same pad buffer is used by both the sending side and the receiving side for each individual packet 2 11 3 Populating the Pad Buffer There are several ways to populate the pad buffer Once easy way is to use a pseudo random number generator to generate 8 bit 0 to 255 random variates The key is the random number seed See the escFillRandom function Also see the following section 15 2 12 Using the AES Advanced Encryption Standard Module To be the most secure the CSC encryption pad buffer should be changed after each connection session This is because if an adversary can get both the encrypted and decrypted copy of a file then the encryption pad buffer can be easily determined which can be used to decode all files using the same pad buffer The solution
19. ge Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page OO MOANA BW KA KM MKM M KM M KM KM MA M A LA LA A A A A LA A A LA A A A REP LO LH E LQ LQ LQ KM KM KM KM L O LO LO 0 0 LH E E E LU MM LA OO OO O 1 Introduction The Client Server Communications Library CSC is a component DLL library used to create server and client programs that can communicate with each other across any TCP IP or UDP network such as the Internet or a private network intranet or LAN local area net The CSC component library uses the Windows sockets API for all communication A simple interface provides the capability to quickly develop Client Server software applications using TCP IP or UDP protocols CSC can be used to communicate with other CSC programs or used to communicate with other TCP programs such as DNS POP3 SMTP FTP HTTP etc CSC provides the capability to connect to devices such as a relay device scale device GPS device or embedded computer device that is controlled by sending commands to its TCP IP address CSC can also be used to encrypt and decrypt data and files and can also be used with the MarshallSoft AES Encryption Library AES for strong encryption Client Server Communications functions can easily be called from any program written in any language such as C C C NET Visual C Delphi Visual Basic VB NET PowerBASIC Visual FoxPro dBase Xbase
20. ibrary without the evaluation info screen e Free downloadable updates to the registered DLLs for one 1 year e Free technical support by email and telephone for one 1 year 1 4 1 Academic Discount We offer an academic price of 40 off the normal price for prepaid email orders to faculty and full time students currently enrolled in any accredited high school college or university The software must be used for educational purposes The academic discount does not apply to source code To qualify for the discount your school must have a web site and you must have an email address at your school that is not forwarded When ordering ask for the academic discount or enter student at or faculty at and your schools web site address URL in the comments field of the order form on our web site order page Your order will be sent to your email address at your school This offer is not retroactive and cannot be used with any other discount Products bought with academic pricing cannot be used for any commercial purpose nor can the CSC DLL be distributed 1 4 2 Source Code Source code is available for the purpose of re compiling CSC32 DLL and CSC64 DLL Source code for the DLL library is standard ANSI C The source code is copyrighted by MarshallSoft Computing and may not be released in whole or in part There are two ways to order Source Code for the Client Server Communication Library SDK 1 Source Code can be ordered at the
21. ms CSC program can be used in several classes of applications Some ideas follow 1 Client and Server Programs designed to communicate with each other e Chat server amp client e File transfer server amp client such as an FTP replacement e Secure and private messaging 2 Client Programs designed to talk to TCP servers on the net TCP Examples POP3 or IMAP client that gets emails waiting on server HTTP web client that downloads pages or files from web site SMTP client that sends a simple text message Control external devices via their TCP IP ports relays scales etc UDP Examples e DNS Client that gets the MX email record from a DNS server e Network Time Client that gets current time from a Network Timer Server 3 Proxy Programs e SMTP proxy that extracts a copy of all recipient addresses for outgoing email e POP3 proxy that filter incoming email for spam e HTTP web proxy used to filter content 1 2 Documentation Set The complete set of documentation is provided in Adobe PDF format This is the second manual CSC_USR PDF in the set e CSC 4x Programmer s Manual CSC_4x PDF e CSC User s Manual CSC_USR PDF e CSC Reference Manual CSC_REF PDF The CSC_4x Programmer s Manual is the programming language specific manual All language dependent programming issues including installation compiling and example programs are discussed in this manual The language specific manuals
22. of several methods of control RS232 serial USB and direct TCP IP control To use RS232 serial or USB control a serial communications library can be used such as our Windows Standard Serial Communications Library See http www marshallsoft com serial communication library htm To use CSC for direct device control you must first know the assigned IP address and port number of the device If your network uses dynamic assignment of IP addresses DHCP the IP address can be found by 1 Looking in the router s DHCP table 2 Searching the list of allowed IP addresses assigned by your router by attempting to connect using cscClient to each IP on the chosen port Once the IP address and port are known the logic required to send a command or commands to the external device is as described in section 3 2 Clients with the exception that some external devices do not send greeting messages See the CONTROL example program 17 3 TCP and UDP Sockets There are two types of sockets User datagrams UDP sockets and streams TCP sockets TCP sockets implement bi directional data streams guaranteed to be error free UDP sockets are rarely used in network application programming TCP is used for most application level net programming including most of the example programs CSC provides three UDP functions cscCreateUDP cscPutUDP and cscGetUDP See the uEcho_s UDP echo server and uEcho_c UDP echo client example programs
23. ons from the CLIENT example program Also refer to Section 4 0 Challenge and Response Authentication 18 3 2 Clients The server program must always be running before a client can attempt to connect to it Although not too common a single program can be written that acts as both a server and a client In this case a minimum of two channels see cscAttach Section 2 2 in the CSC Reference Manual CSC REE must be allocated for the server part of the program and one channel for the client side 3 2 1 Client Program Logic The basic program logic for a client is as follows 1 cscAttach attach CSC32 DLL 2 cscClient start client 3 cscGetData read greeting message from server LOOP 4 cscPutData send command to server 5 cscGetData read response from server GO TO LOOP until done 6 cscClose close connection to server 7 cscRelease release CSC32 DLL The cscSendMessage function can also be used to send a Windows message when data is ready to be read Obviously eseSendMessage can be used only in programs written using a Windows message loop Also see the client example programs 3 2 2 Example Client Programs Each CSC product CSC4C CSC4VB CSC4FP and CSC4D contain several server and client programs See the CLIENT example program CLIENT C CLIENT BAS CLIENT FOX or CLI PRJ DPR which connect to the SERVER example program Also refer to Section 4 0 Challenge and Response Authentication
24. p Host does not exist Host not found Try again Non recoverable error has occurred No data is available WINSOCK doesn t support requested version 25 w T HOF 2 CSC aborted 3 CSC accept error 4 CSC already attached 5 Cannot comply 6 No such socket 7 Connect error 8 Listen error 9 No such host 10 CSC not attached 11 NULL argument 12 NULL pointer 13 Cannot allocate memory 14 Buffer size error 15 Packet CRC error 18 Too many sockets 19 File format protocol error 20 File name only 21 Packet timeout 22 Packet error 23 Transfer cancelled 24 File too large 25 No listen socket 26 Argument out of range 27 Data size too large 28 Timed out during connect 29 Maximum packet siz xceeded 30 Cannot resolve name 74 Bad key code 1001 No socket address 1002 No free sockets 1003 No such vsock 1004 Bad status flag 1005 Invalid socket 1006 No such parameter 1007 Cannot comply 1008 String size error 1009 No such server 1010 Buffer length error 1011 Connect error
25. r to provide the capability of one server program to be able to accept clients on more than one port concurrently several changes were necessary to version 3 CSC functions Application programs that use the Client Server Communications CSC library Version 3 0 or earlier will have to be changed as shown below Notice that most of the changes apply to server applications only 2 6 1 cscAttach Server Programs Change cscAttach CONNECTS 1 KeyCode To cscAttach CONNECTS 1 KeyCode Client Programs Change cscAttach CONNECTS KeyCode To cscAttach CONNECTS 0 KeyCode E 2 6 2 cscServer Retain the return value virtual listen socket from cscServer that will be used when calling cscAwaitConnect cscAcceptConnect and cscConnectMessage 2 6 3 cscAwaitConnect Server Programs Change cscAwaitConnect Timeout To cscAwaitConnect Sock Timeout where Sock is the value returned from cscServer 2 7 4 cscAcceptConnect Server Programs Change cscAcceptConnect To cscAcceptConnect Sock where Sock is the value returned from cscServer 2 6 5 cscSendMessage Server Programs Change cscSendMessage Wnd 1 MsgID To cscConnectMessage Wnd Sock MsgID where Sock is the value returned from cscServer Client Programs Change cscSendMessage Wnd Sock MsgID To cscDataMessage Wnd Sock MsgID 12 2 7 Example Client Server Protocol Several of the Client Server Communications Librar
26. t cscGetInteger cscGet Packet cscGetString cscGetUDP cescIsConnected cscMakeDotted cscMakeDotted4 cscNetToHost32 cscPutData cscPutFile cescPutFileExt cescPutPacket cscPutUDP cscReadSize cscRelease cscResolve cscResponse cscServer cscSetInteger cscSetString cscShortToByte cscSleep cscSystemTics cscMulticast Reads receives data Reads receives fil Reads receives file extended Gets integer parameter Reads received data packet Gets string parameter Reads UDP datagram Return TRUE non zero if connected Makes dotted decimal string from IP address Makes dotted decimal string from 4 address components Converts 32 bit integer from network to host byte order Writes transmits data Writes transmits file Writes transmits file extended Writes transmits data packet Write UDP datagram Returns bytes ready to be read Releases CSC32 DLL Resolves a host address into a IP address Computes the correct response for a challenge string Waits for a connection attempt by a client Sets integer parameter Sets string parameter Converts from 16 bit Unicode ASCII to 8 bit ASCII Sleeps specified milliseconds Returns system tics milliseconds since boot up Enables UDP multicast packets to be received The functions cscSleep and cscSystemTics are provided for those programming in languages that do not have such built in functions The functions escShortToB
27. tocol Files are transmitted from the program calling cscPutFileExt to the program calling cscGetFileExt but only that part of the specified file that has not already been successfully received If only part of a file is transferred because of a network or computer malfunction the file transfer will when restarted at a later time continue at the point that it left off These functions are particularly useful when transferring large files 14 2 11 Encryption 2 11 1 Overview Encryption is performed by the following CSC functions escCryptoPutData Encrypts data as it is transmitted cscCryptoGetData Decrypts data as it is received escCryptoPutFile Encrypts a file as it is transmitted escCryptoGetFile Decrypts a file as it is received escCryptoPutPacket Encrypts packet as it is transmitted escCryptoGetPacket Decrypts packet as it is received See the CSC Reference Manual CSC_REF PDF for a description of each function In all cases encryption is performed by XOR ing the data or file with the contents of the pad buffer named after the cryptographic concept of the one time pad For example suppose we want to transmit the three characters ABA Recalling that the hex code is 41H for A and 42H for B and using 13H 5CH 29H as the first 3 bytes in the pad buffer the computation is thus 41H XOR 13H 52H 42H XOR BCH 1EH 41H XOR 29H 68H and the three bytes 52H 1EH and 68H are transmitte
28. value Each time a client attempts to connect to a server a different challenge string will be computed except for once ever 2432 times Thus knowledge of previous challenge response pairs will not help potential attackers See the AUTH S and AUTH C programs for an example of the use of the challenge response protocol 20 5 Resolving Problems The evaluation version example programs must be run on the same machine as on which SETUP was run If you run into problems running the evaluation version with Windows Server contact us Be sure that the proper keycode is passed to escAttach Refer to Section 2 1 Keycode Before attempting to write an application using CSC run several of the example programs Begin by running CSCVER which should display a pop up window for the evaluation version only and also display the CSC version build number and registration string If you cannot get your application to run properly first compile and run the example programs If you call us to report a possible bug in the library the first thing we will ask is if the example programs run correctly All example programs have been compiled and tested Test the code returned from all CSC functions Then call cscErrorText to get the text associated with the error code All functions return an integer code Negative values are always errors Error codes returned by CSC functions can be found in the CSC declaration file and are also listed in Section
29. y and 7 00 AM 5 00 PM Friday The latest versions of our products are available on our web site at http www marshallsoft com and on our anonymous FTP site at ftp ftp marshallsoft com pub Registered users can update for a period of one year to the latest CSC DLL at http www marshallsoft com update htm 1 4 How to Purchase A developer license for the Client Server Communication Library CSC may be purchased for 115 USD for electronic email delivery or 195 USD with ANSII C source code for the DLLs This price is good for one year from the release date CSC can also be purchased together with the MarshallSoft AES Encryption Library AES for 175 USD or 275 USD with ANSI C source code The fastest and easiest way to order is on our web site at http www marshallsoft com order htm You can also order by completing INVOICE TXT pro forma invoice and emailing info at marshallsoft com mailing see our address at top or faxing it to us Our fax number will be provided upon request Multiple copy discounts 3 or more and site licenses are available Please call for details We accept American Express VISA MasterCard Discover PayPal checks in US dollars drawn on a US bank and International Postal Money Orders such as Western Union Print the file INVOICE TXT if a Pro Forma invoice is needed The registered package includes e CSC32 and CSC64 for 64 bit programming environment L
30. y demonstration programs use the following example protocol 1 The server must be running first at a specified IP address using a specified port number known to both client and server A host name may be used instead of an IP address The server waits for a connection attempt by a client 2 The client attempts to connect to the server 3 The server accepts the connection from the client and then sends its greeting message such as CSC Example Server 4 The client receives the server s greeting message 5 The client sends a request command string to the server 6 The server receives the client s request 7 The server sends back its response string 8 Repeat steps 5 6 and 7 until done 9 The client closes its connection to the server The server responds with the following response strings when presented with the corresponding requests REQ from the client REQ Response String Request Example Response Example WHO Sends name of the server WHO W_SERVER VER Sends server version VER 7 0 BYE OK then disconnects BYE OK ECH Sends string after ECHO ECH Hello Hello The above protocol is just an example The programmer can create whatever protocol is required Request strings can be any length although it is best to keep them as short as possible Also see PROTOCOLS TXT 13 2 8 Stream Data I O Like the Windows winsock I O functions the CSC d
31. yte and cscByteToShort are provided to ease programming in languages that use 16 bit Unicode ASCII such as C and Delphi NET 24 9 CSC Error Return List 10004 10009 10013 10014 10022 10024 10035 10036 10037 10038 10039 10040 10041 10042 10043 10044 10045 10047 10048 10049 10050 10051 10052 10053 10054 10055 10056 10057 10058 10060 10061 10064 10065 10091 10092 10093 11001 11002 11003 11004 Interrupted system call Bad file number Access denied Bad address Invalid argument Too many open files Would block socket in non blocking mode Blocking call already in progress Operation already completed Not a valid socket Destination address required Message too big for buffer Protocol mismatch Protocol option invalid Protocol not supported Socket type not supported Socket operation not supported Socket address family not supported Socket address already in use Socket address not available Network error Cannot reach network Connection dropped Connection timed out or aborted Connection reset by remote host Out of buffer space Socket already connected Socket not connected Socket functionality shut down Timed out attempting to connect Connection refused by remote host Host is down No route to host Network not yet ready Sockets not initialized Call WSAStartu
Download Pdf Manuals
Related Search