Commit 468d7b11 by Carlos Martín Nieto

Add an OpenSSL IO stream

This unfortunately isn't as stackable as could be possible, as it
hard-codes the socket stream. This is because the method of using a
custom openssl BIO is not clear, and we do not need this for now. We can
still bring this in if and as we need it.
parent dd4ff2c9
/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#ifdef GIT_SSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/x509v3.h>
#include <ctype.h>
#include "global.h"
#include "posix.h"
#include "stream.h"
#include "socket_stream.h"
#include "git2/transport.h"
static int ssl_set_error(SSL *ssl, int error)
{
int err;
unsigned long e;
err = SSL_get_error(ssl, error);
assert(err != SSL_ERROR_WANT_READ);
assert(err != SSL_ERROR_WANT_WRITE);
switch (err) {
case SSL_ERROR_WANT_CONNECT:
case SSL_ERROR_WANT_ACCEPT:
giterr_set(GITERR_NET, "SSL error: connection failure\n");
break;
case SSL_ERROR_WANT_X509_LOOKUP:
giterr_set(GITERR_NET, "SSL error: x509 error\n");
break;
case SSL_ERROR_SYSCALL:
e = ERR_get_error();
if (e > 0) {
giterr_set(GITERR_NET, "SSL error: %s",
ERR_error_string(e, NULL));
break;
} else if (error < 0) {
giterr_set(GITERR_OS, "SSL error: syscall failure");
break;
}
giterr_set(GITERR_NET, "SSL error: received early EOF");
break;
case SSL_ERROR_SSL:
e = ERR_get_error();
giterr_set(GITERR_NET, "SSL error: %s",
ERR_error_string(e, NULL));
break;
case SSL_ERROR_NONE:
case SSL_ERROR_ZERO_RETURN:
default:
giterr_set(GITERR_NET, "SSL error: unknown error");
break;
}
return -1;
}
static int ssl_teardown(SSL *ssl)
{
int ret;
ret = SSL_shutdown(ssl);
if (ret < 0)
ret = ssl_set_error(ssl, ret);
else
ret = 0;
SSL_free(ssl);
return ret;
}
static int check_host_name(const char *name, const char *host)
{
if (!strcasecmp(name, host))
return 0;
if (gitno__match_host(name, host) < 0)
return -1;
return 0;
}
static int verify_server_cert(SSL *ssl, const char *host)
{
X509 *cert;
X509_NAME *peer_name;
ASN1_STRING *str;
unsigned char *peer_cn = NULL;
int matched = -1, type = GEN_DNS;
GENERAL_NAMES *alts;
struct in6_addr addr6;
struct in_addr addr4;
void *addr;
int i = -1,j;
if (SSL_get_verify_result(ssl) != X509_V_OK) {
giterr_set(GITERR_SSL, "The SSL certificate is invalid");
return -1;
}
/* Try to parse the host as an IP address to see if it is */
if (p_inet_pton(AF_INET, host, &addr4)) {
type = GEN_IPADD;
addr = &addr4;
} else {
if(p_inet_pton(AF_INET6, host, &addr6)) {
type = GEN_IPADD;
addr = &addr6;
}
}
cert = SSL_get_peer_certificate(ssl);
if (!cert) {
giterr_set(GITERR_SSL, "the server did not provide a certificate");
return -1;
}
/* Check the alternative names */
alts = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
if (alts) {
int num;
num = sk_GENERAL_NAME_num(alts);
for (i = 0; i < num && matched != 1; i++) {
const GENERAL_NAME *gn = sk_GENERAL_NAME_value(alts, i);
const char *name = (char *) ASN1_STRING_data(gn->d.ia5);
size_t namelen = (size_t) ASN1_STRING_length(gn->d.ia5);
/* Skip any names of a type we're not looking for */
if (gn->type != type)
continue;
if (type == GEN_DNS) {
/* If it contains embedded NULs, don't even try */
if (memchr(name, '\0', namelen))
continue;
if (check_host_name(name, host) < 0)
matched = 0;
else
matched = 1;
} else if (type == GEN_IPADD) {
/* Here name isn't so much a name but a binary representation of the IP */
matched = !!memcmp(name, addr, namelen);
}
}
}
GENERAL_NAMES_free(alts);
if (matched == 0)
goto cert_fail_name;
if (matched == 1)
return 0;
/* If no alternative names are available, check the common name */
peer_name = X509_get_subject_name(cert);
if (peer_name == NULL)
goto on_error;
if (peer_name) {
/* Get the index of the last CN entry */
while ((j = X509_NAME_get_index_by_NID(peer_name, NID_commonName, i)) >= 0)
i = j;
}
if (i < 0)
goto on_error;
str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(peer_name, i));
if (str == NULL)
goto on_error;
/* Work around a bug in OpenSSL whereby ASN1_STRING_to_UTF8 fails if it's already in utf-8 */
if (ASN1_STRING_type(str) == V_ASN1_UTF8STRING) {
int size = ASN1_STRING_length(str);
if (size > 0) {
peer_cn = OPENSSL_malloc(size + 1);
GITERR_CHECK_ALLOC(peer_cn);
memcpy(peer_cn, ASN1_STRING_data(str), size);
peer_cn[size] = '\0';
}
} else {
int size = ASN1_STRING_to_UTF8(&peer_cn, str);
GITERR_CHECK_ALLOC(peer_cn);
if (memchr(peer_cn, '\0', size))
goto cert_fail_name;
}
if (check_host_name((char *)peer_cn, host) < 0)
goto cert_fail_name;
OPENSSL_free(peer_cn);
return 0;
on_error:
OPENSSL_free(peer_cn);
return ssl_set_error(ssl, 0);
cert_fail_name:
OPENSSL_free(peer_cn);
giterr_set(GITERR_SSL, "hostname does not match certificate");
return GIT_ECERTIFICATE;
}
typedef struct {
git_stream parent;
git_socket_stream *socket;
SSL *ssl;
git_cert_x509 cert_info;
} openssl_stream;
int openssl_close(git_stream *stream);
int openssl_connect(git_stream *stream)
{
int ret;
openssl_stream *st = (openssl_stream *) stream;
if ((ret = git_stream_connect((git_stream *)st->socket)) < 0)
return ret;
if ((ret = SSL_set_fd(st->ssl, st->socket->s)) <= 0) {
openssl_close((git_stream *) st);
return ssl_set_error(st->ssl, ret);
}
if ((ret = SSL_connect(st->ssl)) <= 0)
return ssl_set_error(st->ssl, ret);
return verify_server_cert(st->ssl, st->socket->host);
}
int openssl_certificate(git_cert **out, git_stream *stream)
{
openssl_stream *st = (openssl_stream *) stream;
int len;
X509 *cert = SSL_get_peer_certificate(st->ssl);
unsigned char *guard, *encoded_cert;
/* Retrieve the length of the certificate first */
len = i2d_X509(cert, NULL);
if (len < 0) {
giterr_set(GITERR_NET, "failed to retrieve certificate information");
return -1;
}
encoded_cert = git__malloc(len);
GITERR_CHECK_ALLOC(encoded_cert);
/* i2d_X509 makes 'guard' point to just after the data */
guard = encoded_cert;
len = i2d_X509(cert, &guard);
if (len < 0) {
git__free(encoded_cert);
giterr_set(GITERR_NET, "failed to retrieve certificate information");
return -1;
}
st->cert_info.cert_type = GIT_CERT_X509;
st->cert_info.data = encoded_cert;
st->cert_info.len = len;
*out = (git_cert *)&st->cert_info;
return 0;
}
ssize_t openssl_write(git_stream *stream, void *data, size_t len, int flags)
{
openssl_stream *st = (openssl_stream *) stream;
int ret;
size_t off = 0;
GIT_UNUSED(flags);
while (off < len) {
ret = SSL_write(st->ssl, data + off, len - off);
if (ret <= 0 && ret != SSL_ERROR_WANT_WRITE)
return ssl_set_error(st->ssl, ret);
off += ret;
}
return off;
}
ssize_t openssl_read(git_stream *stream, void *data, size_t len)
{
openssl_stream *st = (openssl_stream *) stream;
int ret;
do {
ret = SSL_read(st->ssl, data, len);
} while (SSL_get_error(st->ssl, ret) == SSL_ERROR_WANT_READ);
if (ret < 0) {
ssl_set_error(st->ssl, ret);
return -1;
}
return ret;
}
int openssl_close(git_stream *stream)
{
openssl_stream *st = (openssl_stream *) stream;
int ret;
if ((ret = ssl_teardown(st->ssl)) < 0)
return -1;
return git_stream_close((git_stream *)st->socket);
}
void openssl_free(git_stream *stream)
{
openssl_stream *st = (openssl_stream *) stream;
git__free(st->cert_info.data);
git_stream_free((git_stream *) st->socket);
git__free(st);
}
int git_openssl_stream_new(git_stream **out, const char *host, const char *port)
{
openssl_stream *st;
st = git__calloc(1, sizeof(openssl_stream));
GITERR_CHECK_ALLOC(st);
if (git_socket_stream_new((git_stream **) &st->socket, host, port))
return -1;
st->ssl = SSL_new(git__ssl_ctx);
if (st->ssl == NULL) {
giterr_set(GITERR_SSL, "failed to create ssl object");
return -1;
}
st->parent.version = GIT_STREAM_VERSION;
st->parent.encrypted = 1;
st->parent.connect = openssl_connect;
st->parent.certificate = openssl_certificate;
st->parent.read = openssl_read;
st->parent.write = openssl_write;
st->parent.close = openssl_close;
st->parent.free = openssl_free;
*out = (git_stream *) st;
return 0;
}
#else
#include "stream.h"
int git_openssl_stream_new(git_stream **out, const char *host, const char *port)
{
giterr_set(GITERR_SSL, "openssl is not supported in this version");
return -1;
}
#endif
/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#ifndef INCLUDE_openssl_stream_h__
#define INCLUDE_openssl_stream_h__
#include "git2/sys/stream.h"
extern int git_openssl_stream_new(git_stream **out, const char *host, const char *port);
#endif
......@@ -7,8 +7,9 @@
#include "common.h"
#include "posix.h"
#include "stream.h"
#include "netops.h"
#include "stream.h"
#include "socket_stream.h"
#ifndef _WIN32
# include <sys/types.h>
......@@ -67,18 +68,11 @@ static int close_socket(GIT_SOCKET s)
}
typedef struct {
git_stream parent;
char *host;
char *port;
GIT_SOCKET s;
} socket_stream;
int socket_connect(git_stream *stream)
{
struct addrinfo *info = NULL, *p;
struct addrinfo hints;
socket_stream *st = (socket_stream *) stream;
git_socket_stream *st = (git_socket_stream *) stream;
GIT_SOCKET s = INVALID_SOCKET;
int ret;
......@@ -142,7 +136,7 @@ ssize_t socket_write(git_stream *stream, void *data, size_t len, int flags)
{
ssize_t ret;
size_t off = 0;
socket_stream *st = (socket_stream *) stream;
git_socket_stream *st = (git_socket_stream *) stream;
while (off < len) {
errno = 0;
......@@ -161,7 +155,7 @@ ssize_t socket_write(git_stream *stream, void *data, size_t len, int flags)
ssize_t socket_read(git_stream *stream, void *data, size_t len)
{
ssize_t ret;
socket_stream *st = (socket_stream *) stream;
git_socket_stream *st = (git_socket_stream *) stream;
if ((ret = p_recv(st->s, data, len, 0)) < 0)
net_set_error("Error receiving socket data");
......@@ -171,7 +165,7 @@ ssize_t socket_read(git_stream *stream, void *data, size_t len)
int socket_close(git_stream *stream)
{
socket_stream *st = (socket_stream *) stream;
git_socket_stream *st = (git_socket_stream *) stream;
int error;
error = close_socket(st->s);
......@@ -182,7 +176,7 @@ int socket_close(git_stream *stream)
void socket_free(git_stream *stream)
{
socket_stream *st = (socket_stream *) stream;
git_socket_stream *st = (git_socket_stream *) stream;
git__free(st->host);
git__free(st->port);
......@@ -191,11 +185,11 @@ void socket_free(git_stream *stream)
int git_socket_stream_new(git_stream **out, const char *host, const char *port)
{
socket_stream *st;
git_socket_stream *st;
assert(out && host);
st = git__calloc(1, sizeof(socket_stream));
st = git__calloc(1, sizeof(git_socket_stream));
GITERR_CHECK_ALLOC(st);
st->host = git__strdup(host);
......
/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#ifndef INCLUDE_socket_stream_h__
#define INCLUDE_socket_stream_h__
#include "netops.h"
typedef struct {
git_stream parent;
char *host;
char *port;
GIT_SOCKET s;
} git_socket_stream;
extern int git_socket_stream_new(git_stream **out, const char *host, const char *port);
#endif
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