1 files changed, 98 insertions, 0 deletions
diff --git a/src/lib/crypto/krb/verify_checksum.c b/src/lib/crypto/krb/verify_checksum.c
new file mode 100644
index 000000000000..09425ea7aa90
--- /dev/null
+++ b/src/lib/crypto/krb/verify_checksum.c
@@ -0,0 +1,98 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include "crypto_int.h"
+
+krb5_error_code KRB5_CALLCONV
+krb5_k_verify_checksum(krb5_context context, krb5_key key,
+                       krb5_keyusage usage, const krb5_data *data,
+                       const krb5_checksum *cksum, krb5_boolean *valid)
+{
+    const struct krb5_cksumtypes *ctp;
+    krb5_cksumtype cksumtype;
+    krb5_crypto_iov iov;
+    krb5_error_code ret;
+    krb5_data cksum_data;
+    krb5_checksum computed;
+
+    iov.flags = KRB5_CRYPTO_TYPE_DATA;
+    iov.data = *data;
+
+    /* A 0 checksum type means use the mandatory checksum. */
+    cksumtype = cksum->checksum_type;
+    if (cksumtype == 0 && key != NULL) {
+        ret = krb5int_c_mandatory_cksumtype(context, key->keyblock.enctype,
+                                            &cksumtype);
+        if (ret)
+            return ret;
+    }
+    ctp = find_cksumtype(cksumtype);
+    if (ctp == NULL)
+        return KRB5_BAD_ENCTYPE;
+
+    ret = verify_key(ctp, key);
+    if (ret != 0)
+        return ret;
+
+    /* If there's actually a verify function, call it. */
+    cksum_data = make_data(cksum->contents, cksum->length);
+    if (ctp->verify != NULL)
+        return ctp->verify(ctp, key, usage, &iov, 1, &cksum_data, valid);
+
+    /* Otherwise, make the checksum again, and compare. */
+    if (cksum->length != ctp->output_size)
+        return KRB5_BAD_MSIZE;
+
+    ret = krb5_k_make_checksum(context, cksum->checksum_type, key, usage,
+                               data, &computed);
+    if (ret)
+        return ret;
+
+    *valid = (k5_bcmp(computed.contents, cksum->contents,
+                      ctp->output_size) == 0);
+
+    free(computed.contents);
+    return 0;
+}
+
+krb5_error_code KRB5_CALLCONV
+krb5_c_verify_checksum(krb5_context context, const krb5_keyblock *keyblock,
+                       krb5_keyusage usage, const krb5_data *data,
+                       const krb5_checksum *cksum, krb5_boolean *valid)
+{
+    krb5_key key = NULL;
+    krb5_error_code ret;
+
+    if (keyblock != NULL) {
+        ret = krb5_k_create_key(context, keyblock, &key);
+        if (ret != 0)
+            return ret;
+    }
+    ret = krb5_k_verify_checksum(context, key, usage, data, cksum, valid);
+    krb5_k_free_key(context, key);
+    return ret;
+}