diff options
Diffstat (limited to 'Utilities/cmcurl/lib/vauth/krb5_gssapi.c')
| -rw-r--r-- | Utilities/cmcurl/lib/vauth/krb5_gssapi.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/vauth/krb5_gssapi.c b/Utilities/cmcurl/lib/vauth/krb5_gssapi.c new file mode 100644 index 0000000..31c8c7d --- /dev/null +++ b/Utilities/cmcurl/lib/vauth/krb5_gssapi.c @@ -0,0 +1,387 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2014 - 2016, 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 https://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 "vauth/vauth.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_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. + * passdwp [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 specifing whether or not mutual authentication + * is enabled. + * chlg64 [in] - Pointer to the optional base64 encoded challenge + * message. + * krb5 [in/out] - The Kerberos 5 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_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 char *chlg64, + struct kerberos5data *krb5, + char **outptr, size_t *outlen) +{ + CURLcode result = CURLE_OK; + size_t chlglen = 0; + unsigned char *chlg = NULL; + 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_OUT_OF_MEMORY; + } + + free(spn); + } + + if(chlg64 && *chlg64) { + /* Decode the base-64 encoded challenge message */ + if(*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; + } + + 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); + + /* Free the decoded challenge as it is not required anymore */ + free(input_token.value); + + 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_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(&unused_status, &output_token); + } + else if(mutual_auth) { + *outptr = strdup(""); + if(!*outptr) + result = CURLE_OUT_OF_MEMORY; + } + + 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. + * chlg64 [in] - Pointer to the optional base64 encoded challenge message. + * krb5 [in/out] - The Kerberos 5 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_auth_create_gssapi_security_message(struct Curl_easy *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 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 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 */ + major_status = gss_inquire_context(&minor_status, krb5->context, + &username, NULL, NULL, NULL, NULL, + NULL, NULL); + if(GSS_ERROR(major_status)) { + Curl_gss_log_error(data, "gss_inquire_context() failed: ", + major_status, minor_status); + + free(chlg); + + return CURLE_OUT_OF_MEMORY; + } + + /* Convert the username from internal format to a displayable token */ + major_status = gss_display_name(&minor_status, username, + &username_token, NULL); + if(GSS_ERROR(major_status)) { + Curl_gss_log_error(data, "gss_display_name() failed: ", + major_status, minor_status); + + 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 */ + 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); + + gss_release_buffer(&unused_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(&unused_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(&unused_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(&unused_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(&unused_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: Despite 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(&unused_status, &username_token); + + /* 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_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(&unused_status, &output_token); + + /* Free the message buffer */ + free(message); + + return result; +} + +/* + * Curl_auth_gssapi_cleanup() + * + * 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_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 */ |