From 96034c4a512ea2c3dbeb38654d993cb49e99bfda Mon Sep 17 00:00:00 2001
From: Steve Holme <steve_holme@hotmail.com>
Date: Sun, 10 Aug 2014 21:32:56 +0100
Subject: imap: Added support for GSSAPI (Kerberos V5) authentication via
Windows SSPI
---
lib/imap.c | 186 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 186 insertions(+)
(limited to 'lib')
diff --git a/lib/imap.c b/lib/imap.c
index 7d44e4408..e80bc03c1 100644
--- a/lib/imap.c
+++ b/lib/imap.c
@@ -1300,6 +1300,158 @@ static CURLcode imap_state_auth_ntlm_type2msg_resp(struct connectdata *conn,
}
#endif
+#if defined(USE_WINDOWS_SSPI)
+/* For AUTHENTICATE GSSAPI (without initial response) responses */
+static CURLcode imap_state_auth_gssapi_resp(struct connectdata *conn,
+ int imapcode,
+ imapstate instate)
+{
+ CURLcode result = CURLE_OK;
+ struct SessionHandle *data = conn->data;
+ struct imap_conn *imapc = &conn->proto.imapc;
+ size_t len = 0;
+ char *respmsg = NULL;
+
+ (void)instate; /* no use for this yet */
+
+ if(imapcode != '+') {
+ failf(data, "Access denied: %d", imapcode);
+ result = CURLE_LOGIN_DENIED;
+ }
+ else {
+ /* Create the initial response message */
+ result = Curl_sasl_create_gssapi_user_message(data, conn->user,
+ conn->passwd, "imap",
+ imapc->mutual_auth,
+ NULL, &conn->krb5,
+ &respmsg, &len);
+ if(!result && respmsg) {
+ /* Send the message */
+ result = Curl_pp_sendf(&imapc->pp, "%s", respmsg);
+
+ if(!result)
+ state(conn, IMAP_AUTHENTICATE_GSSAPI_TOKEN);
+ }
+ }
+
+ Curl_safefree(respmsg);
+
+ return result;
+}
+
+/* For AUTHENTICATE GSSAPI user token responses */
+static CURLcode imap_state_auth_gssapi_token_resp(struct connectdata *conn,
+ int imapcode,
+ imapstate instate)
+{
+ CURLcode result = CURLE_OK;
+ struct SessionHandle *data = conn->data;
+ struct imap_conn *imapc = &conn->proto.imapc;
+ char *chlgmsg = NULL;
+ char *respmsg = NULL;
+ size_t len = 0;
+
+ (void)instate; /* no use for this yet */
+
+ if(imapcode != '+') {
+ failf(data, "Access denied: %d", imapcode);
+ result = CURLE_LOGIN_DENIED;
+ }
+ else {
+ /* Get the challenge message */
+ imap_get_message(data->state.buffer, &chlgmsg);
+
+ if(imapc->mutual_auth)
+ /* Decode the user token challenge and create the optional response
+ message */
+ result = Curl_sasl_create_gssapi_user_message(data, NULL, NULL, NULL,
+ imapc->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(&imapc->pp, "%s", "*");
+
+ if(!result)
+ state(conn, IMAP_AUTHENTICATE_CANCEL);
+ }
+ }
+ else {
+ /* Send the response */
+ if(respmsg)
+ result = Curl_pp_sendf(&imapc->pp, "%s", respmsg);
+ else
+ result = Curl_pp_sendf(&imapc->pp, "%s", "");
+
+ if(!result)
+ state(conn, (imapc->mutual_auth ? IMAP_AUTHENTICATE_GSSAPI_NO_DATA :
+ IMAP_AUTHENTICATE_FINAL));
+ }
+ }
+
+ Curl_safefree(respmsg);
+
+ return result;
+}
+
+/* For AUTHENTICATE GSSAPI no data responses */
+static CURLcode imap_state_auth_gssapi_no_data_resp(struct connectdata *conn,
+ int imapcode,
+ imapstate 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(imapcode != '+') {
+ failf(data, "Access denied: %d", imapcode);
+ result = CURLE_LOGIN_DENIED;
+ }
+ else {
+ /* Get the challenge message */
+ imap_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.imapc.pp, "%s", "*");
+
+ if(!result)
+ state(conn, IMAP_AUTHENTICATE_CANCEL);
+ }
+ }
+ else {
+ /* Send the response */
+ if(respmsg) {
+ result = Curl_pp_sendf(&conn->proto.imapc.pp, "%s", respmsg);
+
+ if(!result)
+ state(conn, IMAP_AUTHENTICATE_FINAL);
+ }
+ }
+ }
+
+ Curl_safefree(respmsg);
+
+ return result;
+}
+#endif
+
/* For AUTHENTICATE XOAUTH2 (without initial response) responses */
static CURLcode imap_state_auth_xoauth2_resp(struct connectdata *conn,
int imapcode,
@@ -1759,6 +1911,21 @@ static CURLcode imap_statemach_act(struct connectdata *conn)
break;
#endif
+#if defined(USE_WINDOWS_SSPI)
+ case IMAP_AUTHENTICATE_GSSAPI:
+ result = imap_state_auth_gssapi_resp(conn, imapcode, imapc->state);
+ break;
+
+ case IMAP_AUTHENTICATE_GSSAPI_TOKEN:
+ result = imap_state_auth_gssapi_token_resp(conn, imapcode, imapc->state);
+ break;
+
+ case IMAP_AUTHENTICATE_GSSAPI_NO_DATA:
+ result = imap_state_auth_gssapi_no_data_resp(conn, imapcode,
+ imapc->state);
+ break;
+#endif
+
case IMAP_AUTHENTICATE_XOAUTH2:
result = imap_state_auth_xoauth2_resp(conn, imapcode, imapc->state);
break;
@@ -2636,6 +2803,25 @@ static CURLcode imap_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((imapc->authmechs & SASL_MECH_GSSAPI) &&
+ (imapc->prefmech & SASL_MECH_GSSAPI)) {
+ imapc->mutual_auth = FALSE; /* TODO: Calculate mutual authentication */
+
+ *mech = SASL_MECH_STRING_GSSAPI;
+ *state1 = IMAP_AUTHENTICATE_GSSAPI;
+ *state2 = IMAP_AUTHENTICATE_GSSAPI_TOKEN;
+ imapc->authused = SASL_MECH_GSSAPI;
+
+ if(imapc->ir_supported || data->set.sasl_ir)
+ result = Curl_sasl_create_gssapi_user_message(data, conn->user,
+ conn->passwd, "imap",
+ imapc->mutual_auth,
+ NULL, &conn->krb5,
+ initresp, len);
+ }
+ else
+#endif
#ifndef CURL_DISABLE_CRYPTO_AUTH
if((imapc->authmechs & SASL_MECH_DIGEST_MD5) &&
(imapc->prefmech & SASL_MECH_DIGEST_MD5)) {
--
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