Merge remote-tracking branch 'origin/eap-tls'
[mech_eap.git] / mech_eap / init_sec_context.c
index a67d381..39929a6 100644 (file)
@@ -36,6 +36,9 @@
  */
 
 #include "gssapiP_eap.h"
+#include "radius/radius.h"
+#include "util_radius.h"
+#include "utils/radius_utils.h"
 
 static OM_uint32
 policyVariableToFlag(enum eapol_bool_var variable)
@@ -204,6 +207,143 @@ static struct eapol_callbacks gssEapPolicyCallbacks = {
 extern int wpa_debug_level;
 #endif
 
+#define CHBIND_SERVICE_NAME_FLAG        0x01
+#define CHBIND_HOST_NAME_FLAG           0x02
+#define CHBIND_SERVICE_SPECIFIC_FLAG    0x04
+#define CHBIND_REALM_NAME_FLAG          0x08
+
+static OM_uint32
+peerInitEapChannelBinding(OM_uint32 *minor, gss_ctx_id_t ctx)
+{
+    struct wpabuf *buf = NULL;
+    unsigned int chbindReqFlags = 0;
+    krb5_principal princ = NULL;
+    gss_buffer_desc nameBuf = GSS_C_EMPTY_BUFFER;
+    OM_uint32 major = GSS_S_COMPLETE;
+    krb5_context krbContext = NULL;
+
+    /* XXX is this check redundant? */
+    if (ctx->acceptorName == GSS_C_NO_NAME) {
+        major = GSS_S_BAD_NAME;
+        *minor = GSSEAP_NO_ACCEPTOR_NAME;
+        goto cleanup;
+    }
+
+    princ = ctx->acceptorName->krbPrincipal;
+
+    krbPrincComponentToGssBuffer(princ, 0, &nameBuf);
+    if (nameBuf.length > 0) {
+        major = gssEapRadiusAddAttr(minor, &buf, PW_GSS_ACCEPTOR_SERVICE_NAME,
+                                    0, &nameBuf);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        chbindReqFlags |= CHBIND_SERVICE_NAME_FLAG;
+    }
+
+    krbPrincComponentToGssBuffer(princ, 1, &nameBuf);
+    if (nameBuf.length > 0) {
+        major = gssEapRadiusAddAttr(minor, &buf, PW_GSS_ACCEPTOR_HOST_NAME,
+                                    0, &nameBuf);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        chbindReqFlags |= CHBIND_HOST_NAME_FLAG;
+    }
+
+    GSSEAP_KRB_INIT(&krbContext);
+
+    *minor = krbPrincUnparseServiceSpecifics(krbContext, princ, &nameBuf);
+    if (*minor != 0)
+        goto cleanup;
+
+    if (nameBuf.length > 0) {
+        major = gssEapRadiusAddAttr(minor, &buf,
+                                    PW_GSS_ACCEPTOR_SERVICE_SPECIFICS,
+                                    0, &nameBuf);
+        if (GSS_ERROR(major))
+            goto cleanup;
+
+        chbindReqFlags |= CHBIND_SERVICE_SPECIFIC_FLAG;
+    }
+
+    krbFreeUnparsedName(krbContext, &nameBuf);
+    krbPrincRealmToGssBuffer(princ, &nameBuf);
+
+    if (nameBuf.length > 0) {
+        major = gssEapRadiusAddAttr(minor, &buf,
+                                    PW_GSS_ACCEPTOR_REALM_NAME,
+                                    0, &nameBuf);
+        chbindReqFlags |= CHBIND_REALM_NAME_FLAG;
+    }
+
+    if (chbindReqFlags == 0) {
+        major = GSS_S_BAD_NAME;
+        *minor = GSSEAP_BAD_ACCEPTOR_NAME;
+        goto cleanup;
+    }
+
+    ctx->initiatorCtx.chbindData = buf;
+    ctx->initiatorCtx.chbindReqFlags = chbindReqFlags;
+
+    buf = NULL;
+
+    major = GSS_S_COMPLETE;
+    *minor = 0;
+
+cleanup:
+    krbFreeUnparsedName(krbContext, &nameBuf);
+    wpabuf_free(buf);
+
+    return major;
+}
+
+static void
+peerProcessChbindResponse(void *context, int code, int nsid,
+                          u8 *data, size_t len)
+{
+    radius_parser msg;
+    gss_ctx_id_t ctx = (gss_ctx_id_t )context;
+    void *vsadata;
+    u8 type;
+    u32 vendor_id;
+    u32 chbindRetFlags = 0;
+    size_t vsadata_len;
+
+    if (nsid != CHBIND_NSID_RADIUS)
+        return;
+
+    msg = radius_parser_start(data, len);
+    if (msg == NULL)
+        return;
+
+    while (radius_parser_parse_tlv(msg, &type, &vendor_id, &vsadata,
+                                   &vsadata_len) == 0) {
+        switch (type) {
+        case PW_GSS_ACCEPTOR_SERVICE_NAME:
+            chbindRetFlags |= CHBIND_SERVICE_NAME_FLAG;
+            break;
+        case PW_GSS_ACCEPTOR_HOST_NAME:
+            chbindRetFlags |= CHBIND_HOST_NAME_FLAG;
+            break;
+        case PW_GSS_ACCEPTOR_SERVICE_SPECIFICS:
+            chbindRetFlags |= CHBIND_SERVICE_SPECIFIC_FLAG;
+            break;
+        case PW_GSS_ACCEPTOR_REALM_NAME:
+            chbindRetFlags |= CHBIND_REALM_NAME_FLAG;
+            break;
+        }
+    }
+
+    radius_parser_finish(msg);
+
+    if (code == CHBIND_CODE_SUCCESS &&
+        ((chbindRetFlags & ctx->initiatorCtx.chbindReqFlags) == ctx->initiatorCtx.chbindReqFlags)) {
+        ctx->flags |= CTX_FLAG_EAP_CHBIND_ACCEPT;
+        ctx->gssFlags |= GSS_C_MUTUAL_FLAG;
+    } /* else log failures? */
+}
+
 static OM_uint32
 peerConfigInit(OM_uint32 *minor, gss_ctx_id_t ctx)
 {
@@ -271,6 +411,26 @@ peerConfigInit(OM_uint32 *minor, gss_ctx_id_t ctx)
     eapPeerConfig->subject_match = (unsigned char *)cred->subjectNameConstraint.value;
     eapPeerConfig->altsubject_match = (unsigned char *)cred->subjectAltNameConstraint.value;
 
+    /* eap channel binding */
+    if (ctx->initiatorCtx.chbindData != NULL) {
+        struct eap_peer_chbind_config *chbind_config =
+            (struct eap_peer_chbind_config *)GSSEAP_MALLOC(sizeof(struct eap_peer_chbind_config));
+        if (chbind_config == NULL) {
+            *minor = ENOMEM;
+            return GSS_S_FAILURE;
+        }
+
+        chbind_config->req_data = wpabuf_mhead_u8(ctx->initiatorCtx.chbindData);
+        chbind_config->req_data_len = wpabuf_len(ctx->initiatorCtx.chbindData);
+        chbind_config->nsid = CHBIND_NSID_RADIUS;
+        chbind_config->response_cb = &peerProcessChbindResponse;
+        chbind_config->ctx = ctx;
+        eapPeerConfig->chbind_config = chbind_config;
+        eapPeerConfig->chbind_config_len = 1;
+    } else {
+        eapPeerConfig->chbind_config = NULL;
+        eapPeerConfig->chbind_config_len = 0;
+    }
     if (cred->flags & CRED_FLAG_CERTIFICATE) {
         /*
          * CRED_FLAG_CONFIG_BLOB is an internal flag which will be used in the
@@ -322,18 +482,12 @@ peerConfigFree(OM_uint32 *minor,
  * Mark an initiator context as ready for cryptographic operations
  */
 static OM_uint32
-initReady(OM_uint32 *minor, gss_ctx_id_t ctx, OM_uint32 reqFlags)
+initReady(OM_uint32 *minor, gss_ctx_id_t ctx)
 {
     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))
@@ -595,17 +749,45 @@ eapGssSmInitAcceptorName(OM_uint32 *minor,
                                   outputToken, NULL);
         if (GSS_ERROR(major))
             return major;
-    } else if (inputToken != GSS_C_NO_BUFFER &&
-               ctx->acceptorName == GSS_C_NO_NAME) {
-        /* Accept target name hint from acceptor */
+    } else if (inputToken != GSS_C_NO_BUFFER) {
+        OM_uint32 tmpMinor;
+        gss_name_t nameHint;
+        int equal;
+
+        /* Accept target name hint from acceptor or verify acceptor */
         major = gssEapImportName(minor, inputToken,
                                  GSS_C_NT_USER_NAME,
                                  ctx->mechanismUsed,
-                                 &ctx->acceptorName);
+                                 &nameHint);
         if (GSS_ERROR(major))
             return major;
+
+        if (ctx->acceptorName != GSS_C_NO_NAME) {
+            /* verify name hint matched asserted acceptor name  */
+            major = gssEapCompareName(minor,
+                                      nameHint,
+                                      ctx->acceptorName,
+                                      COMPARE_NAME_FLAG_IGNORE_EMPTY_REALMS,
+                                      &equal);
+            if (GSS_ERROR(major)) {
+                gssEapReleaseName(&tmpMinor, &nameHint);
+                return major;
+            }
+
+            gssEapReleaseName(&tmpMinor, &nameHint);
+
+            if (!equal) {
+                *minor = GSSEAP_WRONG_ACCEPTOR_NAME;
+                return GSS_S_DEFECTIVE_TOKEN;
+            }
+        } else { /* acceptor name is no_name */
+            /* accept acceptor name hint */
+            ctx->acceptorName = nameHint;
+            nameHint = GSS_C_NO_NAME;
+        }
     }
 
+
     /*
      * Currently, other parts of the code assume that the acceptor name
      * is available, hence this check.
@@ -615,6 +797,15 @@ eapGssSmInitAcceptorName(OM_uint32 *minor,
         return GSS_S_FAILURE;
     }
 
+    /*
+     * Generate channel binding data
+     */
+    if (ctx->initiatorCtx.chbindData == NULL) {
+        major = peerInitEapChannelBinding(minor, ctx);
+        if (GSS_ERROR(major))
+            return major;
+    }
+
     return GSS_S_CONTINUE_NEEDED;
 }
 
@@ -715,7 +906,7 @@ eapGssSmInitAuthenticate(OM_uint32 *minor,
 
         resp = eap_get_eapRespData(ctx->initiatorCtx.eap);
     } else if (ctx->flags & CTX_FLAG_EAP_SUCCESS) {
-        major = initReady(minor, ctx, reqFlags);
+        major = initReady(minor, ctx);
         if (GSS_ERROR(major))
             goto cleanup;
 
@@ -793,21 +984,45 @@ eapGssSmInitGssChannelBindings(OM_uint32 *minor,
                                OM_uint32 *smFlags)
 {
     OM_uint32 major;
-    gss_buffer_desc buffer = GSS_C_EMPTY_BUFFER;
+    krb5_error_code code;
+    krb5_context krbContext;
+    krb5_data data;
+    krb5_checksum cksum;
+    gss_buffer_desc cksumBuffer;
 
-    if (chanBindings != GSS_C_NO_CHANNEL_BINDINGS)
-        buffer = chanBindings->application_data;
+    if (chanBindings == GSS_C_NO_CHANNEL_BINDINGS ||
+        chanBindings->application_data.length == 0)
+        return GSS_S_CONTINUE_NEEDED;
 
-    major = gssEapWrap(minor, ctx, TRUE, GSS_C_QOP_DEFAULT,
-                       &buffer, NULL, outputToken);
-    if (GSS_ERROR(major))
-        return major;
+    GSSEAP_KRB_INIT(&krbContext);
 
-    GSSEAP_ASSERT(outputToken->value != NULL);
+    KRB_DATA_INIT(&data);
+
+    gssBufferToKrbData(&chanBindings->application_data, &data);
+
+    code = krb5_c_make_checksum(krbContext, ctx->checksumType,
+                                &ctx->rfc3961Key,
+                                KEY_USAGE_GSSEAP_CHBIND_MIC,
+                                &data, &cksum);
+    if (code != 0) {
+        *minor = code;
+        return GSS_S_FAILURE;
+    }
+
+    cksumBuffer.length = KRB_CHECKSUM_LENGTH(&cksum);
+    cksumBuffer.value  = KRB_CHECKSUM_DATA(&cksum);
+
+    major = duplicateBuffer(minor, &cksumBuffer, outputToken);
+    if (GSS_ERROR(major)) {
+        krb5_free_checksum_contents(krbContext, &cksum);
+        return major;
+    }
 
     *minor = 0;
     *smFlags |= SM_FLAG_OUTPUT_TOKEN_CRITICAL;
 
+    krb5_free_checksum_contents(krbContext, &cksum);
+
     return GSS_S_CONTINUE_NEEDED;
 }
 
@@ -837,7 +1052,7 @@ eapGssSmInitInitiatorMIC(OM_uint32 *minor,
 
     return GSS_S_CONTINUE_NEEDED;
 }
+
 #ifdef GSSEAP_ENABLE_REAUTH
 static OM_uint32
 eapGssSmInitReauthCreds(OM_uint32 *minor,
@@ -884,6 +1099,11 @@ eapGssSmInitAcceptorMIC(OM_uint32 *minor,
     if (GSS_ERROR(major))
         return major;
 
+    /*
+     * As a temporary measure, force mutual authentication until channel binding is
+     * more widely deployed.
+     */
+    ctx->gssFlags |= GSS_C_MUTUAL_FLAG;
     GSSEAP_SM_TRANSITION(ctx, GSSEAP_STATE_ESTABLISHED);
 
     *minor = 0;
@@ -902,7 +1122,8 @@ static struct gss_eap_sm eapGssInitiatorSm[] = {
     {
         ITOK_TYPE_ACCEPTOR_NAME_RESP,
         ITOK_TYPE_ACCEPTOR_NAME_REQ,
-        GSSEAP_STATE_INITIAL | GSSEAP_STATE_AUTHENTICATE,
+        GSSEAP_STATE_INITIAL | GSSEAP_STATE_AUTHENTICATE |
+        GSSEAP_STATE_ACCEPTOR_EXTS,
         0,
         eapGssSmInitAcceptorName
     },
@@ -952,7 +1173,7 @@ static struct gss_eap_sm eapGssInitiatorSm[] = {
         ITOK_TYPE_NONE,
         ITOK_TYPE_GSS_CHANNEL_BINDINGS,
         GSSEAP_STATE_INITIATOR_EXTS,
-        SM_ITOK_FLAG_REQUIRED,
+        0,
         eapGssSmInitGssChannelBindings
     },
     {
@@ -1052,8 +1273,10 @@ gssEapInitSecContext(OM_uint32 *minor,
             goto cleanup;
         }
     }
+
     if (ret_flags != NULL)
         *ret_flags = ctx->gssFlags;
+
     if (time_rec != NULL)
         gssEapContextTime(&tmpMinor, ctx, time_rec);