error:2008F002:BIO routines:BIO_lookup_ex:system lib

[rafay-pk]

I'm having a hard time understanding the error output of this library, and I haven't been able to find it online.
I'm modifying a desktop application to send a post request at its session start. The application was already using OpenSSL and is compiling with the code below. The server is running on a mockoon (local mock api) server at the moment, and I tested it using postman.

Here is a snippet of my code:

#include <iostream>
#include <ostream>
#include <cstring>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/bio.h>
#include <fstream>
#include <ctime>

const char *apiEndpoint = "127.0.0.1:5679/api/endpoint";
const char *apiPath = "/api/endpoint";
const char *postData = "bandwidth=100Mbps";

void logOpenSSLErrors(std::ofstream &logFile)
{
    char errorBuffer[256];
    while (auto error = ERR_get_error())
    {
        ERR_error_string_n(error, errorBuffer, sizeof(errorBuffer));
        logFile << "OpenSSL Error: " << errorBuffer << std::endl;
    }
}

bool Session::initialize()
{
    auto now = std::chrono::system_clock::now();
    std::time_t now_c = std::chrono::system_clock::to_time_t(now);
    struct tm *parts = std::localtime(&now_c);

    char filename[100];
    std::strftime(filename, sizeof(filename), "%Y-%m-%d_%H-%M-%S.log", parts);
    std::ofstream logFile(filename);

    SSL_library_init();
    SSL_load_error_strings();
    OpenSSL_add_all_algorithms();

    SSL_CTX *ctx = SSL_CTX_new(SSLv23_client_method());
    if (!ctx)
    {
        logFile << "SSL_CTX_new() failed." << std::endl;
        logOpenSSLErrors(logFile);
    }

    SSL *ssl = SSL_new(ctx);
    if (!ssl)
    {
        logFile << "SSL_new() failed." << std::endl;
        logOpenSSLErrors(logFile);
    }

    BIO *bio = BIO_new_ssl_connect(ctx);
    if (!bio)
    {
        logFile << "BIO_new_ssl_connect() failed." << std::endl;
        logOpenSSLErrors(logFile);
    }

    BIO_set_conn_hostname(bio, apiEndpoint);
    if (BIO_do_connect(bio) <= 0)
    {
        logFile << "BIO_do_connect() failed." << std::endl;
        logOpenSSLErrors(logFile);
    }

    std::string request = "POST " + std::string(apiPath) + " HTTP/1.1\r\n";
    request += "Host: " + std::string(apiEndpoint) + "\r\n";
    request += "Content-Type: application/x-www-form-urlencoded\r\n";
    request += "Content-Length: " + std::to_string(strlen(postData)) + "\r\n";
    request += "\r\n";
    request += postData;

    int bytesWritten = BIO_write(bio, request.c_str(), request.length());
    if (bytesWritten <= 0)
    {
        logFile << "BIO_write() failed." << std::endl;
        logOpenSSLErrors(logFile);
    }

    char buffer[1024];
    int bytesRead;
    while ((bytesRead = BIO_read(bio, buffer, sizeof(buffer))) > 0)
    {
        logFile.write(buffer, bytesRead);
    }

    BIO_free_all(bio);
    SSL_CTX_free(ctx);
    ERR_free_strings();

    logFile.close();
}

And here is the output:

BIO_do_connect() failed.
OpenSSL Error: error:2008F002:BIO routines:BIO_lookup_ex:system lib
BIO_write() failed.
OpenSSL Error: error:2008F002:BIO routines:BIO_lookup_ex:system lib

[levitte]

You might want to print errors with ERR_print_errors_cb() where the callback outputs to a suitable C++ stream. OpenSSL errors may have multiple error records, see...

[rafay-pk]

Using ERR_print_errors_cb(), the errors become

BIO_do_connect() failed.
OpenSSL Error: 22524:error:2008F002:BIO routines:BIO_lookup_ex:system lib:crypto\bio\b_addr.c:730:T

BIO_write() failed.
OpenSSL Error: 22524:error:2008F002:BIO routines:BIO_lookup_ex:system lib:crypto\bio\b_addr.c:730:T

[levitte]

Those lines look truncated. The T at the end is the start of the system error

[rafay-pk]

Hmm... How would you output it considering that you can't log it to the console?

int customErrorCallback(const char *str, size_t len, void *logStream)
{
    std::ostream *logFile = reinterpret_cast<std::ostream *>(logStream);
    (*logFile) << "OpenSSL Error: " << std::string(str, len) << std::endl;
    return 0;
}

void logOpenSSLErrors(std::ostream &logFile)
{
    ERR_print_errors_cb(customErrorCallback, &logFile);
}

[levitte]

I have no idea why the truncation happens, so it's a bit hard for me to tell you how to fix it. I only know that there's more text after the T I mentioned.

You could check the value of len (perhaps print it as well), just to check that it's reasonable...

[rafay-pk]

It outputs to 84 which is the length of the error string all the way to T

[nhorman]

I'm not sure what the trucation issue is either, but that failure is almost certainly happening because you are passing apiEndpoint (which is set to "127.0.0.1:5679/api/endpoint" ) as your hostname. BIO_set_conn_hostname expects a hostname (and optional port), not a full url endpoint.

[rafay-pk]

Really silly mistake on my part I guess 😅

[AbduSami-bK]

Try changing:

const char *apiEndpoint = "127.0.0.1:5679/api/endpoint";

To:

const char *apiEndpoint = "127.0.0.1:5679";

When you call:

BIO_set_conn_hostname(bio, apiEndpoint);

. Try to append the /api/endpoint/ later when you are sending the POST request.