900 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			900 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
| /* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
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|  *
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|  * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan
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|  * (Royal Institute of Technology, Stockholm, Sweden).
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|  * Copyright (c) 2004 - 2021 Daniel Stenberg
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  *
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * 3. Neither the name of the Institute nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.  */
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| 
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| #include "curl_setup.h"
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| 
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| #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_FTP)
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| 
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| #ifdef HAVE_NETDB_H
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| #include <netdb.h>
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| #endif
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| 
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| #include "urldata.h"
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| #include "curl_base64.h"
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| #include "ftp.h"
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| #include "curl_gssapi.h"
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| #include "sendf.h"
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| #include "curl_krb5.h"
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| #include "warnless.h"
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| #include "non-ascii.h"
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| #include "strcase.h"
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| #include "strdup.h"
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| 
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| /* The last 3 #include files should be in this order */
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| #include "curl_printf.h"
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| #include "curl_memory.h"
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| #include "memdebug.h"
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| 
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| static CURLcode ftpsend(struct Curl_easy *data, struct connectdata *conn,
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|                         const char *cmd)
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| {
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|   ssize_t bytes_written;
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| #define SBUF_SIZE 1024
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|   char s[SBUF_SIZE];
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|   size_t write_len;
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|   char *sptr = s;
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|   CURLcode result = CURLE_OK;
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| #ifdef HAVE_GSSAPI
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|   enum protection_level data_sec = conn->data_prot;
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| #endif
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| 
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|   if(!cmd)
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|     return CURLE_BAD_FUNCTION_ARGUMENT;
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| 
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|   write_len = strlen(cmd);
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|   if(!write_len || write_len > (sizeof(s) -3))
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|     return CURLE_BAD_FUNCTION_ARGUMENT;
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| 
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|   memcpy(&s, cmd, write_len);
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|   strcpy(&s[write_len], "\r\n"); /* append a trailing CRLF */
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|   write_len += 2;
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|   bytes_written = 0;
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| 
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|   result = Curl_convert_to_network(data, s, write_len);
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|   /* Curl_convert_to_network calls failf if unsuccessful */
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|   if(result)
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|     return result;
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| 
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|   for(;;) {
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| #ifdef HAVE_GSSAPI
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|     conn->data_prot = PROT_CMD;
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| #endif
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|     result = Curl_write(data, conn->sock[FIRSTSOCKET], sptr, write_len,
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|                         &bytes_written);
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| #ifdef HAVE_GSSAPI
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|     DEBUGASSERT(data_sec > PROT_NONE && data_sec < PROT_LAST);
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|     conn->data_prot = data_sec;
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| #endif
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| 
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|     if(result)
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|       break;
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| 
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|     Curl_debug(data, CURLINFO_HEADER_OUT, sptr, (size_t)bytes_written);
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| 
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|     if(bytes_written != (ssize_t)write_len) {
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|       write_len -= bytes_written;
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|       sptr += bytes_written;
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|     }
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|     else
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|       break;
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|   }
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| 
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|   return result;
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| }
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| 
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| static int
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| krb5_init(void *app_data)
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| {
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|   gss_ctx_id_t *context = app_data;
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|   /* Make sure our context is initialized for krb5_end. */
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|   *context = GSS_C_NO_CONTEXT;
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|   return 0;
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| }
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| 
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| static int
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| krb5_check_prot(void *app_data, int level)
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| {
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|   (void)app_data; /* unused */
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|   if(level == PROT_CONFIDENTIAL)
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|     return -1;
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|   return 0;
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| }
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| 
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| static int
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| krb5_decode(void *app_data, void *buf, int len,
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|             int level UNUSED_PARAM,
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|             struct connectdata *conn UNUSED_PARAM)
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| {
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|   gss_ctx_id_t *context = app_data;
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|   OM_uint32 maj, min;
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|   gss_buffer_desc enc, dec;
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| 
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|   (void)level;
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|   (void)conn;
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| 
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|   enc.value = buf;
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|   enc.length = len;
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|   maj = gss_unwrap(&min, *context, &enc, &dec, NULL, NULL);
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|   if(maj != GSS_S_COMPLETE) {
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|     if(len >= 4)
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|       strcpy(buf, "599 ");
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|     return -1;
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|   }
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| 
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|   memcpy(buf, dec.value, dec.length);
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|   len = curlx_uztosi(dec.length);
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|   gss_release_buffer(&min, &dec);
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| 
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|   return len;
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| }
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| 
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| static int
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| krb5_encode(void *app_data, const void *from, int length, int level, void **to)
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| {
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|   gss_ctx_id_t *context = app_data;
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|   gss_buffer_desc dec, enc;
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|   OM_uint32 maj, min;
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|   int state;
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|   int len;
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| 
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|   /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal
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|    * libraries modify the input buffer in gss_wrap()
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|    */
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|   dec.value = (void *)from;
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|   dec.length = length;
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|   maj = gss_wrap(&min, *context,
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|                  level == PROT_PRIVATE,
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|                  GSS_C_QOP_DEFAULT,
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|                  &dec, &state, &enc);
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| 
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|   if(maj != GSS_S_COMPLETE)
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|     return -1;
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| 
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|   /* malloc a new buffer, in case gss_release_buffer doesn't work as
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|      expected */
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|   *to = malloc(enc.length);
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|   if(!*to)
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|     return -1;
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|   memcpy(*to, enc.value, enc.length);
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|   len = curlx_uztosi(enc.length);
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|   gss_release_buffer(&min, &enc);
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|   return len;
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| }
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| 
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| static int
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| krb5_auth(void *app_data, struct Curl_easy *data, struct connectdata *conn)
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| {
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|   int ret = AUTH_OK;
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|   char *p;
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|   const char *host = conn->host.name;
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|   ssize_t nread;
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|   curl_socklen_t l = sizeof(conn->local_addr);
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|   CURLcode result;
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|   const char *service = data->set.str[STRING_SERVICE_NAME] ?
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|                         data->set.str[STRING_SERVICE_NAME] :
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|                         "ftp";
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|   const char *srv_host = "host";
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|   gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp;
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|   OM_uint32 maj, min;
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|   gss_name_t gssname;
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|   gss_ctx_id_t *context = app_data;
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|   struct gss_channel_bindings_struct chan;
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|   size_t base64_sz = 0;
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|   struct sockaddr_in **remote_addr =
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|     (struct sockaddr_in **)&conn->ip_addr->ai_addr;
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|   char *stringp;
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| 
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|   if(getsockname(conn->sock[FIRSTSOCKET],
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|                  (struct sockaddr *)&conn->local_addr, &l) < 0)
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|     perror("getsockname()");
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| 
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|   chan.initiator_addrtype = GSS_C_AF_INET;
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|   chan.initiator_address.length = l - 4;
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|   chan.initiator_address.value = &conn->local_addr.sin_addr.s_addr;
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|   chan.acceptor_addrtype = GSS_C_AF_INET;
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|   chan.acceptor_address.length = l - 4;
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|   chan.acceptor_address.value = &(*remote_addr)->sin_addr.s_addr;
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|   chan.application_data.length = 0;
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|   chan.application_data.value = NULL;
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| 
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|   /* this loop will execute twice (once for service, once for host) */
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|   for(;;) {
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|     /* this really shouldn't be repeated here, but can't help it */
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|     if(service == srv_host) {
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|       result = ftpsend(data, conn, "AUTH GSSAPI");
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|       if(result)
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|         return -2;
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| 
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|       if(Curl_GetFTPResponse(data, &nread, NULL))
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|         return -1;
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| 
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|       if(data->state.buffer[0] != '3')
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|         return -1;
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|     }
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| 
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|     stringp = aprintf("%s@%s", service, host);
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|     if(!stringp)
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|       return -2;
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| 
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|     input_buffer.value = stringp;
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|     input_buffer.length = strlen(stringp);
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|     maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE,
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|                           &gssname);
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|     free(stringp);
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|     if(maj != GSS_S_COMPLETE) {
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|       gss_release_name(&min, &gssname);
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|       if(service == srv_host) {
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|         failf(data, "Error importing service name %s@%s", service, host);
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|         return AUTH_ERROR;
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|       }
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|       service = srv_host;
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|       continue;
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|     }
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|     /* We pass NULL as |output_name_type| to avoid a leak. */
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|     gss_display_name(&min, gssname, &output_buffer, NULL);
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|     infof(data, "Trying against %s", output_buffer.value);
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|     gssresp = GSS_C_NO_BUFFER;
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|     *context = GSS_C_NO_CONTEXT;
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| 
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|     do {
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|       /* Release the buffer at each iteration to avoid leaking: the first time
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|          we are releasing the memory from gss_display_name. The last item is
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|          taken care by a final gss_release_buffer. */
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|       gss_release_buffer(&min, &output_buffer);
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|       ret = AUTH_OK;
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|       maj = Curl_gss_init_sec_context(data,
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|                                       &min,
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|                                       context,
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|                                       gssname,
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|                                       &Curl_krb5_mech_oid,
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|                                       &chan,
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|                                       gssresp,
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|                                       &output_buffer,
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|                                       TRUE,
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|                                       NULL);
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| 
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|       if(gssresp) {
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|         free(_gssresp.value);
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|         gssresp = NULL;
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|       }
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| 
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|       if(GSS_ERROR(maj)) {
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|         infof(data, "Error creating security context");
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|         ret = AUTH_ERROR;
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|         break;
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|       }
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| 
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|       if(output_buffer.length) {
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|         char *cmd;
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| 
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|         result = Curl_base64_encode(data, (char *)output_buffer.value,
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|                                     output_buffer.length, &p, &base64_sz);
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|         if(result) {
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|           infof(data, "base64-encoding: %s", curl_easy_strerror(result));
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|           ret = AUTH_ERROR;
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|           break;
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|         }
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| 
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|         cmd = aprintf("ADAT %s", p);
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|         if(cmd)
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|           result = ftpsend(data, conn, cmd);
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|         else
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|           result = CURLE_OUT_OF_MEMORY;
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| 
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|         free(p);
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|         free(cmd);
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| 
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|         if(result) {
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|           ret = -2;
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|           break;
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|         }
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| 
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|         if(Curl_GetFTPResponse(data, &nread, NULL)) {
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|           ret = -1;
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|           break;
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|         }
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| 
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|         if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') {
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|           infof(data, "Server didn't accept auth data");
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|           ret = AUTH_ERROR;
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|           break;
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|         }
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| 
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|         _gssresp.value = NULL; /* make sure it is initialized */
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|         p = data->state.buffer + 4;
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|         p = strstr(p, "ADAT=");
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|         if(p) {
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|           result = Curl_base64_decode(p + 5,
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|                                       (unsigned char **)&_gssresp.value,
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|                                       &_gssresp.length);
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|           if(result) {
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|             failf(data, "base64-decoding: %s", curl_easy_strerror(result));
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|             ret = AUTH_CONTINUE;
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|             break;
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|           }
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|         }
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| 
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|         gssresp = &_gssresp;
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|       }
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|     } while(maj == GSS_S_CONTINUE_NEEDED);
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| 
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|     gss_release_name(&min, &gssname);
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|     gss_release_buffer(&min, &output_buffer);
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| 
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|     if(gssresp)
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|       free(_gssresp.value);
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| 
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|     if(ret == AUTH_OK || service == srv_host)
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|       return ret;
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| 
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|     service = srv_host;
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|   }
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|   return ret;
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| }
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| 
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| static void krb5_end(void *app_data)
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| {
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|     OM_uint32 min;
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|     gss_ctx_id_t *context = app_data;
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|     if(*context != GSS_C_NO_CONTEXT) {
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|       OM_uint32 maj = gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER);
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|       (void)maj;
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|       DEBUGASSERT(maj == GSS_S_COMPLETE);
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|     }
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| }
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| 
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| static const struct Curl_sec_client_mech Curl_krb5_client_mech = {
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|   "GSSAPI",
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|   sizeof(gss_ctx_id_t),
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|   krb5_init,
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|   krb5_auth,
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|   krb5_end,
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|   krb5_check_prot,
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| 
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|   krb5_encode,
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|   krb5_decode
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| };
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| 
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| static const struct {
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|   enum protection_level level;
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|   const char *name;
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| } level_names[] = {
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|   { PROT_CLEAR, "clear" },
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|   { PROT_SAFE, "safe" },
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|   { PROT_CONFIDENTIAL, "confidential" },
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|   { PROT_PRIVATE, "private" }
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| };
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| 
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| static enum protection_level
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| name_to_level(const char *name)
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| {
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|   int i;
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|   for(i = 0; i < (int)sizeof(level_names)/(int)sizeof(level_names[0]); i++)
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|     if(curl_strequal(name, level_names[i].name))
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|       return level_names[i].level;
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|   return PROT_NONE;
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| }
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| 
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| /* Convert a protocol |level| to its char representation.
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|    We take an int to catch programming mistakes. */
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| static char level_to_char(int level)
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| {
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|   switch(level) {
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|   case PROT_CLEAR:
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|     return 'C';
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|   case PROT_SAFE:
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|     return 'S';
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|   case PROT_CONFIDENTIAL:
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|     return 'E';
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|   case PROT_PRIVATE:
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|     return 'P';
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|   case PROT_CMD:
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|     /* Fall through */
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|   default:
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|     /* Those 2 cases should not be reached! */
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|     break;
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|   }
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|   DEBUGASSERT(0);
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|   /* Default to the most secure alternative. */
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|   return 'P';
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| }
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| 
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| /* Send an FTP command defined by |message| and the optional arguments. The
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|    function returns the ftp_code. If an error occurs, -1 is returned. */
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| static int ftp_send_command(struct Curl_easy *data, const char *message, ...)
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| {
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|   int ftp_code;
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|   ssize_t nread = 0;
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|   va_list args;
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|   char print_buffer[50];
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| 
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|   va_start(args, message);
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|   mvsnprintf(print_buffer, sizeof(print_buffer), message, args);
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|   va_end(args);
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| 
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|   if(ftpsend(data, data->conn, print_buffer)) {
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|     ftp_code = -1;
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|   }
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|   else {
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|     if(Curl_GetFTPResponse(data, &nread, &ftp_code))
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|       ftp_code = -1;
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|   }
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| 
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|   (void)nread; /* Unused */
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|   return ftp_code;
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| }
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| 
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| /* Read |len| from the socket |fd| and store it in |to|. Return a CURLcode
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|    saying whether an error occurred or CURLE_OK if |len| was read. */
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| static CURLcode
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| socket_read(curl_socket_t fd, void *to, size_t len)
 | |
| {
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|   char *to_p = to;
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|   CURLcode result;
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|   ssize_t nread = 0;
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| 
 | |
|   while(len > 0) {
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|     result = Curl_read_plain(fd, to_p, len, &nread);
 | |
|     if(!result) {
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|       len -= nread;
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|       to_p += nread;
 | |
|     }
 | |
|     else {
 | |
|       if(result == CURLE_AGAIN)
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|         continue;
 | |
|       return result;
 | |
|     }
 | |
|   }
 | |
|   return CURLE_OK;
 | |
| }
 | |
| 
 | |
| 
 | |
| /* Write |len| bytes from the buffer |to| to the socket |fd|. Return a
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|    CURLcode saying whether an error occurred or CURLE_OK if |len| was
 | |
|    written. */
 | |
| static CURLcode
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| socket_write(struct Curl_easy *data, curl_socket_t fd, const void *to,
 | |
|              size_t len)
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| {
 | |
|   const char *to_p = to;
 | |
|   CURLcode result;
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|   ssize_t written;
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| 
 | |
|   while(len > 0) {
 | |
|     result = Curl_write_plain(data, fd, to_p, len, &written);
 | |
|     if(!result) {
 | |
|       len -= written;
 | |
|       to_p += written;
 | |
|     }
 | |
|     else {
 | |
|       if(result == CURLE_AGAIN)
 | |
|         continue;
 | |
|       return result;
 | |
|     }
 | |
|   }
 | |
|   return CURLE_OK;
 | |
| }
 | |
| 
 | |
| static CURLcode read_data(struct connectdata *conn,
 | |
|                           curl_socket_t fd,
 | |
|                           struct krb5buffer *buf)
 | |
| {
 | |
|   int len;
 | |
|   CURLcode result;
 | |
| 
 | |
|   result = socket_read(fd, &len, sizeof(len));
 | |
|   if(result)
 | |
|     return result;
 | |
| 
 | |
|   if(len) {
 | |
|     /* only realloc if there was a length */
 | |
|     len = ntohl(len);
 | |
|     buf->data = Curl_saferealloc(buf->data, len);
 | |
|   }
 | |
|   if(!len || !buf->data)
 | |
|     return CURLE_OUT_OF_MEMORY;
 | |
| 
 | |
|   result = socket_read(fd, buf->data, len);
 | |
|   if(result)
 | |
|     return result;
 | |
|   buf->size = conn->mech->decode(conn->app_data, buf->data, len,
 | |
|                                  conn->data_prot, conn);
 | |
|   buf->index = 0;
 | |
|   return CURLE_OK;
 | |
| }
 | |
| 
 | |
| static size_t
 | |
| buffer_read(struct krb5buffer *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;
 | |
| }
 | |
| 
 | |
| /* Matches Curl_recv signature */
 | |
| static ssize_t sec_recv(struct Curl_easy *data, int sockindex,
 | |
|                         char *buffer, size_t len, CURLcode *err)
 | |
| {
 | |
|   size_t bytes_read;
 | |
|   size_t total_read = 0;
 | |
|   struct connectdata *conn = data->conn;
 | |
|   curl_socket_t fd = conn->sock[sockindex];
 | |
| 
 | |
|   *err = CURLE_OK;
 | |
| 
 | |
|   /* Handle clear text response. */
 | |
|   if(conn->sec_complete == 0 || conn->data_prot == PROT_CLEAR)
 | |
|     return sread(fd, buffer, len);
 | |
| 
 | |
|   if(conn->in_buffer.eof_flag) {
 | |
|     conn->in_buffer.eof_flag = 0;
 | |
|     return 0;
 | |
|   }
 | |
| 
 | |
|   bytes_read = buffer_read(&conn->in_buffer, buffer, len);
 | |
|   len -= bytes_read;
 | |
|   total_read += bytes_read;
 | |
|   buffer += bytes_read;
 | |
| 
 | |
|   while(len > 0) {
 | |
|     if(read_data(conn, fd, &conn->in_buffer))
 | |
|       return -1;
 | |
|     if(conn->in_buffer.size == 0) {
 | |
|       if(bytes_read > 0)
 | |
|         conn->in_buffer.eof_flag = 1;
 | |
|       return bytes_read;
 | |
|     }
 | |
|     bytes_read = buffer_read(&conn->in_buffer, buffer, len);
 | |
|     len -= bytes_read;
 | |
|     total_read += bytes_read;
 | |
|     buffer += bytes_read;
 | |
|   }
 | |
|   return total_read;
 | |
| }
 | |
| 
 | |
| /* Send |length| bytes from |from| to the |fd| socket taking care of encoding
 | |
|    and negotiating with the server. |from| can be NULL. */
 | |
| static void do_sec_send(struct Curl_easy *data, struct connectdata *conn,
 | |
|                         curl_socket_t fd, const char *from, int length)
 | |
| {
 | |
|   int bytes, htonl_bytes; /* 32-bit integers for htonl */
 | |
|   char *buffer = NULL;
 | |
|   char *cmd_buffer;
 | |
|   size_t cmd_size = 0;
 | |
|   CURLcode error;
 | |
|   enum protection_level prot_level = conn->data_prot;
 | |
|   bool iscmd = (prot_level == PROT_CMD)?TRUE:FALSE;
 | |
| 
 | |
|   DEBUGASSERT(prot_level > PROT_NONE && prot_level < PROT_LAST);
 | |
| 
 | |
|   if(iscmd) {
 | |
|     if(!strncmp(from, "PASS ", 5) || !strncmp(from, "ACCT ", 5))
 | |
|       prot_level = PROT_PRIVATE;
 | |
|     else
 | |
|       prot_level = conn->command_prot;
 | |
|   }
 | |
|   bytes = conn->mech->encode(conn->app_data, from, length, prot_level,
 | |
|                              (void **)&buffer);
 | |
|   if(!buffer || bytes <= 0)
 | |
|     return; /* error */
 | |
| 
 | |
|   if(iscmd) {
 | |
|     error = Curl_base64_encode(data, buffer, curlx_sitouz(bytes),
 | |
|                                &cmd_buffer, &cmd_size);
 | |
|     if(error) {
 | |
|       free(buffer);
 | |
|       return; /* error */
 | |
|     }
 | |
|     if(cmd_size > 0) {
 | |
|       static const char *enc = "ENC ";
 | |
|       static const char *mic = "MIC ";
 | |
|       if(prot_level == PROT_PRIVATE)
 | |
|         socket_write(data, fd, enc, 4);
 | |
|       else
 | |
|         socket_write(data, fd, mic, 4);
 | |
| 
 | |
|       socket_write(data, fd, cmd_buffer, cmd_size);
 | |
|       socket_write(data, fd, "\r\n", 2);
 | |
|       infof(data, "Send: %s%s", prot_level == PROT_PRIVATE?enc:mic,
 | |
|             cmd_buffer);
 | |
|       free(cmd_buffer);
 | |
|     }
 | |
|   }
 | |
|   else {
 | |
|     htonl_bytes = htonl(bytes);
 | |
|     socket_write(data, fd, &htonl_bytes, sizeof(htonl_bytes));
 | |
|     socket_write(data, fd, buffer, curlx_sitouz(bytes));
 | |
|   }
 | |
|   free(buffer);
 | |
| }
 | |
| 
 | |
| static ssize_t sec_write(struct Curl_easy *data, struct connectdata *conn,
 | |
|                          curl_socket_t fd, const char *buffer, size_t length)
 | |
| {
 | |
|   ssize_t tx = 0, len = conn->buffer_size;
 | |
| 
 | |
|   if(len <= 0)
 | |
|     len = length;
 | |
|   while(length) {
 | |
|     if(length < (size_t)len)
 | |
|       len = length;
 | |
| 
 | |
|     do_sec_send(data, conn, fd, buffer, curlx_sztosi(len));
 | |
|     length -= len;
 | |
|     buffer += len;
 | |
|     tx += len;
 | |
|   }
 | |
|   return tx;
 | |
| }
 | |
| 
 | |
| /* Matches Curl_send signature */
 | |
| static ssize_t sec_send(struct Curl_easy *data, int sockindex,
 | |
|                         const void *buffer, size_t len, CURLcode *err)
 | |
| {
 | |
|   struct connectdata *conn = data->conn;
 | |
|   curl_socket_t fd = conn->sock[sockindex];
 | |
|   *err = CURLE_OK;
 | |
|   return sec_write(data, conn, fd, buffer, len);
 | |
| }
 | |
| 
 | |
| int Curl_sec_read_msg(struct Curl_easy *data, struct connectdata *conn,
 | |
|                       char *buffer, enum protection_level level)
 | |
| {
 | |
|   /* decoded_len should be size_t or ssize_t but conn->mech->decode returns an
 | |
|      int */
 | |
|   int decoded_len;
 | |
|   char *buf;
 | |
|   int ret_code = 0;
 | |
|   size_t decoded_sz = 0;
 | |
|   CURLcode error;
 | |
| 
 | |
|   (void) data;
 | |
| 
 | |
|   if(!conn->mech)
 | |
|     /* not initialized, return error */
 | |
|     return -1;
 | |
| 
 | |
|   DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
 | |
| 
 | |
|   error = Curl_base64_decode(buffer + 4, (unsigned char **)&buf, &decoded_sz);
 | |
|   if(error || decoded_sz == 0)
 | |
|     return -1;
 | |
| 
 | |
|   if(decoded_sz > (size_t)INT_MAX) {
 | |
|     free(buf);
 | |
|     return -1;
 | |
|   }
 | |
|   decoded_len = curlx_uztosi(decoded_sz);
 | |
| 
 | |
|   decoded_len = conn->mech->decode(conn->app_data, buf, decoded_len,
 | |
|                                    level, conn);
 | |
|   if(decoded_len <= 0) {
 | |
|     free(buf);
 | |
|     return -1;
 | |
|   }
 | |
| 
 | |
|   {
 | |
|     buf[decoded_len] = '\n';
 | |
|     Curl_debug(data, CURLINFO_HEADER_IN, buf, decoded_len + 1);
 | |
|   }
 | |
| 
 | |
|   buf[decoded_len] = '\0';
 | |
|   if(decoded_len <= 3)
 | |
|     /* suspiciously short */
 | |
|     return 0;
 | |
| 
 | |
|   if(buf[3] != '-')
 | |
|     /* safe to ignore return code */
 | |
|     (void)sscanf(buf, "%d", &ret_code);
 | |
| 
 | |
|   if(buf[decoded_len - 1] == '\n')
 | |
|     buf[decoded_len - 1] = '\0';
 | |
|   strcpy(buffer, buf);
 | |
|   free(buf);
 | |
|   return ret_code;
 | |
| }
 | |
| 
 | |
| static int sec_set_protection_level(struct Curl_easy *data)
 | |
| {
 | |
|   int code;
 | |
|   struct connectdata *conn = data->conn;
 | |
|   enum protection_level level = conn->request_data_prot;
 | |
| 
 | |
|   DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
 | |
| 
 | |
|   if(!conn->sec_complete) {
 | |
|     infof(data, "Trying to change the protection level after the"
 | |
|                 " completion of the data exchange.");
 | |
|     return -1;
 | |
|   }
 | |
| 
 | |
|   /* Bail out if we try to set up the same level */
 | |
|   if(conn->data_prot == level)
 | |
|     return 0;
 | |
| 
 | |
|   if(level) {
 | |
|     char *pbsz;
 | |
|     unsigned int buffer_size = 1 << 20; /* 1048576 */
 | |
| 
 | |
|     code = ftp_send_command(data, "PBSZ %u", buffer_size);
 | |
|     if(code < 0)
 | |
|       return -1;
 | |
| 
 | |
|     if(code/100 != 2) {
 | |
|       failf(data, "Failed to set the protection's buffer size.");
 | |
|       return -1;
 | |
|     }
 | |
|     conn->buffer_size = buffer_size;
 | |
| 
 | |
|     pbsz = strstr(data->state.buffer, "PBSZ=");
 | |
|     if(pbsz) {
 | |
|       /* ignore return code, use default value if it fails */
 | |
|       (void)sscanf(pbsz, "PBSZ=%u", &buffer_size);
 | |
|       if(buffer_size < conn->buffer_size)
 | |
|         conn->buffer_size = buffer_size;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   /* Now try to negotiate the protection level. */
 | |
|   code = ftp_send_command(data, "PROT %c", level_to_char(level));
 | |
| 
 | |
|   if(code < 0)
 | |
|     return -1;
 | |
| 
 | |
|   if(code/100 != 2) {
 | |
|     failf(data, "Failed to set the protection level.");
 | |
|     return -1;
 | |
|   }
 | |
| 
 | |
|   conn->data_prot = level;
 | |
|   if(level == PROT_PRIVATE)
 | |
|     conn->command_prot = level;
 | |
| 
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| int
 | |
| Curl_sec_request_prot(struct connectdata *conn, const char *level)
 | |
| {
 | |
|   enum protection_level l = name_to_level(level);
 | |
|   if(l == PROT_NONE)
 | |
|     return -1;
 | |
|   DEBUGASSERT(l > PROT_NONE && l < PROT_LAST);
 | |
|   conn->request_data_prot = l;
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| static CURLcode choose_mech(struct Curl_easy *data, struct connectdata *conn)
 | |
| {
 | |
|   int ret;
 | |
|   void *tmp_allocation;
 | |
|   const struct Curl_sec_client_mech *mech = &Curl_krb5_client_mech;
 | |
| 
 | |
|   tmp_allocation = realloc(conn->app_data, mech->size);
 | |
|   if(!tmp_allocation) {
 | |
|     failf(data, "Failed realloc of size %zu", mech->size);
 | |
|     mech = NULL;
 | |
|     return CURLE_OUT_OF_MEMORY;
 | |
|   }
 | |
|   conn->app_data = tmp_allocation;
 | |
| 
 | |
|   if(mech->init) {
 | |
|     ret = mech->init(conn->app_data);
 | |
|     if(ret) {
 | |
|       infof(data, "Failed initialization for %s. Skipping it.",
 | |
|             mech->name);
 | |
|       return CURLE_FAILED_INIT;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   infof(data, "Trying mechanism %s...", mech->name);
 | |
|   ret = ftp_send_command(data, "AUTH %s", mech->name);
 | |
|   if(ret < 0)
 | |
|     return CURLE_COULDNT_CONNECT;
 | |
| 
 | |
|   if(ret/100 != 3) {
 | |
|     switch(ret) {
 | |
|     case 504:
 | |
|       infof(data, "Mechanism %s is not supported by the server (server "
 | |
|             "returned ftp code: 504).", mech->name);
 | |
|       break;
 | |
|     case 534:
 | |
|       infof(data, "Mechanism %s was rejected by the server (server returned "
 | |
|             "ftp code: 534).", mech->name);
 | |
|       break;
 | |
|     default:
 | |
|       if(ret/100 == 5) {
 | |
|         infof(data, "server does not support the security extensions");
 | |
|         return CURLE_USE_SSL_FAILED;
 | |
|       }
 | |
|       break;
 | |
|     }
 | |
|     return CURLE_LOGIN_DENIED;
 | |
|   }
 | |
| 
 | |
|   /* Authenticate */
 | |
|   ret = mech->auth(conn->app_data, data, conn);
 | |
| 
 | |
|   if(ret != AUTH_CONTINUE) {
 | |
|     if(ret != AUTH_OK) {
 | |
|       /* Mechanism has dumped the error to stderr, don't error here. */
 | |
|       return CURLE_USE_SSL_FAILED;
 | |
|     }
 | |
|     DEBUGASSERT(ret == AUTH_OK);
 | |
| 
 | |
|     conn->mech = mech;
 | |
|     conn->sec_complete = 1;
 | |
|     conn->recv[FIRSTSOCKET] = sec_recv;
 | |
|     conn->send[FIRSTSOCKET] = sec_send;
 | |
|     conn->recv[SECONDARYSOCKET] = sec_recv;
 | |
|     conn->send[SECONDARYSOCKET] = sec_send;
 | |
|     conn->command_prot = PROT_SAFE;
 | |
|     /* Set the requested protection level */
 | |
|     /* BLOCKING */
 | |
|     (void)sec_set_protection_level(data);
 | |
|   }
 | |
| 
 | |
|   return CURLE_OK;
 | |
| }
 | |
| 
 | |
| CURLcode
 | |
| Curl_sec_login(struct Curl_easy *data, struct connectdata *conn)
 | |
| {
 | |
|   return choose_mech(data, conn);
 | |
| }
 | |
| 
 | |
| 
 | |
| void
 | |
| Curl_sec_end(struct connectdata *conn)
 | |
| {
 | |
|   if(conn->mech != NULL && conn->mech->end)
 | |
|     conn->mech->end(conn->app_data);
 | |
|   free(conn->app_data);
 | |
|   conn->app_data = NULL;
 | |
|   if(conn->in_buffer.data) {
 | |
|     free(conn->in_buffer.data);
 | |
|     conn->in_buffer.data = NULL;
 | |
|     conn->in_buffer.size = 0;
 | |
|     conn->in_buffer.index = 0;
 | |
|     conn->in_buffer.eof_flag = 0;
 | |
|   }
 | |
|   conn->sec_complete = 0;
 | |
|   conn->data_prot = PROT_CLEAR;
 | |
|   conn->mech = NULL;
 | |
| }
 | |
| 
 | |
| #endif /* HAVE_GSSAPI && !CURL_DISABLE_FTP */
 |