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-rw-r--r--lib/common/digest.c278
1 files changed, 278 insertions, 0 deletions
diff --git a/lib/common/digest.c b/lib/common/digest.c
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+++ b/lib/common/digest.c
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+/*
+ * Copyright 2015-2022 the Pacemaker project contributors
+ *
+ * The version control history for this file may have further details.
+ *
+ * This source code is licensed under the GNU Lesser General Public License
+ * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
+ */
+
+#include <crm_internal.h>
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <md5.h>
+
+#include <crm/crm.h>
+#include <crm/msg_xml.h>
+#include <crm/common/xml.h>
+#include "crmcommon_private.h"
+
+#define BEST_EFFORT_STATUS 0
+
+/*!
+ * \internal
+ * \brief Dump XML in a format used with v1 digests
+ *
+ * \param[in] xml Root of XML to dump
+ *
+ * \return Newly allocated buffer containing dumped XML
+ */
+static GString *
+dump_xml_for_digest(xmlNodePtr xml)
+{
+ GString *buffer = g_string_sized_new(1024);
+
+ /* for compatibility with the old result which is used for v1 digests */
+ g_string_append_c(buffer, ' ');
+ pcmk__xml2text(xml, 0, buffer, 0);
+ g_string_append_c(buffer, '\n');
+
+ return buffer;
+}
+
+/*!
+ * \brief Calculate and return v1 digest of XML tree
+ *
+ * \param[in] input Root of XML to digest
+ * \param[in] sort Whether to sort the XML before calculating digest
+ * \param[in] ignored Not used
+ *
+ * \return Newly allocated string containing digest
+ * \note Example return value: "c048eae664dba840e1d2060f00299e9d"
+ */
+static char *
+calculate_xml_digest_v1(xmlNode *input, gboolean sort, gboolean ignored)
+{
+ char *digest = NULL;
+ GString *buffer = NULL;
+ xmlNode *copy = NULL;
+
+ if (sort) {
+ crm_trace("Sorting xml...");
+ copy = sorted_xml(input, NULL, TRUE);
+ crm_trace("Done");
+ input = copy;
+ }
+
+ buffer = dump_xml_for_digest(input);
+ CRM_CHECK(buffer->len > 0, free_xml(copy);
+ g_string_free(buffer, TRUE);
+ return NULL);
+
+ digest = crm_md5sum((const char *) buffer->str);
+ crm_log_xml_trace(input, "digest:source");
+
+ g_string_free(buffer, TRUE);
+ free_xml(copy);
+ return digest;
+}
+
+/*!
+ * \brief Calculate and return v2 digest of XML tree
+ *
+ * \param[in] source Root of XML to digest
+ * \param[in] do_filter Whether to filter certain XML attributes
+ *
+ * \return Newly allocated string containing digest
+ */
+static char *
+calculate_xml_digest_v2(xmlNode *source, gboolean do_filter)
+{
+ char *digest = NULL;
+ GString *buffer = g_string_sized_new(1024);
+
+ crm_trace("Begin digest %s", do_filter?"filtered":"");
+ pcmk__xml2text(source, (do_filter? pcmk__xml_fmt_filtered : 0), buffer, 0);
+
+ CRM_ASSERT(buffer != NULL);
+ digest = crm_md5sum((const char *) buffer->str);
+
+ pcmk__if_tracing(
+ {
+ char *trace_file = crm_strdup_printf("%s/digest-%s",
+ pcmk__get_tmpdir(), digest);
+
+ crm_trace("Saving %s.%s.%s to %s",
+ crm_element_value(source, XML_ATTR_GENERATION_ADMIN),
+ crm_element_value(source, XML_ATTR_GENERATION),
+ crm_element_value(source, XML_ATTR_NUMUPDATES),
+ trace_file);
+ save_xml_to_file(source, "digest input", trace_file);
+ free(trace_file);
+ },
+ {}
+ );
+ g_string_free(buffer, TRUE);
+ crm_trace("End digest");
+ return digest;
+}
+
+/*!
+ * \brief Calculate and return digest of XML tree, suitable for storing on disk
+ *
+ * \param[in] input Root of XML to digest
+ *
+ * \return Newly allocated string containing digest
+ */
+char *
+calculate_on_disk_digest(xmlNode *input)
+{
+ /* Always use the v1 format for on-disk digests
+ * a) it's a compatibility nightmare
+ * b) we only use this once at startup, all other
+ * invocations are in a separate child process
+ */
+ return calculate_xml_digest_v1(input, FALSE, FALSE);
+}
+
+/*!
+ * \brief Calculate and return digest of XML operation
+ *
+ * \param[in] input Root of XML to digest
+ * \param[in] version Unused
+ *
+ * \return Newly allocated string containing digest
+ */
+char *
+calculate_operation_digest(xmlNode *input, const char *version)
+{
+ /* We still need the sorting for operation digests */
+ return calculate_xml_digest_v1(input, TRUE, FALSE);
+}
+
+/*!
+ * \brief Calculate and return digest of XML tree
+ *
+ * \param[in] input Root of XML to digest
+ * \param[in] sort Whether to sort XML before calculating digest
+ * \param[in] do_filter Whether to filter certain XML attributes
+ * \param[in] version CRM feature set version (used to select v1/v2 digest)
+ *
+ * \return Newly allocated string containing digest
+ */
+char *
+calculate_xml_versioned_digest(xmlNode *input, gboolean sort,
+ gboolean do_filter, const char *version)
+{
+ /*
+ * @COMPAT digests (on-disk or in diffs/patchsets) created <1.1.4;
+ * removing this affects even full-restart upgrades from old versions
+ *
+ * The sorting associated with v1 digest creation accounted for 23% of
+ * the CIB manager's CPU usage on the server. v2 drops this.
+ *
+ * The filtering accounts for an additional 2.5% and we may want to
+ * remove it in future.
+ *
+ * v2 also uses the xmlBuffer contents directly to avoid additional copying
+ */
+ if (version == NULL || compare_version("3.0.5", version) > 0) {
+ crm_trace("Using v1 digest algorithm for %s",
+ pcmk__s(version, "unknown feature set"));
+ return calculate_xml_digest_v1(input, sort, do_filter);
+ }
+ crm_trace("Using v2 digest algorithm for %s",
+ pcmk__s(version, "unknown feature set"));
+ return calculate_xml_digest_v2(input, do_filter);
+}
+
+/*!
+ * \internal
+ * \brief Check whether calculated digest of given XML matches expected digest
+ *
+ * \param[in] input Root of XML tree to digest
+ * \param[in] expected Expected digest in on-disk format
+ *
+ * \return true if digests match, false on mismatch or error
+ */
+bool
+pcmk__verify_digest(xmlNode *input, const char *expected)
+{
+ char *calculated = NULL;
+ bool passed;
+
+ if (input != NULL) {
+ calculated = calculate_on_disk_digest(input);
+ if (calculated == NULL) {
+ crm_perror(LOG_ERR, "Could not calculate digest for comparison");
+ return false;
+ }
+ }
+ passed = pcmk__str_eq(expected, calculated, pcmk__str_casei);
+ if (passed) {
+ crm_trace("Digest comparison passed: %s", calculated);
+ } else {
+ crm_err("Digest comparison failed: expected %s, calculated %s",
+ expected, calculated);
+ }
+ free(calculated);
+ return passed;
+}
+
+/*!
+ * \internal
+ * \brief Check whether an XML attribute should be excluded from CIB digests
+ *
+ * \param[in] name XML attribute name
+ *
+ * \return true if XML attribute should be excluded from CIB digest calculation
+ */
+bool
+pcmk__xa_filterable(const char *name)
+{
+ static const char *filter[] = {
+ XML_ATTR_ORIGIN,
+ XML_CIB_ATTR_WRITTEN,
+ XML_ATTR_UPDATE_ORIG,
+ XML_ATTR_UPDATE_CLIENT,
+ XML_ATTR_UPDATE_USER,
+ };
+
+ for (int i = 0; i < PCMK__NELEM(filter); i++) {
+ if (strcmp(name, filter[i]) == 0) {
+ return true;
+ }
+ }
+ return false;
+}
+
+char *
+crm_md5sum(const char *buffer)
+{
+ int lpc = 0, len = 0;
+ char *digest = NULL;
+ unsigned char raw_digest[MD5_DIGEST_SIZE];
+
+ if (buffer == NULL) {
+ buffer = "";
+ }
+ len = strlen(buffer);
+
+ crm_trace("Beginning digest of %d bytes", len);
+ digest = malloc(2 * MD5_DIGEST_SIZE + 1);
+ if (digest) {
+ md5_buffer(buffer, len, raw_digest);
+ for (lpc = 0; lpc < MD5_DIGEST_SIZE; lpc++) {
+ sprintf(digest + (2 * lpc), "%02x", raw_digest[lpc]);
+ }
+ digest[(2 * MD5_DIGEST_SIZE)] = 0;
+ crm_trace("Digest %s.", digest);
+
+ } else {
+ crm_err("Could not create digest");
+ }
+ return digest;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 22:43:46 +0000