1 /* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
3 * Copyright (c) 1995, 1996, 1997, 1998, 1999, 2013 Kungliga Tekniska Högskolan
4 * (Royal Institute of Technology, Stockholm, Sweden).
5 * Copyright (c) 2004 - 2015 Daniel Stenberg
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #include "curl_setup.h"
37 #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_FTP)
44 #include "curl_base64.h"
46 #include "curl_gssapi.h"
49 #include "curl_memory.h"
52 #define _MPRINTF_REPLACE /* use our functions only */
53 #include <curl/mprintf.h>
55 /* The last #include file should be: */
58 #define LOCAL_ADDR (&conn->local_addr)
59 #define REMOTE_ADDR conn->ip_addr->ai_addr
62 krb5_init(void *app_data)
64 gss_ctx_id_t *context = app_data;
65 /* Make sure our context is initialized for krb5_end. */
66 *context = GSS_C_NO_CONTEXT;
71 krb5_check_prot(void *app_data, int level)
73 (void)app_data; /* unused */
74 if(level == PROT_CONFIDENTIAL)
80 krb5_decode(void *app_data, void *buf, int len,
81 int level UNUSED_PARAM,
82 struct connectdata *conn UNUSED_PARAM)
84 gss_ctx_id_t *context = app_data;
86 gss_buffer_desc enc, dec;
93 maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL);
94 if(maj != GSS_S_COMPLETE) {
100 memcpy(buf, dec.value, dec.length);
101 len = curlx_uztosi(dec.length);
102 gss_release_buffer(&min, &dec);
108 krb5_overhead(void *app_data, int level, int len)
110 /* no arguments are used */
118 krb5_encode(void *app_data, const void *from, int length, int level, void **to)
120 gss_ctx_id_t *context = app_data;
121 gss_buffer_desc dec, enc;
126 /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal
127 * libraries modify the input buffer in gss_seal()
129 dec.value = (void*)from;
131 maj = gss_seal(&min, *context,
132 level == PROT_PRIVATE,
136 if(maj != GSS_S_COMPLETE)
139 /* malloc a new buffer, in case gss_release_buffer doesn't work as
141 *to = malloc(enc.length);
144 memcpy(*to, enc.value, enc.length);
145 len = curlx_uztosi(enc.length);
146 gss_release_buffer(&min, &enc);
151 krb5_auth(void *app_data, struct connectdata *conn)
155 const char *host = conn->host.name;
157 curl_socklen_t l = sizeof(conn->local_addr);
158 struct SessionHandle *data = conn->data;
160 const char *service = "ftp", *srv_host = "host";
161 gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp;
164 gss_ctx_id_t *context = app_data;
165 struct gss_channel_bindings_struct chan;
166 size_t base64_sz = 0;
168 if(getsockname(conn->sock[FIRSTSOCKET],
169 (struct sockaddr *)LOCAL_ADDR, &l) < 0)
170 perror("getsockname()");
172 chan.initiator_addrtype = GSS_C_AF_INET;
173 chan.initiator_address.length = l - 4;
174 chan.initiator_address.value =
175 &((struct sockaddr_in *)LOCAL_ADDR)->sin_addr.s_addr;
176 chan.acceptor_addrtype = GSS_C_AF_INET;
177 chan.acceptor_address.length = l - 4;
178 chan.acceptor_address.value =
179 &((struct sockaddr_in *)REMOTE_ADDR)->sin_addr.s_addr;
180 chan.application_data.length = 0;
181 chan.application_data.value = NULL;
183 /* this loop will execute twice (once for service, once for host) */
185 /* this really shouldn't be repeated here, but can't help it */
186 if(service == srv_host) {
187 result = Curl_ftpsendf(conn, "AUTH GSSAPI");
191 if(Curl_GetFTPResponse(&nread, conn, NULL))
194 if(data->state.buffer[0] != '3')
198 input_buffer.value = data->state.buffer;
199 input_buffer.length = snprintf(input_buffer.value, BUFSIZE, "%s@%s",
201 maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE,
203 if(maj != GSS_S_COMPLETE) {
204 gss_release_name(&min, &gssname);
205 if(service == srv_host) {
206 Curl_failf(data, "Error importing service name %s",
213 /* We pass NULL as |output_name_type| to avoid a leak. */
214 gss_display_name(&min, gssname, &output_buffer, NULL);
215 Curl_infof(data, "Trying against %s\n", output_buffer.value);
216 gssresp = GSS_C_NO_BUFFER;
217 *context = GSS_C_NO_CONTEXT;
220 /* Release the buffer at each iteration to avoid leaking: the first time
221 we are releasing the memory from gss_display_name. The last item is
222 taken care by a final gss_release_buffer. */
223 gss_release_buffer(&min, &output_buffer);
225 maj = Curl_gss_init_sec_context(data,
237 free(_gssresp.value);
242 Curl_infof(data, "Error creating security context\n");
247 if(output_buffer.length != 0) {
248 result = Curl_base64_encode(data, (char *)output_buffer.value,
249 output_buffer.length, &p, &base64_sz);
251 Curl_infof(data,"base64-encoding: %s\n", curl_easy_strerror(result));
256 result = Curl_ftpsendf(conn, "ADAT %s", p);
265 if(Curl_GetFTPResponse(&nread, conn, NULL)) {
270 if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') {
271 Curl_infof(data, "Server didn't accept auth data\n");
276 p = data->state.buffer + 4;
277 p = strstr(p, "ADAT=");
279 result = Curl_base64_decode(p + 5,
280 (unsigned char **)&_gssresp.value,
283 Curl_failf(data,"base64-decoding: %s", curl_easy_strerror(result));
291 } while(maj == GSS_S_CONTINUE_NEEDED);
293 gss_release_name(&min, &gssname);
294 gss_release_buffer(&min, &output_buffer);
297 free(_gssresp.value);
299 if(ret == AUTH_OK || service == srv_host)
307 static void krb5_end(void *app_data)
310 gss_ctx_id_t *context = app_data;
311 if(*context != GSS_C_NO_CONTEXT) {
315 gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER);
316 DEBUGASSERT(maj == GSS_S_COMPLETE);
320 struct Curl_sec_client_mech Curl_krb5_client_mech = {
322 sizeof(gss_ctx_id_t),
332 #endif /* HAVE_GSSAPI && !CURL_DISABLE_FTP */