openssl/crypto/ct/ct_log.c

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2023-05-09 22:08:48 +00:00
/*
* Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdlib.h>
#include <string.h>
#include <openssl/conf.h>
#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/safestack.h>
#include "internal/cryptlib.h"
/*
* Information about a CT log server.
*/
struct ctlog_st {
char *name;
uint8_t log_id[CT_V1_HASHLEN];
EVP_PKEY *public_key;
};
/*
* A store for multiple CTLOG instances.
* It takes ownership of any CTLOG instances added to it.
*/
struct ctlog_store_st {
STACK_OF(CTLOG) *logs;
};
/* The context when loading a CT log list from a CONF file. */
typedef struct ctlog_store_load_ctx_st {
CTLOG_STORE *log_store;
CONF *conf;
size_t invalid_log_entries;
} CTLOG_STORE_LOAD_CTX;
/*
* Creates an empty context for loading a CT log store.
* It should be populated before use.
*/
static CTLOG_STORE_LOAD_CTX *ctlog_store_load_ctx_new(void);
/*
* Deletes a CT log store load context.
* Does not delete any of the fields.
*/
static void ctlog_store_load_ctx_free(CTLOG_STORE_LOAD_CTX* ctx);
static CTLOG_STORE_LOAD_CTX *ctlog_store_load_ctx_new(void)
{
CTLOG_STORE_LOAD_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
if (ctx == NULL)
CTerr(CT_F_CTLOG_STORE_LOAD_CTX_NEW, ERR_R_MALLOC_FAILURE);
return ctx;
}
static void ctlog_store_load_ctx_free(CTLOG_STORE_LOAD_CTX* ctx)
{
OPENSSL_free(ctx);
}
/* Converts a log's public key into a SHA256 log ID */
static int ct_v1_log_id_from_pkey(EVP_PKEY *pkey,
unsigned char log_id[CT_V1_HASHLEN])
{
int ret = 0;
unsigned char *pkey_der = NULL;
int pkey_der_len = i2d_PUBKEY(pkey, &pkey_der);
if (pkey_der_len <= 0) {
CTerr(CT_F_CT_V1_LOG_ID_FROM_PKEY, CT_R_LOG_KEY_INVALID);
goto err;
}
SHA256(pkey_der, pkey_der_len, log_id);
ret = 1;
err:
OPENSSL_free(pkey_der);
return ret;
}
CTLOG_STORE *CTLOG_STORE_new(void)
{
CTLOG_STORE *ret = OPENSSL_zalloc(sizeof(*ret));
if (ret == NULL) {
CTerr(CT_F_CTLOG_STORE_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
ret->logs = sk_CTLOG_new_null();
if (ret->logs == NULL)
goto err;
return ret;
err:
OPENSSL_free(ret);
return NULL;
}
void CTLOG_STORE_free(CTLOG_STORE *store)
{
if (store != NULL) {
sk_CTLOG_pop_free(store->logs, CTLOG_free);
OPENSSL_free(store);
}
}
static int ctlog_new_from_conf(CTLOG **ct_log, const CONF *conf, const char *section)
{
const char *description = NCONF_get_string(conf, section, "description");
char *pkey_base64;
if (description == NULL) {
CTerr(CT_F_CTLOG_NEW_FROM_CONF, CT_R_LOG_CONF_MISSING_DESCRIPTION);
return 0;
}
pkey_base64 = NCONF_get_string(conf, section, "key");
if (pkey_base64 == NULL) {
CTerr(CT_F_CTLOG_NEW_FROM_CONF, CT_R_LOG_CONF_MISSING_KEY);
return 0;
}
return CTLOG_new_from_base64(ct_log, pkey_base64, description);
}
int CTLOG_STORE_load_default_file(CTLOG_STORE *store)
{
const char *fpath = ossl_safe_getenv(CTLOG_FILE_EVP);
if (fpath == NULL)
fpath = CTLOG_FILE;
return CTLOG_STORE_load_file(store, fpath);
}
/*
* Called by CONF_parse_list, which stops if this returns <= 0,
* Otherwise, one bad log entry would stop loading of any of
* the following log entries.
* It may stop parsing and returns -1 on any internal (malloc) error.
*/
static int ctlog_store_load_log(const char *log_name, int log_name_len,
void *arg)
{
CTLOG_STORE_LOAD_CTX *load_ctx = arg;
CTLOG *ct_log = NULL;
/* log_name may not be null-terminated, so fix that before using it */
char *tmp;
int ret = 0;
/* log_name will be NULL for empty list entries */
if (log_name == NULL)
return 1;
tmp = OPENSSL_strndup(log_name, log_name_len);
if (tmp == NULL)
goto mem_err;
ret = ctlog_new_from_conf(&ct_log, load_ctx->conf, tmp);
OPENSSL_free(tmp);
if (ret < 0) {
/* Propagate any internal error */
return ret;
}
if (ret == 0) {
/* If we can't load this log, record that fact and skip it */
++load_ctx->invalid_log_entries;
return 1;
}
if (!sk_CTLOG_push(load_ctx->log_store->logs, ct_log)) {
goto mem_err;
}
return 1;
mem_err:
CTLOG_free(ct_log);
CTerr(CT_F_CTLOG_STORE_LOAD_LOG, ERR_R_MALLOC_FAILURE);
return -1;
}
int CTLOG_STORE_load_file(CTLOG_STORE *store, const char *file)
{
int ret = 0;
char *enabled_logs;
CTLOG_STORE_LOAD_CTX* load_ctx = ctlog_store_load_ctx_new();
if (load_ctx == NULL)
return 0;
load_ctx->log_store = store;
load_ctx->conf = NCONF_new(NULL);
if (load_ctx->conf == NULL)
goto end;
if (NCONF_load(load_ctx->conf, file, NULL) <= 0) {
CTerr(CT_F_CTLOG_STORE_LOAD_FILE, CT_R_LOG_CONF_INVALID);
goto end;
}
enabled_logs = NCONF_get_string(load_ctx->conf, NULL, "enabled_logs");
if (enabled_logs == NULL) {
CTerr(CT_F_CTLOG_STORE_LOAD_FILE, CT_R_LOG_CONF_INVALID);
goto end;
}
if (!CONF_parse_list(enabled_logs, ',', 1, ctlog_store_load_log, load_ctx) ||
load_ctx->invalid_log_entries > 0) {
CTerr(CT_F_CTLOG_STORE_LOAD_FILE, CT_R_LOG_CONF_INVALID);
goto end;
}
ret = 1;
end:
NCONF_free(load_ctx->conf);
ctlog_store_load_ctx_free(load_ctx);
return ret;
}
/*
* Initialize a new CTLOG object.
* Takes ownership of the public key.
* Copies the name.
*/
CTLOG *CTLOG_new(EVP_PKEY *public_key, const char *name)
{
CTLOG *ret = OPENSSL_zalloc(sizeof(*ret));
if (ret == NULL) {
CTerr(CT_F_CTLOG_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
ret->name = OPENSSL_strdup(name);
if (ret->name == NULL) {
CTerr(CT_F_CTLOG_NEW, ERR_R_MALLOC_FAILURE);
goto err;
}
if (ct_v1_log_id_from_pkey(public_key, ret->log_id) != 1)
goto err;
ret->public_key = public_key;
return ret;
err:
CTLOG_free(ret);
return NULL;
}
/* Frees CT log and associated structures */
void CTLOG_free(CTLOG *log)
{
if (log != NULL) {
OPENSSL_free(log->name);
EVP_PKEY_free(log->public_key);
OPENSSL_free(log);
}
}
const char *CTLOG_get0_name(const CTLOG *log)
{
return log->name;
}
void CTLOG_get0_log_id(const CTLOG *log, const uint8_t **log_id,
size_t *log_id_len)
{
*log_id = log->log_id;
*log_id_len = CT_V1_HASHLEN;
}
EVP_PKEY *CTLOG_get0_public_key(const CTLOG *log)
{
return log->public_key;
}
/*
* Given a log ID, finds the matching log.
* Returns NULL if no match found.
*/
const CTLOG *CTLOG_STORE_get0_log_by_id(const CTLOG_STORE *store,
const uint8_t *log_id,
size_t log_id_len)
{
int i;
for (i = 0; i < sk_CTLOG_num(store->logs); ++i) {
const CTLOG *log = sk_CTLOG_value(store->logs, i);
if (memcmp(log->log_id, log_id, log_id_len) == 0)
return log;
}
return NULL;
}