file_store.c
/*
* Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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
*/
/* This file has quite some overlap with engines/e_loader_attic.c */
#include <string.h>
#include <sys/stat.h>
#include <ctype.h> /* isdigit */
#include <assert.h>
#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/core_object.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/params.h>
#include <openssl/decoder.h>
#include <openssl/proverr.h>
#include <openssl/store.h> /* The OSSL_STORE_INFO type numbers */
#include "internal/cryptlib.h"
#include "internal/o_dir.h"
#include "crypto/decoder.h"
#include "crypto/ctype.h" /* ossl_isdigit() */
#include "prov/implementations.h"
#include "prov/bio.h"
#include "file_store_local.h"
DEFINE_STACK_OF(OSSL_STORE_INFO)
#ifdef _WIN32
# define stat _stat
#endif
#ifndef S_ISDIR
# define S_ISDIR(a) (((a) & S_IFMT) == S_IFDIR)
#endif
static OSSL_FUNC_store_open_fn file_open;
static OSSL_FUNC_store_attach_fn file_attach;
static OSSL_FUNC_store_settable_ctx_params_fn file_settable_ctx_params;
static OSSL_FUNC_store_set_ctx_params_fn file_set_ctx_params;
static OSSL_FUNC_store_load_fn file_load;
static OSSL_FUNC_store_eof_fn file_eof;
static OSSL_FUNC_store_close_fn file_close;
/*
* This implementation makes full use of OSSL_DECODER, and then some.
* It uses its own internal decoder implementation that reads DER and
* passes that on to the data callback; this decoder is created with
* internal OpenSSL functions, thereby bypassing the need for a surrounding
* provider. This is ok, since this is a local decoder, not meant for
* public consumption.
* Finally, it sets up its own construct and cleanup functions.
*
* Essentially, that makes this implementation a kind of glorified decoder.
*/
struct file_ctx_st {
void *provctx;
char *uri; /* The URI we currently try to load */
enum {
IS_FILE = 0, /* Read file and pass results */
IS_DIR /* Pass directory entry names */
} type;
union {
/* Used with |IS_FILE| */
struct {
BIO *file;
OSSL_DECODER_CTX *decoderctx;
char *input_type;
char *propq; /* The properties we got as a parameter */
} file;
/* Used with |IS_DIR| */
struct {
OPENSSL_DIR_CTX *ctx;
int end_reached;
/*
* When a search expression is given, these are filled in.
* |search_name| contains the file basename to look for.
* The string is exactly 8 characters long.
*/
char search_name[9];
/*
* The directory reading utility we have combines opening with
* reading the first name. To make sure we can detect the end
* at the right time, we read early and cache the name.
*/
const char *last_entry;
int last_errno;
} dir;
} _;
/* Expected object type. May be unspecified */
int expected_type;
};
static void free_file_ctx(struct file_ctx_st *ctx)
{
if (ctx == NULL)
return;
OPENSSL_free(ctx->uri);
if (ctx->type != IS_DIR) {
OSSL_DECODER_CTX_free(ctx->_.file.decoderctx);
OPENSSL_free(ctx->_.file.propq);
OPENSSL_free(ctx->_.file.input_type);
}
OPENSSL_free(ctx);
}
static struct file_ctx_st *new_file_ctx(int type, const char *uri,
void *provctx)
{
struct file_ctx_st *ctx = NULL;
if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL
&& (uri == NULL || (ctx->uri = OPENSSL_strdup(uri)) != NULL)) {
ctx->type = type;
ctx->provctx = provctx;
return ctx;
}
free_file_ctx(ctx);
return NULL;
}
static OSSL_DECODER_CONSTRUCT file_load_construct;
static OSSL_DECODER_CLEANUP file_load_cleanup;
/*-
* Opening / attaching streams and directories
* -------------------------------------------
*/
/*
* Function to service both file_open() and file_attach()
*
*
*/
static struct file_ctx_st *file_open_stream(BIO *source, const char *uri,
void *provctx)
{
struct file_ctx_st *ctx;
if ((ctx = new_file_ctx(IS_FILE, uri, provctx)) == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_PROV_LIB);
goto err;
}
ctx->_.file.file = source;
return ctx;
err:
free_file_ctx(ctx);
return NULL;
}
static void *file_open_dir(const char *path, const char *uri, void *provctx)
{
struct file_ctx_st *ctx;
if ((ctx = new_file_ctx(IS_DIR, uri, provctx)) == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_PROV_LIB);
return NULL;
}
ctx->_.dir.last_entry = OPENSSL_DIR_read(&ctx->_.dir.ctx, path);
ctx->_.dir.last_errno = errno;
if (ctx->_.dir.last_entry == NULL) {
if (ctx->_.dir.last_errno != 0) {
ERR_raise_data(ERR_LIB_SYS, ctx->_.dir.last_errno,
"Calling OPENSSL_DIR_read(\"%s\")", path);
goto err;
}
ctx->_.dir.end_reached = 1;
}
return ctx;
err:
file_close(ctx);
return NULL;
}
static void *file_open(void *provctx, const char *uri)
{
struct file_ctx_st *ctx = NULL;
struct stat st;
struct {
const char *path;
unsigned int check_absolute:1;
} path_data[2];
size_t path_data_n = 0, i;
const char *path, *p = uri, *q;
BIO *bio;
ERR_set_mark();
/*
* First step, just take the URI as is.
*/
path_data[path_data_n].check_absolute = 0;
path_data[path_data_n++].path = uri;
/*
* Second step, if the URI appears to start with the "file" scheme,
* extract the path and make that the second path to check.
* There's a special case if the URI also contains an authority, then
* the full URI shouldn't be used as a path anywhere.
*/
if (CHECK_AND_SKIP_CASE_PREFIX(p, "file:")) {
q = p;
if (CHECK_AND_SKIP_CASE_PREFIX(q, "//")) {
path_data_n--; /* Invalidate using the full URI */
if (CHECK_AND_SKIP_CASE_PREFIX(q, "localhost/")
|| CHECK_AND_SKIP_CASE_PREFIX(q, "/")) {
p = q - 1;
} else {
ERR_clear_last_mark();
ERR_raise(ERR_LIB_PROV, PROV_R_URI_AUTHORITY_UNSUPPORTED);
return NULL;
}
}
path_data[path_data_n].check_absolute = 1;
#ifdef _WIN32
/* Windows "file:" URIs with a drive letter start with a '/' */
if (p[0] == '/' && p[2] == ':' && p[3] == '/') {
char c = tolower(p[1]);
if (c >= 'a' && c <= 'z') {
p++;
/* We know it's absolute, so no need to check */
path_data[path_data_n].check_absolute = 0;
}
}
#endif
path_data[path_data_n++].path = p;
}
for (i = 0, path = NULL; path == NULL && i < path_data_n; i++) {
/*
* If the scheme "file" was an explicit part of the URI, the path must
* be absolute. So says RFC 8089
*/
if (path_data[i].check_absolute && path_data[i].path[0] != '/') {
ERR_clear_last_mark();
ERR_raise_data(ERR_LIB_PROV, PROV_R_PATH_MUST_BE_ABSOLUTE,
"Given path=%s", path_data[i].path);
return NULL;
}
if (stat(path_data[i].path, &st) < 0) {
ERR_raise_data(ERR_LIB_SYS, errno,
"calling stat(%s)",
path_data[i].path);
} else {
path = path_data[i].path;
}
}
if (path == NULL) {
ERR_clear_last_mark();
return NULL;
}
/* Successfully found a working path, clear possible collected errors */
ERR_pop_to_mark();
if (S_ISDIR(st.st_mode))
ctx = file_open_dir(path, uri, provctx);
else if ((bio = BIO_new_file(path, "rb")) == NULL
|| (ctx = file_open_stream(bio, uri, provctx)) == NULL)
BIO_free_all(bio);
return ctx;
}
void *file_attach(void *provctx, OSSL_CORE_BIO *cin)
{
struct file_ctx_st *ctx;
BIO *new_bio = ossl_bio_new_from_core_bio(provctx, cin);
if (new_bio == NULL)
return NULL;
ctx = file_open_stream(new_bio, NULL, provctx);
if (ctx == NULL)
BIO_free(new_bio);
return ctx;
}
/*-
* Setting parameters
* ------------------
*/
static const OSSL_PARAM *file_settable_ctx_params(void *provctx)
{
static const OSSL_PARAM known_settable_ctx_params[] = {
OSSL_PARAM_utf8_string(OSSL_STORE_PARAM_PROPERTIES, NULL, 0),
OSSL_PARAM_int(OSSL_STORE_PARAM_EXPECT, NULL),
OSSL_PARAM_octet_string(OSSL_STORE_PARAM_SUBJECT, NULL, 0),
OSSL_PARAM_utf8_string(OSSL_STORE_PARAM_INPUT_TYPE, NULL, 0),
OSSL_PARAM_END
};
return known_settable_ctx_params;
}
static int file_set_ctx_params(void *loaderctx, const OSSL_PARAM params[])
{
struct file_ctx_st *ctx = loaderctx;
const OSSL_PARAM *p;
if (params == NULL)
return 1;
if (ctx->type != IS_DIR) {
/* these parameters are ignored for directories */
p = OSSL_PARAM_locate_const(params, OSSL_STORE_PARAM_PROPERTIES);
if (p != NULL) {
OPENSSL_free(ctx->_.file.propq);
ctx->_.file.propq = NULL;
if (!OSSL_PARAM_get_utf8_string(p, &ctx->_.file.propq, 0))
return 0;
}
p = OSSL_PARAM_locate_const(params, OSSL_STORE_PARAM_INPUT_TYPE);
if (p != NULL) {
OPENSSL_free(ctx->_.file.input_type);
ctx->_.file.input_type = NULL;
if (!OSSL_PARAM_get_utf8_string(p, &ctx->_.file.input_type, 0))
return 0;
}
}
p = OSSL_PARAM_locate_const(params, OSSL_STORE_PARAM_EXPECT);
if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->expected_type))
return 0;
p = OSSL_PARAM_locate_const(params, OSSL_STORE_PARAM_SUBJECT);
if (p != NULL) {
const unsigned char *der = NULL;
size_t der_len = 0;
X509_NAME *x509_name;
unsigned long hash;
int ok;
if (ctx->type != IS_DIR) {
ERR_raise(ERR_LIB_PROV,
PROV_R_SEARCH_ONLY_SUPPORTED_FOR_DIRECTORIES);
return 0;
}
if (!OSSL_PARAM_get_octet_string_ptr(p, (const void **)&der, &der_len)
|| (x509_name = d2i_X509_NAME(NULL, &der, der_len)) == NULL)
return 0;
hash = X509_NAME_hash_ex(x509_name,
ossl_prov_ctx_get0_libctx(ctx->provctx), NULL,
&ok);
BIO_snprintf(ctx->_.dir.search_name, sizeof(ctx->_.dir.search_name),
"%08lx", hash);
X509_NAME_free(x509_name);
if (ok == 0)
return 0;
}
return 1;
}
/*-
* Loading an object from a stream
* -------------------------------
*/
struct file_load_data_st {
OSSL_CALLBACK *object_cb;
void *object_cbarg;
};
static int file_load_construct(OSSL_DECODER_INSTANCE *decoder_inst,
const OSSL_PARAM *params, void *construct_data)
{
struct file_load_data_st *data = construct_data;
/*
* At some point, we may find it justifiable to recognise PKCS#12 and
* handle it specially here, making |file_load()| return pass its
* contents one piece at ta time, like |e_loader_attic.c| does.
*
* However, that currently means parsing them out, which converts the
* DER encoded PKCS#12 into a bunch of EVP_PKEYs and X509s, just to
* have to re-encode them into DER to create an object abstraction for
* each of them.
* It's much simpler (less churn) to pass on the object abstraction we
* get to the load_result callback and leave it to that one to do the
* work. If that's libcrypto code, we know that it has much better
* possibilities to handle the EVP_PKEYs and X509s without the extra
* churn.
*/
return data->object_cb(params, data->object_cbarg);
}
void file_load_cleanup(void *construct_data)
{
/* Nothing to do */
}
static int file_setup_decoders(struct file_ctx_st *ctx)
{
OSSL_LIB_CTX *libctx = ossl_prov_ctx_get0_libctx(ctx->provctx);
const OSSL_ALGORITHM *to_algo = NULL;
int ok = 0;
/* Setup for this session, so only if not already done */
if (ctx->_.file.decoderctx == NULL) {
if ((ctx->_.file.decoderctx = OSSL_DECODER_CTX_new()) == NULL) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
/* Make sure the input type is set */
if (!OSSL_DECODER_CTX_set_input_type(ctx->_.file.decoderctx,
ctx->_.file.input_type)) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
/*
* Where applicable, set the outermost structure name.
* The goal is to avoid the STORE object types that are
* potentially password protected but aren't interesting
* for this load.
*/
switch (ctx->expected_type) {
case OSSL_STORE_INFO_CERT:
if (!OSSL_DECODER_CTX_set_input_structure(ctx->_.file.decoderctx,
"Certificate")) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
break;
case OSSL_STORE_INFO_CRL:
if (!OSSL_DECODER_CTX_set_input_structure(ctx->_.file.decoderctx,
"CertificateList")) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
break;
default:
break;
}
for (to_algo = ossl_any_to_obj_algorithm;
to_algo->algorithm_names != NULL;
to_algo++) {
OSSL_DECODER *to_obj = NULL;
OSSL_DECODER_INSTANCE *to_obj_inst = NULL;
/*
* Create the internal last resort decoder implementation
* together with a "decoder instance".
* The decoder doesn't need any identification or to be
* attached to any provider, since it's only used locally.
*/
to_obj = ossl_decoder_from_algorithm(0, to_algo, NULL);
if (to_obj != NULL)
to_obj_inst = ossl_decoder_instance_new(to_obj, ctx->provctx);
OSSL_DECODER_free(to_obj);
if (to_obj_inst == NULL)
goto err;
if (!ossl_decoder_ctx_add_decoder_inst(ctx->_.file.decoderctx,
to_obj_inst)) {
ossl_decoder_instance_free(to_obj_inst);
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
}
/* Add on the usual extra decoders */
if (!OSSL_DECODER_CTX_add_extra(ctx->_.file.decoderctx,
libctx, ctx->_.file.propq)) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
/*
* Then install our constructor hooks, which just passes decoded
* data to the load callback
*/
if (!OSSL_DECODER_CTX_set_construct(ctx->_.file.decoderctx,
file_load_construct)
|| !OSSL_DECODER_CTX_set_cleanup(ctx->_.file.decoderctx,
file_load_cleanup)) {
ERR_raise(ERR_LIB_PROV, ERR_R_OSSL_DECODER_LIB);
goto err;
}
}
ok = 1;
err:
return ok;
}
static int file_load_file(struct file_ctx_st *ctx,
OSSL_CALLBACK *object_cb, void *object_cbarg,
OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)
{
struct file_load_data_st data;
int ret, err;
/* Setup the decoders (one time shot per session */
if (!file_setup_decoders(ctx))
return 0;
/* Setup for this object */
data.object_cb = object_cb;
data.object_cbarg = object_cbarg;
OSSL_DECODER_CTX_set_construct_data(ctx->_.file.decoderctx, &data);
OSSL_DECODER_CTX_set_passphrase_cb(ctx->_.file.decoderctx, pw_cb, pw_cbarg);
/* Launch */
ERR_set_mark();
ret = OSSL_DECODER_from_bio(ctx->_.file.decoderctx, ctx->_.file.file);
if (BIO_eof(ctx->_.file.file)
&& ((err = ERR_peek_last_error()) != 0)
&& ERR_GET_LIB(err) == ERR_LIB_OSSL_DECODER
&& ERR_GET_REASON(err) == ERR_R_UNSUPPORTED)
ERR_pop_to_mark();
else
ERR_clear_last_mark();
return ret;
}
/*-
* Loading a name object from a directory
* --------------------------------------
*/
static char *file_name_to_uri(struct file_ctx_st *ctx, const char *name)
{
char *data = NULL;
assert(name != NULL);
{
const char *pathsep = ossl_ends_with_dirsep(ctx->uri) ? "" : "/";
long calculated_length = strlen(ctx->uri) + strlen(pathsep)
+ strlen(name) + 1 /* \0 */;
data = OPENSSL_zalloc(calculated_length);
if (data == NULL)
return NULL;
OPENSSL_strlcat(data, ctx->uri, calculated_length);
OPENSSL_strlcat(data, pathsep, calculated_length);
OPENSSL_strlcat(data, name, calculated_length);
}
return data;
}
static int file_name_check(struct file_ctx_st *ctx, const char *name)
{
const char *p = NULL;
size_t len = strlen(ctx->_.dir.search_name);
/* If there are no search criteria, all names are accepted */
if (ctx->_.dir.search_name[0] == '\0')
return 1;
/* If the expected type isn't supported, no name is accepted */
if (ctx->expected_type != 0
&& ctx->expected_type != OSSL_STORE_INFO_CERT
&& ctx->expected_type != OSSL_STORE_INFO_CRL)
return 0;
/*
* First, check the basename
*/
if (OPENSSL_strncasecmp(name, ctx->_.dir.search_name, len) != 0
|| name[len] != '.')
return 0;
p = &name[len + 1];
/*
* Then, if the expected type is a CRL, check that the extension starts
* with 'r'
*/
if (*p == 'r') {
p++;
if (ctx->expected_type != 0
&& ctx->expected_type != OSSL_STORE_INFO_CRL)
return 0;
} else if (ctx->expected_type == OSSL_STORE_INFO_CRL) {
return 0;
}
/*
* Last, check that the rest of the extension is a decimal number, at
* least one digit long.
*/
if (!isdigit((unsigned char)*p))
return 0;
while (isdigit((unsigned char)*p))
p++;
#ifdef __VMS
/*
* One extra step here, check for a possible generation number.
*/
if (*p == ';')
for (p++; *p != '\0'; p++)
if (!ossl_isdigit((unsigned char)*p))
break;
#endif
/*
* If we've reached the end of the string at this point, we've successfully
* found a fitting file name.
*/
return *p == '\0';
}
static int file_load_dir_entry(struct file_ctx_st *ctx,
OSSL_CALLBACK *object_cb, void *object_cbarg,
OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)
{
/* Prepare as much as possible in advance */
static const int object_type = OSSL_OBJECT_NAME;
OSSL_PARAM object[] = {
OSSL_PARAM_int(OSSL_OBJECT_PARAM_TYPE, (int *)&object_type),
OSSL_PARAM_utf8_string(OSSL_OBJECT_PARAM_DATA, NULL, 0),
OSSL_PARAM_END
};
char *newname = NULL;
int ok;
/* Loop until we get an error or until we have a suitable name */
do {
if (ctx->_.dir.last_entry == NULL) {
if (!ctx->_.dir.end_reached) {
assert(ctx->_.dir.last_errno != 0);
ERR_raise(ERR_LIB_SYS, ctx->_.dir.last_errno);
}
/* file_eof() will tell if EOF was reached */
return 0;
}
/* flag acceptable names */
if (ctx->_.dir.last_entry[0] != '.'
&& file_name_check(ctx, ctx->_.dir.last_entry)) {
/* If we can't allocate the new name, we fail */
if ((newname =
file_name_to_uri(ctx, ctx->_.dir.last_entry)) == NULL)
return 0;
}
/*
* On the first call (with a NULL context), OPENSSL_DIR_read()
* cares about the second argument. On the following calls, it
* only cares that it isn't NULL. Therefore, we can safely give
* it our URI here.
*/
ctx->_.dir.last_entry = OPENSSL_DIR_read(&ctx->_.dir.ctx, ctx->uri);
ctx->_.dir.last_errno = errno;
if (ctx->_.dir.last_entry == NULL && ctx->_.dir.last_errno == 0)
ctx->_.dir.end_reached = 1;
} while (newname == NULL);
object[1].data = newname;
object[1].data_size = strlen(newname);
ok = object_cb(object, object_cbarg);
OPENSSL_free(newname);
return ok;
}
/*-
* Loading, local dispatcher
* -------------------------
*/
static int file_load(void *loaderctx,
OSSL_CALLBACK *object_cb, void *object_cbarg,
OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)
{
struct file_ctx_st *ctx = loaderctx;
switch (ctx->type) {
case IS_FILE:
return file_load_file(ctx, object_cb, object_cbarg, pw_cb, pw_cbarg);
case IS_DIR:
return
file_load_dir_entry(ctx, object_cb, object_cbarg, pw_cb, pw_cbarg);
default:
break;
}
/* ctx->type has an unexpected value */
assert(0);
return 0;
}
/*-
* Eof detection and closing
* -------------------------
*/
static int file_eof(void *loaderctx)
{
struct file_ctx_st *ctx = loaderctx;
switch (ctx->type) {
case IS_DIR:
return ctx->_.dir.end_reached;
case IS_FILE:
/*
* BIO_pending() checks any filter BIO.
* BIO_eof() checks the source BIO.
*/
return !BIO_pending(ctx->_.file.file)
&& BIO_eof(ctx->_.file.file);
}
/* ctx->type has an unexpected value */
assert(0);
return 1;
}
static int file_close_dir(struct file_ctx_st *ctx)
{
if (ctx->_.dir.ctx != NULL)
OPENSSL_DIR_end(&ctx->_.dir.ctx);
free_file_ctx(ctx);
return 1;
}
static int file_close_stream(struct file_ctx_st *ctx)
{
/*
* This frees either the provider BIO filter (for file_attach()) OR
* the allocated file BIO (for file_open()).
*/
BIO_free(ctx->_.file.file);
ctx->_.file.file = NULL;
free_file_ctx(ctx);
return 1;
}
static int file_close(void *loaderctx)
{
struct file_ctx_st *ctx = loaderctx;
switch (ctx->type) {
case IS_DIR:
return file_close_dir(ctx);
case IS_FILE:
return file_close_stream(ctx);
}
/* ctx->type has an unexpected value */
assert(0);
return 1;
}
const OSSL_DISPATCH ossl_file_store_functions[] = {
{ OSSL_FUNC_STORE_OPEN, (void (*)(void))file_open },
{ OSSL_FUNC_STORE_ATTACH, (void (*)(void))file_attach },
{ OSSL_FUNC_STORE_SETTABLE_CTX_PARAMS,
(void (*)(void))file_settable_ctx_params },
{ OSSL_FUNC_STORE_SET_CTX_PARAMS, (void (*)(void))file_set_ctx_params },
{ OSSL_FUNC_STORE_LOAD, (void (*)(void))file_load },
{ OSSL_FUNC_STORE_EOF, (void (*)(void))file_eof },
{ OSSL_FUNC_STORE_CLOSE, (void (*)(void))file_close },
OSSL_DISPATCH_END,
};
