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-rw-r--r--runtime/librsgt.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/runtime/librsgt.c b/runtime/librsgt.c
new file mode 100644
index 00000000..4ad4ec26
--- /dev/null
+++ b/runtime/librsgt.c
@@ -0,0 +1,309 @@
+/* librsgt.c - rsyslog's guardtime support library
+ *
+ * Regarding the online algorithm for Merkle tree signing. Expected
+ * calling sequence is:
+ *
+ * sigblkConstruct
+ * for each signature block:
+ * sigblkInit
+ * for each record:
+ * sigblkAddRecord
+ * sigblkFinish
+ * sigblkDestruct
+ *
+ * Obviously, the next call after sigblkFinsh must either be to
+ * sigblkInit or sigblkDestruct (if no more signature blocks are
+ * to be emitted, e.g. on file close). sigblkDestruct saves state
+ * information (most importantly last block hash) and sigblkConstruct
+ * reads (or initilizes if not present) it.
+ *
+ * Copyright 2013 Adiscon GmbH.
+ *
+ * This file is part of rsyslog.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * -or-
+ * see COPYING.ASL20 in the source distribution
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#include <assert.h>
+
+#include <gt_base.h>
+#include <gt_http.h>
+
+#include "librsgt.h"
+
+typedef unsigned char uchar;
+#ifndef VERSION
+#define VERSION "no-version"
+#endif
+
+static void
+outputhash(GTDataHash *hash)
+{
+ int i;
+ for(i = 0 ; i < hash->digest_length ; ++i)
+ printf("%2.2x", hash->digest[i]);
+ printf("\n");
+}
+
+
+
+void
+rsgtInit(char *usragent)
+{
+ int ret = GT_OK;
+
+ srand(time(NULL) * 7); /* see comments in seedIV() */
+
+ ret = GT_init();
+ if(ret != GT_OK) {
+ fprintf(stderr, "GT_init() failed: %d (%s)\n",
+ ret, GT_getErrorString(ret));
+ goto done;
+ }
+ ret = GTHTTP_init(usragent, 1);
+ if(ret != GT_OK) {
+ fprintf(stderr, "GTHTTP_init() failed: %d (%s)\n",
+ ret, GTHTTP_getErrorString(ret));
+ goto done;
+ }
+done: return;
+}
+
+void
+rsgtExit(void)
+{
+ GTHTTP_finalize();
+ GT_finalize();
+}
+
+
+void
+seedIV(gtctx ctx)
+{
+ /* FIXME: this currently is "kindergarten cryptography" - use a
+ * sufficiently strong PRNG instead! Just a PoC so far! Do NOT
+ * use in production!!!
+ */
+ ctx->IV = rand() * 1000037;
+}
+
+gtctx
+rsgtCtxNew(void)
+{
+ return calloc(1, sizeof(struct gtctx_s));
+}
+
+void
+rsgtCtxDel(gtctx ctx)
+{
+ if(ctx == NULL)
+ goto done;
+ free(ctx);
+ /* TODO: persist! */
+done: return;
+}
+
+/* new sigblk is initialized, but maybe in existing ctx */
+void
+sigblkInit(gtctx ctx)
+{
+ seedIV(ctx);
+// if(ctx->x_prev == NULL) {
+ ctx->x_prev = NULL;
+ /* FIXME: do the real thing - or in a later step as currently? */
+// }
+ memset(ctx->roots_valid, 0, sizeof(ctx->roots_valid)/sizeof(char));
+ ctx->nRoots = 0;
+}
+
+
+/* concat: add IV to buffer */
+static inline void
+bufAddIV(gtctx ctx, uchar *buf, size_t *len)
+{
+ memcpy(buf+*len, &ctx->IV, sizeof(ctx->IV));
+ *len += sizeof(ctx->IV);
+}
+
+/* concat: add hash to buffer */
+static inline void
+bufAddHash(gtctx ctx, uchar *buf, size_t *len, GTDataHash *hash)
+{
+ if(hash == NULL) {
+ memset(buf+*len, 0, 32); /* FIXME: depends on hash function! */
+ *len += 32;
+ } else {
+ memcpy(buf+*len, hash->digest, hash->digest_length);
+ *len += hash->digest_length;
+ }
+}
+/* concat: add tree level to buffer */
+static inline void
+bufAddLevel(gtctx ctx, uchar *buf, size_t *len, int level)
+{
+ memcpy(buf+*len, &level, sizeof(level));
+ *len += sizeof(level);
+}
+
+
+static void
+hash_m(gtctx ctx, GTDataHash **m)
+{
+ // m = hash(concat(ctx->x_prev, IV));
+ int r;
+ uchar concatBuf[16*1024];
+ size_t len = 0;
+
+ bufAddHash(ctx, concatBuf, &len, ctx->x_prev);
+ bufAddIV(ctx, concatBuf, &len);
+ r = GTDataHash_create(GT_HASHALG_SHA256, concatBuf, len, m);
+}
+
+static void
+hash_r(gtctx ctx, GTDataHash **r, const uchar *rec, const size_t len)
+{
+ // r = hash(canonicalize(rec));
+ int ret;
+
+ ret = GTDataHash_create(GT_HASHALG_SHA256, rec, len, r);
+}
+
+
+static void
+hash_node(gtctx ctx, GTDataHash **node, GTDataHash *m, GTDataHash *r, int level)
+{
+ // x = hash(concat(m, r, 0)); /* hash leaf */
+ int ret;
+ uchar concatBuf[16*1024];
+ size_t len = 0;
+
+ bufAddHash(ctx, concatBuf, &len, m);
+ bufAddHash(ctx, concatBuf, &len, r);
+ bufAddLevel(ctx, concatBuf, &len, level);
+ ret = GTDataHash_create(GT_HASHALG_SHA256, concatBuf, len, node);
+}
+void
+sigblkAddRecord(gtctx ctx, const uchar *rec, const size_t len)
+{
+ GTDataHash *x; /* current hash */
+ GTDataHash *m, *r, *t;
+ int8_t j;
+ int ret;
+
+ hash_m(ctx, &m);
+ hash_r(ctx, &r, rec, len);
+ hash_node(ctx, &x, m, r, 0); /* hash leaf */
+ /* persists x here if Merkle tree needs to be persisted! */
+ /* add x to the forest as new leaf, update roots list */
+ t = x;
+ for(j = 0 ; j < ctx->nRoots ; ++j) {
+ if(ctx->roots_valid[j] == 0) {
+ GTDataHash_free(ctx->roots_hash[j]);
+ ctx->roots_hash[j] = t;
+ ctx->roots_valid[j] = 1;
+ t = NULL;
+ } else if(t != NULL) {
+ /* hash interim node */
+ hash_node(ctx, &t, ctx->roots_hash[j], t, j+1);
+ ctx->roots_valid[j] = 0;
+ }
+ }
+ if(t != NULL) {
+ /* new level, append "at the top" */
+ ctx->roots_hash[ctx->nRoots] = t;
+ ++ctx->nRoots;
+ assert(ctx->nRoots < MAX_ROOTS);
+ t = NULL;
+ }
+ ctx->x_prev = x; /* single var may be sufficient */
+
+ /* cleanup */
+ GTDataHash_free(m);
+ GTDataHash_free(r);
+}
+
+static void
+timestampIt(gtctx ctx, GTDataHash *hash)
+{
+ int r = GT_OK;
+ GTTimestamp *timestamp = NULL;
+ unsigned char *der = NULL;
+ char *sigFile = "logsigner.TIMESTAMP";
+ size_t der_len;
+
+ /* Get the timestamp. */
+ r = GTHTTP_createTimestampHash(hash,
+ "http://stamper.guardtime.net/gt-signingservice", &timestamp);
+
+ if(r != GT_OK) {
+ fprintf(stderr, "GTHTTP_createTimestampHash() failed: %d (%s)\n",
+ r, GTHTTP_getErrorString(r));
+ goto done;
+ }
+
+ /* Encode timestamp. */
+ r = GTTimestamp_getDEREncoded(timestamp, &der, &der_len);
+ if(r != GT_OK) {
+ fprintf(stderr, "GTTimestamp_getDEREncoded() failed: %d (%s)\n",
+ r, GT_getErrorString(r));
+ goto done;
+ }
+
+ /* Save DER-encoded timestamp to file. */
+ r = GT_saveFile(sigFile, der, der_len);
+ if(r != GT_OK) {
+ fprintf(stderr, "Cannot save timestamp to file %s: %d (%s)\n",
+ sigFile, r, GT_getErrorString(r));
+ if(r == GT_IO_ERROR) {
+ fprintf(stderr, "\t%d (%s)\n", errno, strerror(errno));
+ }
+ goto done;
+ }
+ printf("Timestamping succeeded!\n");
+done:
+ GT_free(der);
+ GTTimestamp_free(timestamp);
+}
+
+
+void
+sigblkFinish(gtctx ctx)
+{
+ GTDataHash *root, *rootDel;
+ int8_t j;
+
+ root = NULL;
+ for(j = 0 ; j < ctx->nRoots ; ++j) {
+ if(root == NULL) {
+ root = ctx->roots_hash[j];
+ ctx->roots_valid[j] = 0; /* guess this is redundant with init, maybe del */
+ } else if(ctx->roots_valid[j]) {
+ rootDel = root;
+ hash_node(ctx, &root, ctx->roots_hash[j], root, j+1);
+ ctx->roots_valid[j] = 0; /* guess this is redundant with init, maybe del */
+ GTDataHash_free(rootDel);
+ }
+ }
+ /* persist root value here (callback?) */
+printf("root hash is:\n"); outputhash(root);
+ timestampIt(ctx, root);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-25 05:09:18 +0000