smtp: Added support for GSSAPI (Kerberos V5) authentication via Windows SSPI (56632724) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP curl

lib/smtp.c

+186 −0

Original line number	Diff line number	Diff line
		@@ -1150,6 +1150,158 @@ static CURLcode smtp_state_auth_ntlm_type2msg_resp(struct connectdata *conn,
		}
		#endif

		#if defined(USE_WINDOWS_SSPI)
		/* For AUTH GSSAPI (without initial response) responses */
		static CURLcode smtp_state_auth_gssapi_resp(struct connectdata *conn,
		int smtpcode,
		smtpstate instate)
		{
		CURLcode result = CURLE_OK;
		struct SessionHandle *data = conn->data;
		struct smtp_conn *smtpc = &conn->proto.smtpc;
		char *respmsg = NULL;
		size_t len = 0;

		(void)instate; /* no use for this yet */

		if(smtpcode != 334) {
		failf(data, "Access denied: %d", smtpcode);
		result = CURLE_LOGIN_DENIED;
		}
		else {
		/* Create the initial response message */
		result = Curl_sasl_create_gssapi_user_message(data, conn->user,
		conn->passwd, "smtp",
		smtpc->mutual_auth, NULL,
		&conn->krb5,
		&respmsg, &len);
		if(!result && respmsg) {
		/* Send the message */
		result = Curl_pp_sendf(&smtpc->pp, "%s", respmsg);

		if(!result)
		state(conn, SMTP_AUTH_GSSAPI_TOKEN);
		}
		}

		Curl_safefree(respmsg);

		return result;
		}

		/* For AUTH GSSAPI user token responses */
		static CURLcode smtp_state_auth_gssapi_token_resp(struct connectdata *conn,
		int smtpcode,
		smtpstate instate)
		{
		CURLcode result = CURLE_OK;
		struct SessionHandle *data = conn->data;
		struct smtp_conn *smtpc = &conn->proto.smtpc;
		char *chlgmsg = NULL;
		char *respmsg = NULL;
		size_t len = 0;

		(void)instate; /* no use for this yet */

		if(smtpcode != 334) {
		failf(data, "Access denied: %d", smtpcode);
		result = CURLE_LOGIN_DENIED;
		}
		else {
		/* Get the challenge message */
		smtp_get_message(data->state.buffer, &chlgmsg);

		if(smtpc->mutual_auth)
		/* Decode the user token challenge and create the optional response
		message */
		result = Curl_sasl_create_gssapi_user_message(data, NULL, NULL, NULL,
		smtpc->mutual_auth,
		chlgmsg, &conn->krb5,
		&respmsg, &len);
		else
		/* Decode the security challenge and create the response message */
		result = Curl_sasl_create_gssapi_security_message(data, chlgmsg,
		&conn->krb5,
		&respmsg, &len);

		if(result) {
		if(result == CURLE_BAD_CONTENT_ENCODING) {
		/* Send the cancellation */
		result = Curl_pp_sendf(&smtpc->pp, "%s", "*");

		if(!result)
		state(conn, SMTP_AUTH_CANCEL);
		}
		}
		else {
		/* Send the response */
		if(respmsg)
		result = Curl_pp_sendf(&smtpc->pp, "%s", respmsg);
		else
		result = Curl_pp_sendf(&smtpc->pp, "%s", "");

		if(!result)
		state(conn, (smtpc->mutual_auth ? SMTP_AUTH_GSSAPI_NO_DATA :
		SMTP_AUTH_FINAL));
		}
		}

		Curl_safefree(respmsg);

		return result;
		}

		/* For AUTH GSSAPI no data responses */
		static CURLcode smtp_state_auth_gssapi_no_data_resp(struct connectdata *conn,
		int smtpcode,
		smtpstate instate)
		{
		CURLcode result = CURLE_OK;
		struct SessionHandle *data = conn->data;
		char *chlgmsg = NULL;
		char *respmsg = NULL;
		size_t len = 0;

		(void)instate; /* no use for this yet */

		if(smtpcode != 334) {
		failf(data, "Access denied: %d", smtpcode);
		result = CURLE_LOGIN_DENIED;
		}
		else {
		/* Get the challenge message */
		smtp_get_message(data->state.buffer, &chlgmsg);

		/* Decode the security challenge and create the response message */
		result = Curl_sasl_create_gssapi_security_message(data, chlgmsg,
		&conn->krb5,
		&respmsg, &len);
		if(result) {
		if(result == CURLE_BAD_CONTENT_ENCODING) {
		/* Send the cancellation */
		result = Curl_pp_sendf(&conn->proto.smtpc.pp, "%s", "*");

		if(!result)
		state(conn, SMTP_AUTH_CANCEL);
		}
		}
		else {
		/* Send the response */
		if(respmsg) {
		result = Curl_pp_sendf(&conn->proto.smtpc.pp, "%s", respmsg);

		if(!result)
		state(conn, SMTP_AUTH_FINAL);
		}
		}
		}

		Curl_safefree(respmsg);

		return result;
		}
		#endif

		/* For AUTH XOAUTH2 (without initial response) responses */
		static CURLcode smtp_state_auth_xoauth2_resp(struct connectdata *conn,
		int smtpcode, smtpstate instate)
		@@ -1478,6 +1630,21 @@ static CURLcode smtp_statemach_act(struct connectdata *conn)
		break;
		#endif

		#if defined(USE_WINDOWS_SSPI)
		case SMTP_AUTH_GSSAPI:
		result = smtp_state_auth_gssapi_resp(conn, smtpcode, smtpc->state);
		break;

		case SMTP_AUTH_GSSAPI_TOKEN:
		result = smtp_state_auth_gssapi_token_resp(conn, smtpcode, smtpc->state);
		break;

		case SMTP_AUTH_GSSAPI_NO_DATA:
		result = smtp_state_auth_gssapi_no_data_resp(conn, smtpcode,
		smtpc->state);
		break;
		#endif

		case SMTP_AUTH_XOAUTH2:
		result = smtp_state_auth_xoauth2_resp(conn, smtpcode, smtpc->state);
		break;
		@@ -2039,6 +2206,25 @@ static CURLcode smtp_calc_sasl_details(struct connectdata *conn,

		/* Calculate the supported authentication mechanism, by decreasing order of
		security, as well as the initial response where appropriate */
		#if defined(USE_WINDOWS_SSPI)
		if((smtpc->authmechs & SASL_MECH_GSSAPI) &&
		(smtpc->prefmech & SASL_MECH_GSSAPI)) {
		smtpc->mutual_auth = FALSE; /* TODO: Calculate mutual authentication */

		*mech = SASL_MECH_STRING_GSSAPI;
		*state1 = SMTP_AUTH_GSSAPI;
		*state2 = SMTP_AUTH_GSSAPI_TOKEN;
		smtpc->authused = SASL_MECH_GSSAPI;

		if(data->set.sasl_ir)
		result = Curl_sasl_create_gssapi_user_message(data, conn->user,
		conn->passwd, "smtp",
		smtpc->mutual_auth,
		NULL, &conn->krb5,
		initresp, len);
		}
		else
		#endif
		#ifndef CURL_DISABLE_CRYPTO_AUTH
		if((smtpc->authmechs & SASL_MECH_DIGEST_MD5) &&
		(smtpc->prefmech & SASL_MECH_DIGEST_MD5)) {