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-rw-r--r--modules/cookies/cookiectl.c689
1 files changed, 689 insertions, 0 deletions
diff --git a/modules/cookies/cookiectl.c b/modules/cookies/cookiectl.c
new file mode 100644
index 0000000..f1ab80a
--- /dev/null
+++ b/modules/cookies/cookiectl.c
@@ -0,0 +1,689 @@
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <ccan/json/json.h>
+#include <ctype.h>
+#include <libknot/rrtype/opt-cookie.h>
+#include <libknot/db/db_lmdb.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lib/cookies/alg_containers.h"
+#include "modules/cookies/cookiectl.h"
+
+#define NAME_CLIENT_ENABLED "client_enabled"
+#define NAME_CLIENT_SECRET "client_secret"
+#define NAME_CLIENT_COOKIE_ALG "client_cookie_alg"
+#define NAME_AVAILABLE_CLIENT_COOKIE_ALGS "available_client_cookie_algs"
+
+#define NAME_SERVER_ENABLED "server_enabled"
+#define NAME_SERVER_SECRET "server_secret"
+#define NAME_SERVER_COOKIE_ALG "server_cookie_alg"
+#define NAME_AVAILABLE_SERVER_COOKIE_ALGS "available_server_cookie_algs"
+
+/**
+ * @brief Initialises cookie control context.
+ * @param ctx cookie control context
+ */
+static void kr_cookie_ctx_init(struct kr_cookie_ctx *ctx)
+{
+ if (!ctx) {
+ return;
+ }
+
+ memset(ctx, 0, sizeof(*ctx));
+
+ ctx->clnt.current.alg_id = ctx->clnt.recent.alg_id = -1;
+ ctx->srvr.current.alg_id = ctx->srvr.recent.alg_id = -1;
+}
+
+/**
+ * @brief Check whether node holds proper 'enabled' value.
+ * @param node JSON node holding the value
+ * @return true if value OK
+ */
+static bool enabled_ok(const JsonNode *node)
+{
+ if (kr_fails_assert(node))
+ return false;
+
+ return node->tag == JSON_BOOL;
+}
+
+/**
+ * @brief Check whether node holds proper 'secret' value.
+ * @param node JSON node holding the value
+ * @return true if value OK
+ */
+static bool secret_ok(const JsonNode *node)
+{
+ if (kr_fails_assert(node))
+ return false;
+
+ if (node->tag != JSON_STRING) {
+ return false;
+ }
+
+ const char *hexstr = node->string_;
+
+ size_t len = strlen(hexstr);
+ if ((len % 2) != 0) {
+ return false;
+ }
+ /* A check for minimal required length could also be performed. */
+
+ for (size_t i = 0; i < len; ++i) {
+ if (!isxdigit(tolower(hexstr[i]))) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/**
+ * @brief Find hash function with given name.
+ * @param node JSON node holding the value
+ * @param table lookup table with algorithm names
+ * @return pointer to table entry or NULL on error if does not exist
+ */
+static const knot_lookup_t *hash_func_lookup(const JsonNode *node,
+ const knot_lookup_t table[])
+{
+ if (!node || node->tag != JSON_STRING) {
+ return NULL;
+ }
+
+ return knot_lookup_by_name(table, node->string_);
+}
+
+/**
+ * @brief Creates a cookie secret structure.
+ * @param size size of the actual secret
+ * @param zero set to true if value should be cleared
+ * @return pointer to new structure, NULL on failure or if @size is zero
+ */
+static struct kr_cookie_secret *new_cookie_secret(size_t size, bool zero)
+{
+ if (size == 0) {
+ return NULL;
+ }
+
+ struct kr_cookie_secret *sq = malloc(sizeof(*sq) + size);
+ if (!sq) {
+ return NULL;
+ }
+
+ sq->size = size;
+ if (zero) {
+ memset(sq->data, 0, size);
+ }
+ return sq;
+}
+
+/**
+ * @brief Clone a cookie secret.
+ * @param sec secret to be cloned
+ * @return pointer to new structure, NULL on failure or if @size is zero
+ */
+static struct kr_cookie_secret *clone_cookie_secret(const struct kr_cookie_secret *sec)
+{
+ if (!sec || sec->size == 0) {
+ return NULL;
+ }
+
+ struct kr_cookie_secret *sq = malloc(sizeof(*sq) + sec->size);
+ if (!sq) {
+ return NULL;
+ }
+
+ sq->size = sec->size;
+ memcpy(sq->data, sec->data, sq->size);
+ return sq;
+}
+
+static int hexchar2val(int d)
+{
+ if (('0' <= d) && (d <= '9')) {
+ return d - '0';
+ } else if (('a' <= d) && (d <= 'f')) {
+ return d - 'a' + 0x0a;
+ } else {
+ return -1;
+ }
+}
+
+static int hexval2char(int i)
+{
+ if ((0 <= i) && (i <= 9)) {
+ return i + '0';
+ } else if ((0x0a <= i) && (i <= 0x0f)) {
+ return i - 0x0a + 'A';
+ } else {
+ return -1;
+ }
+}
+
+/**
+ * @brief Converts string containing two-digit hexadecimal number into int.
+ * @param hexstr hexadecimal string
+ * @return -1 on error, value from 0 to 255 else.
+ */
+static int hexbyte2int(const char *hexstr)
+{
+ if (!hexstr) {
+ return -1;
+ }
+
+ int dhi = tolower(hexstr[0]);
+ if (!isxdigit(dhi)) {
+ /* Exit also on empty string. */
+ return -1;
+ }
+ int dlo = tolower(hexstr[1]);
+ if (!isxdigit(dlo)) {
+ return -1;
+ }
+
+ dhi = hexchar2val(dhi);
+ if (kr_fails_assert(dhi != -1))
+ return -1;
+ dlo = hexchar2val(dlo);
+ if (kr_fails_assert(dlo != -1))
+ return -1;
+
+ return (dhi << 4) | dlo;
+}
+
+/**
+ * @brief Writes two hexadecimal digits (two byes) into given memory location.
+ * @param tgt target location
+ * @param i number from 0 to 255
+ * @return 0 on success, -1 on failure
+ */
+static int int2hexbyte(char *tgt, int i)
+{
+ if (!tgt || i < 0x00 || i > 0xff) {
+ return -1;
+ }
+
+ int ilo = hexval2char(i & 0x0f);
+ if (kr_fails_assert(ilo != -1))
+ return -1;
+ int ihi = hexval2char((i >> 4) & 0x0f);
+ if (kr_fails_assert(ihi != -1))
+ return -1;
+
+ tgt[0] = ihi;
+ tgt[1] = ilo;
+
+ return 0;
+}
+
+/**
+ * @brief Reads a string containing hexadecimal values.
+ * @note String must consist of hexadecimal digits only and must have even
+ * non-zero length.
+ */
+static struct kr_cookie_secret *new_sq_from_hexstr(const char *hexstr)
+{
+ if (!hexstr) {
+ return NULL;
+ }
+
+ size_t len = strlen(hexstr);
+ if ((len % 2) != 0) {
+ return NULL;
+ }
+
+ struct kr_cookie_secret *sq = new_cookie_secret(len / 2, false);
+ if (!sq) {
+ return NULL;
+ }
+
+ uint8_t *data = sq->data;
+ for (size_t i = 0; i < len; i += 2) {
+ int num = hexbyte2int(hexstr + i);
+ if (num == -1) {
+ free(sq);
+ return NULL;
+ }
+ if (kr_fails_assert(0x00 <= num && num <= 0xff)) {
+ free(sq);
+ return NULL;
+ }
+ *data = num;
+ ++data;
+ }
+
+ return sq;
+}
+
+/**
+ * @brief Creates new secret.
+ * @param node JSON node holding the secret value
+ * @return pointer to newly allocated secret, NULL on error
+ */
+static struct kr_cookie_secret *create_secret(const JsonNode *node)
+{
+ if (!node) {
+ return NULL;
+ }
+
+ if (node->tag != JSON_STRING) {
+ return NULL;
+ }
+
+ return new_sq_from_hexstr(node->string_);
+}
+
+/**
+ * @brief Check whether configuration node contains valid values.
+ */
+static bool configuration_node_ok(const JsonNode *node)
+{
+ if (kr_fails_assert(node))
+ return false;
+
+ if (!node->key) {
+ /* All top most nodes must have names. */
+ return false;
+ }
+
+ if (strcmp(node->key, NAME_CLIENT_ENABLED) == 0) {
+ return enabled_ok(node);
+ } else if (strcmp(node->key, NAME_CLIENT_SECRET) == 0) {
+ return secret_ok(node);
+ } else if (strcmp(node->key, NAME_CLIENT_COOKIE_ALG) == 0) {
+ return hash_func_lookup(node, kr_cc_alg_names) != NULL;
+ } else if (strcmp(node->key, NAME_SERVER_ENABLED) == 0) {
+ return enabled_ok(node);
+ } else if (strcmp(node->key, NAME_SERVER_SECRET) == 0) {
+ return secret_ok(node);
+ } else if (strcmp(node->key, NAME_SERVER_COOKIE_ALG) == 0) {
+ return hash_func_lookup(node, kr_sc_alg_names) != NULL;
+ }
+
+ return false;
+}
+
+/**
+ * @brief Creates a new string from secret quantity.
+ * @param sq secret quantity
+ * @return newly allocated string or NULL on error
+ */
+static char *new_hexstr_from_sq(const struct kr_cookie_secret *sq)
+{
+ if (!sq) {
+ return NULL;
+ }
+
+ char *new_str = malloc((sq->size * 2) + 1);
+ if (!new_str) {
+ return NULL;
+ }
+
+ char *tgt = new_str;
+ for (size_t i = 0; i < sq->size; ++i) {
+ if (0 != int2hexbyte(tgt, sq->data[i])) {
+ free(new_str);
+ return NULL;
+ }
+ tgt += 2;
+ }
+
+ *tgt = '\0';
+ return new_str;
+}
+
+static bool read_secret(JsonNode *root, const char *node_name,
+ const struct kr_cookie_secret *secret)
+{
+ if (kr_fails_assert(root && node_name && secret))
+ return false;
+
+ char *secret_str = new_hexstr_from_sq(secret);
+ if (!secret_str) {
+ return false;
+ }
+
+ JsonNode *str_node = json_mkstring(secret_str);
+ if (!str_node) {
+ free(secret_str);
+ return false;
+ }
+
+ json_append_member(root, node_name, str_node);
+
+ free(secret_str);
+ return true;
+}
+
+static bool read_available_hashes(JsonNode *root, const char *root_name,
+ const knot_lookup_t table[])
+{
+ if (kr_fails_assert(root && root_name && table))
+ return false;
+
+ JsonNode *array = json_mkarray();
+ if (!array) {
+ return false;
+ }
+
+ const knot_lookup_t *aux_ptr = table;
+ while (aux_ptr && (aux_ptr->id >= 0) && aux_ptr->name) {
+ JsonNode *element = json_mkstring(aux_ptr->name);
+ if (!element) {
+ goto fail;
+ }
+ json_append_element(array, element);
+ ++aux_ptr;
+ }
+
+ json_append_member(root, root_name, array);
+
+ return true;
+
+fail:
+ if (array) {
+ json_delete(array);
+ }
+ return false;
+}
+
+/**
+ * @brief Check whether new settings are different from the old ones.
+ */
+static bool is_modified(const struct kr_cookie_comp *running,
+ struct kr_cookie_secret *secr,
+ const knot_lookup_t *alg_lookup)
+{
+ if (kr_fails_assert(running))
+ return false;
+
+ if (alg_lookup && alg_lookup->id >= 0) {
+ if (running->alg_id != alg_lookup->id) {
+ return true;
+ }
+ }
+
+ if (secr) {
+ if (kr_fails_assert(secr->size > 0))
+ return false;
+ if (running->secr->size != secr->size ||
+ 0 != memcmp(running->secr->data, secr->data,
+ running->secr->size)) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * @brief Returns newly allocated secret via pointer argument.
+ */
+static bool obtain_secret(JsonNode *root_node, struct kr_cookie_secret **secret,
+ const char *name)
+{
+ if (kr_fails_assert(secret && name))
+ return false;
+
+ const JsonNode *node;
+ if ((node = json_find_member(root_node, name)) != NULL) {
+ *secret = create_secret(node);
+ if (!*secret) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/**
+ * @brief Updates the current configuration and moves current to recent.
+ */
+static void update_running(struct kr_cookie_settings *running,
+ struct kr_cookie_secret **secret,
+ const knot_lookup_t *alg_lookup)
+{
+ if (kr_fails_assert(running && secret) || kr_fails_assert(*secret || alg_lookup))
+ return;
+
+ running->recent.alg_id = -1;
+ free(running->recent.secr);
+ running->recent.secr = NULL;
+
+ running->recent.alg_id = running->current.alg_id;
+ if (alg_lookup) {
+ if (kr_fails_assert(alg_lookup->id >= 0))
+ return;
+ running->current.alg_id = alg_lookup->id;
+ }
+
+ if (*secret) {
+ running->recent.secr = running->current.secr;
+ running->current.secr = *secret;
+ *secret = NULL;
+ } else {
+ running->recent.secr = clone_cookie_secret(running->current.secr);
+ }
+}
+
+/**
+ * @brief Applies modification onto client/server running configuration.
+ * @note The @a secret is going to be consumed.
+ * @param secret pointer to new secret
+ * @param alg_lookup new algorithm
+ * @param enabled JSON node holding boolean value
+ */
+static void apply_changes(struct kr_cookie_settings *running,
+ struct kr_cookie_secret **secret,
+ const knot_lookup_t *alg_lookup,
+ const JsonNode *enabled)
+{
+ if (kr_fails_assert(running && secret))
+ return;
+
+ if (is_modified(&running->current, *secret, alg_lookup)) {
+ update_running(running, secret, alg_lookup);
+ }
+
+ if (enabled) {
+ kr_assert(enabled->tag == JSON_BOOL);
+ running->enabled = enabled->bool_;
+ }
+}
+
+/**
+ * @brief Applies configuration.
+ *
+ * @note The function must be called after the input values have been checked
+ * for validity. Only first found values are applied.
+ *
+ * @param ctx cookie configuration context
+ * @param root_node JSON root node
+ * @return true if changes were applied
+ */
+static bool config_apply_json(struct kr_cookie_ctx *ctx, JsonNode *root_node)
+{
+ if (kr_fails_assert(ctx && root_node))
+ return;
+
+ /*
+ * These must be allocated before actual change. Allocation failure
+ * should not leave configuration in inconsistent state.
+ */
+ struct kr_cookie_secret *new_clnt_secret = NULL;
+ struct kr_cookie_secret *new_srvr_secret = NULL;
+ if (!obtain_secret(root_node, &new_clnt_secret, NAME_CLIENT_SECRET)) {
+ return false;
+ }
+ if (!obtain_secret(root_node, &new_srvr_secret, NAME_SERVER_SECRET)) {
+ free(new_clnt_secret);
+ return false;
+ }
+
+ /* Algorithm pointers. */
+ const knot_lookup_t *clnt_lookup = hash_func_lookup(json_find_member(root_node, NAME_CLIENT_COOKIE_ALG), kr_cc_alg_names);
+ const knot_lookup_t *srvr_lookup = hash_func_lookup(json_find_member(root_node, NAME_SERVER_COOKIE_ALG), kr_sc_alg_names);
+
+ const JsonNode *clnt_enabled_node = json_find_member(root_node, NAME_CLIENT_ENABLED);
+ const JsonNode *srvr_enabled_node = json_find_member(root_node, NAME_SERVER_ENABLED);
+
+ apply_changes(&ctx->clnt, &new_clnt_secret, clnt_lookup, clnt_enabled_node);
+ apply_changes(&ctx->srvr, &new_srvr_secret, srvr_lookup, srvr_enabled_node);
+
+ /*
+ * Allocated secrets should be already consumed. There is no need to
+ * free them.
+ */
+
+ return true;
+}
+
+bool config_apply(struct kr_cookie_ctx *ctx, const char *args)
+{
+ if (!ctx) {
+ return false;
+ }
+
+ if (!args || !strlen(args)) {
+ return true;
+ }
+
+ if (!args || !strlen(args)) {
+ return true;
+ }
+
+ bool success = false;
+
+ /* Check whether all supplied data are valid. */
+ JsonNode *root_node = json_decode(args);
+ if (!root_node) {
+ return false;
+ }
+ JsonNode *node;
+ json_foreach (node, root_node) {
+ success = configuration_node_ok(node);
+ if (!success) {
+ break;
+ }
+ }
+
+ /* Apply configuration if values seem to be OK. */
+ if (success) {
+ success = config_apply_json(ctx, root_node);
+ }
+
+ json_delete(root_node);
+
+ return success;
+}
+
+char *config_read(struct kr_cookie_ctx *ctx)
+{
+ if (!ctx) {
+ return NULL;
+ }
+
+ const knot_lookup_t *lookup;
+ char *result;
+ JsonNode *root_node = json_mkobject();
+ if (!root_node) {
+ return NULL;
+ }
+
+ json_append_member(root_node, NAME_CLIENT_ENABLED,
+ json_mkbool(ctx->clnt.enabled));
+
+ read_secret(root_node, NAME_CLIENT_SECRET, ctx->clnt.current.secr);
+
+ lookup = knot_lookup_by_id(kr_cc_alg_names, ctx->clnt.current.alg_id);
+ if (lookup) {
+ json_append_member(root_node, NAME_CLIENT_COOKIE_ALG,
+ json_mkstring(lookup->name));
+ }
+
+ read_available_hashes(root_node, NAME_AVAILABLE_CLIENT_COOKIE_ALGS,
+ kr_cc_alg_names);
+
+ json_append_member(root_node, NAME_SERVER_ENABLED,
+ json_mkbool(ctx->srvr.enabled));
+
+ read_secret(root_node, NAME_SERVER_SECRET, ctx->srvr.current.secr);
+
+ lookup = knot_lookup_by_id(kr_sc_alg_names, ctx->srvr.current.alg_id);
+ if (lookup) {
+ json_append_member(root_node, NAME_SERVER_COOKIE_ALG,
+ json_mkstring(lookup->name));
+ }
+
+ read_available_hashes(root_node, NAME_AVAILABLE_SERVER_COOKIE_ALGS,
+ kr_sc_alg_names);
+
+ result = json_encode(root_node);
+ json_delete(root_node);
+ return result;
+}
+
+int config_init(struct kr_cookie_ctx *ctx)
+{
+ if (!ctx) {
+ return kr_error(EINVAL);
+ }
+
+ kr_cookie_ctx_init(ctx);
+
+ struct kr_cookie_secret *cs = new_cookie_secret(KNOT_OPT_COOKIE_CLNT,
+ true);
+ struct kr_cookie_secret *ss = new_cookie_secret(KNOT_OPT_COOKIE_CLNT,
+ true);
+ if (!cs || !ss) {
+ free(cs);
+ free(ss);
+ return kr_error(ENOMEM);
+ }
+
+ const knot_lookup_t *clookup = knot_lookup_by_name(kr_cc_alg_names,
+ "FNV-64");
+ const knot_lookup_t *slookup = knot_lookup_by_name(kr_sc_alg_names,
+ "FNV-64");
+ if (!clookup || !slookup) {
+ free(cs);
+ free(ss);
+ return kr_error(ENOENT);
+ }
+
+ ctx->clnt.current.secr = cs;
+ ctx->clnt.current.alg_id = clookup->id;
+
+ ctx->srvr.current.secr = ss;
+ ctx->srvr.current.alg_id = slookup->id;
+
+ return kr_ok();
+}
+
+void config_deinit(struct kr_cookie_ctx *ctx)
+{
+ if (!ctx) {
+ return;
+ }
+
+ ctx->clnt.enabled = false;
+
+ free(ctx->clnt.recent.secr);
+ ctx->clnt.recent.secr = NULL;
+
+ free(ctx->clnt.current.secr);
+ ctx->clnt.current.secr = NULL;
+
+ ctx->srvr.enabled = false;
+
+ free(ctx->srvr.recent.secr);
+ ctx->srvr.recent.secr = NULL;
+
+ free(ctx->srvr.current.secr);
+ ctx->srvr.current.secr = NULL;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-07 05:30:33 +0000