curl/lib/ssluse.c
2001-03-07 17:08:20 +00:00

350 lines
9.1 KiB
C

/*****************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 2000, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* In order to be useful for every potential user, curl and libcurl are
* dual-licensed under the MPL and the MIT/X-derivate licenses.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the MPL or the MIT/X-derivate
* licenses. You may pick one of these licenses.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id$
*****************************************************************************/
/*
* The original SSL code was written by
* Linas Vepstas <linas@linas.org> and Sampo Kellomaki <sampo@iki.fi>
*/
#include "setup.h"
#include <string.h>
#include <stdlib.h>
#include "urldata.h"
#include "sendf.h"
#include "formdata.h" /* for the boundary function */
#ifdef USE_SSLEAY
#include <openssl/rand.h>
static char global_passwd[64];
static int passwd_callback(char *buf, int num, int verify
#if OPENSSL_VERSION_NUMBER >= 0x00904100L
/* This was introduced in 0.9.4, we can set this
using SSL_CTX_set_default_passwd_cb_userdata()
*/
, void *userdata
#endif
)
{
if(verify)
fprintf(stderr, "%s\n", buf);
else {
if(num > strlen(global_passwd)) {
strcpy(buf, global_passwd);
return strlen(buf);
}
}
return 0;
}
static
bool seed_enough(struct connectdata *conn, /* unused for now */
int nread)
{
#ifdef HAVE_RAND_STATUS
/* only available in OpenSSL 0.9.5a and later */
if(RAND_status())
return TRUE;
#else
if(nread > 500)
/* this is a very silly decision to make */
return TRUE;
#endif
return FALSE; /* not enough */
}
static
int random_the_seed(struct connectdata *conn)
{
char *buf = conn->data->buffer; /* point to the big buffer */
int nread=0;
/* Q: should we add support for a random file name as a libcurl option?
A: Yes */
#if 0
/* something like this */
nread += RAND_load_file(filename, number_of_bytes);
#endif
/* generates a default path for the random seed file */
buf[0]=0; /* blank it first */
RAND_file_name(buf, BUFSIZE);
if ( buf[0] ) {
/* we got a file name to try */
nread += RAND_load_file(buf, 16384);
if(seed_enough(conn, nread))
return nread;
}
#ifdef RANDOM_FILE
nread += RAND_load_file(RANDOM_FILE, 16384);
if(seed_enough(conn, nread))
return nread;
#endif
#if defined(HAVE_RAND_EGD) && defined(EGD_SOCKET)
/* only available in OpenSSL 0.9.5 and later */
/* EGD_SOCKET is set at configure time */
{
int ret = RAND_egd(EGD_SOCKET);
if(-1 != ret) {
nread += ret;
if(seed_enough(conn, nread))
return nread;
}
}
#endif
/* If we get here, it means we need to seed the PRNG using a "silly"
approach! */
#ifdef HAVE_RAND_SCREEN
/* This one gets a random value by reading the currently shown screen */
RAND_screen();
nread = 100; /* just a value */
#else
{
int len;
char *area = Curl_FormBoundary();
if(!area)
return 3; /* out of memory */
len = strlen(area);
RAND_seed(area, len);
free(area); /* now remove the random junk */
#endif
}
infof(conn->data, "Your connection is using a weak random seed!\n");
return nread;
}
static
int cert_stuff(struct connectdata *conn,
char *cert_file,
char *key_file)
{
struct UrlData *data = conn->data;
if (cert_file != NULL) {
SSL *ssl;
X509 *x509;
if(data->cert_passwd) {
/*
* If password has been given, we store that in the global
* area (*shudder*) for a while:
*/
strcpy(global_passwd, data->cert_passwd);
/* Set passwd callback: */
SSL_CTX_set_default_passwd_cb(conn->ssl.ctx, passwd_callback);
}
if (SSL_CTX_use_certificate_file(conn->ssl.ctx,
cert_file,
SSL_FILETYPE_PEM) <= 0) {
failf(data, "unable to set certificate file (wrong password?)\n");
return(0);
}
if (key_file == NULL)
key_file=cert_file;
if (SSL_CTX_use_PrivateKey_file(conn->ssl.ctx,
key_file,
SSL_FILETYPE_PEM) <= 0) {
failf(data, "unable to set public key file\n");
return(0);
}
ssl=SSL_new(conn->ssl.ctx);
x509=SSL_get_certificate(ssl);
if (x509 != NULL)
EVP_PKEY_copy_parameters(X509_get_pubkey(x509),
SSL_get_privatekey(ssl));
SSL_free(ssl);
/* If we are using DSA, we can copy the parameters from
* the private key */
/* Now we know that a key and cert have been set against
* the SSL context */
if (!SSL_CTX_check_private_key(conn->ssl.ctx)) {
failf(data, "Private key does not match the certificate public key\n");
return(0);
}
/* erase it now */
memset(global_passwd, 0, sizeof(global_passwd));
}
return(1);
}
static
int cert_verify_callback(int ok, X509_STORE_CTX *ctx)
{
X509 *err_cert;
char buf[256];
err_cert=X509_STORE_CTX_get_current_cert(ctx);
X509_NAME_oneline(X509_get_subject_name(err_cert),buf,256);
return 1;
}
#endif
/* ====================================================== */
int
Curl_SSLConnect(struct connectdata *conn)
{
#ifdef USE_SSLEAY
struct UrlData *data = conn->data;
int err;
char * str;
SSL_METHOD *req_method;
/* mark this is being ssl enabled from here on out. */
conn->ssl.use = TRUE;
/* Lets get nice error messages */
SSL_load_error_strings();
/* Make funny stuff to get random input */
random_the_seed(conn);
/* Setup all the global SSL stuff */
SSLeay_add_ssl_algorithms();
switch(data->ssl.version) {
default:
req_method = SSLv23_client_method();
break;
case 2:
req_method = SSLv2_client_method();
break;
case 3:
req_method = SSLv3_client_method();
break;
}
conn->ssl.ctx = SSL_CTX_new(req_method);
if(!conn->ssl.ctx) {
failf(data, "SSL: couldn't create a context!");
return 1;
}
if(data->cert) {
if (!cert_stuff(conn, data->cert, data->cert)) {
failf(data, "couldn't use certificate!\n");
return 2;
}
}
if(data->ssl.verifypeer){
SSL_CTX_set_verify(conn->ssl.ctx,
SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT|
SSL_VERIFY_CLIENT_ONCE,
cert_verify_callback);
if (!SSL_CTX_load_verify_locations(conn->ssl.ctx,
data->ssl.CAfile,
data->ssl.CApath)) {
failf(data,"error setting cerficate verify locations\n");
return 2;
}
}
else
SSL_CTX_set_verify(conn->ssl.ctx, SSL_VERIFY_NONE, cert_verify_callback);
/* Lets make an SSL structure */
conn->ssl.handle = SSL_new (conn->ssl.ctx);
SSL_set_connect_state (conn->ssl.handle);
conn->ssl.server_cert = 0x0;
/* pass the raw socket into the SSL layers */
SSL_set_fd (conn->ssl.handle, conn->firstsocket);
err = SSL_connect (conn->ssl.handle);
if (-1 == err) {
err = ERR_get_error();
failf(data, "SSL: %s", ERR_error_string(err, NULL));
return 10;
}
/* Informational message */
infof (data, "SSL connection using %s\n",
SSL_get_cipher(conn->ssl.handle));
/* Get server's certificate (note: beware of dynamic allocation) - opt */
/* major serious hack alert -- we should check certificates
* to authenticate the server; otherwise we risk man-in-the-middle
* attack
*/
conn->ssl.server_cert = SSL_get_peer_certificate (conn->ssl.handle);
if(!conn->ssl.server_cert) {
failf(data, "SSL: couldn't get peer certificate!");
return 3;
}
infof (data, "Server certificate:\n");
str = X509_NAME_oneline (X509_get_subject_name (conn->ssl.server_cert),
NULL, 0);
if(!str) {
failf(data, "SSL: couldn't get X509-subject!");
return 4;
}
infof(data, "\t subject: %s\n", str);
CRYPTO_free(str);
str = X509_NAME_oneline (X509_get_issuer_name (conn->ssl.server_cert),
NULL, 0);
if(!str) {
failf(data, "SSL: couldn't get X509-issuer name!");
return 5;
}
infof(data, "\t issuer: %s\n", str);
CRYPTO_free(str);
/* We could do all sorts of certificate verification stuff here before
deallocating the certificate. */
if(data->ssl.verifypeer) {
data->ssl.certverifyresult=SSL_get_verify_result(conn->ssl.handle);
infof(data, "Verify result: %d\n", data->ssl.certverifyresult);
}
else
data->ssl.certverifyresult=0;
X509_free(conn->ssl.server_cert);
#else /* USE_SSLEAY */
/* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */
(void) data;
#endif
return 0;
}