Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 1 | /* GSSAPI/krb5 support for FTP - loosely based on old krb4.c |
| 2 | * |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 3 | * Copyright (c) 1995, 1996, 1997, 1998, 1999, 2010 Kungliga Tekniska Högskolan |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 4 | * (Royal Institute of Technology, Stockholm, Sweden). |
| 5 | * Copyright (c) 2004 - 2009 Daniel Stenberg |
| 6 | * All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * |
| 12 | * 1. Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * |
| 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. |
| 18 | * |
| 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. |
| 22 | * |
| 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 |
| 31 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 32 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 33 | * SUCH DAMAGE. */ |
| 34 | |
| 35 | #include "setup.h" |
| 36 | |
| 37 | #ifndef CURL_DISABLE_FTP |
| 38 | #ifdef HAVE_GSSAPI |
| 39 | |
| 40 | #ifdef HAVE_OLD_GSSMIT |
| 41 | #define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name |
| 42 | #endif |
| 43 | |
| 44 | #include <stdlib.h> |
| 45 | #ifdef HAVE_NETDB_H |
| 46 | #include <netdb.h> |
| 47 | #endif |
| 48 | #include <string.h> |
| 49 | |
| 50 | #ifdef HAVE_GSSGNU |
| 51 | # include <gss.h> |
| 52 | #elif defined HAVE_GSSMIT |
| 53 | /* MIT style */ |
| 54 | # include <gssapi/gssapi.h> |
| 55 | # include <gssapi/gssapi_generic.h> |
| 56 | # include <gssapi/gssapi_krb5.h> |
| 57 | #else |
| 58 | /* Heimdal-style */ |
| 59 | # include <gssapi.h> |
| 60 | #endif |
| 61 | |
| 62 | #include "urldata.h" |
| 63 | #include "curl_base64.h" |
| 64 | #include "ftp.h" |
| 65 | #include "sendf.h" |
| 66 | #include "krb4.h" |
| 67 | #include "curl_memory.h" |
| 68 | |
| 69 | #define _MPRINTF_REPLACE /* use our functions only */ |
| 70 | #include <curl/mprintf.h> |
| 71 | |
| 72 | /* The last #include file should be: */ |
| 73 | #include "memdebug.h" |
| 74 | |
| 75 | #define LOCAL_ADDR (&conn->local_addr) |
| 76 | #define REMOTE_ADDR conn->ip_addr->ai_addr |
| 77 | |
| 78 | static int |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 79 | krb5_init(void *app_data) |
| 80 | { |
| 81 | gss_ctx_id_t *context = app_data; |
| 82 | /* Make sure our context is initialized for krb5_end. */ |
| 83 | *context = GSS_C_NO_CONTEXT; |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | static int |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 88 | krb5_check_prot(void *app_data, int level) |
| 89 | { |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 90 | (void)app_data; /* unused */ |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 91 | if(level == prot_confidential) |
| 92 | return -1; |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static int |
| 97 | krb5_decode(void *app_data, void *buf, int len, int level, |
| 98 | struct connectdata *conn) |
| 99 | { |
| 100 | gss_ctx_id_t *context = app_data; |
| 101 | OM_uint32 maj, min; |
| 102 | gss_buffer_desc enc, dec; |
| 103 | |
| 104 | /* shut gcc up */ |
| 105 | level = 0; |
| 106 | conn = NULL; |
| 107 | |
| 108 | enc.value = buf; |
| 109 | enc.length = len; |
| 110 | maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL); |
| 111 | if(maj != GSS_S_COMPLETE) { |
| 112 | if(len >= 4) |
| 113 | strcpy(buf, "599 "); |
| 114 | return -1; |
| 115 | } |
| 116 | |
| 117 | memcpy(buf, dec.value, dec.length); |
| 118 | len = dec.length; |
| 119 | gss_release_buffer(&min, &dec); |
| 120 | |
| 121 | return len; |
| 122 | } |
| 123 | |
| 124 | static int |
| 125 | krb5_overhead(void *app_data, int level, int len) |
| 126 | { |
| 127 | /* no arguments are used, just init them to prevent compiler warnings */ |
| 128 | app_data = NULL; |
| 129 | level = 0; |
| 130 | len = 0; |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static int |
| 135 | krb5_encode(void *app_data, const void *from, int length, int level, void **to, |
| 136 | struct connectdata *conn) |
| 137 | { |
| 138 | gss_ctx_id_t *context = app_data; |
| 139 | gss_buffer_desc dec, enc; |
| 140 | OM_uint32 maj, min; |
| 141 | int state; |
| 142 | int len; |
| 143 | |
| 144 | /* shut gcc up */ |
| 145 | conn = NULL; |
| 146 | |
| 147 | /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal |
| 148 | * libraries modify the input buffer in gss_seal() |
| 149 | */ |
| 150 | dec.value = (void*)from; |
| 151 | dec.length = length; |
| 152 | maj = gss_seal(&min, *context, |
| 153 | level == prot_private, |
| 154 | GSS_C_QOP_DEFAULT, |
| 155 | &dec, &state, &enc); |
| 156 | |
| 157 | if(maj != GSS_S_COMPLETE) |
| 158 | return -1; |
| 159 | |
| 160 | /* malloc a new buffer, in case gss_release_buffer doesn't work as expected */ |
| 161 | *to = malloc(enc.length); |
| 162 | if(!*to) |
| 163 | return -1; |
| 164 | memcpy(*to, enc.value, enc.length); |
| 165 | len = enc.length; |
| 166 | gss_release_buffer(&min, &enc); |
| 167 | return len; |
| 168 | } |
| 169 | |
| 170 | static int |
| 171 | krb5_auth(void *app_data, struct connectdata *conn) |
| 172 | { |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 173 | int ret = AUTH_OK; |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 174 | char *p; |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 175 | const char *host = conn->host.name; |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 176 | ssize_t nread; |
| 177 | curl_socklen_t l = sizeof(conn->local_addr); |
| 178 | struct SessionHandle *data = conn->data; |
| 179 | CURLcode result; |
| 180 | const char *service = "ftp", *srv_host = "host"; |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 181 | gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp; |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 182 | OM_uint32 maj, min; |
| 183 | gss_name_t gssname; |
| 184 | gss_ctx_id_t *context = app_data; |
| 185 | struct gss_channel_bindings_struct chan; |
| 186 | |
| 187 | if(getsockname(conn->sock[FIRSTSOCKET], |
| 188 | (struct sockaddr *)LOCAL_ADDR, &l) < 0) |
| 189 | perror("getsockname()"); |
| 190 | |
| 191 | chan.initiator_addrtype = GSS_C_AF_INET; |
| 192 | chan.initiator_address.length = l - 4; |
| 193 | chan.initiator_address.value = |
| 194 | &((struct sockaddr_in *)LOCAL_ADDR)->sin_addr.s_addr; |
| 195 | chan.acceptor_addrtype = GSS_C_AF_INET; |
| 196 | chan.acceptor_address.length = l - 4; |
| 197 | chan.acceptor_address.value = |
| 198 | &((struct sockaddr_in *)REMOTE_ADDR)->sin_addr.s_addr; |
| 199 | chan.application_data.length = 0; |
| 200 | chan.application_data.value = NULL; |
| 201 | |
| 202 | /* this loop will execute twice (once for service, once for host) */ |
| 203 | while(1) { |
| 204 | /* this really shouldn't be repeated here, but can't help it */ |
| 205 | if(service == srv_host) { |
| 206 | result = Curl_ftpsendf(conn, "AUTH GSSAPI"); |
| 207 | |
| 208 | if(result) |
| 209 | return -2; |
| 210 | if(Curl_GetFTPResponse(&nread, conn, NULL)) |
| 211 | return -1; |
| 212 | |
| 213 | if(data->state.buffer[0] != '3') |
| 214 | return -1; |
| 215 | } |
| 216 | |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 217 | input_buffer.value = data->state.buffer; |
| 218 | input_buffer.length = snprintf(input_buffer.value, BUFSIZE, "%s@%s", |
| 219 | service, host); |
| 220 | maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE, |
| 221 | &gssname); |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 222 | if(maj != GSS_S_COMPLETE) { |
| 223 | gss_release_name(&min, &gssname); |
| 224 | if(service == srv_host) { |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 225 | Curl_failf(data, "Error importing service name %s", input_buffer.value); |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 226 | return AUTH_ERROR; |
| 227 | } |
| 228 | service = srv_host; |
| 229 | continue; |
| 230 | } |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 231 | /* We pass NULL as |output_name_type| to avoid a leak. */ |
| 232 | gss_display_name(&min, gssname, &output_buffer, NULL); |
| 233 | Curl_infof(data, "Trying against %s\n", output_buffer.value); |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 234 | gssresp = GSS_C_NO_BUFFER; |
| 235 | *context = GSS_C_NO_CONTEXT; |
| 236 | |
| 237 | do { |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 238 | /* Release the buffer at each iteration to avoid leaking: the first time |
| 239 | we are releasing the memory from gss_display_name. The last item is |
| 240 | taken care by a final gss_release_buffer. */ |
| 241 | gss_release_buffer(&min, &output_buffer); |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 242 | ret = AUTH_OK; |
| 243 | maj = gss_init_sec_context(&min, |
| 244 | GSS_C_NO_CREDENTIAL, |
| 245 | context, |
| 246 | gssname, |
| 247 | GSS_C_NO_OID, |
| 248 | GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG, |
| 249 | 0, |
| 250 | &chan, |
| 251 | gssresp, |
| 252 | NULL, |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 253 | &output_buffer, |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 254 | NULL, |
| 255 | NULL); |
| 256 | |
| 257 | if(gssresp) { |
| 258 | free(_gssresp.value); |
| 259 | gssresp = NULL; |
| 260 | } |
| 261 | |
| 262 | if(maj != GSS_S_COMPLETE && maj != GSS_S_CONTINUE_NEEDED) { |
| 263 | Curl_infof(data, "Error creating security context"); |
| 264 | ret = AUTH_ERROR; |
| 265 | break; |
| 266 | } |
| 267 | |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 268 | if(output_buffer.length != 0) { |
| 269 | if(Curl_base64_encode(data, (char *)output_buffer.value, |
| 270 | output_buffer.length, &p) < 1) { |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 271 | Curl_infof(data, "Out of memory base64-encoding"); |
| 272 | ret = AUTH_CONTINUE; |
| 273 | break; |
| 274 | } |
| 275 | |
| 276 | result = Curl_ftpsendf(conn, "ADAT %s", p); |
| 277 | |
| 278 | free(p); |
| 279 | |
| 280 | if(result) { |
| 281 | ret = -2; |
| 282 | break; |
| 283 | } |
| 284 | |
| 285 | if(Curl_GetFTPResponse(&nread, conn, NULL)) { |
| 286 | ret = -1; |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3'){ |
| 291 | Curl_infof(data, "Server didn't accept auth data\n"); |
| 292 | ret = AUTH_ERROR; |
| 293 | break; |
| 294 | } |
| 295 | |
| 296 | p = data->state.buffer + 4; |
| 297 | p = strstr(p, "ADAT="); |
| 298 | if(p) { |
| 299 | _gssresp.length = Curl_base64_decode(p + 5, (unsigned char **) |
| 300 | &_gssresp.value); |
| 301 | if(_gssresp.length < 1) { |
| 302 | Curl_failf(data, "Out of memory base64-encoding"); |
| 303 | ret = AUTH_CONTINUE; |
| 304 | break; |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | gssresp = &_gssresp; |
| 309 | } |
| 310 | } while(maj == GSS_S_CONTINUE_NEEDED); |
| 311 | |
| 312 | gss_release_name(&min, &gssname); |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 313 | gss_release_buffer(&min, &output_buffer); |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 314 | |
| 315 | if(gssresp) |
| 316 | free(_gssresp.value); |
| 317 | |
| 318 | if(ret == AUTH_OK || service == srv_host) |
| 319 | return ret; |
| 320 | |
| 321 | service = srv_host; |
| 322 | } |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 323 | return ret; |
| 324 | } |
| 325 | |
| 326 | static void krb5_end(void *app_data) |
| 327 | { |
| 328 | OM_uint32 maj, min; |
| 329 | gss_ctx_id_t *context = app_data; |
| 330 | if (*context != GSS_C_NO_CONTEXT) { |
| 331 | maj = gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER); |
| 332 | DEBUGASSERT(maj == GSS_S_COMPLETE); |
| 333 | } |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 334 | } |
| 335 | |
| 336 | struct Curl_sec_client_mech Curl_krb5_client_mech = { |
| 337 | "GSSAPI", |
| 338 | sizeof(gss_ctx_id_t), |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 339 | krb5_init, |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 340 | krb5_auth, |
Lucas Eckels | 9bd90e6 | 2012-08-06 15:07:02 -0700 | [diff] [blame^] | 341 | krb5_end, |
Kristian Monsen | 5ab5018 | 2010-05-14 18:53:44 +0100 | [diff] [blame] | 342 | krb5_check_prot, |
| 343 | krb5_overhead, |
| 344 | krb5_encode, |
| 345 | krb5_decode |
| 346 | }; |
| 347 | |
| 348 | #endif /* HAVE_GSSAPI */ |
| 349 | #endif /* CURL_DISABLE_FTP */ |