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-rw-r--r--libcurl/src/lib/krb5.c332
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diff --git a/libcurl/src/lib/krb5.c b/libcurl/src/lib/krb5.c
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+/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
+ *
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * Copyright (c) 2004 - 2015 Daniel Stenberg
+ * 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 "curl_setup.h"
+
+#if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_FTP)
+
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+
+#include "urldata.h"
+#include "curl_base64.h"
+#include "ftp.h"
+#include "curl_gssapi.h"
+#include "sendf.h"
+#include "curl_sec.h"
+#include "warnless.h"
+#include "curl_printf.h"
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+#define LOCAL_ADDR (&conn->local_addr)
+#define REMOTE_ADDR conn->ip_addr->ai_addr
+
+static int
+krb5_init(void *app_data)
+{
+ gss_ctx_id_t *context = app_data;
+ /* Make sure our context is initialized for krb5_end. */
+ *context = GSS_C_NO_CONTEXT;
+ return 0;
+}
+
+static int
+krb5_check_prot(void *app_data, int level)
+{
+ (void)app_data; /* unused */
+ if(level == PROT_CONFIDENTIAL)
+ return -1;
+ return 0;
+}
+
+static int
+krb5_decode(void *app_data, void *buf, int len,
+ int level UNUSED_PARAM,
+ struct connectdata *conn UNUSED_PARAM)
+{
+ gss_ctx_id_t *context = app_data;
+ OM_uint32 maj, min;
+ gss_buffer_desc enc, dec;
+
+ (void)level;
+ (void)conn;
+
+ enc.value = buf;
+ enc.length = len;
+ maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL);
+ if(maj != GSS_S_COMPLETE) {
+ if(len >= 4)
+ strcpy(buf, "599 ");
+ return -1;
+ }
+
+ memcpy(buf, dec.value, dec.length);
+ len = curlx_uztosi(dec.length);
+ gss_release_buffer(&min, &dec);
+
+ return len;
+}
+
+static int
+krb5_overhead(void *app_data, int level, int len)
+{
+ /* no arguments are used */
+ (void)app_data;
+ (void)level;
+ (void)len;
+ return 0;
+}
+
+static int
+krb5_encode(void *app_data, const void *from, int length, int level, void **to)
+{
+ gss_ctx_id_t *context = app_data;
+ gss_buffer_desc dec, enc;
+ OM_uint32 maj, min;
+ int state;
+ int len;
+
+ /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal
+ * libraries modify the input buffer in gss_seal()
+ */
+ dec.value = (void*)from;
+ dec.length = length;
+ maj = gss_seal(&min, *context,
+ level == PROT_PRIVATE,
+ GSS_C_QOP_DEFAULT,
+ &dec, &state, &enc);
+
+ if(maj != GSS_S_COMPLETE)
+ return -1;
+
+ /* malloc a new buffer, in case gss_release_buffer doesn't work as
+ expected */
+ *to = malloc(enc.length);
+ if(!*to)
+ return -1;
+ memcpy(*to, enc.value, enc.length);
+ len = curlx_uztosi(enc.length);
+ gss_release_buffer(&min, &enc);
+ return len;
+}
+
+static int
+krb5_auth(void *app_data, struct connectdata *conn)
+{
+ int ret = AUTH_OK;
+ char *p;
+ const char *host = conn->host.name;
+ ssize_t nread;
+ curl_socklen_t l = sizeof(conn->local_addr);
+ struct SessionHandle *data = conn->data;
+ CURLcode result;
+ const char *service = "ftp", *srv_host = "host";
+ gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp;
+ OM_uint32 maj, min;
+ gss_name_t gssname;
+ gss_ctx_id_t *context = app_data;
+ struct gss_channel_bindings_struct chan;
+ size_t base64_sz = 0;
+
+ if(getsockname(conn->sock[FIRSTSOCKET],
+ (struct sockaddr *)LOCAL_ADDR, &l) < 0)
+ perror("getsockname()");
+
+ chan.initiator_addrtype = GSS_C_AF_INET;
+ chan.initiator_address.length = l - 4;
+ chan.initiator_address.value =
+ &((struct sockaddr_in *)LOCAL_ADDR)->sin_addr.s_addr;
+ chan.acceptor_addrtype = GSS_C_AF_INET;
+ chan.acceptor_address.length = l - 4;
+ chan.acceptor_address.value =
+ &((struct sockaddr_in *)REMOTE_ADDR)->sin_addr.s_addr;
+ chan.application_data.length = 0;
+ chan.application_data.value = NULL;
+
+ /* this loop will execute twice (once for service, once for host) */
+ for(;;) {
+ /* this really shouldn't be repeated here, but can't help it */
+ if(service == srv_host) {
+ result = Curl_ftpsendf(conn, "AUTH GSSAPI");
+
+ if(result)
+ return -2;
+ if(Curl_GetFTPResponse(&nread, conn, NULL))
+ return -1;
+
+ if(data->state.buffer[0] != '3')
+ return -1;
+ }
+
+ input_buffer.value = data->state.buffer;
+ input_buffer.length = snprintf(input_buffer.value, BUFSIZE, "%s@%s",
+ service, host);
+ maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE,
+ &gssname);
+ if(maj != GSS_S_COMPLETE) {
+ gss_release_name(&min, &gssname);
+ if(service == srv_host) {
+ Curl_failf(data, "Error importing service name %s",
+ input_buffer.value);
+ return AUTH_ERROR;
+ }
+ service = srv_host;
+ continue;
+ }
+ /* We pass NULL as |output_name_type| to avoid a leak. */
+ gss_display_name(&min, gssname, &output_buffer, NULL);
+ Curl_infof(data, "Trying against %s\n", output_buffer.value);
+ gssresp = GSS_C_NO_BUFFER;
+ *context = GSS_C_NO_CONTEXT;
+
+ do {
+ /* Release the buffer at each iteration to avoid leaking: the first time
+ we are releasing the memory from gss_display_name. The last item is
+ taken care by a final gss_release_buffer. */
+ gss_release_buffer(&min, &output_buffer);
+ ret = AUTH_OK;
+ maj = Curl_gss_init_sec_context(data,
+ &min,
+ context,
+ gssname,
+ &Curl_krb5_mech_oid,
+ &chan,
+ gssresp,
+ &output_buffer,
+ TRUE,
+ NULL);
+
+ if(gssresp) {
+ free(_gssresp.value);
+ gssresp = NULL;
+ }
+
+ if(GSS_ERROR(maj)) {
+ Curl_infof(data, "Error creating security context\n");
+ ret = AUTH_ERROR;
+ break;
+ }
+
+ if(output_buffer.length != 0) {
+ result = Curl_base64_encode(data, (char *)output_buffer.value,
+ output_buffer.length, &p, &base64_sz);
+ if(result) {
+ Curl_infof(data, "base64-encoding: %s\n",
+ curl_easy_strerror(result));
+ ret = AUTH_CONTINUE;
+ break;
+ }
+
+ result = Curl_ftpsendf(conn, "ADAT %s", p);
+
+ free(p);
+
+ if(result) {
+ ret = -2;
+ break;
+ }
+
+ if(Curl_GetFTPResponse(&nread, conn, NULL)) {
+ ret = -1;
+ break;
+ }
+
+ if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') {
+ Curl_infof(data, "Server didn't accept auth data\n");
+ ret = AUTH_ERROR;
+ break;
+ }
+
+ p = data->state.buffer + 4;
+ p = strstr(p, "ADAT=");
+ if(p) {
+ result = Curl_base64_decode(p + 5,
+ (unsigned char **)&_gssresp.value,
+ &_gssresp.length);
+ if(result) {
+ Curl_failf(data, "base64-decoding: %s",
+ curl_easy_strerror(result));
+ ret = AUTH_CONTINUE;
+ break;
+ }
+ }
+
+ gssresp = &_gssresp;
+ }
+ } while(maj == GSS_S_CONTINUE_NEEDED);
+
+ gss_release_name(&min, &gssname);
+ gss_release_buffer(&min, &output_buffer);
+
+ if(gssresp)
+ free(_gssresp.value);
+
+ if(ret == AUTH_OK || service == srv_host)
+ return ret;
+
+ service = srv_host;
+ }
+ return ret;
+}
+
+static void krb5_end(void *app_data)
+{
+ OM_uint32 min;
+ gss_ctx_id_t *context = app_data;
+ if(*context != GSS_C_NO_CONTEXT) {
+#ifdef DEBUGBUILD
+ OM_uint32 maj =
+#endif
+ gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER);
+ DEBUGASSERT(maj == GSS_S_COMPLETE);
+ }
+}
+
+struct Curl_sec_client_mech Curl_krb5_client_mech = {
+ "GSSAPI",
+ sizeof(gss_ctx_id_t),
+ krb5_init,
+ krb5_auth,
+ krb5_end,
+ krb5_check_prot,
+ krb5_overhead,
+ krb5_encode,
+ krb5_decode
+};
+
+#endif /* HAVE_GSSAPI && !CURL_DISABLE_FTP */