Externals: Add libcurl.

Externals/curl/lib/krb5.c

@@ -0,0 +1,332 @@
+/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
+ *
+ * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska H<>gskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * Copyright (c) 2004 - 2016 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"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+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 = data->set.str[STRING_SERVICE_NAME] ?
+                        data->set.str[STRING_SERVICE_NAME] :
+                        "ftp";
+  const char *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;
+  struct sockaddr_in **remote_addr =
+    (struct sockaddr_in **)&conn->ip_addr->ai_addr;
+
+  if(getsockname(conn->sock[FIRSTSOCKET],
+                 (struct sockaddr *)&conn->local_addr, &l) < 0)
+    perror("getsockname()");
+
+  chan.initiator_addrtype = GSS_C_AF_INET;
+  chan.initiator_address.length = l - 4;
+  chan.initiator_address.value = &conn->local_addr.sin_addr.s_addr;
+  chan.acceptor_addrtype = GSS_C_AF_INET;
+  chan.acceptor_address.length = l - 4;
+  chan.acceptor_address.value = &(*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 */