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curl/lib/security.c

542 lines
13 KiB
C

/* This source code was modified by Martin Hedenfalk <mhe@stacken.kth.se> for
* use in Curl. His latest changes were done 2000-09-18.
*
* It has since been patched and modified a lot by Daniel Stenberg
* <daniel@haxx.se> to make it better applied to curl conditions, and to make
* it not use globals, pollute name space and more. This source code awaits a
* rewrite to work around the paragraph 2 in the BSD licenses as explained
* below.
*
* Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
*
* Copyright (C) 2001 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. */
#include "setup.h"
#ifndef CURL_DISABLE_FTP
#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
#define _MPRINTF_REPLACE /* we want curl-functions instead of native ones */
#include <curl/mprintf.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "urldata.h"
#include "krb4.h"
#include "base64.h"
#include "sendf.h"
#include "ftp.h"
#include "memory.h"
/* The last #include file should be: */
#include "memdebug.h"
static const struct {
enum protection_level level;
const char *name;
} level_names[] = {
{ prot_clear, "clear" },
{ prot_safe, "safe" },
{ prot_confidential, "confidential" },
{ prot_private, "private" }
};
static enum protection_level
name_to_level(const char *name)
{
int i;
for(i = 0; i < (int)sizeof(level_names)/(int)sizeof(level_names[0]); i++)
if(curl_strnequal(level_names[i].name, name, strlen(name)))
return level_names[i].level;
return (enum protection_level)-1;
}
static const struct Curl_sec_client_mech * const mechs[] = {
#ifdef HAVE_GSSAPI
&Curl_krb5_client_mech,
#endif
#ifdef HAVE_KRB4
&Curl_krb4_client_mech,
#endif
NULL
};
int
Curl_sec_getc(struct connectdata *conn, FILE *F)
{
if(conn->sec_complete && conn->data_prot) {
char c;
if(Curl_sec_read(conn, fileno(F), &c, 1) <= 0)
return EOF;
return c;
}
else
return getc(F);
}
static int
block_read(int fd, void *buf, size_t len)
{
unsigned char *p = buf;
int b;
while(len) {
b = read(fd, p, len);
if(b == 0)
return 0;
else if(b < 0 && (errno == EINTR || errno == EAGAIN))
continue;
else if(b < 0)
return -1;
len -= b;
p += b;
}
return p - (unsigned char*)buf;
}
static int
block_write(int fd, const void *buf, size_t len)
{
const unsigned char *p = buf;
int b;
while(len) {
b = write(fd, p, len);
if(b < 0 && (errno == EINTR || errno == EAGAIN))
continue;
else if(b < 0)
return -1;
len -= b;
p += b;
}
return p - (unsigned char*)buf;
}
static int
sec_get_data(struct connectdata *conn,
int fd, struct krb4buffer *buf)
{
int len;
int b;
b = block_read(fd, &len, sizeof(len));
if(b == 0)
return 0;
else if(b < 0)
return -1;
len = ntohl(len);
buf->data = realloc(buf->data, len);
b = buf->data ? block_read(fd, buf->data, len) : -1;
if(b == 0)
return 0;
else if(b < 0)
return -1;
buf->size = (conn->mech->decode)(conn->app_data, buf->data, len,
conn->data_prot, conn);
buf->index = 0;
return 0;
}
static size_t
buffer_read(struct krb4buffer *buf, void *data, size_t len)
{
if(buf->size - buf->index < len)
len = buf->size - buf->index;
memcpy(data, (char*)buf->data + buf->index, len);
buf->index += len;
return len;
}
static size_t
buffer_write(struct krb4buffer *buf, void *data, size_t len)
{
if(buf->index + len > buf->size) {
void *tmp;
if(buf->data == NULL)
tmp = malloc(1024);
else
tmp = realloc(buf->data, buf->index + len);
if(tmp == NULL)
return -1;
buf->data = tmp;
buf->size = buf->index + len;
}
memcpy((char*)buf->data + buf->index, data, len);
buf->index += len;
return len;
}
int
Curl_sec_read(struct connectdata *conn, int fd, void *buffer, int length)
{
size_t len;
int rx = 0;
if(conn->sec_complete == 0 || conn->data_prot == 0)
return read(fd, buffer, length);
if(conn->in_buffer.eof_flag){
conn->in_buffer.eof_flag = 0;
return 0;
}
len = buffer_read(&conn->in_buffer, buffer, length);
length -= len;
rx += len;
buffer = (char*)buffer + len;
while(length) {
if(sec_get_data(conn, fd, &conn->in_buffer) < 0)
return -1;
if(conn->in_buffer.size == 0) {
if(rx)
conn->in_buffer.eof_flag = 1;
return rx;
}
len = buffer_read(&conn->in_buffer, buffer, length);
length -= len;
rx += len;
buffer = (char*)buffer + len;
}
return rx;
}
static int
sec_send(struct connectdata *conn, int fd, const char *from, int length)
{
int bytes;
void *buf;
enum protection_level protlevel = conn->data_prot;
int iscmd = protlevel == prot_cmd;
if(iscmd) {
if(!strncmp(from, "PASS ", 5) || !strncmp(from, "ACCT ", 5))
protlevel = prot_private;
else
protlevel = conn->command_prot;
}
bytes = (conn->mech->encode)(conn->app_data, from, length, protlevel,
&buf, conn);
if(iscmd) {
char *cmdbuf;
bytes = Curl_base64_encode(conn->data, (char *)buf, bytes, &cmdbuf);
if(bytes > 0) {
if(protlevel == prot_private)
block_write(fd, "ENC ", 4);
else
block_write(fd, "MIC ", 4);
block_write(fd, cmdbuf, bytes);
block_write(fd, "\r\n", 2);
Curl_infof(conn->data, "%s %s\n",
protlevel == prot_private ? "ENC" : "MIC", cmdbuf);
free(cmdbuf);
}
}
else {
bytes = htonl(bytes);
block_write(fd, &bytes, sizeof(bytes));
block_write(fd, buf, ntohl(bytes));
}
free(buf);
return length;
}
int
Curl_sec_fflush_fd(struct connectdata *conn, int fd)
{
if(conn->data_prot != prot_clear) {
if(conn->out_buffer.index > 0){
Curl_sec_write(conn, fd,
conn->out_buffer.data, conn->out_buffer.index);
conn->out_buffer.index = 0;
}
sec_send(conn, fd, NULL, 0);
}
return 0;
}
int
Curl_sec_write(struct connectdata *conn, int fd, const char *buffer, int length)
{
int len = conn->buffer_size;
int tx = 0;
if(conn->data_prot == prot_clear)
return write(fd, buffer, length);
len -= (conn->mech->overhead)(conn->app_data, conn->data_prot, len);
if(len <= 0)
len = length;
while(length){
if(length < len)
len = length;
sec_send(conn, fd, buffer, len);
length -= len;
buffer += len;
tx += len;
}
return tx;
}
ssize_t
Curl_sec_send(struct connectdata *conn, int num, const char *buffer, int length)
{
curl_socket_t fd = conn->sock[num];
return (ssize_t)Curl_sec_write(conn, fd, buffer, length);
}
int
Curl_sec_putc(struct connectdata *conn, int c, FILE *F)
{
char ch = c;
if(conn->data_prot == prot_clear)
return putc(c, F);
buffer_write(&conn->out_buffer, &ch, 1);
if(c == '\n' || conn->out_buffer.index >= 1024 /* XXX */) {
Curl_sec_write(conn, fileno(F), conn->out_buffer.data,
conn->out_buffer.index);
conn->out_buffer.index = 0;
}
return c;
}
int
Curl_sec_read_msg(struct connectdata *conn, char *s, int level)
{
int len;
unsigned char *buf;
int code;
len = Curl_base64_decode(s + 4, &buf); /* XXX */
if(len > 0)
len = (conn->mech->decode)(conn->app_data, buf, len, level, conn);
else
return -1;
if(len < 0) {
free(buf);
return -1;
}
if(conn->data->set.verbose) {
buf[len] = '\n';
Curl_debug(conn->data, CURLINFO_HEADER_IN, (char *)buf, len + 1, conn);
}
buf[len] = '\0';
if(buf[3] == '-')
code = 0;
else
sscanf((char *)buf, "%d", &code);
if(buf[len-1] == '\n')
buf[len-1] = '\0';
strcpy(s, (char *)buf);
free(buf);
return code;
}
enum protection_level
Curl_set_command_prot(struct connectdata *conn, enum protection_level level)
{
enum protection_level old = conn->command_prot;
conn->command_prot = level;
return old;
}
static int
sec_prot_internal(struct connectdata *conn, int level)
{
char *p;
unsigned int s = 1048576;
ssize_t nread;
if(!conn->sec_complete){
infof(conn->data, "No security data exchange has taken place.\n");
return -1;
}
if(level){
int code;
if(Curl_ftpsendf(conn, "PBSZ %u", s))
return -1;
if(Curl_GetFTPResponse(&nread, conn, &code))
return -1;
if(code/100 != 2){
failf(conn->data, "Failed to set protection buffer size.");
return -1;
}
conn->buffer_size = s;
p = strstr(conn->data->state.buffer, "PBSZ=");
if(p)
sscanf(p, "PBSZ=%u", &s);
if(s < conn->buffer_size)
conn->buffer_size = s;
}
if(Curl_ftpsendf(conn, "PROT %c", level["CSEP"]))
return -1;
if(Curl_GetFTPResponse(&nread, conn, NULL))
return -1;
if(conn->data->state.buffer[0] != '2'){
failf(conn->data, "Failed to set protection level.");
return -1;
}
conn->data_prot = (enum protection_level)level;
if(level == prot_private)
conn->command_prot = (enum protection_level)level;
return 0;
}
void
Curl_sec_set_protection_level(struct connectdata *conn)
{
if(conn->sec_complete && conn->data_prot != conn->request_data_prot)
sec_prot_internal(conn, conn->request_data_prot);
}
int
Curl_sec_request_prot(struct connectdata *conn, const char *level)
{
int l = name_to_level(level);
if(l == -1)
return -1;
conn->request_data_prot = (enum protection_level)l;
return 0;
}
int
Curl_sec_login(struct connectdata *conn)
{
int ret;
const struct Curl_sec_client_mech * const *m;
ssize_t nread;
struct SessionHandle *data=conn->data;
int ftpcode;
for(m = mechs; *m && (*m)->name; m++) {
void *tmp;
tmp = realloc(conn->app_data, (*m)->size);
if(tmp == NULL) {
failf (data, "realloc %u failed", (*m)->size);
return -1;
}
conn->app_data = tmp;
if((*m)->init && (*(*m)->init)(conn->app_data) != 0) {
infof(data, "Skipping %s...\n", (*m)->name);
continue;
}
infof(data, "Trying %s...\n", (*m)->name);
if(Curl_ftpsendf(conn, "AUTH %s", (*m)->name))
return -1;
if(Curl_GetFTPResponse(&nread, conn, &ftpcode))
return -1;
if(conn->data->state.buffer[0] != '3'){
switch(ftpcode) {
case 504:
infof(data,
"%s is not supported by the server.\n", (*m)->name);
break;
case 534:
infof(data, "%s rejected as security mechanism.\n", (*m)->name);
break;
default:
if(conn->data->state.buffer[0] == '5') {
infof(data, "The server doesn't support the FTP "
"security extensions.\n");
return -1;
}
break;
}
continue;
}
ret = (*(*m)->auth)(conn->app_data, conn);
if(ret == AUTH_CONTINUE)
continue;
else if(ret != AUTH_OK){
/* mechanism is supposed to output error string */
return -1;
}
conn->mech = *m;
conn->sec_complete = 1;
conn->command_prot = prot_safe;
/* Set the requested protection level */
/* BLOCKING */
Curl_sec_set_protection_level(conn);
break;
}
return *m == NULL;
}
void
Curl_sec_end(struct connectdata *conn)
{
if(conn->mech != NULL) {
if(conn->mech->end)
(conn->mech->end)(conn->app_data);
memset(conn->app_data, 0, conn->mech->size);
free(conn->app_data);
conn->app_data = NULL;
}
conn->sec_complete = 0;
conn->data_prot = (enum protection_level)0;
conn->mech=NULL;
}
#endif /* HAVE_KRB4 */
#endif /* CURL_DISABLE_FTP */