Imported Upstream version 4.6.2

daemons/ipa-slapi-plugins/libotp/hotp.c

@@ -0,0 +1,170 @@
+/** BEGIN COPYRIGHT BLOCK
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Additional permission under GPLv3 section 7:
+ *
+ * In the following paragraph, "GPL" means the GNU General Public
+ * License, version 3 or any later version, and "Non-GPL Code" means
+ * code that is governed neither by the GPL nor a license
+ * compatible with the GPL.
+ *
+ * You may link the code of this Program with Non-GPL Code and convey
+ * linked combinations including the two, provided that such Non-GPL
+ * Code only links to the code of this Program through those well
+ * defined interfaces identified in the file named EXCEPTION found in
+ * the source code files (the "Approved Interfaces"). The files of
+ * Non-GPL Code may instantiate templates or use macros or inline
+ * functions from the Approved Interfaces without causing the resulting
+ * work to be covered by the GPL. Only the copyright holders of this
+ * Program may make changes or additions to the list of Approved
+ * Interfaces.
+ *
+ * Authors:
+ * Nathaniel McCallum <npmccallum@redhat.com>
+ *
+ * Copyright (C) 2013 Red Hat, Inc.
+ * All rights reserved.
+ * END COPYRIGHT BLOCK **/
+
+/*
+ * This file contains an implementation of HOTP (RFC 4226) and TOTP (RFC 6238).
+ * For details of how these algorithms work, please see the relevant RFCs.
+ */
+
+#include "hotp.h"
+#include <time.h>
+
+#include <nss.h>
+#include <pk11pub.h>
+#include <hasht.h>
+#include <prnetdb.h>
+
+struct digest_buffer {
+    uint8_t buf[SHA512_LENGTH];
+    unsigned int len;
+};
+
+static const struct {
+    const char *algo;
+    CK_MECHANISM_TYPE mech;
+} algo2mech[] = {
+    { "sha1",   CKM_SHA_1_HMAC },
+    { "sha256", CKM_SHA256_HMAC },
+    { "sha384", CKM_SHA384_HMAC },
+    { "sha512", CKM_SHA512_HMAC },
+    { }
+};
+
+/*
+ * This code is mostly cargo-cult taken from here:
+ *   http://www.mozilla.org/projects/security/pki/nss/tech-notes/tn5.html
+ *
+ * It should implement HMAC with the given mechanism (SHA: 1, 256, 384, 512).
+ */
+static bool hmac(SECItem *key, CK_MECHANISM_TYPE mech, const SECItem *in,
+                 struct digest_buffer *out)
+{
+    SECItem param = { siBuffer, NULL, 0 };
+    PK11SlotInfo *slot = NULL;
+    PK11SymKey *symkey = NULL;
+    PK11Context *ctx = NULL;
+    bool ret = false;
+    SECStatus s;
+
+    slot = PK11_GetBestSlot(mech, NULL);
+    if (slot == NULL) {
+        slot = PK11_GetInternalKeySlot();
+        if (slot == NULL) {
+            goto done;
+        }
+    }
+
+    symkey = PK11_ImportSymKey(slot, mech, PK11_OriginUnwrap,
+                               CKA_SIGN, key, NULL);
+    if (symkey == NULL)
+        goto done;
+
+    ctx = PK11_CreateContextBySymKey(mech, CKA_SIGN, symkey, &param);
+    if (ctx == NULL)
+        goto done;
+
+    s = PK11_DigestBegin(ctx);
+    if (s != SECSuccess)
+        goto done;
+
+    s = PK11_DigestOp(ctx, in->data, in->len);
+    if (s != SECSuccess)
+        goto done;
+
+    s = PK11_DigestFinal(ctx, out->buf, &out->len, sizeof(out->buf));
+    if (s != SECSuccess)
+        goto done;
+
+    ret = true;
+
+done:
+    if (ctx != NULL)
+        PK11_DestroyContext(ctx, PR_TRUE);
+    if (symkey != NULL)
+        PK11_FreeSymKey(symkey);
+    if (slot != NULL)
+        PK11_FreeSlot(slot);
+    return ret;
+}
+
+/*
+ * An implementation of HOTP (RFC 4226).
+ */
+bool hotp(const struct hotp_token *token, uint64_t counter, uint32_t *out)
+{
+    const SECItem cntr = { siBuffer, (uint8_t *) &counter, sizeof(counter) };
+    SECItem keyitm = { siBuffer, token->key.bytes, token->key.len };
+    CK_MECHANISM_TYPE mech = CKM_SHA_1_HMAC;
+    PRUint64 offset, binary, div;
+    struct digest_buffer digest;
+    int digits = token->digits;
+    int i;
+
+    /* Convert counter to network byte order. */
+    counter = PR_htonll(counter);
+
+    /* Find the mech. */
+    for (i = 0; algo2mech[i].algo; i++) {
+        if (strcasecmp(algo2mech[i].algo, token->algo) == 0) {
+            mech = algo2mech[i].mech;
+            break;
+        }
+    }
+
+    /* Create the digits divisor. */
+    for (div = 1; digits > 0; digits--) {
+        div *= 10;
+    }
+
+    /* Do the digest. */
+    if (!hmac(&keyitm, mech, &cntr, &digest)) {
+        return false;
+    }
+
+    /* Truncate. */
+    offset  = digest.buf[digest.len - 1] & 0xf;
+    binary  = (digest.buf[offset + 0] & 0x7f) << 0x18;
+    binary |= (digest.buf[offset + 1] & 0xff) << 0x10;
+    binary |= (digest.buf[offset + 2] & 0xff) << 0x08;
+    binary |= (digest.buf[offset + 3] & 0xff) << 0x00;
+    binary  = binary % div;
+
+    *out = binary;
+    return true;
+}