make reauth support conditionaly compilable
[mech_eap.git] / accept_sec_context.c
index 80b2697..2258d24 100644 (file)
 
 #include "gssapiP_eap.h"
 
+#ifdef GSSEAP_ENABLE_REAUTH
+static OM_uint32
+eapGssSmAcceptGssReauth(OM_uint32 *minor,
+                        gss_ctx_id_t ctx,
+                        gss_cred_id_t cred,
+                        gss_buffer_t inputToken,
+                        gss_channel_bindings_t chanBindings,
+                        gss_buffer_t outputToken);
+#endif
+
+/*
+ * Mark a context as ready for cryptographic operations
+ */
+static OM_uint32
+acceptReadyEap(OM_uint32 *minor, gss_ctx_id_t ctx, gss_cred_id_t cred)
+{
+    OM_uint32 major, tmpMinor;
+    VALUE_PAIR *vp;
+    gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
+
+    /* Cache encryption type derived from selected mechanism OID */
+    major = gssEapOidToEnctype(minor, ctx->mechanismUsed,
+                               &ctx->encryptionType);
+    if (GSS_ERROR(major))
+        return major;
+
+    gssEapReleaseName(&tmpMinor, &ctx->initiatorName);
+
+    vp = rc_avpair_get(ctx->acceptorCtx.avps, PW_USER_NAME, 0);
+    if (vp != NULL) {
+        nameBuf.length = vp->lvalue;
+        nameBuf.value = vp->strvalue;
+    } else {
+        ctx->gssFlags |= GSS_C_ANON_FLAG;
+    }
+
+    major = gssEapImportName(minor, &nameBuf, GSS_C_NT_USER_NAME,
+                             &ctx->initiatorName);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->initiatorName->attrCtx = gssEapCreateAttrContext(cred, ctx);
+
+    vp = rc_avpair_get(ctx->acceptorCtx.avps,
+                       VENDOR_ATTR_MS_MPPE_SEND_KEY,
+                       VENDOR_ID_MICROSOFT);
+    if (ctx->encryptionType != ENCTYPE_NULL && vp != NULL) {
+        major = gssEapDeriveRfc3961Key(minor,
+                                       (unsigned char *)vp->strvalue,
+                                       vp->lvalue,
+                                       ctx->encryptionType,
+                                       &ctx->rfc3961Key);
+        if (GSS_ERROR(major))
+            return major;
+
+        major = rfc3961ChecksumTypeForKey(minor, &ctx->rfc3961Key,
+                                           &ctx->checksumType);
+        if (GSS_ERROR(major))
+            return major;
+    } else {
+        /*
+         * draft-howlett-eap-gss says that integrity/confidentialty should
+         * always be advertised as available, but if we have no keying
+         * material it seems confusing to the caller to advertise this.
+         */
+        ctx->gssFlags &= ~(GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG);
+        ctx->encryptionType = ENCTYPE_NULL;
+    }
+
+    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;
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+eapGssSmAcceptIdentity(OM_uint32 *minor,
+                       gss_ctx_id_t ctx,
+                       gss_cred_id_t cred,
+                       gss_buffer_t inputToken,
+                       gss_channel_bindings_t chanBindings,
+                       gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+    union {
+        struct eap_hdr pdu;
+        unsigned char data[5];
+    } pkt;
+    gss_buffer_desc pktBuffer;
+
+    if (inputToken != GSS_C_NO_BUFFER && inputToken->length != 0)
+        return GSS_S_DEFECTIVE_TOKEN;
+
+    assert(ctx->acceptorCtx.radHandle == NULL);
+
+    major = gssEapRadiusAllocHandle(minor, cred, &ctx->acceptorCtx.radHandle);
+    if (GSS_ERROR(major))
+        return major;
+
+    assert(ctx->acceptorName == GSS_C_NO_NAME);
+
+    if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
+        major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
+        if (GSS_ERROR(major))
+            return major;
+    }
+
+    pkt.pdu.code = EAP_CODE_REQUEST;
+    pkt.pdu.identifier = 0;
+    pkt.pdu.length = htons(sizeof(pkt.data));
+    pkt.data[4] = EAP_TYPE_IDENTITY;
+
+    pktBuffer.length = sizeof(pkt.data);
+    pktBuffer.value = pkt.data;
+
+    major = duplicateBuffer(minor, &pktBuffer, outputToken);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->state = EAP_STATE_AUTHENTICATE;
+
+    return GSS_S_CONTINUE_NEEDED;
+}
+
+static OM_uint32
+setAcceptorIdentity(OM_uint32 *minor,
+                    gss_ctx_id_t ctx,
+                    VALUE_PAIR **avps)
+{
+    OM_uint32 major;
+    gss_buffer_desc nameBuf;
+    krb5_context krbContext = NULL;
+    krb5_principal krbPrinc;
+
+    /* Awaits further specification */
+    if (ctx->acceptorName == GSS_C_NO_NAME)
+        return GSS_S_COMPLETE;
+
+    GSSEAP_KRB_INIT(&krbContext);
+
+    krbPrinc = ctx->acceptorName->krbPrincipal;
+    assert(krbPrinc != NULL);
+
+    if (krb5_princ_size(krbContext, krbPrinc) < 2)
+        return GSS_S_BAD_NAME;
+
+    /* Acceptor-Service-Name */
+    krbDataToGssBuffer(krb5_princ_component(krbContext, krbPrinc, 0), &nameBuf);
+
+    major = addAvpFromBuffer(minor, ctx->acceptorCtx.radHandle, avps,
+                             VENDOR_ATTR_GSS_ACCEPTOR_SERVICE_NAME,
+                             VENDOR_ID_UKERNA,
+                             &nameBuf);
+    if (GSS_ERROR(major))
+        return major;
+
+    /* Acceptor-Host-Name */
+    krbDataToGssBuffer(krb5_princ_component(krbContext, krbPrinc, 1), &nameBuf);
+
+    major = addAvpFromBuffer(minor, ctx->acceptorCtx.radHandle, avps,
+                             VENDOR_ATTR_GSS_ACCEPTOR_HOST_NAME,
+                             VENDOR_ID_UKERNA,
+                             &nameBuf);
+    if (GSS_ERROR(major))
+        return major;
+
+    if (krb5_princ_size(krbContext, krbPrinc) > 2) {
+        /* Acceptor-Service-Specific */
+        krb5_principal_data ssiPrinc = *krbPrinc;
+        char *ssi;
+
+        krb5_princ_size(krbContext, &ssiPrinc) -= 2;
+        krb5_princ_name(krbContext, &ssiPrinc) += 2;
+
+        *minor = krb5_unparse_name_flags(krbContext, &ssiPrinc,
+                                         KRB5_PRINCIPAL_UNPARSE_NO_REALM, &ssi);
+        if (*minor != 0)
+            return GSS_S_FAILURE;
+
+        nameBuf.value = ssi;
+        nameBuf.length = strlen(ssi);
+
+        major = addAvpFromBuffer(minor, ctx->acceptorCtx.radHandle, avps,
+                                 VENDOR_ATTR_GSS_ACCEPTOR_SERVICE_SPECIFIC,
+                                 VENDOR_ID_UKERNA,
+                                 &nameBuf);
+
+        if (GSS_ERROR(major)) {
+            krb5_free_unparsed_name(krbContext, ssi);
+            return major;
+        }
+        krb5_free_unparsed_name(krbContext, ssi);
+    }
+
+    krbDataToGssBuffer(krb5_princ_realm(krbContext, krbPrinc), &nameBuf);
+    if (nameBuf.length != 0) {
+        /* Acceptor-Realm-Name */
+        major = addAvpFromBuffer(minor, ctx->acceptorCtx.radHandle, avps,
+                                 VENDOR_ATTR_GSS_ACCEPTOR_REALM_NAME,
+                                 VENDOR_ID_UKERNA,
+                                 &nameBuf);
+        if (GSS_ERROR(major))
+            return major;
+    }
+
+    return GSS_S_COMPLETE;
+}
+
 static OM_uint32
 eapGssSmAcceptAuthenticate(OM_uint32 *minor,
                            gss_ctx_id_t ctx,
@@ -41,13 +254,205 @@ eapGssSmAcceptAuthenticate(OM_uint32 *minor,
                            gss_buffer_t outputToken)
 {
     OM_uint32 major, tmpMinor;
+    int code;
+    VALUE_PAIR *send = NULL;
+    VALUE_PAIR *received = NULL;
+    rc_handle *rh = ctx->acceptorCtx.radHandle;
+    char msgBuffer[4096];
+    struct eap_hdr *pdu;
+    unsigned char *pos;
+    gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
+
+    pdu = (struct eap_hdr *)inputToken->value;
+    pos = (unsigned char *)(pdu + 1);
+
+    if (inputToken->length > sizeof(*pdu) &&
+        pdu->code == EAP_CODE_RESPONSE &&
+        pos[0] == EAP_TYPE_IDENTITY) {
+        /*
+         * XXX TODO do we really need to set User-Name? FreeRADIUS does
+         * not appear to require it.
+         */
+        major = addAvpFromBuffer(minor, rh, &send, PW_USER_NAME, 0, &nameBuf);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        major = setAcceptorIdentity(minor, ctx, &send);
+        if (GSS_ERROR(major))
+            goto cleanup;
+    }
+
+    major = addAvpFromBuffer(minor, rh, &send, PW_EAP_MESSAGE, 0, inputToken);
+    if (GSS_ERROR(major))
+        goto cleanup;
+
+    if (ctx->acceptorCtx.lastStatus == CHALLENGE_RC) {
+        major = addAvpFromBuffer(minor, rh, &send, PW_STATE, 0,
+                                 &ctx->acceptorCtx.state);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        gss_release_buffer(&tmpMinor, &ctx->acceptorCtx.state);
+    }
+
+    code = rc_auth(rh, 0, send, &received, msgBuffer);
+    switch (code) {
+    case OK_RC:
+    case CHALLENGE_RC:
+        major = GSS_S_CONTINUE_NEEDED;
+        break;
+    case TIMEOUT_RC:
+        major = GSS_S_UNAVAILABLE;
+        break;
+    case REJECT_RC:
+        major = GSS_S_DEFECTIVE_CREDENTIAL;
+        break;
+    default:
+        major = GSS_S_FAILURE;
+        goto cleanup;
+    }
+
+    if (GSS_ERROR(major))
+        goto cleanup;
+
+    ctx->acceptorCtx.lastStatus = code;
+
+    major = getBufferFromAvps(minor, received, PW_EAP_MESSAGE, 0,
+                              outputToken, TRUE);
+    if ((major == GSS_S_UNAVAILABLE && code != OK_RC) ||
+        GSS_ERROR(major))
+        goto cleanup;
+
+    if (code == CHALLENGE_RC) {
+        major = getBufferFromAvps(minor, received, PW_STATE, 0,
+                                  &ctx->acceptorCtx.state, TRUE);
+        if (major != GSS_S_UNAVAILABLE && GSS_ERROR(major))
+            goto cleanup;
+    } else {
+        ctx->acceptorCtx.avps = received;
+        received = NULL;
+
+        major = acceptReadyEap(minor, ctx, cred);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        ctx->state = EAP_STATE_EXTENSIONS_REQ;
+    }
+
+    major = GSS_S_CONTINUE_NEEDED;
 
 cleanup:
+    if (received != NULL)
+        rc_avpair_free(received);
+
+    return major;
+}
+
+static OM_uint32
+acceptGssChannelBindings(OM_uint32 *minor,
+                         gss_ctx_id_t ctx,
+                         gss_cred_id_t cred,
+                         gss_buffer_t inputToken,
+                         gss_channel_bindings_t chanBindings)
+{
+    OM_uint32 major, tmpMinor;
+    gss_iov_buffer_desc iov[2];
+
+    iov[0].type = GSS_IOV_BUFFER_TYPE_DATA | GSS_IOV_BUFFER_FLAG_ALLOCATE;
+    iov[0].buffer.length = 0;
+    iov[0].buffer.value = NULL;
+
+    iov[1].type = GSS_IOV_BUFFER_TYPE_STREAM;
+    iov[1].buffer = *inputToken;
+
+    major = gssEapUnwrapOrVerifyMIC(minor, ctx, NULL, NULL,
+                                    iov, 2, TOK_TYPE_WRAP);
+    if (GSS_ERROR(major))
+        return major;
+
+    if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS &&
+        !bufferEqual(&iov[0].buffer, &chanBindings->application_data)) {
+        major = GSS_S_BAD_BINDINGS;
+    } else {
+        major = GSS_S_CONTINUE_NEEDED;
+    }
+
+    gss_release_buffer(&tmpMinor, &iov[0].buffer);
+
     return major;
 }
 
+static OM_uint32
+eapGssSmAcceptExtensionsReq(OM_uint32 *minor,
+                            gss_ctx_id_t ctx,
+                            gss_cred_id_t cred,
+                            gss_buffer_t inputToken,
+                            gss_channel_bindings_t chanBindings,
+                            gss_buffer_t outputToken)
+{
+    OM_uint32 major;
+
+    outputToken->length = 0;
+    outputToken->value = NULL;
+
+    major = acceptGssChannelBindings(minor, ctx, cred, inputToken,
+                                     chanBindings);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->state = EAP_STATE_EXTENSIONS_RESP;
+
+    return GSS_S_CONTINUE_NEEDED;
+}
+
+static OM_uint32
+eapGssSmAcceptExtensionsResp(OM_uint32 *minor,
+                             gss_ctx_id_t ctx,
+                             gss_cred_id_t cred,
+                             gss_buffer_t inputToken,
+                             gss_channel_bindings_t chanBindings,
+                             gss_buffer_t outputToken)
+{
+    OM_uint32 major, tmpMinor;
+    gss_buffer_desc credsToken = GSS_C_EMPTY_BUFFER;
+
+#ifdef GSSEAP_ENABLE_REAUTH
+    major = gssEapMakeReauthCreds(minor, ctx, cred, &credsToken);
+    if (GSS_ERROR(major))
+        return major;
+#else
+    credsToken.value = "";
+#endif /* GSSEAP_ENABLE_REAUTH */
+
+    major = duplicateBuffer(minor, &credsToken, outputToken);
+    if (GSS_ERROR(major)) {
+        gss_release_buffer(&tmpMinor, &credsToken);
+        return major;
+    }
+
+#ifdef GSSEAP_ENABLE_REAUTH
+    gss_release_buffer(&tmpMinor, &credsToken);
+#endif
+
+    ctx->state = EAP_STATE_ESTABLISHED;
+
+    return GSS_S_COMPLETE;
+}
 
-static struct eap_gss_acceptor_sm {
+static OM_uint32
+eapGssSmAcceptEstablished(OM_uint32 *minor,
+                          gss_ctx_id_t ctx,
+                          gss_cred_id_t cred,
+                          gss_buffer_t inputToken,
+                          gss_channel_bindings_t chanBindings,
+                          gss_buffer_t outputToken)
+{
+    /* Called with already established context */
+    *minor = EINVAL;
+    return GSS_S_BAD_STATUS;
+}
+
+static struct gss_eap_acceptor_sm {
     enum gss_eap_token_type inputTokenType;
     enum gss_eap_token_type outputTokenType;
     OM_uint32 (*processToken)(OM_uint32 *,
@@ -57,7 +462,14 @@ static struct eap_gss_acceptor_sm {
                               gss_channel_bindings_t,
                               gss_buffer_t);
 } eapGssAcceptorSm[] = {
-    { TOK_TYPE_EAP_RESP, TOK_TYPE_EAP_REQ, NULL },
+    { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,    eapGssSmAcceptIdentity           },
+    { TOK_TYPE_EAP_RESP,    TOK_TYPE_EAP_REQ,    eapGssSmAcceptAuthenticate       },
+    { TOK_TYPE_EXT_REQ,     TOK_TYPE_NONE,       eapGssSmAcceptExtensionsReq      },
+    { TOK_TYPE_NONE,        TOK_TYPE_EXT_RESP,   eapGssSmAcceptExtensionsResp     },
+    { TOK_TYPE_NONE,        TOK_TYPE_NONE,       eapGssSmAcceptEstablished        },
+#ifdef GSSEAP_ENABLE_REAUTH
+    { TOK_TYPE_GSS_REAUTH,  TOK_TYPE_GSS_REAUTH, eapGssSmAcceptGssReauth          },
+#endif
 };
 
 OM_uint32
@@ -73,15 +485,16 @@ gss_accept_sec_context(OM_uint32 *minor,
                        OM_uint32 *time_rec,
                        gss_cred_id_t *delegated_cred_handle)
 {
-    OM_uint32 major, tmpMinor;
+    OM_uint32 major;
+    OM_uint32 tmpMajor, tmpMinor;
     gss_ctx_id_t ctx = *context_handle;
-    struct eap_gss_acceptor_sm *sm = NULL;
-    gss_buffer_desc innerInputToken, innerOutputToken;
-    
-    *minor = 0;
+    struct gss_eap_acceptor_sm *sm = NULL;
+    gss_buffer_desc innerInputToken = GSS_C_EMPTY_BUFFER;
+    gss_buffer_desc innerOutputToken = GSS_C_EMPTY_BUFFER;
+    enum gss_eap_token_type tokType;
+    int initialContextToken = 0;
 
-    innerOutputToken.length = 0;
-    innerOutputToken.value = NULL;
+    *minor = 0;
 
     output_token->length = 0;
     output_token->value = NULL;
@@ -99,6 +512,7 @@ gss_accept_sec_context(OM_uint32 *minor,
         if (GSS_ERROR(major))
             return major;
 
+        initialContextToken = 1;
         *context_handle = ctx;
     }
 
@@ -107,11 +521,30 @@ gss_accept_sec_context(OM_uint32 *minor,
     sm = &eapGssAcceptorSm[ctx->state];
 
     major = gssEapVerifyToken(minor, ctx, input_token,
-                              sm->inputTokenType, &innerInputToken);
+                              &tokType, &innerInputToken);
     if (GSS_ERROR(major))
         goto cleanup;
 
+#ifdef GSSEAP_ENABLE_REAUTH
+    if (tokType == TOK_TYPE_GSS_REAUTH && initialContextToken) {
+        ctx->state = EAP_STATE_KRB_REAUTH_GSS;
+    } else
+#endif
+    if (tokType != sm->inputTokenType) {
+        major = GSS_S_DEFECTIVE_TOKEN;
+        goto cleanup;
+    }
+
+    /* If credentials were provided, check they're usable with this mech */
+    if (cred != GSS_C_NO_CREDENTIAL &&
+        !gssEapCredAvailable(cred, ctx->mechanismUsed)) {
+        major = GSS_S_BAD_MECH;
+        goto cleanup;
+    }
+
     do {
+        sm = &eapGssAcceptorSm[ctx->state];
+
         major = (sm->processToken)(minor,
                                    ctx,
                                    cred,
@@ -122,28 +555,34 @@ gss_accept_sec_context(OM_uint32 *minor,
             goto cleanup;
     } while (major == GSS_S_CONTINUE_NEEDED && innerOutputToken.length == 0);
 
-    if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
-        major = gss_duplicate_name(&minor, ctx->initiatorName, src_name);
-        if (GSS_ERROR(major))
-            goto cleanup;
-    }
     if (mech_type != NULL) {
         if (!gssEapInternalizeOid(ctx->mechanismUsed, mech_type))
             duplicateOid(&tmpMinor, ctx->mechanismUsed, 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);
     if (delegated_cred_handle != NULL)
         *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 
+    if (major == GSS_S_COMPLETE) {
+        if (src_name != NULL && ctx->initiatorName != GSS_C_NO_NAME) {
+            major = gssEapDuplicateName(&tmpMinor, ctx->initiatorName, src_name);
+            if (GSS_ERROR(major))
+                goto cleanup;
+        }
+        if (time_rec != NULL)
+            gssEapContextTime(&tmpMinor, ctx, time_rec);
+    }
+
     assert(ctx->state == EAP_STATE_ESTABLISHED || major == GSS_S_CONTINUE_NEEDED);
 
 cleanup:
@@ -156,3 +595,76 @@ cleanup:
 
     return major;
 }
+
+#ifdef GSSEAP_ENABLE_REAUTH
+static OM_uint32
+acceptReadyKrb(OM_uint32 *minor,
+               gss_ctx_id_t ctx,
+               gss_cred_id_t cred,
+               const gss_name_t initiator,
+               const gss_OID mech,
+               OM_uint32 timeRec)
+{
+    OM_uint32 major;
+
+    major = gssEapGlueToMechName(minor, initiator, &ctx->initiatorName);
+    if (GSS_ERROR(major))
+        return major;
+
+    if (cred != GSS_C_NO_CREDENTIAL && cred->name != GSS_C_NO_NAME) {
+        major = gssEapDuplicateName(minor, cred->name, &ctx->acceptorName);
+        if (GSS_ERROR(major))
+            return major;
+    }
+
+    major = gssEapReauthComplete(minor, ctx, cred, mech, timeRec);
+    if (GSS_ERROR(major))
+        return major;
+
+    ctx->state = EAP_STATE_ESTABLISHED;
+
+    return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+eapGssSmAcceptGssReauth(OM_uint32 *minor,
+                        gss_ctx_id_t ctx,
+                        gss_cred_id_t cred,
+                        gss_buffer_t inputToken,
+                        gss_channel_bindings_t chanBindings,
+                        gss_buffer_t outputToken)
+{
+    OM_uint32 major, tmpMinor;
+    gss_cred_id_t krbCred = GSS_C_NO_CREDENTIAL;
+    gss_name_t krbInitiator = GSS_C_NO_NAME;
+    gss_OID mech = GSS_C_NO_OID;
+    OM_uint32 gssFlags, timeRec = GSS_C_INDEFINITE;
+
+    ctx->flags |= CTX_FLAG_KRB_REAUTH_GSS;
+
+    if (cred != GSS_C_NO_CREDENTIAL)
+        krbCred = cred->krbCred;
+
+    major = gssAcceptSecContext(minor,
+                                &ctx->kerberosCtx,
+                                krbCred,
+                                inputToken,
+                                chanBindings,
+                                &krbInitiator,
+                                &mech,
+                                outputToken,
+                                &gssFlags,
+                                &timeRec,
+                                NULL);
+    if (major == GSS_S_COMPLETE) {
+        major = acceptReadyKrb(minor, ctx, cred,
+                               krbInitiator, mech, timeRec);
+    }
+
+    ctx->gssFlags = gssFlags;
+
+    gssReleaseName(&tmpMinor, &krbInitiator);
+
+    return major;
+}
+#endif /* GSSEAP_ENABLE_REAUTH */