| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) 2014 - 2015, Steve Holme, <steve_holme@hotmail.com>. |
| * Copyright (C) 2015, 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. |
| * |
| * RFC4752 The Kerberos V5 ("GSSAPI") SASL Mechanism |
| * |
| ***************************************************************************/ |
| |
| #include "curl_setup.h" |
| |
| #if defined(HAVE_GSSAPI) && defined(USE_KERBEROS5) |
| |
| #include <curl/curl.h> |
| |
| #include "curl_sasl.h" |
| #include "urldata.h" |
| #include "curl_base64.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_sasl_build_gssapi_spn() |
| * |
| * This is used to build a SPN string in the format service@host. |
| * |
| * Parameters: |
| * |
| * serivce [in] - The service type such as www, smtp, pop or imap. |
| * host [in] - The host name or realm. |
| * |
| * Returns a pointer to the newly allocated SPN. |
| */ |
| char *Curl_sasl_build_gssapi_spn(const char *service, const char *host) |
| { |
| /* Generate and return our SPN */ |
| return aprintf("%s@%s", service, host); |
| } |
| |
| /* |
| * Curl_sasl_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. |
| * passdwp [in] - The user's password. |
| * service [in] - The service type such as www, smtp, pop or imap. |
| * mutual_auth [in] - Flag specifing whether or not mutual authentication |
| * is enabled. |
| * chlg64 [in] - Pointer to the optional base64 encoded challenge |
| * message. |
| * krb5 [in/out] - The gssapi data struct being used and modified. |
| * outptr [in/out] - The address where a pointer to newly allocated memory |
| * holding the result will be stored upon completion. |
| * outlen [out] - The length of the output message. |
| * |
| * Returns CURLE_OK on success. |
| */ |
| CURLcode Curl_sasl_create_gssapi_user_message(struct SessionHandle *data, |
| const char *userp, |
| const char *passwdp, |
| const char *service, |
| const bool mutual_auth, |
| const char *chlg64, |
| struct kerberos5data *krb5, |
| char **outptr, size_t *outlen) |
| { |
| CURLcode result = CURLE_OK; |
| size_t chlglen = 0; |
| unsigned char *chlg = NULL; |
| OM_uint32 gss_status; |
| OM_uint32 gss_major_status; |
| OM_uint32 gss_minor_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->context == GSS_C_NO_CONTEXT) { |
| /* Generate our SPN */ |
| char *spn = Curl_sasl_build_gssapi_spn(service, |
| data->easy_conn->host.name); |
| if(!spn) |
| return CURLE_OUT_OF_MEMORY; |
| |
| /* Populate the SPN structure */ |
| spn_token.value = spn; |
| spn_token.length = strlen(spn); |
| |
| /* Import the SPN */ |
| gss_major_status = gss_import_name(&gss_minor_status, &spn_token, |
| GSS_C_NT_HOSTBASED_SERVICE, &krb5->spn); |
| if(GSS_ERROR(gss_major_status)) { |
| Curl_gss_log_error(data, gss_minor_status, "gss_import_name() failed: "); |
| |
| free(spn); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| free(spn); |
| } |
| else { |
| /* Decode the base-64 encoded challenge message */ |
| if(strlen(chlg64) && *chlg64 != '=') { |
| result = Curl_base64_decode(chlg64, &chlg, &chlglen); |
| if(result) |
| return result; |
| } |
| |
| /* Ensure we have a valid challenge message */ |
| if(!chlg) { |
| infof(data, "GSSAPI handshake failure (empty challenge message)\n"); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Setup the challenge "input" security buffer */ |
| input_token.value = chlg; |
| input_token.length = chlglen; |
| } |
| |
| gss_major_status = Curl_gss_init_sec_context(data, |
| &gss_minor_status, |
| &krb5->context, |
| krb5->spn, |
| &Curl_krb5_mech_oid, |
| GSS_C_NO_CHANNEL_BINDINGS, |
| &input_token, |
| &output_token, |
| mutual_auth, |
| NULL); |
| |
| free(input_token.value); |
| |
| if(GSS_ERROR(gss_major_status)) { |
| if(output_token.value) |
| gss_release_buffer(&gss_status, &output_token); |
| |
| Curl_gss_log_error(data, gss_minor_status, |
| "gss_init_sec_context() failed: "); |
| |
| return CURLE_RECV_ERROR; |
| } |
| |
| if(output_token.value && output_token.length) { |
| /* Base64 encode the response */ |
| result = Curl_base64_encode(data, (char *) output_token.value, |
| output_token.length, outptr, outlen); |
| |
| gss_release_buffer(&gss_status, &output_token); |
| } |
| |
| return result; |
| } |
| |
| /* |
| * Curl_sasl_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. |
| * chlg64 [in] - Pointer to the optional base64 encoded challenge message. |
| * krb5 [in/out] - The gssapi data struct being used and modified. |
| * outptr [in/out] - The address where a pointer to newly allocated memory |
| * holding the result will be stored upon completion. |
| * outlen [out] - The length of the output message. |
| * |
| * Returns CURLE_OK on success. |
| */ |
| CURLcode Curl_sasl_create_gssapi_security_message(struct SessionHandle *data, |
| const char *chlg64, |
| struct kerberos5data *krb5, |
| char **outptr, |
| size_t *outlen) |
| { |
| CURLcode result = CURLE_OK; |
| size_t chlglen = 0; |
| size_t messagelen = 0; |
| unsigned char *chlg = NULL; |
| unsigned char *message = NULL; |
| OM_uint32 gss_status; |
| OM_uint32 gss_major_status; |
| OM_uint32 gss_minor_status; |
| gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER; |
| gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER; |
| unsigned int indata = 0; |
| unsigned int outdata = 0; |
| gss_qop_t qop = GSS_C_QOP_DEFAULT; |
| unsigned int sec_layer = 0; |
| unsigned int max_size = 0; |
| gss_name_t username = GSS_C_NO_NAME; |
| gss_buffer_desc username_token; |
| |
| /* Decode the base-64 encoded input message */ |
| if(strlen(chlg64) && *chlg64 != '=') { |
| result = Curl_base64_decode(chlg64, &chlg, &chlglen); |
| if(result) |
| return result; |
| } |
| |
| /* Ensure we have a valid challenge message */ |
| if(!chlg) { |
| infof(data, "GSSAPI handshake failure (empty security message)\n"); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Get the fully qualified username back from the context */ |
| gss_major_status = gss_inquire_context(&gss_minor_status, krb5->context, |
| &username, NULL, NULL, NULL, NULL, |
| NULL, NULL); |
| if(GSS_ERROR(gss_major_status)) { |
| Curl_gss_log_error(data, gss_minor_status, |
| "gss_inquire_context() failed: "); |
| |
| free(chlg); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Convert the username from internal format to a displayable token */ |
| gss_major_status = gss_display_name(&gss_minor_status, username, |
| &username_token, NULL); |
| if(GSS_ERROR(gss_major_status)) { |
| Curl_gss_log_error(data, gss_minor_status, "gss_display_name() failed: "); |
| |
| free(chlg); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Setup the challenge "input" security buffer */ |
| input_token.value = chlg; |
| input_token.length = chlglen; |
| |
| /* Decrypt the inbound challenge and obtain the qop */ |
| gss_major_status = gss_unwrap(&gss_minor_status, krb5->context, &input_token, |
| &output_token, NULL, &qop); |
| if(GSS_ERROR(gss_major_status)) { |
| Curl_gss_log_error(data, gss_minor_status, "gss_unwrap() failed: "); |
| |
| gss_release_buffer(&gss_status, &username_token); |
| free(chlg); |
| |
| 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)\n"); |
| |
| gss_release_buffer(&gss_status, &username_token); |
| free(chlg); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Copy the data out and free the challenge as it is not required anymore */ |
| memcpy(&indata, output_token.value, 4); |
| gss_release_buffer(&gss_status, &output_token); |
| free(chlg); |
| |
| /* Extract the security layer */ |
| sec_layer = indata & 0x000000FF; |
| if(!(sec_layer & GSSAUTH_P_NONE)) { |
| infof(data, "GSSAPI handshake failure (invalid security layer)\n"); |
| |
| gss_release_buffer(&gss_status, &username_token); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Extract the maximum message size the server can receive */ |
| max_size = ntohl(indata & 0xFFFFFF00); |
| 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 = sizeof(outdata) + username_token.length + 1; |
| message = malloc(messagelen); |
| if(!message) { |
| gss_release_buffer(&gss_status, &username_token); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Populate the message with the security layer, client supported receive |
| message size and authorization identity including the 0x00 based |
| terminator. Note: Dispite RFC4752 Section 3.1 stating "The authorization |
| identity is not terminated with the zero-valued (%x00) octet." it seems |
| necessary to include it. */ |
| outdata = htonl(max_size) | sec_layer; |
| memcpy(message, &outdata, sizeof(outdata)); |
| memcpy(message + sizeof(outdata), username_token.value, |
| username_token.length); |
| message[messagelen - 1] = '\0'; |
| |
| /* Free the username token as it is not required anymore */ |
| gss_release_buffer(&gss_status, &username_token); |
| |
| /* Setup the "authentication data" security buffer */ |
| input_token.value = message; |
| input_token.length = messagelen; |
| |
| /* Encrypt the data */ |
| gss_major_status = gss_wrap(&gss_minor_status, krb5->context, 0, |
| GSS_C_QOP_DEFAULT, &input_token, NULL, |
| &output_token); |
| if(GSS_ERROR(gss_major_status)) { |
| Curl_gss_log_error(data, gss_minor_status, "gss_wrap() failed: "); |
| |
| free(message); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Base64 encode the response */ |
| result = Curl_base64_encode(data, (char *) output_token.value, |
| output_token.length, outptr, outlen); |
| |
| /* Free the output buffer */ |
| gss_release_buffer(&gss_status, &output_token); |
| |
| /* Free the message buffer */ |
| free(message); |
| |
| return result; |
| } |
| |
| /* |
| * Curl_sasl_gssapi_cleanup() |
| * |
| * This is used to clean up the gssapi specific data. |
| * |
| * Parameters: |
| * |
| * krb5 [in/out] - The kerberos 5 data struct being cleaned up. |
| * |
| */ |
| void Curl_sasl_gssapi_cleanup(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 */ |
