* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
+ * Copyright (C) 2014, Steve Holme, <steve_holme@hotmail.com>.
* Copyright (C) 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
*
* RFC2831 DIGEST-MD5 authentication
* RFC4422 Simple Authentication and Security Layer (SASL)
+ * RFC4752 The Kerberos V5 ("GSSAPI") SASL Mechanism
*
***************************************************************************/
#endif /* !CURL_DISABLE_CRYPTO_AUTH */
+/*
+ * 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 [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,
+ const char *chlg64,
+ struct kerberos5data *krb5,
+ char **outptr, size_t *outlen)
+{
+ CURLcode result = CURLE_OK;
+ size_t chlglen = 0;
+ unsigned char *chlg = NULL;
+ unsigned char *resp = NULL;
+ CtxtHandle context;
+ PSecPkgInfo SecurityPackage;
+ SecBuffer chlg_buf;
+ SecBuffer resp_buf;
+ SecBufferDesc chlg_desc;
+ SecBufferDesc resp_desc;
+ SECURITY_STATUS status;
+ unsigned long attrs;
+ TimeStamp tsDummy; /* For Windows 9x compatibility of SSPI calls */
+
+ if(!krb5->credentials) {
+ /* Query the security package for Kerberos */
+ status = s_pSecFn->QuerySecurityPackageInfo((TCHAR *) TEXT("Kerberos"),
+ &SecurityPackage);
+ if(status != SEC_E_OK) {
+ return CURLE_NOT_BUILT_IN;
+ }
+
+ krb5->token_max = SecurityPackage->cbMaxToken;
+
+ /* Release the package buffer as it is not required anymore */
+ s_pSecFn->FreeContextBuffer(SecurityPackage);
+
+ /* Generate our SPN */
+ krb5->spn = Curl_sasl_build_spn(service, data->easy_conn->host.name);
+ if(!krb5->spn)
+ return CURLE_OUT_OF_MEMORY;
+
+ if(userp && *userp) {
+ CURLcode result;
+
+ /* 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;
+
+ /* Allocate our response buffer */
+ krb5->output_token = malloc(krb5->token_max);
+ if(!krb5->output_token)
+ return CURLE_OUT_OF_MEMORY;
+ }
+ else
+ /* Use the current Windows user */
+ krb5->p_identity = NULL;
+
+ /* Allocate our credentials handle */
+ krb5->credentials = malloc(sizeof(CredHandle));
+ if(!krb5->credentials)
+ return CURLE_OUT_OF_MEMORY;
+
+ memset(krb5->credentials, 0, sizeof(CredHandle));
+
+ /* Acquire our credientials handle */
+ status = s_pSecFn->AcquireCredentialsHandle(NULL,
+ (TCHAR *) TEXT("Kerberos"),
+ SECPKG_CRED_OUTBOUND, NULL,
+ krb5->p_identity, NULL, NULL,
+ krb5->credentials, &tsDummy);
+ if(status != SEC_E_OK)
+ return CURLE_OUT_OF_MEMORY;
+
+ /* Allocate our new context handle */
+ krb5->context = malloc(sizeof(CtxtHandle));
+ if(!krb5->context)
+ return CURLE_OUT_OF_MEMORY;
+
+ memset(krb5->context, 0, sizeof(CtxtHandle));
+ }
+ 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)
+ 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 = chlg;
+ chlg_buf.cbBuffer = curlx_uztoul(chlglen);
+ }
+
+ /* 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 ?
+ ISC_REQ_MUTUAL_AUTH : 0),
+ 0, SECURITY_NATIVE_DREP,
+ chlg ? &chlg_desc : NULL, 0,
+ &context,
+ &resp_desc, &attrs,
+ &tsDummy);
+
+ if(status != SEC_E_OK && status != SEC_I_CONTINUE_NEEDED)
+ return CURLE_RECV_ERROR;
+
+ if(memcmp(&context, krb5->context, sizeof(context))) {
+ s_pSecFn->DeleteSecurityContext(krb5->context);
+
+ memcpy(krb5->context, &context, sizeof(context));
+ }
+
+ if(resp_buf.cbBuffer) {
+ /* Base64 encode the response */
+ result = Curl_base64_encode(data, (char *)resp_buf.pvBuffer,
+ resp_buf.cbBuffer, outptr, outlen);
+ }
+
+ 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 offset = 0;
+ size_t chlglen = 0;
+ size_t messagelen = 0;
+ size_t appdatalen = 0;
+ unsigned char *chlg = NULL;
+ 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 long indata = 0;
+ unsigned long qop = 0;
+ unsigned long sec_layer = 0;
+ unsigned long max_size = 0;
+ SecPkgContext_Sizes sizes;
+ SecPkgCredentials_Names names;
+ SECURITY_STATUS status;
+
+ /* TODO: Verify the unicodeness of this function */
+
+ /* 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)
+ return CURLE_BAD_CONTENT_ENCODING;
+
+ /* Get our response size information */
+ status = s_pSecFn->QueryContextAttributes(krb5->context,
+ SECPKG_ATTR_SIZES,
+ &sizes);
+ if(status != SEC_E_OK) {
+ Curl_safefree(chlg);
+
+ return CURLE_OUT_OF_MEMORY;
+ }
+
+ /* Get the fully qualified username back from the context */
+ status = s_pSecFn->QueryCredentialsAttributes(krb5->credentials,
+ SECPKG_CRED_ATTR_NAMES,
+ &names);
+ if(status != SEC_E_OK) {
+ Curl_safefree(chlg);
+
+ return CURLE_RECV_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 = chlg;
+ input_buf[0].cbBuffer = curlx_uztoul(chlglen);
+ input_buf[1].BufferType = SECBUFFER_DATA;
+ input_buf[1].pvBuffer = NULL;
+ input_buf[1].cbBuffer = 0;
+
+ /* Decrypt in the inbound challenge obtaining the qop */
+ status = s_pSecFn->DecryptMessage(krb5->context, &input_desc, 0, &qop);
+ if(status != SEC_E_OK) {
+ Curl_safefree(chlg);
+
+ return CURLE_RECV_ERROR;
+ }
+
+ /* Not 4 octets long to fail as per RFC4752 Section 3.1 */
+ if(input_buf[1].cbBuffer != 4) {
+ Curl_safefree(chlg);
+
+ return CURLE_RECV_ERROR;
+ }
+
+ /* Copy the data out into a coinput_bufnvenient variable and free the SSPI
+ allocated buffer as it is not required anymore */
+ memcpy(&indata, input_buf[1].pvBuffer, 4);
+ s_pSecFn->FreeContextBuffer(input_buf[1].pvBuffer);
+
+ /* Extract the security layer */
+ sec_layer = indata & 0x000000FF;
+ if(!(sec_layer & KERB_WRAP_NO_ENCRYPT)) {
+ Curl_safefree(chlg);
+
+ return CURLE_RECV_ERROR;
+ }
+
+ /* Extract the maximum message size the server can receive */
+ max_size = ntohl(indata & 0xFFFFFF00);
+
+ /* Allocate the trailer */
+ trailer = malloc(sizes.cbSecurityTrailer);
+ if(!trailer) {
+ Curl_safefree(chlg);
+
+ return CURLE_OUT_OF_MEMORY;
+ }
+
+ /* Allocate our message */
+ messagelen = 4 + strlen(names.sUserName) + 1;
+ message = malloc(messagelen);
+ if(!message) {
+ Curl_safefree(trailer);
+ Curl_safefree(chlg);
+
+ return CURLE_OUT_OF_MEMORY;
+ }
+
+ /* Populate the message with the security layer, client supported receive
+ message size (lets claim to support the same as the server) 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. */
+ memcpy(message, &indata, 4);
+ strcpy((char *)message + 4, names.sUserName);
+
+ /* Allocate the padding */
+ padding = malloc(sizes.cbBlockSize);
+ if(!padding) {
+ Curl_safefree(message);
+ Curl_safefree(trailer);
+ Curl_safefree(chlg);
+
+ 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) {
+ Curl_safefree(padding);
+ Curl_safefree(message);
+ Curl_safefree(trailer);
+ Curl_safefree(chlg);
+
+ return CURLE_RECV_ERROR;
+ }
+
+ /* Allocate the encryption (wrap) buffer */
+ appdatalen = wrap_buf[0].cbBuffer + wrap_buf[1].cbBuffer +
+ wrap_buf[2].cbBuffer;
+ appdata = malloc(appdatalen);
+ if(!appdata) {
+ Curl_safefree(padding);
+ Curl_safefree(message);
+ Curl_safefree(trailer);
+ Curl_safefree(chlg);
+
+ 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);
+
+ /* Base64 encode the response */
+ result = Curl_base64_encode(data, (char *)appdata, appdatalen, outptr,
+ outlen);
+
+ /* Free all of our local buffers */
+ Curl_safefree(appdata);
+ Curl_safefree(padding);
+ Curl_safefree(message);
+ Curl_safefree(trailer);
+ Curl_safefree(chlg);
+
+ return result;
+}
+
+void Curl_sasl_gssapi_cleanup(struct kerberos5data *krb5)
+{
+ /* Free the context */
+ if(krb5->context) {
+ s_pSecFn->DeleteSecurityContext(krb5->context);
+ free(krb5->context);
+ krb5->context = NULL;
+ }
+
+ /* Free the credientials 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 */
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