Demo code for SSL_CONF API

Two example programs one for command line argument processing and
one for configuration file processing.
(cherry picked from commit 3646578ae7)

demos/bio/Makefile

@@ -1,7 +1,7 @@
 CC=cc
 CFLAGS= -g -I../../include
-LIBS= -L../.. ../../libssl.a ../../libcrypto.a
-EXAMPLES=saccept sconnect
+LIBS= -L../.. ../../libssl.a ../../libcrypto.a -ldl
+EXAMPLES=saccept sconnect client-arg client-conf
 
 all: $(EXAMPLES) 
 
@@ -11,6 +11,12 @@ saccept: saccept.o
 sconnect: sconnect.o
 	$(CC) -o sconnect sconnect.o $(LIBS)
 
+client-arg: client-arg.o
+	$(CC) -o client-arg client-arg.o $(LIBS)
+
+client-conf: client-conf.o
+	$(CC) -o client-conf client-conf.o $(LIBS)
+
 clean:	
 	rm -f $(EXAMPLES) *.o
 

demos/bio/README

@@ -1,3 +1,6 @@
 This directory contains some simple examples of the use of BIO's
 to simplify socket programming.
 
+The client-conf and client-arg include examples of how to use the SSL_CONF
+API for configuration file or command line processing.
+

demos/bio/client-arg.c

@@ -0,0 +1,115 @@
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+
+int main(int argc, char **argv)
+	{
+	BIO *sbio = NULL, *out = NULL;
+	int len;
+	char tmpbuf[1024];
+	SSL_CTX *ctx;
+	SSL_CONF_CTX *cctx;
+	SSL *ssl;
+	char **args = argv + 1;
+	const char *connect_str = "localhost:4433";
+	int nargs = argc - 1;
+
+	ERR_load_crypto_strings();
+	ERR_load_SSL_strings();
+	SSL_library_init();
+
+	ctx = SSL_CTX_new(SSLv23_client_method());
+	cctx = SSL_CONF_CTX_new();
+	SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
+	SSL_CONF_CTX_set_ssl_ctx(cctx, ctx);
+	while(*args && **args == '-')
+		{
+		int rv;
+		/* Parse standard arguments */
+		rv = SSL_CONF_cmd_argv(cctx, &nargs, &args);
+		if (rv == -3)
+			{
+			fprintf(stderr, "Missing argument for %s\n", *args);
+			goto end;
+			}
+		if (rv < 0)
+			{
+			fprintf(stderr, "Error in command %s\n", *args);
+			ERR_print_errors_fp(stderr);
+			goto end;
+			}
+		/* If rv > 0 we processed something so proceed to next arg */
+		if (rv > 0)
+			continue;
+		/* Otherwise application specific argument processing */
+		if (!strcmp(*args, "-connect"))
+			{
+			connect_str = args[1];
+			if (connect_str == NULL)
+				{
+				fprintf(stderr, "Missing -connect argument\n");
+				goto end;
+				}
+			args += 2;
+			nargs -= 2;
+			continue;
+			}
+		else
+			{
+			fprintf(stderr, "Unknown argument %s\n", *args);
+			goto end;
+			}
+		}
+
+	/* We'd normally set some stuff like the verify paths and
+	* mode here because as things stand this will connect to
+	* any server whose certificate is signed by any CA.
+	 */
+
+	sbio = BIO_new_ssl_connect(ctx);
+
+	BIO_get_ssl(sbio, &ssl);
+
+	if(!ssl)
+		{
+		fprintf(stderr, "Can't locate SSL pointer\n");
+	  	goto end;
+		}
+
+	/* Don't want any retries */
+	SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
+
+	/* We might want to do other things with ssl here */
+
+	BIO_set_conn_hostname(sbio, connect_str);
+
+	out = BIO_new_fp(stdout, BIO_NOCLOSE);
+	if(BIO_do_connect(sbio) <= 0)
+		{
+		fprintf(stderr, "Error connecting to server\n");
+		ERR_print_errors_fp(stderr);
+		goto end;
+		}
+
+	if(BIO_do_handshake(sbio) <= 0)
+		{
+		fprintf(stderr, "Error establishing SSL connection\n");
+		ERR_print_errors_fp(stderr);
+		goto end;
+		}
+
+	/* Could examine ssl here to get connection info */
+
+	BIO_puts(sbio, "GET / HTTP/1.0\n\n");
+	for(;;)
+		{	
+		len = BIO_read(sbio, tmpbuf, 1024);
+		if(len <= 0) break;
+		BIO_write(out, tmpbuf, len);
+		}
+	end:
+	SSL_CONF_CTX_free(cctx);
+	BIO_free_all(sbio);
+	BIO_free(out);
+	return 0;
+	}
+

demos/bio/client-conf.c

@@ -0,0 +1,125 @@
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+#include <openssl/conf.h>
+
+int main(int argc, char **argv)
+	{
+	BIO *sbio = NULL, *out = NULL;
+	int i, len, rv;
+	char tmpbuf[1024];
+	SSL_CTX *ctx = NULL;
+	SSL_CONF_CTX *cctx = NULL;
+	SSL *ssl = NULL;
+	CONF *conf = NULL;
+	STACK_OF(CONF_VALUE) *sect = NULL;
+	CONF_VALUE *cnf;
+	const char *connect_str = "localhost:4433";
+	long errline = -1;
+
+	ERR_load_crypto_strings();
+	ERR_load_SSL_strings();
+	SSL_library_init();
+
+	conf = NCONF_new(NULL);
+
+	if (NCONF_load(conf, "connect.cnf", &errline) <= 0)
+		{
+		if (errline <= 0)
+			fprintf(stderr, "Error processing config file\n");
+		else
+			fprintf(stderr, "Error on line %ld\n", errline);
+		goto end;
+		}
+
+	sect = NCONF_get_section(conf, "default");
+
+	if (sect == NULL)
+		{
+		fprintf(stderr, "Error retrieving default section\n");
+		goto end;
+		}
+
+	ctx = SSL_CTX_new(SSLv23_client_method());
+	cctx = SSL_CONF_CTX_new();
+	SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_CLIENT);
+	SSL_CONF_CTX_set_flags(cctx, SSL_CONF_FLAG_FILE);
+	SSL_CONF_CTX_set_ssl_ctx(cctx, ctx);
+	for (i = 0; i < sk_CONF_VALUE_num(sect); i++)
+		{
+		cnf = sk_CONF_VALUE_value(sect, i);
+		rv = SSL_CONF_cmd(cctx, cnf->name, cnf->value);
+		if (rv > 0)
+			continue;
+		if (rv != -2)
+			{
+			fprintf(stderr, "Error processing %s = %s\n",
+						cnf->name, cnf->value);
+			ERR_print_errors_fp(stderr);
+			goto end;
+			}
+		if (!strcmp(cnf->name, "Connect"))
+			{
+			connect_str = cnf->value;
+			}
+		else
+			{
+			fprintf(stderr, "Unknown configuration option %s\n",
+							cnf->name);
+			goto end;
+			}
+		}
+			
+	/* We'd normally set some stuff like the verify paths and
+	* mode here because as things stand this will connect to
+	* any server whose certificate is signed by any CA.
+	 */
+
+	sbio = BIO_new_ssl_connect(ctx);
+
+	BIO_get_ssl(sbio, &ssl);
+
+	if(!ssl)
+		{
+		fprintf(stderr, "Can't locate SSL pointer\n");
+	  	goto end;
+		}
+
+	/* Don't want any retries */
+	SSL_set_mode(ssl, SSL_MODE_AUTO_RETRY);
+
+	/* We might want to do other things with ssl here */
+
+	BIO_set_conn_hostname(sbio, connect_str);
+
+	out = BIO_new_fp(stdout, BIO_NOCLOSE);
+	if(BIO_do_connect(sbio) <= 0)
+		{
+		fprintf(stderr, "Error connecting to server\n");
+		ERR_print_errors_fp(stderr);
+		goto end;
+		}
+
+	if(BIO_do_handshake(sbio) <= 0)
+		{
+		fprintf(stderr, "Error establishing SSL connection\n");
+		ERR_print_errors_fp(stderr);
+		goto end;
+		}
+
+	/* Could examine ssl here to get connection info */
+
+	BIO_puts(sbio, "GET / HTTP/1.0\n\n");
+	for(;;)
+		{	
+		len = BIO_read(sbio, tmpbuf, 1024);
+		if(len <= 0) break;
+		BIO_write(out, tmpbuf, len);
+		}
+	end:
+	SSL_CONF_CTX_free(cctx);
+	BIO_free_all(sbio);
+	BIO_free(out);
+	NCONF_free(conf);
+	return 0;
+	}
+

demos/bio/connect.cnf

@@ -0,0 +1,9 @@
+# Example configuration file
+# Connects to the default port of s_server
+Connect = localhost:4433
+# Disable TLS v1.2 for test.
+# Protocol = ALL, -TLSv1.2
+# Only support 3 curves
+Curves = P-521:P-384:P-256
+# Restricted signature algorithms
+SignatureAlgorithms = RSA+SHA512:ECDSA+SHA512