text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at http://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  
  #include "curl_setup.h"
  
  #ifdef HAVE_GSSAPI
  #ifdef HAVE_OLD_GSSMIT
  #define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
  #define NCOMPAT 1
  #endif
  
  #ifndef CURL_DISABLE_HTTP
  
  #include "urldata.h"
  #include "sendf.h"
  #include "curl_gssapi.h"
  #include "rawstr.h"
  #include "curl_base64.h"
  #include "http_negotiate.h"
  #include "curl_memory.h"
  #include "url.h"
  
  #ifdef HAVE_SPNEGO
  #  include <spnegohelp.h>
  #  ifdef USE_SSLEAY
  #    ifdef USE_OPENSSL
  #      include <openssl/objects.h>
  #    else
  #      include <objects.h>
  #    endif
  #  else
  #    error "Can't compile SPNEGO support without OpenSSL."
  #  endif
  #endif
  
  #define _MPRINTF_REPLACE /* use our functions only */
  #include <XMCurl/mprintf.h>
  
  /* The last #include file should be: */
  #include "memdebug.h"
  
  static int
  get_gss_name(struct connectdata *conn, bool proxy, gss_name_t *server)
  {
    struct negotiatedata *neg_ctx = proxy?&conn->data->state.proxyneg:
      &conn->data->state.negotiate;
    OM_uint32 major_status, minor_status;
    gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
    char name[2048];
    const char* service;
  
    /* GSSAPI implementation by Globus (known as GSI) requires the name to be
       of form "<service>/<fqdn>" instead of <service>@<fqdn> (ie. slash instead
       of at-sign). Also GSI servers are often identified as 'host' not 'khttp'.
       Change following lines if you want to use GSI */
  
    /* IIS uses the <service>@<fqdn> form but uses 'http' as the service name */
  
    if(neg_ctx->gss)
      service = "KHTTP";
    else
      service = "HTTP";
  
    token.length = strlen(service) + 1 + strlen(proxy ? conn->proxy.name :
                                                conn->host.name) + 1;
    if(token.length + 1 > sizeof(name))
      return EMSGSIZE;
  
    snprintf(name, sizeof(name), "%s@%s", service, proxy ? conn->proxy.name :
             conn->host.name);
  
    token.value = (void *) name;
    major_status = gss_import_name(&minor_status,
                                   &token,
                                   GSS_C_NT_HOSTBASED_SERVICE,
                                   server);
  
    return GSS_ERROR(major_status) ? -1 : 0;
  }
  
  static void
  log_gss_error(struct connectdata *conn, OM_uint32 error_status,
                const char *prefix)
  {
    OM_uint32 maj_stat, min_stat;
    OM_uint32 msg_ctx = 0;
    gss_buffer_desc status_string;
    char buf[1024];
    size_t len;
  
    snprintf(buf, sizeof(buf), "%s", prefix);
    len = strlen(buf);
    do {
      maj_stat = gss_display_status(&min_stat,
                                    error_status,
                                    GSS_C_MECH_CODE,
                                    GSS_C_NO_OID,
                                    &msg_ctx,
                                    &status_string);
        if(sizeof(buf) > len + status_string.length + 1) {
          snprintf(buf + len, sizeof(buf) - len,
                   ": %s", (char*) status_string.value);
        len += status_string.length;
      }
      gss_release_buffer(&min_stat, &status_string);
    } while(!GSS_ERROR(maj_stat) && msg_ctx != 0);
  
    infof(conn->data, "%s\n", buf);
  }
  
  /* returning zero (0) means success, everything else is treated as "failure"
     with no care exactly what the failure was */
  int Curl_input_negotiate(struct connectdata *conn, bool proxy,
                           const char *header)
  {
    struct SessionHandle *data = conn->data;
    struct negotiatedata *neg_ctx = proxy?&data->state.proxyneg:
      &data->state.negotiate;
    OM_uint32 major_status, minor_status, discard_st;
    gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
    gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
    int ret;
    size_t len;
    size_t rawlen = 0;
    bool gss;
    const char* protocol;
    CURLcode error;
  
    while(*header && ISSPACE(*header))
      header++;
    if(checkprefix("GSS-Negotiate", header)) {
      protocol = "GSS-Negotiate";
      gss = TRUE;
    }
    else if(checkprefix("Negotiate", header)) {
      protocol = "Negotiate";
      gss = FALSE;
    }
    else
      return -1;
  
    if(neg_ctx->context) {
      if(neg_ctx->gss != gss) {
        return -1;
      }
    }
    else {
      neg_ctx->protocol = protocol;
      neg_ctx->gss = gss;
    }
  
    if(neg_ctx->context && neg_ctx->status == GSS_S_COMPLETE) {
      /* We finished successfully our part of authentication, but server
       * rejected it (since we're again here). Exit with an error since we
       * can't invent anything better */
      Curl_cleanup_negotiate(data);
      return -1;
    }
  
    if(neg_ctx->server_name == NULL &&
        (ret = get_gss_name(conn, proxy, &neg_ctx->server_name)))
      return ret;
  
    header += strlen(neg_ctx->protocol);
    while(*header && ISSPACE(*header))
      header++;
  
    len = strlen(header);
    if(len > 0) {
      error = Curl_base64_decode(header,
                                 (unsigned char **)&input_token.value, &rawlen);
      if(error || rawlen == 0)
        return -1;
      input_token.length = rawlen;
  
      DEBUGASSERT(input_token.value != NULL);
  
  #ifdef HAVE_SPNEGO /* Handle SPNEGO */
      if(checkprefix("Negotiate", header)) {
        unsigned char  *spnegoToken       = NULL;
        size_t          spnegoTokenLength = 0;
        gss_buffer_desc mechToken         = GSS_C_EMPTY_BUFFER;
  
        spnegoToken = malloc(input_token.length);
        if(spnegoToken == NULL) {
          Curl_safefree(input_token.value);
          return CURLE_OUT_OF_MEMORY;
        }
        memcpy(spnegoToken, input_token.value, input_token.length);
        spnegoTokenLength = input_token.length;
  
        if(!parseSpnegoTargetToken(spnegoToken,
                                   spnegoTokenLength,
                                   NULL,
                                   NULL,
                                   (unsigned char**)&mechToken.value,
                                   &mechToken.length,
                                   NULL,
                                   NULL)) {
          Curl_safefree(spnegoToken);
          infof(data, "Parse SPNEGO Target Token failed\n");
        }
        else if(!mechToken.value || !mechToken.length) {
          Curl_safefree(spnegoToken);
          if(mechToken.value)
            gss_release_buffer(&discard_st, &mechToken);
          infof(data, "Parse SPNEGO Target Token succeeded (NULL token)\n");
        }
        else {
          Curl_safefree(spnegoToken);
          Curl_safefree(input_token.value);
          input_token.value = malloc(mechToken.length);
          if(input_token.value == NULL) {
            gss_release_buffer(&discard_st, &mechToken);
            return CURLE_OUT_OF_MEMORY;
          }
          memcpy(input_token.value, mechToken.value, mechToken.length);
          input_token.length = mechToken.length;
          gss_release_buffer(&discard_st, &mechToken);
          infof(data, "Parse SPNEGO Target Token succeeded\n");
        }
      }
  #endif
    }
  
    major_status = Curl_gss_init_sec_context(data,
                                             &minor_status,
                                             &neg_ctx->context,
                                             neg_ctx->server_name,
                                             GSS_C_NO_CHANNEL_BINDINGS,
                                             &input_token,
                                             &output_token,
                                             NULL);
    Curl_safefree(input_token.value);
  
    neg_ctx->status = major_status;
    if(GSS_ERROR(major_status)) {
      if(output_token.value)
        gss_release_buffer(&discard_st, &output_token);
      log_gss_error(conn, minor_status, "gss_init_sec_context() failed: ");
      return -1;
    }
  
    if(!output_token.value || !output_token.length) {
      if(output_token.value)
        gss_release_buffer(&discard_st, &output_token);
      return -1;
    }
  
    neg_ctx->output_token = output_token;
    return 0;
  }
  
  
  CURLcode Curl_output_negotiate(struct connectdata *conn, bool proxy)
  {
    struct negotiatedata *neg_ctx = proxy?&conn->data->state.proxyneg:
      &conn->data->state.negotiate;
    char *encoded = NULL;
    size_t len = 0;
    char *userp;
    CURLcode error;
    OM_uint32 discard_st;
  
  #ifdef HAVE_SPNEGO /* Handle SPNEGO */
    if(checkprefix("Negotiate", neg_ctx->protocol)) {
      ASN1_OBJECT    *object              = NULL;
      unsigned char  *responseToken       = NULL;
      size_t          responseTokenLength = 0;
      gss_buffer_desc spnegoToken         = GSS_C_EMPTY_BUFFER;
  
      responseToken = malloc(neg_ctx->output_token.length);
      if(responseToken == NULL)
        return CURLE_OUT_OF_MEMORY;
      memcpy(responseToken, neg_ctx->output_token.value,
             neg_ctx->output_token.length);
      responseTokenLength = neg_ctx->output_token.length;
  
      object = OBJ_txt2obj("1.2.840.113554.1.2.2", 1);
      if(!object) {
        Curl_safefree(responseToken);
        return CURLE_OUT_OF_MEMORY;
      }
  
      if(!makeSpnegoInitialToken(object,
                                 responseToken,
                                 responseTokenLength,
                                 (unsigned char**)&spnegoToken.value,
                                 &spnegoToken.length)) {
        Curl_safefree(responseToken);
        ASN1_OBJECT_free(object);
        infof(conn->data, "Make SPNEGO Initial Token failed\n");
      }
      else if(!spnegoToken.value || !spnegoToken.length) {
        Curl_safefree(responseToken);
        ASN1_OBJECT_free(object);
        if(spnegoToken.value)
          gss_release_buffer(&discard_st, &spnegoToken);
        infof(conn->data, "Make SPNEGO Initial Token succeeded (NULL token)\n");
      }
      else {
        Curl_safefree(responseToken);
        ASN1_OBJECT_free(object);
        gss_release_buffer(&discard_st, &neg_ctx->output_token);
        neg_ctx->output_token.value = spnegoToken.value;
        neg_ctx->output_token.length = spnegoToken.length;
        infof(conn->data, "Make SPNEGO Initial Token succeeded\n");
      }
    }
  #endif
    error = Curl_base64_encode(conn->data,
                               neg_ctx->output_token.value,
                               neg_ctx->output_token.length,
                               &encoded, &len);
    if(error) {
      gss_release_buffer(&discard_st, &neg_ctx->output_token);
      neg_ctx->output_token.value = NULL;
      neg_ctx->output_token.length = 0;
      return error;
    }
  
    if(!encoded || !len) {
      gss_release_buffer(&discard_st, &neg_ctx->output_token);
      neg_ctx->output_token.value = NULL;
      neg_ctx->output_token.length = 0;
      return CURLE_REMOTE_ACCESS_DENIED;
    }
  
    userp = aprintf("%sAuthorization: %s %s\r\n", proxy ? "Proxy-" : "",
                    neg_ctx->protocol, encoded);
    if(proxy) {
      Curl_safefree(conn->allocptr.proxyuserpwd);
      conn->allocptr.proxyuserpwd = userp;
    }
    else {
      Curl_safefree(conn->allocptr.userpwd);
      conn->allocptr.userpwd = userp;
    }
  
    Curl_safefree(encoded);
    Curl_cleanup_negotiate(conn->data);
  
    return (userp == NULL) ? CURLE_OUT_OF_MEMORY : CURLE_OK;
  }
  
  static void cleanup(struct negotiatedata *neg_ctx)
  {
    OM_uint32 minor_status;
    if(neg_ctx->context != GSS_C_NO_CONTEXT)
      gss_delete_sec_context(&minor_status, &neg_ctx->context, GSS_C_NO_BUFFER);
  
    if(neg_ctx->output_token.value)
      gss_release_buffer(&minor_status, &neg_ctx->output_token);
  
    if(neg_ctx->server_name != GSS_C_NO_NAME)
      gss_release_name(&minor_status, &neg_ctx->server_name);
  
    memset(neg_ctx, 0, sizeof(*neg_ctx));
  }
  
  void Curl_cleanup_negotiate(struct SessionHandle *data)
  {
    cleanup(&data->state.negotiate);
    cleanup(&data->state.proxyneg);
  }
  
  
  #endif
  #endif
  