c - Read certificate files from memory instead of a file using OpenSSL

Question

I have a server which would listen on HTTPS using OpenSSL. For this, I have to provide the certificate to use. However, the current implementation uses a filename to be provided to the OpenSSL API.

I want the certificate information to be read from memory, so that I don't have to ship the certificate file opening. I tried to google, but I didn't come up with any options.

Is is possible? If so, how do I read certificate files from memory instead of a file using OpenSSL?

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EDIT: The following was moved from the comments to the question.

// CURRENT
void start_server()
{
    const char *fileName = "cert_and_key.pem";
    set_server_ssl_file(fileName);
}
set_server_ssl_file(const char *fileName)
{
    //initialize context
    SSL_CTX_use_certificate_file(CTX, pem, SSL_FILETYPE_PEM); 
    SSL_CTX_use_PrivateKey_file(CTX, pem, SSL_FILETYPE_PEM);
}

//REQUIRED
void start_server()
{
    const char *cert = "--BEGIN CERTIFICATE--............";
    const char *key = "--BEGIN RSA PRIVATE KEY--.......";
    set_server_ssl_options(cert, key);
}
set_server_ssl_options(const char *cert, const char *key)
{
    //IMPLEMENTATION REQUIRED
}

Answer 1

The following code did the job for me:

 
SSL_CTX *CTX;
X509 *cert = NULL;
RSA *rsa = NULL;
BIO *cbio, *kbio;
const char *cert_buffer = "";
const char *key_buffer = "";

cbio = BIO_new_mem_buf((void*)cert_buffer, -1);
cert = PEM_read_bio_X509(cbio, NULL, 0, NULL);
assert(cert != NULL);
SSL_CTX_use_certificate(CTX, cert);

kbio = BIO_new_mem_buf((void*)key_buffer, -1);
rsa = PEM_read_bio_RSAPrivateKey(kbio, NULL, 0, NULL);
assert(rsa != NULL);
SSL_CTX_use_RSAPrivateKey(CTX, rsa);