| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) 2014 - 2021, Steve Holme, <[email protected]>. |
| * |
| * 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. |
| * |
| * RFC4752 The Kerberos V5 ("GSSAPI") SASL Mechanism |
| * |
| ***************************************************************************/ |
| |
| #include "curl_setup.h" |
| |
| #if defined(USE_WINDOWS_SSPI) && defined(USE_KERBEROS5) |
| |
| #include <curl/curl.h> |
| |
| #include "vauth/vauth.h" |
| #include "urldata.h" |
| #include "warnless.h" |
| #include "curl_multibyte.h" |
| #include "sendf.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 Windows SSPI. |
| */ |
| bool Curl_auth_is_gssapi_supported(void) |
| { |
| PSecPkgInfo SecurityPackage; |
| SECURITY_STATUS status; |
| |
| /* Query the security package for Kerberos */ |
| status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) |
| TEXT(SP_NAME_KERBEROS), |
| &SecurityPackage); |
| |
| /* Release the package buffer as it is not required anymore */ |
| if(status == SEC_E_OK) { |
| s_pSecFn->FreeContextBuffer(SecurityPackage); |
| } |
| |
| return (status == SEC_E_OK ? TRUE : FALSE); |
| } |
| |
| /* |
| * 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 in the format User or Domain\User. |
| * 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; |
| CtxtHandle context; |
| PSecPkgInfo SecurityPackage; |
| SecBuffer chlg_buf; |
| SecBuffer resp_buf; |
| SecBufferDesc chlg_desc; |
| SecBufferDesc resp_desc; |
| SECURITY_STATUS status; |
| unsigned long attrs; |
| TimeStamp expiry; /* For Windows 9x compatibility of SSPI calls */ |
| |
| if(!krb5->spn) { |
| /* Generate our SPN */ |
| krb5->spn = Curl_auth_build_spn(service, host, NULL); |
| if(!krb5->spn) |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| if(!krb5->output_token) { |
| /* Query the security package for Kerberos */ |
| status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) |
| TEXT(SP_NAME_KERBEROS), |
| &SecurityPackage); |
| if(status != SEC_E_OK) { |
| failf(data, "SSPI: couldn't get auth info"); |
| return CURLE_AUTH_ERROR; |
| } |
| |
| krb5->token_max = SecurityPackage->cbMaxToken; |
| |
| /* Release the package buffer as it is not required anymore */ |
| s_pSecFn->FreeContextBuffer(SecurityPackage); |
| |
| /* Allocate our response buffer */ |
| krb5->output_token = malloc(krb5->token_max); |
| if(!krb5->output_token) |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| if(!krb5->credentials) { |
| /* Do we have credentials to use or are we using single sign-on? */ |
| if(userp && *userp) { |
| /* Populate our identity structure */ |
| result = Curl_create_sspi_identity(userp, passwdp, &krb5->identity); |
| if(result) |
| return result; |
| |
| /* Allow proper cleanup of the identity structure */ |
| krb5->p_identity = &krb5->identity; |
| } |
| else |
| /* Use the current Windows user */ |
| krb5->p_identity = NULL; |
| |
| /* Allocate our credentials handle */ |
| krb5->credentials = calloc(1, sizeof(CredHandle)); |
| if(!krb5->credentials) |
| return CURLE_OUT_OF_MEMORY; |
| |
| /* Acquire our credentials handle */ |
| status = s_pSecFn->AcquireCredentialsHandle(NULL, |
| (TCHAR *) |
| TEXT(SP_NAME_KERBEROS), |
| SECPKG_CRED_OUTBOUND, NULL, |
| krb5->p_identity, NULL, NULL, |
| krb5->credentials, &expiry); |
| if(status != SEC_E_OK) |
| return CURLE_LOGIN_DENIED; |
| |
| /* Allocate our new context handle */ |
| krb5->context = calloc(1, sizeof(CtxtHandle)); |
| if(!krb5->context) |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| if(chlg) { |
| if(!Curl_bufref_len(chlg)) { |
| infof(data, "GSSAPI handshake failure (empty challenge message)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Setup the challenge "input" security buffer */ |
| chlg_desc.ulVersion = SECBUFFER_VERSION; |
| chlg_desc.cBuffers = 1; |
| chlg_desc.pBuffers = &chlg_buf; |
| chlg_buf.BufferType = SECBUFFER_TOKEN; |
| chlg_buf.pvBuffer = (void *) Curl_bufref_ptr(chlg); |
| chlg_buf.cbBuffer = curlx_uztoul(Curl_bufref_len(chlg)); |
| } |
| |
| /* Setup the response "output" security buffer */ |
| resp_desc.ulVersion = SECBUFFER_VERSION; |
| resp_desc.cBuffers = 1; |
| resp_desc.pBuffers = &resp_buf; |
| resp_buf.BufferType = SECBUFFER_TOKEN; |
| resp_buf.pvBuffer = krb5->output_token; |
| resp_buf.cbBuffer = curlx_uztoul(krb5->token_max); |
| |
| /* Generate our challenge-response message */ |
| status = s_pSecFn->InitializeSecurityContext(krb5->credentials, |
| chlg ? krb5->context : NULL, |
| krb5->spn, |
| (mutual_auth ? |
| ISC_REQ_MUTUAL_AUTH : 0), |
| 0, SECURITY_NATIVE_DREP, |
| chlg ? &chlg_desc : NULL, 0, |
| &context, |
| &resp_desc, &attrs, |
| &expiry); |
| |
| if(status == SEC_E_INSUFFICIENT_MEMORY) |
| return CURLE_OUT_OF_MEMORY; |
| |
| if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED) |
| return CURLE_AUTH_ERROR; |
| |
| if(memcmp(&context, krb5->context, sizeof(context))) { |
| s_pSecFn->DeleteSecurityContext(krb5->context); |
| |
| memcpy(krb5->context, &context, sizeof(context)); |
| } |
| |
| if(resp_buf.cbBuffer) { |
| result = Curl_bufref_memdup(out, resp_buf.pvBuffer, resp_buf.cbBuffer); |
| } |
| else if(mutual_auth) |
| Curl_bufref_set(out, "", 0, NULL); |
| else |
| Curl_bufref_set(out, 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] - The 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) |
| { |
| size_t offset = 0; |
| size_t messagelen = 0; |
| size_t appdatalen = 0; |
| unsigned char *trailer = NULL; |
| unsigned char *message = NULL; |
| unsigned char *padding = NULL; |
| unsigned char *appdata = NULL; |
| SecBuffer input_buf[2]; |
| SecBuffer wrap_buf[3]; |
| SecBufferDesc input_desc; |
| SecBufferDesc wrap_desc; |
| unsigned char *indata; |
| unsigned long qop = 0; |
| unsigned long sec_layer = 0; |
| unsigned long max_size = 0; |
| SecPkgContext_Sizes sizes; |
| SECURITY_STATUS status; |
| |
| #if defined(CURL_DISABLE_VERBOSE_STRINGS) |
| (void) data; |
| #endif |
| |
| /* 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; |
| } |
| |
| /* Get our response size information */ |
| status = s_pSecFn->QueryContextAttributes(krb5->context, |
| SECPKG_ATTR_SIZES, |
| &sizes); |
| |
| if(status == SEC_E_INSUFFICIENT_MEMORY) |
| return CURLE_OUT_OF_MEMORY; |
| |
| if(status != SEC_E_OK) |
| return CURLE_AUTH_ERROR; |
| |
| /* Setup the "input" security buffer */ |
| input_desc.ulVersion = SECBUFFER_VERSION; |
| input_desc.cBuffers = 2; |
| input_desc.pBuffers = input_buf; |
| input_buf[0].BufferType = SECBUFFER_STREAM; |
| input_buf[0].pvBuffer = (void *) Curl_bufref_ptr(chlg); |
| input_buf[0].cbBuffer = curlx_uztoul(Curl_bufref_len(chlg)); |
| input_buf[1].BufferType = SECBUFFER_DATA; |
| input_buf[1].pvBuffer = NULL; |
| input_buf[1].cbBuffer = 0; |
| |
| /* Decrypt the inbound challenge and obtain the qop */ |
| status = s_pSecFn->DecryptMessage(krb5->context, &input_desc, 0, &qop); |
| if(status != SEC_E_OK) { |
| infof(data, "GSSAPI handshake failure (empty security message)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Not 4 octets long so fail as per RFC4752 Section 3.1 */ |
| if(input_buf[1].cbBuffer != 4) { |
| infof(data, "GSSAPI handshake failure (invalid security data)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| /* Extract the security layer and the maximum message size */ |
| indata = input_buf[1].pvBuffer; |
| sec_layer = indata[0]; |
| max_size = (indata[1] << 16) | (indata[2] << 8) | indata[3]; |
| |
| /* Free the challenge as it is not required anymore */ |
| s_pSecFn->FreeContextBuffer(input_buf[1].pvBuffer); |
| |
| /* Process the security layer */ |
| if(!(sec_layer & KERB_WRAP_NO_ENCRYPT)) { |
| infof(data, "GSSAPI handshake failure (invalid security layer)"); |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| sec_layer &= KERB_WRAP_NO_ENCRYPT; /* 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 the trailer */ |
| trailer = malloc(sizes.cbSecurityTrailer); |
| if(!trailer) |
| return CURLE_OUT_OF_MEMORY; |
| |
| /* Allocate our message */ |
| messagelen = 4; |
| if(authzid) |
| messagelen += strlen(authzid); |
| message = malloc(messagelen); |
| if(!message) { |
| free(trailer); |
| |
| 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); |
| |
| /* Allocate the padding */ |
| padding = malloc(sizes.cbBlockSize); |
| if(!padding) { |
| free(message); |
| free(trailer); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Setup the "authentication data" security buffer */ |
| wrap_desc.ulVersion = SECBUFFER_VERSION; |
| wrap_desc.cBuffers = 3; |
| wrap_desc.pBuffers = wrap_buf; |
| wrap_buf[0].BufferType = SECBUFFER_TOKEN; |
| wrap_buf[0].pvBuffer = trailer; |
| wrap_buf[0].cbBuffer = sizes.cbSecurityTrailer; |
| wrap_buf[1].BufferType = SECBUFFER_DATA; |
| wrap_buf[1].pvBuffer = message; |
| wrap_buf[1].cbBuffer = curlx_uztoul(messagelen); |
| wrap_buf[2].BufferType = SECBUFFER_PADDING; |
| wrap_buf[2].pvBuffer = padding; |
| wrap_buf[2].cbBuffer = sizes.cbBlockSize; |
| |
| /* Encrypt the data */ |
| status = s_pSecFn->EncryptMessage(krb5->context, KERB_WRAP_NO_ENCRYPT, |
| &wrap_desc, 0); |
| if(status != SEC_E_OK) { |
| free(padding); |
| free(message); |
| free(trailer); |
| |
| if(status == SEC_E_INSUFFICIENT_MEMORY) |
| return CURLE_OUT_OF_MEMORY; |
| |
| return CURLE_AUTH_ERROR; |
| } |
| |
| /* Allocate the encryption (wrap) buffer */ |
| appdatalen = wrap_buf[0].cbBuffer + wrap_buf[1].cbBuffer + |
| wrap_buf[2].cbBuffer; |
| appdata = malloc(appdatalen); |
| if(!appdata) { |
| free(padding); |
| free(message); |
| free(trailer); |
| |
| return CURLE_OUT_OF_MEMORY; |
| } |
| |
| /* Populate the encryption buffer */ |
| memcpy(appdata, wrap_buf[0].pvBuffer, wrap_buf[0].cbBuffer); |
| offset += wrap_buf[0].cbBuffer; |
| memcpy(appdata + offset, wrap_buf[1].pvBuffer, wrap_buf[1].cbBuffer); |
| offset += wrap_buf[1].cbBuffer; |
| memcpy(appdata + offset, wrap_buf[2].pvBuffer, wrap_buf[2].cbBuffer); |
| |
| /* Free all of our local buffers */ |
| free(padding); |
| free(message); |
| free(trailer); |
| |
| /* Return the response. */ |
| Curl_bufref_set(out, appdata, appdatalen, curl_free); |
| return CURLE_OK; |
| } |
| |
| /* |
| * 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) |
| { |
| /* Free our security context */ |
| if(krb5->context) { |
| s_pSecFn->DeleteSecurityContext(krb5->context); |
| free(krb5->context); |
| krb5->context = NULL; |
| } |
| |
| /* Free our credentials handle */ |
| if(krb5->credentials) { |
| s_pSecFn->FreeCredentialsHandle(krb5->credentials); |
| free(krb5->credentials); |
| krb5->credentials = NULL; |
| } |
| |
| /* Free our identity */ |
| Curl_sspi_free_identity(krb5->p_identity); |
| krb5->p_identity = NULL; |
| |
| /* Free the SPN and output token */ |
| Curl_safefree(krb5->spn); |
| Curl_safefree(krb5->output_token); |
| |
| /* Reset any variables */ |
| krb5->token_max = 0; |
| } |
| |
| #endif /* USE_WINDOWS_SSPI && USE_KERBEROS5*/ |
