openssl_server.c

	#include <openssl/ssl.h> #include <openssl/bio.h>
	#include <openssl/err.h>
	#include <string>
	#include <sys/socket.h>
	#include <netinet/in.h>
	#define IP_ADDR INADDR_ANY
	#define PORT 8081
	int password_cb(char *buf, int size, int rwflag, void *password);
	EVP_PKEY *generatePrivateKey();
	X509 *generateCertificate(EVP_PKEY *pkey);
	/**
	* Example SSL server that accepts a client and echos back anything it receives.
	* Test using `curl -I https://127.0.0.1:8081 --insecure`
	*/
	int main(int arc, char **argv)
	{
	int fd = socket(AF_INET, SOCK_STREAM, 0);
	if (fd < 0) {
	printf("opening socket\n");
	return -4;
	}
	struct sockaddr_in s_addr;
	bzero((char *)&s_addr, sizeof(s_addr));
	s_addr.sin_family = AF_INET;
	s_addr.sin_addr.s_addr = IP_ADDR;
	s_addr.sin_port = htons(PORT);
	if (bind(fd, (struct sockaddr*)&s_addr, sizeof(s_addr)) < 0) {
	printf("binding\n");
	return -5;
	}
	listen(fd, 2);
	int cfd;
	while (cfd = accept(fd, 0, 0))
	{
	SSL_load_error_strings();
	ERR_load_crypto_strings();
	OpenSSL_add_all_algorithms();
	SSL_library_init();
	SSL_CTX *ctx = SSL_CTX_new(SSLv3_server_method());
	if (ctx == NULL) {
	printf("errored; unable to load context.\n");
	ERR_print_errors_fp(stderr);
	return -3;
	}
	EVP_PKEY *pkey = generatePrivateKey();
	X509 *x509 = generateCertificate(pkey);
	SSL_CTX_use_certificate(ctx, x509);
	SSL_CTX_set_default_passwd_cb(ctx, password_cb);
	SSL_CTX_use_PrivateKey(ctx, pkey);
	RSA *rsa=RSA_generate_key(512, RSA_F4, NULL, NULL);
	SSL_CTX_set_tmp_rsa(ctx, rsa);
	RSA_free(rsa);
	SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, 0);
	SSL *ssl = SSL_new(ctx);
	BIO *accept_bio = BIO_new_socket(cfd, BIO_CLOSE);
	SSL_set_bio(ssl, accept_bio, accept_bio);
	SSL_accept(ssl);
	ERR_print_errors_fp(stderr);
	BIO *bio = BIO_pop(accept_bio);
	char buf[1024];
	while (1)
	{
	// first read data
	int r = SSL_read(ssl, buf, 1024);
	switch (SSL_get_error(ssl, r))
	{
	case SSL_ERROR_NONE:
	break;
	case SSL_ERROR_ZERO_RETURN:
	goto end;
	default:
	printf("SSL read problem");
	goto end;
	}
	int len = r;
	// now keep writing until we've written everything
	int offset = 0;
	while (len)
	{
	r = SSL_write(ssl, buf + offset, len);
	switch (SSL_get_error(ssl, r))
	{
	case SSL_ERROR_NONE:
	len -= r;
	offset += r;
	break;
	default:
	printf("SSL write problem");
	goto end;
	}
	}
	}
	end:
	SSL_shutdown(ssl);
	BIO_free_all(bio);
	BIO_free_all(accept_bio);
	}
	return 0;
	}
	int password_cb(char *buf, int size, int rwflag, void *password)
	{
	strncpy(buf, (char *)(password), size);
	buf[size - 1] = '\0';
	return strlen(buf);
	}
	EVP_PKEY *generatePrivateKey()
	{
	EVP_PKEY *pkey = NULL;
	EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
	EVP_PKEY_keygen_init(pctx);
	EVP_PKEY_CTX_set_rsa_keygen_bits(pctx, 2048);
	EVP_PKEY_keygen(pctx, &pkey);
	return pkey;
	}
	X509 *generateCertificate(EVP_PKEY *pkey)
	{
	X509 *x509 = X509_new();
	X509_set_version(x509, 2);
	ASN1_INTEGER_set(X509_get_serialNumber(x509), 0);
	X509_gmtime_adj(X509_get_notBefore(x509), 0);
	X509_gmtime_adj(X509_get_notAfter(x509), (long)60*60*24*365);
	X509_set_pubkey(x509, pkey);
	X509_NAME *name = X509_get_subject_name(x509);
	X509_NAME_add_entry_by_txt(name, "C", MBSTRING_ASC, (const unsigned char*)"US", -1, -1, 0);
	X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC, (const unsigned char*)"YourCN", -1, -1, 0);
	X509_set_issuer_name(x509, name);
	X509_sign(x509, pkey, EVP_md5());
	return x509;
	}