| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) Steve Holme, <steve_holme@hotmail.com>. |
| * Copyright (C) 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 https://curl.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. |
| * |
| * SPDX-License-Identifier: curl |
| * |
| * RFC4752 The Kerberos V5 ("GSSAPI") SASL Mechanism |
| * |
| ***************************************************************************/ |
| |
| #include "curl_setup.h" |
| |
| #if defined(HAVE_GSSAPI) && defined(USE_KERBEROS5) |
| |
| #include <curl/curl.h> |
| |
| #include "vauth/vauth.h" |
| #include "curl_sasl.h" |
| #include "urldata.h" |
| #include "curl_gssapi.h" |
| #include "sendf.h" |
| #include "curl_printf.h" |
| |
| /* The last #include files should be: */ |
| #include "curl_memory.h" |
| #include "memdebug.h" |
| |
| /* |
| * Curl_auth_is_gssapi_supported() |
| * |
| * This is used to evaluate if GSSAPI (Kerberos V5) is supported. |
| * |
| * Parameters: None |
| * |
| * Returns TRUE if Kerberos V5 is supported by the GSS-API library. |
| */ |
| bool Curl_auth_is_gssapi_supported(void) |
| { |
| return TRUE; |
| } |
| |
| /* |
| * Curl_auth_create_gssapi_user_message() |
| * |
| * This is used to generate an already encoded GSSAPI (Kerberos V5) user token |
| * message ready for sending to the recipient. |
| * |
| * Parameters: |
| * |
| * data [in] - The session handle. |
| * userp [in] - The user name. |
| * passwdp [in] - The user's password. |
| * service [in] - The service type such as http, smtp, pop or imap. |
| * host [in[ - The host name. |
| * mutual_auth [in] - Flag specifying whether or not mutual authentication |
| * is enabled. |
| * chlg [in] - Optional challenge message. |
| * krb5 [in/out] - The Kerberos 5 data struct being used and modified. |
| * out [out] - The result storage. |
| * |
| * Returns CURLE_OK on success. |
| */ |
| CURLcode Curl_auth_create_gssapi_user_message(struct Curl_easy *data, |
| const char *userp, |
| const char *passwdp, |
| const char *service, |
| const char *host, |
| const bool mutual_auth, |
| const struct bufref *chlg, |
| struct kerberos5data *krb5, |
| struct bufref *out) |
| { |
| CURLcode result = CURLE_OK; |
| OM_uint32 major_status; |
| OM_uint32 minor_status; |
| OM_uint32 unused_status; |
| gss_buffer_desc spn_token = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER; |
| |
| (void) userp; |
| (void) passwdp; |
| |
| if(!krb5->spn) { |
| /* Generate our SPN */ |
| char *spn = Curl_auth_build_spn(service, NULL, host); |
| if(!spn) |
| return CURLE_OUT_OF_MEMORY; |
| |
| /* Populate the SPN structure */ |
| spn_token.value = spn; |
| spn_token.length = strlen(spn); |
| |
| /* Import the SPN */ |
| major_status = gss_import_name(&minor_status, &spn_token, |
| GSS_C_NT_HOSTBASED_SERVICE, &krb5->spn); |
| if(GSS_ERROR(major_status)) { |
| Curl_gss_log_error(data, "gss_import_name() failed: ", |
| major_status, minor_status); |
| |
| free(spn); |
| |
| return CURLE_AUTH_ERROR; |
| } |
| |
| free(spn); |
| } |
| |
| if(chlg) { |
| if(!Curl_bufref_len(chlg)) { |
| infof(data, "GSSAPI handshake failure (empty challenge message)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| input_token.value = (void *) Curl_bufref_ptr(chlg); |
| input_token.length = Curl_bufref_len(chlg); |
| } |
| |
| major_status = Curl_gss_init_sec_context(data, |
| &minor_status, |
| &krb5->context, |
| krb5->spn, |
| &Curl_krb5_mech_oid, |
| GSS_C_NO_CHANNEL_BINDINGS, |
| &input_token, |
| &output_token, |
| mutual_auth, |
| NULL); |
| |
| if(GSS_ERROR(major_status)) { |
| if(output_token.value) |
| gss_release_buffer(&unused_status, &output_token); |
| |
| Curl_gss_log_error(data, "gss_init_sec_context() failed: ", |
| major_status, minor_status); |
| |
| return CURLE_AUTH_ERROR; |
| } |
| |
| if(output_token.value && output_token.length) { |
| result = Curl_bufref_memdup(out, output_token.value, output_token.length); |
| gss_release_buffer(&unused_status, &output_token); |
| } |
| else |
| Curl_bufref_set(out, mutual_auth? "": NULL, 0, NULL); |
| |
| return result; |
| } |
| |
| /* |
| * Curl_auth_create_gssapi_security_message() |
| * |
| * This is used to generate an already encoded GSSAPI (Kerberos V5) security |
| * token message ready for sending to the recipient. |
| * |
| * Parameters: |
| * |
| * data [in] - The session handle. |
| * authzid [in] - The authorization identity if some. |
| * chlg [in] - Optional challenge message. |
| * krb5 [in/out] - The Kerberos 5 data struct being used and modified. |
| * out [out] - The result storage. |
| * |
| * Returns CURLE_OK on success. |
| */ |
| CURLcode Curl_auth_create_gssapi_security_message(struct Curl_easy *data, |
| const char *authzid, |
| const struct bufref *chlg, |
| struct kerberos5data *krb5, |
| struct bufref *out) |
| { |
| CURLcode result = CURLE_OK; |
| size_t messagelen = 0; |
| unsigned char *message = NULL; |
| OM_uint32 major_status; |
| OM_uint32 minor_status; |
| OM_uint32 unused_status; |
| gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER; |
| unsigned char *indata; |
| gss_qop_t qop = GSS_C_QOP_DEFAULT; |
| unsigned int sec_layer = 0; |
| unsigned int max_size = 0; |
| |
| /* Ensure we have a valid challenge message */ |
| if(!Curl_bufref_len(chlg)) { |
| infof(data, "GSSAPI handshake failure (empty security message)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Setup the challenge "input" security buffer */ |
| input_token.value = (void *) Curl_bufref_ptr(chlg); |
| input_token.length = Curl_bufref_len(chlg); |
| |
| /* Decrypt the inbound challenge and obtain the qop */ |
| major_status = gss_unwrap(&minor_status, krb5->context, &input_token, |
| &output_token, NULL, &qop); |
| if(GSS_ERROR(major_status)) { |
| Curl_gss_log_error(data, "gss_unwrap() failed: ", |
| major_status, minor_status); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Not 4 octets long so fail as per RFC4752 Section 3.1 */ |
| if(output_token.length != 4) { |
| infof(data, "GSSAPI handshake failure (invalid security data)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Extract the security layer and the maximum message size */ |
| indata = output_token.value; |
| sec_layer = indata[0]; |
| max_size = ((unsigned int)indata[1] << 16) | |
| ((unsigned int)indata[2] << 8) | indata[3]; |
| |
| /* Free the challenge as it is not required anymore */ |
| gss_release_buffer(&unused_status, &output_token); |
| |
| /* Process the security layer */ |
| if(!(sec_layer & GSSAUTH_P_NONE)) { |
| infof(data, "GSSAPI handshake failure (invalid security layer)"); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| sec_layer &= GSSAUTH_P_NONE; /* We do not support a security layer */ |
| |
| /* Process the maximum message size the server can receive */ |
| if(max_size > 0) { |
| /* The server has told us it supports a maximum receive buffer, however, as |
| we don't require one unless we are encrypting data, we tell the server |
| our receive buffer is zero. */ |
| max_size = 0; |
| } |
| |
| /* Allocate our message */ |
| messagelen = 4; |
| if(authzid) |
| messagelen += strlen(authzid); |
| message = malloc(messagelen); |
| if(!message) |
| return CURLE_OUT_OF_MEMORY; |
| |
| /* Populate the message with the security layer and client supported receive |
| message size. */ |
| message[0] = sec_layer & 0xFF; |
| message[1] = (max_size >> 16) & 0xFF; |
| message[2] = (max_size >> 8) & 0xFF; |
| message[3] = max_size & 0xFF; |
| |
| /* If given, append the authorization identity. */ |
| |
| if(authzid && *authzid) |
| memcpy(message + 4, authzid, messagelen - 4); |
| |
| /* Setup the "authentication data" security buffer */ |
| input_token.value = message; |
| input_token.length = messagelen; |
| |
| /* Encrypt the data */ |
| major_status = gss_wrap(&minor_status, krb5->context, 0, |
| GSS_C_QOP_DEFAULT, &input_token, NULL, |
| &output_token); |
| if(GSS_ERROR(major_status)) { |
| Curl_gss_log_error(data, "gss_wrap() failed: ", |
| major_status, minor_status); |
| free(message); |
| return CURLE_AUTH_ERROR; |
| } |
| |
| /* Return the response. */ |
| result = Curl_bufref_memdup(out, output_token.value, output_token.length); |
| /* Free the output buffer */ |
| gss_release_buffer(&unused_status, &output_token); |
| |
| /* Free the message buffer */ |
| free(message); |
| |
| return result; |
| } |
| |
| /* |
| * Curl_auth_cleanup_gssapi() |
| * |
| * This is used to clean up the GSSAPI (Kerberos V5) specific data. |
| * |
| * Parameters: |
| * |
| * krb5 [in/out] - The Kerberos 5 data struct being cleaned up. |
| * |
| */ |
| void Curl_auth_cleanup_gssapi(struct kerberos5data *krb5) |
| { |
| OM_uint32 minor_status; |
| |
| /* Free our security context */ |
| if(krb5->context != GSS_C_NO_CONTEXT) { |
| gss_delete_sec_context(&minor_status, &krb5->context, GSS_C_NO_BUFFER); |
| krb5->context = GSS_C_NO_CONTEXT; |
| } |
| |
| /* Free the SPN */ |
| if(krb5->spn != GSS_C_NO_NAME) { |
| gss_release_name(&minor_status, &krb5->spn); |
| krb5->spn = GSS_C_NO_NAME; |
| } |
| } |
| |
| #endif /* HAVE_GSSAPI && USE_KERBEROS5 */ |
