+static OM_uint32
+gssEapImportPartialContext(OM_uint32 *minor,
+ unsigned char **pBuf,
+ size_t *pRemain,
+ gss_ctx_id_t ctx)
+{
+ unsigned char *p = *pBuf;
+ size_t remain = *pRemain;
+ gss_buffer_desc buf;
+
+ if (remain < 4) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ buf.length = load_uint32_be(p);
+
+ if (buf.length != 0) {
+ *minor = EINVAL;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ *minor = 0;
+ return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+importMechanismOid(OM_uint32 *minor,
+ unsigned char **pBuf,
+ size_t *pRemain,
+ gss_OID *pOid)
+{
+ OM_uint32 major;
+ unsigned char *p = *pBuf;
+ size_t remain = *pRemain;
+ gss_OID_desc oidBuf;
+
+ oidBuf.length = load_uint32_be(p);
+ if (remain < 4 + oidBuf.length || oidBuf.length == 0) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ oidBuf.elements = &p[4];
+
+ if (!gssEapIsConcreteMechanismOid(&oidBuf)) {
+ return GSS_S_BAD_MECH;
+ }
+
+ if (!gssEapInternalizeOid(&oidBuf, pOid)) {
+ major = duplicateOid(minor, &oidBuf, pOid);
+ if (GSS_ERROR(major))
+ return major;
+ }
+
+ *pBuf += 4 + oidBuf.length;
+ *pRemain -= 4 + oidBuf.length;
+
+ *minor = 0;
+ return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+importKerberosKey(OM_uint32 *minor,
+ unsigned char **pBuf,
+ size_t *pRemain,
+ krb5_keyblock *key)
+{
+ unsigned char *p = *pBuf;
+ size_t remain = *pRemain;
+ OM_uint32 encryptionType;
+ OM_uint32 length;
+ gss_buffer_desc tmp;
+
+ if (remain < 8) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ encryptionType = load_uint32_be(&p[0]);
+ length = load_uint32_be(&p[4]);
+
+ if ((length != 0) != (encryptionType != ENCTYPE_NULL)) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (remain - 8 < length) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (load_buffer(&p[8], length, &tmp) == NULL) {
+ *minor = ENOMEM;
+ return GSS_S_FAILURE;
+ }
+
+ KRB_KEY_TYPE(key) = encryptionType;
+ KRB_KEY_LENGTH(key) = tmp.length;
+ KRB_KEY_DATA(key) = (unsigned char *)tmp.value;
+
+ *pBuf += 8 + length;
+ *pRemain -= 8 + length;
+
+ *minor = 0;
+ return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+importName(OM_uint32 *minor,
+ unsigned char **pBuf,
+ size_t *pRemain,
+ gss_name_t *pName)
+{
+ OM_uint32 major;
+ unsigned char *p = *pBuf;
+ size_t remain = *pRemain;
+ gss_buffer_desc tmp;
+
+ if (remain < 4) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ tmp.length = load_uint32_be(p);
+ if (tmp.length != 0) {
+ if (remain - 4 < tmp.length) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ tmp.value = p + 4;
+
+ major = gssEapImportName(minor, &tmp, GSS_C_NT_EXPORT_NAME, pName);
+ if (GSS_ERROR(major))
+ return major;
+ }
+
+ *pBuf += 4 + tmp.length;
+ *pRemain -= 4 + tmp.length;
+
+ *minor = 0;
+ return GSS_S_COMPLETE;
+}
+
+static OM_uint32
+gssEapImportContext(OM_uint32 *minor,
+ gss_buffer_t token,
+ gss_ctx_id_t ctx)
+{
+ OM_uint32 major;
+ unsigned char *p = (unsigned char *)token->value;
+ size_t remain = token->length;
+
+ if (remain < 16) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+ if (load_uint32_be(&p[0]) != EAP_EXPORT_CONTEXT_V1) {
+ *minor = EINVAL;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+ ctx->state = load_uint32_be(&p[4]);
+ ctx->flags = load_uint32_be(&p[8]);
+ ctx->gssFlags = load_uint32_be(&p[12]);
+ p += 16;
+ remain -= 16;
+
+ /* Validate state */
+ if (ctx->state < EAP_STATE_AUTHENTICATE ||
+ ctx->state > EAP_STATE_ESTABLISHED)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ /* Only acceptor can export partial context tokens */
+ if (CTX_IS_INITIATOR(ctx) && !CTX_IS_ESTABLISHED(ctx))
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ major = importMechanismOid(minor, &p, &remain, &ctx->mechanismUsed);
+ if (GSS_ERROR(major))
+ return major;
+
+ major = importKerberosKey(minor, &p, &remain, &ctx->rfc3961Key);
+ if (GSS_ERROR(major))
+ return major;
+
+ ctx->encryptionType = KRB_KEY_TYPE(&ctx->rfc3961Key);
+
+ major = importName(minor, &p, &remain, &ctx->initiatorName);
+ if (GSS_ERROR(major))
+ return major;
+
+ major = importName(minor, &p, &remain, &ctx->acceptorName);
+ if (GSS_ERROR(major))
+ return major;
+
+ /* Check that, if context is established, names are valid */
+ if (CTX_IS_ESTABLISHED(ctx) &&
+ (CTX_IS_INITIATOR(ctx) ? ctx->acceptorName == GSS_C_NO_NAME
+ : ctx->initiatorName == GSS_C_NO_NAME)) {
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (remain < 24 + sequenceSize(ctx->seqState)) {
+ *minor = ERANGE;
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+ ctx->expiryTime = (time_t)load_uint64_be(&p[0]); /* XXX */
+ ctx->sendSeq = load_uint64_be(&p[8]);
+ ctx->recvSeq = load_uint64_be(&p[16]);
+ p += 24;
+ remain -= 24;
+
+ *minor = sequenceInternalize(&ctx->seqState, &p, &remain);
+ if (*minor != 0)
+ return GSS_S_FAILURE;
+
+ /*
+ * The partial context should only be expected for unestablished
+ * acceptor contexts.
+ */
+ if (!CTX_IS_INITIATOR(ctx) && !CTX_IS_ESTABLISHED(ctx)) {
+ major = gssEapImportPartialContext(minor, &p, &remain, ctx);
+ if (GSS_ERROR(major))
+ return major;
+ }
+
+ assert(remain == 0);
+
+ *minor = 0;
+ major = GSS_S_COMPLETE;
+
+ return major;
+}
+