RSA BSAFE Micro Edition Suite

Streamlined security for mobile and embedded devices

Search  Print

p7ssl_server.c

/* $Id: p7ssl_server.c,v 1.4 2005/06/17 05:33:48 build Exp $ */

/*
 * Copyright (C) 1999-2003 RSA Security Inc. All rights reserved.
 *
 * This work contains proprietary information of RSA Security.
 * Distribution is limited to authorized licensees of RSA
 * Security. Any unauthorized reproduction, distribution or
 * modification of this work is strictly prohibited.
 */

/*
 * A source of pseudo random numbers is required for various aspects of the
 * security protocol and components included in this product. Failure to
 * appropriately seed the Pseudo Random Number Generator (PRNG) will
 * seriously impact the security provided. Your application should provide this
 * random seed.
 *
 * The exact requirements for this seeding process may depend upon your
 * application and the environment for which your application is designed.
 * See RFC 1750 - Randomness Recommendations for Security.
 */

#include "r_prod.h"
#include "server_defaults.h"           /* Default values for server samples */
#include "builtin_cert_pkey.h"      /* Built-in certificate and private key */
#include "debug_cb.h"                    /* BIO and SSL state dump callback */
#include "arguments.h"                      /* Program arguments processing */

/* Global BIO for output to standard error */
BIO *bio_err;

static void print_connection_source(BIO *accept_bio,BIO *bio_out);

int main(int argc, char *argv[])
{
    int ret = R_ERROR_FAILED;                      /* Function return value */
    BIO *bio = NULL;
    BIO *bio_out = NULL;
    BIO *abio = NULL;
    int bytes_read;                     /* Number of bytes read from client */
    int bytes_written = 0;         /* The number of Bytes written to client */
    int sock_fd;                              /* The socket file descriptor */
    int ssl_err;                                    /* SSL error identifier */
    static char buf[2000];  /* Application I/O buffer */
    char *port = SSL_SERVER_PORT_DEFAULT;         /* Port to accept clients */
    char *ciphers = NULL;                /* Cipher list, NULL means default */
    int debug = 0;                         /* Switch for extra debug output */
    int state = 0;                                   /* Print the SSL state */
    int connections = SSL_SERVER_UNLIMITED_CONNECTIONS; /* Connection count */
    int extra_args;                    /* Extra arguments from command line */
    int arg;                                            /* Argument counter */
    SSL_METHOD *meth = NULL;                /* Pointer to server SSL method */
    SSL *ssl = NULL;                               /* SSL connection object */
    SSL_CTX *ssl_ctx = NULL;                      /* Pointer to SSL context */
    R_LIB_CTX *lib_ctx = NULL;                /* Pointer to library context */
    SSLCERT *server_cert = NULL;           /* Pointer to server certificate */
    EVP_PKEY *pkey = NULL;                 /* Pointer to server private key */
    int off = 0;                                      /* Additional options */
    static unsigned char rand_seed[] = "A bad seed for software PRNG";
    int mode = R_LIB_CTX_FIPS140_MODE;            /* Library's default mode */
    R_CM_CTX         *ctx       = NULL;
    R_CR_ALG_ID       id;
    R_CM             *obj       = NULL;
    R_PKEY_CTX       *key_ctx   = NULL;
    R_CERT_TYPE       certtype;
    R_FORMAT          certform;
    R_PKEY_TYPE       keytype;
    R_FORMAT          keyform;
    unsigned int      consumed_len;
    int               is_verified;
    char             *verify_result;

    certtype     = R_CERT_TYPE_X509;
    certform     = R_FORMAT_BINARY;
    keytype      = R_PKEY_TYPE_RSA;
    keyform      = R_FORMAT_BINARY;
    id           = R_CR_ID_MD5;

    /* Create an output channel */
    if ((bio_err = BIO_new_fp(stderr, BIO_NOCLOSE)) == NULL)
    {
        goto end;
    }
    BIO_set_flags(bio_err, BIO_FLAGS_FLUSH_ON_WRITE);

    /* Create an output channel */
    if ((bio_out = BIO_new_fp(stdout, BIO_NOCLOSE)) == NULL)
    {
        goto end;
    }
    BIO_set_flags(bio_out, BIO_FLAGS_FLUSH_ON_WRITE);

    /* Parse server arguments */
    if (server_parse_arguments(argc, argv, bio_err, bio_out, &port,
        &connections, &debug, &state, &meth, &extra_args, &off, &ciphers,
        &mode))
    {
        server_usage(bio_err, argv[0]);
        goto end;
    }

    /* If there are extra unparsed arguments then print usage and exit */
    if (extra_args > 0)
    {
        /* Report the first command line problem */
        for (arg = 1; arg < argc; arg++)
        {
            if (argv[arg] != NULL)
            {
                BIO_printf(bio_err, "\nUnknown argument : %s\n", argv[arg]);
                break;
            }
        }

        /* Report program usage and exit */
        server_usage(bio_err, argv[0]);
        goto end;
    }

    /* Initialize the SSL library using the default resources */
    if (PRODUCT_LIBRARY_NEW(PRODUCT_DEFAULT_RESOURCE_LIST(), R_RES_FLAG_DEF,
        &lib_ctx) != R_ERROR_NONE)
    {
        BIO_printf(bio_err, "Unable to create library context\n");
        goto end;
    }

    /* Create a new key context */
    if ((ret = R_PKEY_CTX_new(lib_ctx, R_RES_FLAG_DEF, keytype, &key_ctx)) !=
        R_ERROR_NONE)
    {
        BIO_printf(bio_out, "Key context new failure\n");
        goto end;
    }

    /* Create a new cryptographic message context */
    if ((ret = R_CM_CTX_new(lib_ctx, R_RES_FLAG_DEF, R_CM_TYPE_DEFAULT,
        &ctx)) != R_ERROR_NONE)
    {
        BIO_printf(bio_err, "R_CM_CTX_new failure\n");
        goto end;
    }

    /*
         * This demonstrates how to seed the software PRNG of the SSL library.
         * Seeding information gathered using software methods is not the best
         * source, so do not use the following example of application-specified
         * entropy in production. RNG hardware is considered the best source of
         * random information.
     */
     if (R_rand_seed(R_rand_get_default(), rand_seed, sizeof(rand_seed)) == 0)
    {
        BIO_printf(bio_err, "Unable to seed the PRNG\n");
        goto end;
    }

#ifndef SSLC_SMALL_CODE
    SSL_load_error_strings();
#endif /* !SSLC_SMALL_CODE */

    /* Set the server default method if it is not set */
    if (meth == NULL)
    {
#if defined(NO_SSL2)
        /* MES compilation (No SSLv2) - default support for SSLv3 & TLS */
        meth = TLSv1_server_method();
        BIO_printf(bio_out, "Doing TLSv1_server_method\n");
#else
        /* SSLC compilation - default support for SSLv2, SSLv3 & TLSv1 */
        meth = SSLv23_server_method();
        BIO_printf(bio_out, "Doing SSLv23_server_method\n");
#endif
    }

    /* Create an SSL context structure */
    if ((ssl_ctx = SSL_CTX_new(meth)) == NULL)
    {
        BIO_printf(bio_err, "Unable to create SSL context\n");
        goto end;
    }

    /*
     * Set the mode of operation of the context. Note this is only applicable
     * to libraries that support FIPS/non-FIPS modes of operations.
     */
    (void)SSL_CTX_set_R_LIB_CTX(ssl_ctx, lib_ctx, mode);

#ifndef SSLC_SMALL_CODE
    /*
     * Set the server temporary key generation mode. The temporary key
     * will be generated during the handshake.
     */
    if (!SSL_CTX_set_tmp_key_mode(ssl_ctx, SSL_TMP_512_DH|SSL_TMP_1024_DH|
        SSL_TMP_512_RSA, SSL_TMP_GENERATE_LATER))
    {
        BIO_printf(bio_err, "Unable to set temporary key mode\n");
        goto end;
    }
#endif /* !SSLC_SMALL_CODE */

    /* Set the cipher list if specified. Otherwise use the default. */
    if (ciphers != NULL)
    {
        SSL_CTX_set_cipher_list(ssl_ctx, ciphers);
    }

    /* Set the SSL information callback to print the SSL state */
    if (state)
    {
        SSL_CTX_set_info_cb(ssl_ctx, ssl_state_info_cb);
    }

    /* Enable all vendor bug compatibility options */
    SSL_CTX_set_options(ssl_ctx, SSL_OP_ALL | off);

    /* Load the built-in server certificate */
    BIO_printf(bio_out, "Server is using the built-in certificate\n");
    server_cert = sslcert_get_certificate();
    if (!SSL_CTX_use_certificate(ssl_ctx, server_cert))
    {
        BIO_printf(bio_err, "Unable to load server certificate\n");
        goto end;
    }

    /* Load the built-in server private key */
    BIO_printf(bio_out, "Server is using the builtin RSA key\n");
    pkey = get_rsa512_priv_server();
    if (!SSL_CTX_use_PrivateKey(ssl_ctx, pkey))
    {
        BIO_printf(bio_err, "Unable to load server private key\n");
        goto end;
    }

   /*
    * Check that the certificate and private key match. This is a common error
    * which should be avoided before starting the server, as the SSL handshake
    * cannot be completed without a certificate and matching private key.
    */
    if (!SSL_CTX_check_private_key(ssl_ctx))
    {
        BIO_printf(bio_err, "Private key check failed\n");
        goto end;
    }

    /* Set up an accept BIO to simplify the process of setting up a server */
    if ((abio = BIO_new_accept(port)) == NULL)
    {
        BIO_printf(bio_err, "Unable to create accept BIO\n");
        goto end;
    }

    /* Allow for easy restart of the server accept socket */
    BIO_set_bind_mode(abio, SIO_BIND_REUSEADDR);

    /*
     * The first call to BIO_do_accept() sets up the socket for accepting
     * incoming connections by establishing a listener.
     */
    if (BIO_do_accept(abio) <= 0)
    {
        BIO_printf(bio_err, "Unable to initialize server socket\n");
        goto end;
    }

    /*
     * In debug mode add a BIO callback to output all data passing through the
     * connection. This can be done on the accept socket because the callback
     * reference is passed on to the accepting socket.
     */
    if (debug)
    {
        BIO_set_cb(abio, bio_dump_cb);
        BIO_set_cb_arg(abio, (char *)bio_out);
    }

    /*
     * Create the SSL structure. Defaults are inherited from the SSL_CTX.
     * Options are usually set against the SSL_CTX with those requiring
     * modification set against the SSL.
     */
    if ((ssl = SSL_new(ssl_ctx)) == NULL)
    {
        BIO_printf(bio_err, "Unable to create SSL structure\n");
        goto end;
    }

    /* Enable anytime shutdown to handle https requests properly */
    SSL_set_options(ssl, SSL_OP_ANYTIME_SHUTDOWN);

    /*
     * Enter the web server loop which will allow a set number of
     * connections before exiting. The number of connections will be
     * unlimited if the connections number is negative.
     */
    while (connections != 0)
    {
        /* Decrement the connection count */
        connections--;

        BIO_printf(bio_out, "\nWaiting for new connection ...\n");

        /*
         * Reset the SSL connection deals to be in an "initial" state
         * ready to begin another handshake.
         */
        SSL_clear(ssl);

        /* Accept a new client socket connection */
        if (BIO_do_accept(abio) < 0)
        {
            /* The accept of a new socket failed */
            BIO_printf(bio_out, "Accept of client connection failed\n");
            ERR_print_errors(bio_out);

            /* Attempt a new socket connection */
            continue;
        }

        /* Pop the newly generated BIO from the listener BIO */
        bio = BIO_pop(abio);

        /* Print feedback about the socket connection */
        print_connection_source(bio, bio_out);

        /*
         * The BIO is taken by SSL_set_bio(). It is not necessary to free it as
         * the SSL clean up process will do so.
         */
        SSL_set_bio(ssl, bio, bio);

        /*
         * Instruct the SSL layer to perform the server-side of the protocol
         * when SSL_do_handshake() is called. SSL_do_handshake() is implicitly
         * called by SSL_read()/SSL_write(). Note that SSL_connect() or
         * SSL_accept() explicitly do the client- or server-side handshake
         * functions.
         */
        SSL_set_accept_state(ssl);

        /*
         * As this is performing non-blocking reads, call SSL_read(). This call
         * performs the full handshake. Read less than a full buffer here to
         * allow for processing later.
         */
        bytes_read = SSL_read(ssl, buf, 2000 - 1);

        /*
         * Categorize the return value from the SSL call to determine how to
         * deal with the error. This call also works when the SSL return code
         * does not indicate an error in which case SSL_ERROR_NONE is always
         * returned here.
         */
        ssl_err = SSL_get_error(ssl, bytes_read);

        switch (ssl_err)
        {
        case SSL_ERROR_NONE:
            /* The handshake finished, so continue parsing the data */
            break;
        case SSL_ERROR_SSL:
            /* A handshake error: report and exit */
            BIO_printf(bio_out, "Handshake failure\n");
            ERR_print_errors(bio_out);
            goto close_connection;
        case SSL_ERROR_ZERO_RETURN:
            break;
        case SSL_ERROR_WANT_READ:
        case SSL_ERROR_WANT_WRITE:
        case SSL_ERROR_WANT_CONNECT:
        case SSL_ERROR_SYSCALL:
        default:
            /*
             * A system call error. This error is different from the
             * SSL_ERROR_SSL in that errno (under unix) has the numeric
             * error value, and is not converted into text. If performing an
             * SSL_read()/SSL_write() there is no recorded error in the error
             * logging because the error could be able to be retried which
             * the library is not aware of.
             */
            BIO_printf(bio_out,
                "System call error (ssl_err=%d,ret=%d,errno=%d)\n",
                ssl_err, bytes_read, R_os_get_last_sys_error());
            ERR_print_errors(bio_out);
            goto close_connection;
            break;
        }

        /* Process the data read from the client */

        BIO_printf(bio_out, "Request received - bytes read %d\n\n", bytes_read);
        /*
         * NULL-terminate the buffer of data read from the client. The
         * assumption here is that the server has just read text data.
         */
        buf[bytes_read] = '\0';

        /*
         * Create and configure the signed data object, using the following
         * sub-steps:
         *    - Create a new signed data message object.
         *    - Include the actual data (created in the previous step).
         */

        /* Create a new signed data message */
        BIO_printf(bio_out, "Create a new signed data message\n");

        if ((ret = R_CM_from_binary(ctx, R_FLAG_SHARE_NONE, R_CM_TYPE_UNKNOWN,
            R_CM_ENCODING_FORMAT_WRAPPED, bytes_read, (unsigned char *)buf,
            &consumed_len, &obj)) != R_ERROR_NONE)

        {
            BIO_printf(bio_err, "Failed to create crypto message to send\n");
            goto end;
        }

        /*
         * Verify the signed data message. The verification has two return values.
         * The first is the verification routine return and the second is the
         * verification status.
         */
        if ((ret = R_CM_signature_verify(obj, R_CM_INDEX_ALL, NULL,
            &is_verified)) != R_ERROR_NONE)
        {
            BIO_printf(bio_out, "R_CM_signature_verify failed\n");
            goto end;
        }

        if (!is_verified)
        {
            ret = R_ERROR_FAILED;
            BIO_printf(bio_out, "Verify data failed\n");
            verify_result = P7SSL_SERVER_RESPONSE_VERIFY_FAIL;
        }
        else
        {
            BIO_printf(bio_out, "Signature Verified!\n");
            verify_result = P7SSL_SERVER_RESPONSE_VERIFY_OK;
        }

        /* Write the prepared response to the client */
        bytes_written = SSL_write(ssl, verify_result, Strlen(verify_result));

close_connection:

        /* Close the SSL connection */
        SSL_shutdown(ssl);

        BIO_get_fd(bio, &sock_fd);
        shutdown(sock_fd, 2);

        /*
         * An error on the blocking socket will close the server. Ensure this
         * check after the socket for the SSL has been closed.
         */
        if (bytes_written < 0)
        {
            BIO_printf(bio_err, "Server write response failed\n");
            goto end;
        }

        /* Report the connection close to standard output */
        BIO_printf(bio_out, "Done\n");

    }

    /* Set program success */
    ret = R_ERROR_NONE;

end:

    /* On error output the error stack */
    if ((ret != R_ERROR_NONE) && (bio_err != NULL))
    {
        ERR_print_errors(bio_err);
    }

    /* Free memory for all structures */
    if (ssl != NULL)
    {
        SSL_free(ssl);
    }

    /* Free the BIOs for standard out and error */
    if (bio_out != NULL)
    {
        BIO_free(bio_out);
    }

    if (obj != NULL)
    {
        R_CM_free(obj);
    }

    if (ctx != NULL)
    {
        R_CM_CTX_free(ctx);
    }

    if (key_ctx != NULL)
    {
        R_PKEY_CTX_free(key_ctx);
    }

    /*
     * The private key and certificate were generated as structures in memory
     * before being associated with the SSL. The application therefore still
     * has a reference to the private key and certificate which must be freed
     * now.
     */
    if (pkey != NULL)
    {
        SSLCERT_PKEY_free(pkey);
    }

    if (server_cert != NULL)
    {
        SSLCERT_free(server_cert);
    }

    if (ssl_ctx != NULL)
    {
        /*
         * Do not check for the return as no more memory freeing will be
         * performed
         */
        SSL_CTX_free(ssl_ctx);
    }

    /* Free the SSL library context */
    if (lib_ctx != NULL)
    {
        PRODUCT_LIBRARY_FREE(lib_ctx);
    }

    /* Free the accept BIO */
    if (abio != NULL)
    {
        BIO_free(abio);
    }

    if (bio_err != NULL)
    {
        BIO_free(bio_err);
        bio_err = NULL;
    }

    return(R_ERROR_EXIT_CODE(ret));
}

static void print_connection_source(BIO *accept_bio, BIO *bio_out)
{
    int sock;                                     /* Socket file descriptor */
    unsigned long len;                   /* Length of socket data structure */
    struct sockaddr_in name;                       /* Socket data structure */
    static char hostbuf[128];            /* Buffer for the host name string */
    int hostlen = 0;                       /* Length of the hostname string */
    int i;

    /* Extract the file descriptor from the BIO */
    BIO_get_fd(accept_bio, &sock);

    /* Make a socket call to get the socket address details */
    len = sizeof(name);
    i = SIO_getsockname(sock, (struct sockaddr *) &name, &len);

    /* Get the peer host name from the address */
    if (i == 0)
    {
        /* Initialize the hostname string to be empty */
        hostbuf[0] = '\0';
        hostlen = SIO_gethostbyaddr((unsigned char *)&name, (int)len,
            hostbuf, sizeof(hostbuf));
    }
    else
    {
        BIO_printf(bio_out, "getsockname failed - %d\n",
            R_os_get_last_sys_error());
    }

    /* Report the host name if it was found */
    if (hostlen != 0)
    {
        BIO_printf(bio_out, "New connection from %s\n", hostbuf);
    }
    else
    {
        BIO_printf(bio_out, "New connection\n");
    }

    return;
}

Copyright (c) 1999-2005 RSA Security Inc. All rights reserved. 072-001001-2100-001-000 - 2.1