Client and Server communication using ssl c/c++ - SSL protocol don't works

Question

I\'m trying use an SSL client/server example from:http://simplestcodings.blogspot.com.br/2010/08/secure-server-client-using-openssl-in-c.html to create a secure connection u

Answer 1

you must to modify your code (server side): your code:

int main()
{   SSL_CTX *ctx;
    int server;
    **char portnum[]="5000";**

        char CertFile[] = "/home/myCA/mycert.pem";
        char KeyFile[] = "/home/myCA/mycert.pem";

    SSL_library_init();

    **portnum = strings[1];**

instead you should use this:

int main(int argc, char **argv)
{   SSL_CTX *ctx;
    int server;
    //char portnum[]="5000"; ---> You can pass it as an argument

        char CertFile[] = "/home/myCA/mycert.pem";
        char KeyFile[] = "/home/myCA/mycert.pem";

    SSL_library_init();

    //portnum = strings[1]; 
    portnum = argv[1];  // ---> You can pass port number here, instead of put it in the code

I got this output (client):

toc@UnixServer:~$ ./ssl_client 
Connected with AES256-SHA encryption
Server certificates:
Subject: /C=FR/ST=Some-State/L=PARIS/O=TOC/OU=TOC/CN=TOC/emailAddress=toc@toc.com
Issuer: /C=FR/ST=Some-State/L=PARIS/O=TOC/OU=TOC/CN=TOC/emailAddress=toc@toc.com
Received: "
Hello???

"

And this output (server):

Connection: 127.0.0.1:59066
Server certificates:
Subject: /C=FR/ST=Some-State/L=PARIS/O=TOC/OU=TOC/CN=TOC/emailAddress=toc@toc.com
Issuer: /C=FR/ST=Some-State/L=PARIS/O=TOC/OU=TOC/CN=TOC/emailAddress=toc@toc.com
Client msg: "Hello???"

When you use a tool like ssldump (http://www.rtfm.com/ssldump/) (on unix box), you can see clearly what's going on:

toc@UnixServer:~$sudo ssldump -i lo port 5000
New TCP connection #1: localhost(59071) <-> localhost(5000)
1 1  0.0012 (0.0012)  C>S  Handshake
      ClientHello
        Version 3.0 
        cipher suites
        Unknown value 0xc014
        Unknown value 0xc00a
        SSL_DHE_RSA_WITH_AES_256_CBC_SHA
        SSL_DHE_DSS_WITH_AES_256_CBC_SHA
        Unknown value 0x88
        Unknown value 0x87
        Unknown value 0xc00f
        Unknown value 0xc005
        SSL_RSA_WITH_AES_256_CBC_SHA
        Unknown value 0x84
        Unknown value 0xc012
        Unknown value 0xc008
        SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA
        SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA
        Unknown value 0xc00d
        Unknown value 0xc003
        SSL_RSA_WITH_3DES_EDE_CBC_SHA
        Unknown value 0xc013
        Unknown value 0xc009
        SSL_DHE_RSA_WITH_AES_128_CBC_SHA
        SSL_DHE_DSS_WITH_AES_128_CBC_SHA
        Unknown value 0x9a
        Unknown value 0x99
        Unknown value 0x45
        Unknown value 0x44
        Unknown value 0xc00e
        Unknown value 0xc004
        SSL_RSA_WITH_AES_128_CBC_SHA
        Unknown value 0x96
        Unknown value 0x41
        Unknown value 0xc011
        Unknown value 0xc007
        Unknown value 0xc00c
        Unknown value 0xc002
        SSL_RSA_WITH_RC4_128_SHA
        SSL_RSA_WITH_RC4_128_MD5
        SSL_DHE_RSA_WITH_DES_CBC_SHA
        SSL_DHE_DSS_WITH_DES_CBC_SHA
        SSL_RSA_WITH_DES_CBC_SHA
        SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA
        SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
        SSL_RSA_EXPORT_WITH_DES40_CBC_SHA
        SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5
        SSL_RSA_EXPORT_WITH_RC4_40_MD5
        Unknown value 0xff
        compression methods
                unknown value
                  NULL
1 2  0.0019 (0.0006)  S>C  Handshake
      ServerHello
        Version 3.0 
        session_id[32]=
          13 e2 5a f0 10 93 18 56 c8 66 54 94 29 ab 8b 2d 
          7b c6 9c 3b 7b ea c7 54 e6 86 7d 3a 56 8c 96 14 
        cipherSuite         SSL_RSA_WITH_AES_256_CBC_SHA
        compressionMethod                 unknown value
1 3  0.0019 (0.0000)  S>C  Handshake
      Certificate
1 4  0.0019 (0.0000)  S>C  Handshake
      CertificateRequest
        certificate_types                   rsa_sign
        certificate_types                   dss_sign
      ServerHelloDone
1 5  0.0155 (0.0136)  C>S  Handshake
      Certificate
1 6  0.0155 (0.0000)  C>S  Handshake
      ClientKeyExchange
1 7  0.0155 (0.0000)  C>S  Handshake
      CertificateVerify
        Signature[128]=
          ac 94 31 89 64 75 20 5f 4f 00 73 4e e8 de 51 b7 
          f1 bb 16 da 63 b1 8d e9 15 9b af f8 32 d7 84 f5 
          b5 7d 4f 48 1c 2b 41 58 81 d3 a8 50 40 25 90 95 
          44 de 9d bb c4 79 5c 64 a8 a9 28 f4 16 7c 0e 17 
          b2 77 cf b0 8c a9 90 50 34 a5 76 a2 57 39 8d 37 
          12 d8 a5 8d f4 08 3a 1e 83 7e 6c 0a e9 75 ec 85 
          3d 56 f2 2e 4a 7d 71 88 29 26 99 40 43 4e f3 29 
          26 bf eb 15 be 36 22 72 f3 d9 be 4a e3 c9 0b cc 
1 8  0.0155 (0.0000)  C>S  ChangeCipherSpec
1 9  0.0155 (0.0000)  C>S  Handshake
1 10 0.0245 (0.0089)  S>C  ChangeCipherSpec
1 11 0.0245 (0.0000)  S>C  Handshake
1 12 0.0250 (0.0005)  C>S  application_data
1 13 0.0250 (0.0000)  C>S  application_data
1 14 0.0258 (0.0007)  S>C  application_data
1 15 0.0258 (0.0000)  S>C  application_data
1    0.0261 (0.0002)  C>S  TCP FIN
1    0.0275 (0.0013)  S>C  TCP FIN

Regards.