diff options
Diffstat (limited to 'libcurl/src/lib/curl_sasl_gssapi.c')
| -rw-r--r-- | libcurl/src/lib/curl_sasl_gssapi.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/libcurl/src/lib/curl_sasl_gssapi.c b/libcurl/src/lib/curl_sasl_gssapi.c new file mode 100644 index 0000000..75bf6a7 --- /dev/null +++ b/libcurl/src/lib/curl_sasl_gssapi.c @@ -0,0 +1,392 @@ +/***************************************************************************
+ * _ _ ____ _
+ * 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.
+ */
+CURL_STATIC 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.
+ */
+CURL_STATIC 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.
+ *
+ */
+CURL_STATIC 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 */
|