Construct a openssl service with cipher ECDHE-RSA-AES128-GCM-SHA256 - c

Question

I am building a HTTPS service with Mongoose using using OPENSSL (openssl-1.0.2) on an embedded Linux. I tried it first using the following cipher list "AES128-SHA256:AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384", and it works fine. However, when I try to use only "ECDHE-RSA-AES128-GCM-SHA256", the compilation still works, but when attempting actual HTTPS connection between server and client (Chrome on Windows 10), the connection always failed at handshake.
Here's the openssl supported cipher list:
# openssl ciphers | sed 's/:/\n/g'
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-SHA384
ECDHE-ECDSA-AES256-SHA384
ECDHE-RSA-AES256-SHA
ECDHE-ECDSA-AES256-SHA
...
ECDH-RSA-AES256-GCM-SHA384
ECDH-ECDSA-AES256-GCM-SHA384
ECDH-RSA-AES256-SHA384
ECDH-ECDSA-AES256-SHA384
ECDH-RSA-AES256-SHA
ECDH-ECDSA-AES256-SHA
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-SHA256
ECDHE-ECDSA-AES128-SHA256
ECDHE-RSA-AES128-SHA
ECDHE-ECDSA-AES128-SHA
ECDHE-RSA-DES-CBC3-SHA
ECDHE-ECDSA-DES-CBC3-SHA
...
#
According to the packet capture between server and client, the client does support ECDHE-RSA-AES128-GCM-SHA256, so logically the handshake should work. The certificate is signed using RSA Key.
Here's my code for setting up SSL connection.
const char *pem = ctx->config[SSL_CERTIFICATE];
const char *chain = ctx->config[SSL_CHAIN_FILE];
if (!load_dll(ctx, SSL_LIB, ssl_sw) || !load_dll(ctx, CRYPTO_LIB, crypto_sw))
return 0;
// Initialize SSL crap
SSL_library_init();
SSL_load_error_strings();
**if ((CTX = SSL_CTX_new(TLSv1_2_server_method())) == NULL)
printf("SSL_CTX_new error: %s", ssl_error());**
/** Set cipher list */
//char cipher[128]="AES128-SHA256:AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384";
char cipher[128]="ECDHE-RSA-AES128-GCM-SHA256";
if (SSL_CTX_set_cipher_list(CTX, cipher) <= 0) {
printf("Failed setting the cipher list.\n");
return 0;
}
if (CTX != NULL && SSL_CTX_use_certificate_file(CTX, pem, SSL_FILETYPE_PEM) == 0) {
printf("%s: cannot open %s: %s", __func__, pem, ssl_error());
return 0;
}else if (CTX != NULL && SSL_CTX_use_PrivateKey_file(CTX, pem, SSL_FILETYPE_PEM) == 0) {
printf("%s: cannot open %s: %s", NULL, pem, ssl_error());
return 0;
}
if (CTX != NULL && chain != NULL && SSL_CTX_use_certificate_chain_file(CTX, chain) == 0) {
printf("%s: cannot open %s: %s", NULL, chain, ssl_error());
return 0;
}
All I did are,
Changing the method from SSLv23_server_method() to TLSv1_2_server_method(),
Changing the cipher list from "AES128-SHA256:AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384" to "ECDHE-RSA-AES128-GCM-SHA256"
Any help would be helpful, thanks.