'No Shared Cipher' Error with EDH-RSA-DES-CBC3-SHA

Question

I wanted to test TLS 1.0 connection with cipher EDH-RSA-DES-CBC3-SHA.

I test with openssl s_server and s_client. Works fine. Connection and data exchanges are fine.

openssl s_server -accept 4433 -cert server.pem -key serverkey.pem -cipher EDH-RSA-DES-CBC3-SHA -tls1

openssl s_client -connect 127.0.0.1:443 -cipher EDH-RSA-DES-CBC3-SHA -tls1

Shared ciphers:EDH-RSA-DES-CBC3-SHA

Now, I have another simple OpenSSL server code. With this and s_client the connection fails with server throwing the following:

3077613304:error:1408A0C1:SSL routines:SSL3_GET_CLIENT_HELLO:no shared cipher:s3_srvr.c:1361

I check that the libraries that s_server/s_client use and my server application use are same as follows:

cat /proc/9515/maps | awk '{print $6}' | grep '\.so' | sort | uniq | grep -e ssl -e libcrypto

/usr/lib/libcrypto.so.1.0.1e

/usr/lib/libssl.so.1.0.1e

However, for other ciphers like AES128-SHA, connection from s_client to my server application is fine.

Here is how I set up ctx in my server code:

SSL_CTX* InitServerCTX(void)
{
    SSL_CTX *ctx = NULL;
    SSL_library_init();
    OpenSSL_add_all_algorithms();
    SSL_load_error_strings(); 
    
    ctx = SSL_CTX_new(TLSv1_server_method());
    SSL_CTX_set_cipher_list(ctx,"EDH-RSA-DES-CBC3-SHA"); // Returns 1
    
    SSL_CTX_use_certificate_chain_file(ctx, "server.pem");
    SSL_CTX_use_PrivateKey_file(ctx, "serverkey.pem", SSL_FILETYPE_PEM);
    
    return ctx;
}

Why does my server application throw up 'No shared cipher' error and s_server is fine with same client?

did you set the DH parameters for the ctx ? look at this linux.die.net/man/3/ssl_ctx_set_tmp_dh — cmidi
@cmidi. Hey Thanks! Hadn't set up DH parameters. Got it working. Request you to post your comment as answer. Will mark it as accepted. — Prabhu
Note that s_server uses 512-bit DH parameters, so other programs like wget will fail to connect because wget rejects the small field size. — jww
Note that SSL_CTX_new(TLSv1_server_method()) uses only TLS 1.0. You can get "TLS 1.0 and above" following the code below using the SSLv23_server_method. — jww

cmidi cmidi · Accepted Answer · 2015-04-23T19:53:50

You need to create a DH object and set up the DH parameters for the ssl context ctx. To be more specific setting the primp p and generator g is required once the DH object is allocated.

One way to do that would be to use below example pseudo code

Here dh512_p dh512_g are the primo p and generator g respectively

DH* get_dh512(const unsigned char *dh512_p,const unsigned char *dh512_g)
{
    DH *dh=NULL;
    if ((dh=DH_new()) == NULL) return(NULL);
    dh->p=BN_bin2bn(dh512_p,sizeof(dh512_p),NULL);
    dh->g=BN_bin2bn(dh512_g,sizeof(dh512_g),NULL);
    if ((dh->p == NULL) || (dh->g == NULL))
        return(NULL);

   return(dh);
}

Then set up the parameters in your function using the callback

//if key exchange is based on diffie hellman
DH *dh =  get_dh512(dh512_p,dh512_g)
SSL_CTX_set_tmp_dh(ctx,dh);
SSL_CTX_set_cipher_list(ctx,ciphers);

Please look at the following links for callback details http://linux.die.net/man/3/ssl_ctx_set_tmp_dh

'No Shared Cipher' Error with EDH-RSA-DES-CBC3-SHA

2 Answers