Better error reporting through com_err
[mech_eap.git] / init_sec_context.c
index b9ff0be..f7eda20 100644 (file)
 
 #include "gssapiP_eap.h"
 
+#ifdef GSSEAP_ENABLE_REAUTH
+static OM_uint32
+eapGssSmInitGssReauth(OM_uint32 *minor,
+                      gss_cred_id_t cred,
+                      gss_ctx_id_t ctx,
+                      gss_name_t target,
+                      gss_OID mech,
+                      OM_uint32 reqFlags,
+                      OM_uint32 timeReq,
+                      gss_channel_bindings_t chanBindings,
+                      gss_buffer_t inputToken,
+                      gss_buffer_t outputToken);
+#endif
+
 static OM_uint32
 policyVariableToFlag(enum eapol_bool_var variable)
 {
@@ -70,6 +84,14 @@ policyVariableToFlag(enum eapol_bool_var variable)
     return flag;
 }
 
+static struct eap_peer_config *
+peerGetConfig(void *ctx)
+{
+    gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
+
+    return &gssCtx->initiatorCtx.eapPeerConfig;
+}
+
 static Boolean
 peerGetBool(void *data, enum eapol_bool_var variable)
 {
@@ -102,7 +124,7 @@ peerSetBool(void *data, enum eapol_bool_var variable,
         ctx->flags &= ~(flag);
 }
 
-static int
+static unsigned int
 peerGetInt(void *data, enum eapol_int_var variable)
 {
     gss_ctx_id_t ctx = data;
@@ -139,6 +161,245 @@ peerSetInt(void *data, enum eapol_int_var variable,
     }
 }
 
+static struct wpabuf *
+peerGetEapReqData(void *ctx)
+{
+    gss_ctx_id_t gssCtx = (gss_ctx_id_t)ctx;
+
+    return &gssCtx->initiatorCtx.reqData;
+}
+
+static void
+peerSetConfigBlob(void *ctx, struct wpa_config_blob *blob)
+{
+}
+
+static const struct wpa_config_blob *
+peerGetConfigBlob(void *ctx, const char *name)
+{
+    return NULL;
+}
+
+static void
+peerNotifyPending(void *ctx)
+{
+}
+
+static struct eapol_callbacks gssEapPolicyCallbacks = {
+    peerGetConfig,
+    peerGetBool,
+    peerSetBool,
+    peerGetInt,
+    peerSetInt,
+    peerGetEapReqData,
+    peerSetConfigBlob,
+    peerGetConfigBlob,
+    peerNotifyPending,
+};
+
+extern int wpa_debug_level;
+
+static OM_uint32
+peerConfigInit(OM_uint32 *minor,
+               gss_cred_id_t cred,
+               gss_ctx_id_t ctx)
+{
+    krb5_context krbContext;
+    struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
+    krb5_error_code code;
+    char *identity;
+
+    eapPeerConfig->identity = NULL;
+    eapPeerConfig->identity_len = 0;
+    eapPeerConfig->password = NULL;
+    eapPeerConfig->password_len = 0;
+
+    assert(cred != GSS_C_NO_CREDENTIAL);
+
+    GSSEAP_KRB_INIT(&krbContext);
+
+    eapPeerConfig->fragment_size = 1024;
+    wpa_debug_level = 0;
+
+    code = krb5_unparse_name(krbContext, cred->name->krbPrincipal, &identity);
+    if (code != 0) {
+        *minor = code;
+        return GSS_S_FAILURE;
+    }
+
+    eapPeerConfig->identity = (unsigned char *)identity;
+    eapPeerConfig->identity_len = strlen(identity);
+    eapPeerConfig->password = (unsigned char *)cred->password.value;
+    eapPeerConfig->password_len = cred->password.length;
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+peerConfigFree(OM_uint32 *minor,
+               gss_ctx_id_t ctx)
+{
+    krb5_context krbContext;
+    struct eap_peer_config *eapPeerConfig = &ctx->initiatorCtx.eapPeerConfig;
+
+    GSSEAP_KRB_INIT(&krbContext);
+
+    krb5_free_unparsed_name(krbContext, (char *)eapPeerConfig->identity);
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+initReady(OM_uint32 *minor, gss_ctx_id_t ctx, OM_uint32 reqFlags)
+{
+    OM_uint32 major;
+    const unsigned char *key;
+    size_t keyLength;
+
+#if 1
+    /* XXX actually check for mutual auth */
+    if (reqFlags & GSS_C_MUTUAL_FLAG)
+        ctx->gssFlags |= GSS_C_MUTUAL_FLAG;
+#endif
+
+    /* Cache encryption type derived from selected mechanism OID */
+    major = gssEapOidToEnctype(minor, ctx->mechanismUsed, &ctx->encryptionType);
+    if (GSS_ERROR(major))
+        return major;
+
+    if (!eap_key_available(ctx->initiatorCtx.eap)) {
+        *minor = GSSEAP_KEY_UNAVAILABLE;
+        return GSS_S_UNAVAILABLE;
+    }
+
+    key = eap_get_eapKeyData(ctx->initiatorCtx.eap, &keyLength);
+
+    if (keyLength < EAP_EMSK_LEN) {
+        *minor = GSSEAP_KEY_TOO_SHORT;
+        return GSS_S_UNAVAILABLE;
+    }
+
+    major = gssEapDeriveRfc3961Key(minor,
+                                   &key[EAP_EMSK_LEN / 2],
+                                   EAP_EMSK_LEN / 2,
+                                   ctx->encryptionType,
+                                   &ctx->rfc3961Key);
+       if (GSS_ERROR(major))
+           return major;
+
+    major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
+                                      &ctx->checksumType);
+    if (GSS_ERROR(major))
+        return major;
+
+    major = sequenceInit(minor,
+                         &ctx->seqState,
+                         ctx->recvSeq,
+                         ((ctx->gssFlags & GSS_C_REPLAY_FLAG) != 0),
+                         ((ctx->gssFlags & GSS_C_SEQUENCE_FLAG) != 0),
+                         TRUE);
+    if (GSS_ERROR(major))
+        return major;
+
+    *minor = 0;
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+initBegin(OM_uint32 *minor,
+          gss_cred_id_t cred,
+          gss_ctx_id_t ctx,
+          gss_name_t target,
+          gss_OID mech,
+          OM_uint32 reqFlags,
+          OM_uint32 timeReq,
+          gss_channel_bindings_t chanBindings,
+          gss_buffer_t inputToken,
+          gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+
+    assert(cred != GSS_C_NO_CREDENTIAL);
+
+    if (cred->expiryTime)
+        ctx->expiryTime = cred->expiryTime;
+    else if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
+        ctx->expiryTime = 0;
+    else
+        ctx->expiryTime = time(NULL) + timeReq;
+
+    /*
+     * The credential mutex protects its name, however we need to
+     * explicitly lock the acceptor name (unlikely as it may be
+     * that it has attributes set on it).
+     */
+    major = gssEapDuplicateName(minor, cred->name, &ctx->initiatorName);
+    if (GSS_ERROR(major))
+        return major;
+
+    GSSEAP_MUTEX_LOCK(&target->mutex);
+
+    major = gssEapDuplicateName(minor, target, &ctx->acceptorName);
+    if (GSS_ERROR(major)) {
+        GSSEAP_MUTEX_UNLOCK(&target->mutex);
+        return major;
+    }
+
+    GSSEAP_MUTEX_UNLOCK(&target->mutex);
+
+    if (mech == GSS_C_NULL_OID) {
+        major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
+    } else if (gssEapIsConcreteMechanismOid(mech)) {
+        if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
+            major = duplicateOid(minor, mech, &ctx->mechanismUsed);
+    } else {
+        *minor = GSSEAP_WRONG_MECH;
+        major = GSS_S_BAD_MECH;
+    }
+    if (GSS_ERROR(major))
+        return major;
+
+    /* If credentials were provided, check they're usable with this mech */
+    if (!gssEapCredAvailable(cred, ctx->mechanismUsed))
+        return GSS_S_BAD_MECH;
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+eapGssSmInitIdentity(OM_uint32 *minor,
+                     gss_cred_id_t cred,
+                     gss_ctx_id_t ctx,
+                     gss_name_t target,
+                     gss_OID mech,
+                     OM_uint32 reqFlags,
+                     OM_uint32 timeReq,
+                     gss_channel_bindings_t chanBindings,
+                     gss_buffer_t inputToken,
+                     gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+    int initialContextToken;
+
+    initialContextToken = (inputToken->length == 0);
+    if (!initialContextToken) {
+        *minor = GSSEAP_WRONG_SIZE;
+        return GSS_S_DEFECTIVE_TOKEN;
+    }
+
+    major = initBegin(minor, cred, ctx, target, mech,
+                      reqFlags, timeReq, chanBindings,
+                      inputToken, outputToken);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->state = EAP_STATE_AUTHENTICATE;
+
+    return GSS_S_CONTINUE_NEEDED;
+}
+
+static struct wpabuf emptyWpaBuffer;
+
 static OM_uint32
 eapGssSmInitAuthenticate(OM_uint32 *minor,
                          gss_cred_id_t cred,
@@ -151,46 +412,157 @@ eapGssSmInitAuthenticate(OM_uint32 *minor,
                          gss_buffer_t inputToken,
                          gss_buffer_t outputToken)
 {
-    OM_uint32 major, tmpMinor;
-    time_t now;
+    OM_uint32 major;
+    OM_uint32 tmpMinor;
+    int code;
+    struct wpabuf *resp = NULL;
+    int initialContextToken;
 
-    if (inputToken == GSS_C_NO_BUFFER || inputToken->length == 0) {
-        /* first time */
-        reqFlags &= GSS_C_TRANS_FLAG | GSS_C_REPLAY_FLAG | GSS_C_DCE_STYLE;
-        ctx->gssFlags |= reqFlags;
+    initialContextToken = (inputToken == GSS_C_NO_BUFFER ||
+                           inputToken->length == 0);
 
-        time(&now);
+    major = peerConfigInit(minor, cred, ctx);
+    if (GSS_ERROR(major))
+        goto cleanup;
 
-        if (timeReq == 0 || timeReq == GSS_C_INDEFINITE)
-            ctx->expiryTime = 0;
-        else
-            ctx->expiryTime = now + timeReq;
+    if (ctx->initiatorCtx.eap == NULL) {
+        struct eap_config eapConfig;
 
-        major = gss_duplicate_name(minor, cred->name, &ctx->initiatorName);
-        if (GSS_ERROR(major))
-            goto cleanup;
+        memset(&eapConfig, 0, sizeof(eapConfig));
 
-        major = gss_duplicate_name(minor, target, &ctx->acceptorName);
-        if (GSS_ERROR(major))
+        ctx->initiatorCtx.eap = eap_peer_sm_init(ctx,
+                                                 &gssEapPolicyCallbacks,
+                                                 ctx,
+                                                 &eapConfig);
+        if (ctx->initiatorCtx.eap == NULL) {
+            *minor = GSSEAP_PEER_INIT_FAILURE;
+            major = GSS_S_FAILURE;
             goto cleanup;
-
-        if (mech == GSS_C_NULL_OID || oidEqual(mech, GSS_EAP_MECHANISM)) {
-            major = gssEapDefaultMech(minor, &ctx->mechanismUsed);
-        } else if (gssEapIsConcreteMechanismOid(mech)) {
-            if (!gssEapInternalizeOid(mech, &ctx->mechanismUsed))
-                major = duplicateOid(minor, mech, &ctx->mechanismUsed);
-        } else {
-            major = GSS_S_BAD_MECH;
         }
+
+        ctx->flags |= CTX_FLAG_EAP_RESTART | CTX_FLAG_EAP_PORT_ENABLED;
+    }
+
+    ctx->flags |= CTX_FLAG_EAP_REQ; /* we have a Request from the acceptor */
+
+    wpabuf_set(&ctx->initiatorCtx.reqData,
+               inputToken->value, inputToken->length);
+
+    major = GSS_S_CONTINUE_NEEDED;
+
+    code = eap_peer_sm_step(ctx->initiatorCtx.eap);
+    if (ctx->flags & CTX_FLAG_EAP_RESP) {
+        ctx->flags &= ~(CTX_FLAG_EAP_RESP);
+
+        resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
+    } else if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
+        major = initReady(minor, ctx, reqFlags);
         if (GSS_ERROR(major))
             goto cleanup;
+
+        ctx->flags &= ~(CTX_FLAG_EAP_SUCCESS);
+        major = GSS_S_CONTINUE_NEEDED;
+        ctx->state = EAP_STATE_EXTENSIONS_REQ;
+    } else if (ctx->flags & CTX_FLAG_EAP_FAIL) {
+        *minor = GSSEAP_PEER_AUTH_FAILURE;
+        major = GSS_S_DEFECTIVE_CREDENTIAL;
+    } else if (code == 0 && initialContextToken) {
+        resp = &emptyWpaBuffer;
+        major = GSS_S_CONTINUE_NEEDED;
+    } else {
+        *minor = GSSEAP_PEER_BAD_MESSAGE;
+        major = GSS_S_DEFECTIVE_TOKEN;
     }
 
 cleanup:
+    if (resp != NULL) {
+        OM_uint32 tmpMajor;
+        gss_buffer_desc respBuf;
+
+        assert(major == GSS_S_CONTINUE_NEEDED);
+
+        respBuf.length = wpabuf_len(resp);
+        respBuf.value = (void *)wpabuf_head(resp);
+
+        tmpMajor = duplicateBuffer(&tmpMinor, &respBuf, outputToken);
+        if (GSS_ERROR(tmpMajor)) {
+            major = tmpMajor;
+            *minor = tmpMinor;
+        }
+    }
+
+    wpabuf_set(&ctx->initiatorCtx.reqData, NULL, 0);
+    peerConfigFree(&tmpMinor, ctx);
+
     return major;
 }
 
-static struct eap_gss_initiator_sm {
+static OM_uint32
+eapGssSmInitExtensionsReq(OM_uint32 *minor,
+                          gss_cred_id_t cred,
+                          gss_ctx_id_t ctx,
+                          gss_name_t target,
+                          gss_OID mech,
+                          OM_uint32 reqFlags,
+                          OM_uint32 timeReq,
+                          gss_channel_bindings_t chanBindings,
+                          gss_buffer_t inputToken,
+                          gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+
+    major = gssEapMakeExtensions(minor, cred, ctx, chanBindings, outputToken);
+    if (GSS_ERROR(major))
+        return major;
+
+    assert(outputToken->value != NULL);
+
+    ctx->state = EAP_STATE_EXTENSIONS_RESP;
+
+    return GSS_S_CONTINUE_NEEDED;
+}
+
+static OM_uint32
+eapGssSmInitExtensionsResp(OM_uint32 *minor,
+                           gss_cred_id_t cred,
+                           gss_ctx_id_t ctx,
+                           gss_name_t target,
+                           gss_OID mech,
+                           OM_uint32 reqFlags,
+                           OM_uint32 timeReq,
+                           gss_channel_bindings_t chanBindings,
+                           gss_buffer_t inputToken,
+                           gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+
+    major = gssEapVerifyExtensions(minor, cred, ctx, chanBindings, inputToken);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->state = EAP_STATE_ESTABLISHED;
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+eapGssSmInitEstablished(OM_uint32 *minor,
+                        gss_cred_id_t cred,
+                        gss_ctx_id_t ctx,
+                        gss_name_t target,
+                        gss_OID mech,
+                        OM_uint32 reqFlags,
+                        OM_uint32 timeReq,
+                        gss_channel_bindings_t chanBindings,
+                        gss_buffer_t inputToken,
+                        gss_buffer_t outputToken)
+{
+    /* Called with already established context */
+    *minor = GSSEAP_CONTEXT_ESTABLISHED;
+    return GSS_S_BAD_STATUS;
+}
+
+static struct gss_eap_initiator_sm {
     enum gss_eap_token_type inputTokenType;
     enum gss_eap_token_type outputTokenType;
     OM_uint32 (*processToken)(OM_uint32 *,
@@ -204,7 +576,14 @@ static struct eap_gss_initiator_sm {
                               gss_buffer_t,
                               gss_buffer_t);
 } eapGssInitiatorSm[] = {
-    { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP, eapGssSmInitAuthenticate },
+    { TOK_TYPE_NONE,    TOK_TYPE_EAP_RESP,      eapGssSmInitIdentity            },
+    { TOK_TYPE_EAP_REQ, TOK_TYPE_EAP_RESP,      eapGssSmInitAuthenticate        },
+    { TOK_TYPE_NONE,    TOK_TYPE_EXT_REQ,       eapGssSmInitExtensionsReq       },
+    { TOK_TYPE_EXT_RESP,TOK_TYPE_NONE,          eapGssSmInitExtensionsResp      },
+    { TOK_TYPE_NONE,    TOK_TYPE_NONE,          eapGssSmInitEstablished         },
+#ifdef GSSEAP_ENABLE_REAUTH
+    { TOK_TYPE_GSS_REAUTH, TOK_TYPE_GSS_REAUTH, eapGssSmInitGssReauth           },
+#endif
 };
 
 OM_uint32
@@ -222,25 +601,24 @@ gss_init_sec_context(OM_uint32 *minor,
                      OM_uint32 *ret_flags,
                      OM_uint32 *time_rec)
 {
-    OM_uint32 major, tmpMinor;
+    OM_uint32 major;
+    OM_uint32 tmpMajor, tmpMinor;
     gss_ctx_id_t ctx = *context_handle;
-    struct eap_gss_initiator_sm *sm = NULL;
-    gss_buffer_desc innerInputToken, innerOutputToken;
+    struct gss_eap_initiator_sm *sm = NULL;
+    gss_buffer_desc innerInputToken;
+    gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
+    enum gss_eap_token_type tokType;
+    gss_cred_id_t defaultCred = GSS_C_NO_CREDENTIAL;
+    int initialContextToken = 0;
 
     *minor = 0;
 
-    innerOutputToken.length = 0;
-    innerOutputToken.value = NULL;
-
     output_token->length = 0;
     output_token->value = NULL;
 
-    if (cred != GSS_C_NO_CREDENTIAL && !(cred->flags & CRED_FLAG_INITIATE)) {
-        return GSS_S_NO_CRED;
-    }
-
     if (ctx == GSS_C_NO_CONTEXT) {
         if (input_token != GSS_C_NO_BUFFER && input_token->length != 0) {
+            *minor = GSSEAP_WRONG_SIZE;
             return GSS_S_DEFECTIVE_TOKEN;
         }
 
@@ -250,54 +628,105 @@ gss_init_sec_context(OM_uint32 *minor,
 
         ctx->flags |= CTX_FLAG_INITIATOR;
 
+        initialContextToken = 1;
         *context_handle = ctx;
     }
 
     GSSEAP_MUTEX_LOCK(&ctx->mutex);
 
+    if (cred == GSS_C_NO_CREDENTIAL) {
+        if (ctx->initiatorCtx.defaultCred == GSS_C_NO_CREDENTIAL) {
+            major = gssEapAcquireCred(minor,
+                                      GSS_C_NO_NAME,
+                                      GSS_C_NO_BUFFER,
+                                      time_req,
+                                      GSS_C_NO_OID_SET,
+                                      GSS_C_INITIATE,
+                                      &defaultCred,
+                                      NULL,
+                                      NULL);
+            if (GSS_ERROR(major))
+                goto cleanup;
+        }
+
+        cred = ctx->initiatorCtx.defaultCred;
+    }
+
+    GSSEAP_MUTEX_LOCK(&cred->mutex);
+
+#ifdef GSSEAP_ENABLE_REAUTH
+    if (initialContextToken && gssEapCanReauthP(cred, target_name, time_req))
+        ctx->state = EAP_STATE_KRB_REAUTH_GSS;
+#endif
+
+    if ((cred->flags & CRED_FLAG_INITIATE) == 0) {
+        *minor = GSSEAP_CRED_USAGE_MISMATCH;
+        major = GSS_S_NO_CRED;
+        goto cleanup;
+    }
+
     sm = &eapGssInitiatorSm[ctx->state];
 
     if (input_token != GSS_C_NO_BUFFER) {
         major = gssEapVerifyToken(minor, ctx, input_token,
-                                  sm->inputTokenType, &innerInputToken);
+                                  &tokType, &innerInputToken);
         if (GSS_ERROR(major))
             goto cleanup;
+
+        if (tokType != sm->inputTokenType) {
+            *minor = GSSEAP_WRONG_TOK_ID;
+            major = GSS_S_DEFECTIVE_TOKEN;
+            goto cleanup;
+        }
     } else {
         innerInputToken.length = 0;
         innerInputToken.value = NULL;
     }
 
-    major = (sm->processToken)(minor,
-                               cred,
-                               ctx,
-                               target_name,
-                               mech_type,
-                               req_flags,
-                               time_req,
-                               input_chan_bindings,
-                               &innerInputToken,
-                               &innerOutputToken);
-    if (GSS_ERROR(major))
-        goto cleanup;
+    /*
+     * Advance through state machine whilst empty tokens are emitted and
+     * the status is not GSS_S_COMPLETE or an error status.
+     */
+    do {
+        sm = &eapGssInitiatorSm[ctx->state];
+
+        major = (sm->processToken)(minor,
+                                   cred,
+                                   ctx,
+                                   target_name,
+                                   mech_type,
+                                   req_flags,
+                                   time_req,
+                                   input_chan_bindings,
+                                   &innerInputToken,
+                                   &innerOutputToken);
+        if (GSS_ERROR(major))
+            goto cleanup;
+    } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.value == NULL);
 
     if (actual_mech_type != NULL) {
         if (!gssEapInternalizeOid(ctx->mechanismUsed, actual_mech_type))
             duplicateOid(&tmpMinor, ctx->mechanismUsed, actual_mech_type);
     }
-    if (innerOutputToken.length != 0) {
-        major = gssEapMakeToken(minor, ctx, &innerOutputToken,
-                                sm->outputTokenType, output_token);
-        if (GSS_ERROR(major))
+    if (innerOutputToken.value != NULL) {
+        tmpMajor = gssEapMakeToken(&tmpMinor, ctx, &innerOutputToken,
+                                   sm->outputTokenType, output_token);
+        if (GSS_ERROR(tmpMajor)) {
+            major = tmpMajor;
+            *minor = tmpMinor;
             goto cleanup;
+        }
     }
     if (ret_flags != NULL)
         *ret_flags = ctx->gssFlags;
     if (time_rec != NULL)
-        gss_context_time(&tmpMinor, ctx, time_rec);
+        gssEapContextTime(&tmpMinor, ctx, time_rec);
 
     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 
 cleanup:
+    if (cred != GSS_C_NO_CREDENTIAL)
+        GSSEAP_MUTEX_UNLOCK(&cred->mutex);
     GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
 
     if (GSS_ERROR(major))
@@ -307,3 +736,69 @@ cleanup:
 
     return major;
 }
+
+#ifdef GSSEAP_ENABLE_REAUTH
+static OM_uint32
+eapGssSmInitGssReauth(OM_uint32 *minor,
+                      gss_cred_id_t cred,
+                      gss_ctx_id_t ctx,
+                      gss_name_t target,
+                      gss_OID mech,
+                      OM_uint32 reqFlags,
+                      OM_uint32 timeReq,
+                      gss_channel_bindings_t chanBindings,
+                      gss_buffer_t inputToken,
+                      gss_buffer_t outputToken)
+{
+    OM_uint32 major, tmpMinor;
+    gss_name_t mechTarget = GSS_C_NO_NAME;
+    gss_OID actualMech = GSS_C_NO_OID;
+    OM_uint32 gssFlags, timeRec;
+
+    assert(cred != GSS_C_NO_CREDENTIAL);
+
+    ctx->flags |= CTX_FLAG_KRB_REAUTH_GSS;
+
+    if (inputToken->length == 0) {
+        major = initBegin(minor, cred, ctx, target, mech,
+                          reqFlags, timeReq, chanBindings,
+                          inputToken, outputToken);
+        if (GSS_ERROR(major))
+            goto cleanup;
+    }
+
+    major = gssEapMechToGlueName(minor, target, &mechTarget);
+    if (GSS_ERROR(major))
+        goto cleanup;
+
+    major = gssInitSecContext(minor,
+                              cred->krbCred,
+                              &ctx->kerberosCtx,
+                              mechTarget,
+                              (gss_OID)gss_mech_krb5,
+                              reqFlags, /* | GSS_C_DCE_STYLE, */
+                              timeReq,
+                              chanBindings,
+                              inputToken,
+                              &actualMech,
+                              outputToken,
+                              &gssFlags,
+                              &timeRec);
+    if (GSS_ERROR(major))
+        goto cleanup;
+
+    ctx->gssFlags = gssFlags;
+
+    if (major == GSS_S_COMPLETE) {
+        major = gssEapReauthComplete(minor, ctx, cred, actualMech, timeRec);
+        if (GSS_ERROR(major))
+            goto cleanup;
+        ctx->state = EAP_STATE_ESTABLISHED;
+    }
+
+cleanup:
+    gssReleaseName(&tmpMinor, &mechTarget);
+
+    return major;
+}
+#endif /* GSSEAP_ENABLE_REAUTH */