apr_status_t serf_ssl_negotiate_protocol()

in buckets/ssl_buckets.c [1904:1967]

• 50 lines of code
• 6 McCabe index (conditional complexity)

apr_status_t serf_ssl_negotiate_protocol(serf_ssl_context_t *context,
                                         const char *protocols,
                                         serf_ssl_protocol_result_cb_t callback,
                                         void *callback_data)
{
    apr_pool_t *subpool;
    unsigned char *raw_header;
    unsigned char *at;
    const char *next;
    apr_size_t raw_len = strlen(protocols)+1;
    apr_size_t len;

    if (raw_len >= 65536)
        return APR_EINVAL;

    /* The OpenSSL api wants the value in network format.
       A length byte followed by the value for all items. */

    apr_pool_create(&subpool, context->pool);

    at = raw_header = apr_palloc(subpool, raw_len);

    while ((next = strchr(protocols, ','))) {
        len = (next - protocols);

        if (len > 255) {
            apr_pool_destroy(subpool);
            return APR_EINVAL;
        }

        *at = (unsigned char)len;
        at++;
        memcpy(at, protocols, len);
        at += len;

        protocols = next + 1;
    }

    len = strlen(protocols);
    if (len > 255) {
      apr_pool_destroy(subpool);
      return APR_EINVAL;
    }

    *at = (unsigned char)len;
    at++;
    memcpy(at, protocols, len);
    at += len;

#ifdef SERF_HAVE_OPENSSL_ALPN
    if (SSL_set_alpn_protos(context->ssl, raw_header, raw_len)) {
        ERR_clear_error();
    }
    apr_pool_destroy(subpool);

    context->protocol_callback = callback;
    context->protocol_userdata = callback_data;
    context->selected_protocol = NULL;
    return APR_SUCCESS;
#else
    apr_pool_destroy(subpool);
    return APR_ENOTIMPL;
#endif
}