encoder_lib.c
/*
* Copyright 2019-2022 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
*/
#include <openssl/core_names.h>
#include <openssl/bio.h>
#include <openssl/encoder.h>
#include <openssl/buffer.h>
#include <openssl/params.h>
#include <openssl/provider.h>
#include <openssl/trace.h>
#include "internal/bio.h"
#include "internal/provider.h"
#include "encoder_local.h"
struct encoder_process_data_st {
OSSL_ENCODER_CTX *ctx;
/* Current BIO */
BIO *bio;
/* Index of the current encoder instance to be processed */
int current_encoder_inst_index;
/* Processing data passed down through recursion */
int level; /* Recursion level */
OSSL_ENCODER_INSTANCE *next_encoder_inst;
int count_output_structure;
/* Processing data passed up through recursion */
OSSL_ENCODER_INSTANCE *prev_encoder_inst;
unsigned char *running_output;
size_t running_output_length;
/* Data type = the name of the first succeeding encoder implementation */
const char *data_type;
};
static int encoder_process(struct encoder_process_data_st *data);
int OSSL_ENCODER_to_bio(OSSL_ENCODER_CTX *ctx, BIO *out)
{
struct encoder_process_data_st data;
memset(&data, 0, sizeof(data));
data.ctx = ctx;
data.bio = out;
data.current_encoder_inst_index = OSSL_ENCODER_CTX_get_num_encoders(ctx);
if (data.current_encoder_inst_index == 0) {
ERR_raise_data(ERR_LIB_OSSL_ENCODER, OSSL_ENCODER_R_ENCODER_NOT_FOUND,
"No encoders were found. For standard encoders you need "
"at least one of the default or base providers "
"available. Did you forget to load them?");
return 0;
}
return encoder_process(&data) > 0;
}
#ifndef OPENSSL_NO_STDIO
static BIO *bio_from_file(FILE *fp)
{
BIO *b;
if ((b = BIO_new(BIO_s_file())) == NULL) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_BUF_LIB);
return NULL;
}
BIO_set_fp(b, fp, BIO_NOCLOSE);
return b;
}
int OSSL_ENCODER_to_fp(OSSL_ENCODER_CTX *ctx, FILE *fp)
{
BIO *b = bio_from_file(fp);
int ret = 0;
if (b != NULL)
ret = OSSL_ENCODER_to_bio(ctx, b);
BIO_free(b);
return ret;
}
#endif
int OSSL_ENCODER_to_data(OSSL_ENCODER_CTX *ctx, unsigned char **pdata,
size_t *pdata_len)
{
BIO *out;
BUF_MEM *buf = NULL;
int ret = 0;
if (pdata_len == NULL) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
out = BIO_new(BIO_s_mem());
if (out != NULL
&& OSSL_ENCODER_to_bio(ctx, out)
&& BIO_get_mem_ptr(out, &buf) > 0) {
ret = 1; /* Hope for the best. A too small buffer will clear this */
if (pdata != NULL && *pdata != NULL) {
if (*pdata_len < buf->length)
/*
* It's tempting to do |*pdata_len = (size_t)buf->length|
* However, it's believed to be confusing more than helpful,
* so we don't.
*/
ret = 0;
else
*pdata_len -= buf->length;
} else {
/* The buffer with the right size is already allocated for us */
*pdata_len = (size_t)buf->length;
}
if (ret) {
if (pdata != NULL) {
if (*pdata != NULL) {
memcpy(*pdata, buf->data, buf->length);
*pdata += buf->length;
} else {
/* In this case, we steal the data from BIO_s_mem() */
*pdata = (unsigned char *)buf->data;
buf->data = NULL;
}
}
}
}
BIO_free(out);
return ret;
}
int OSSL_ENCODER_CTX_set_selection(OSSL_ENCODER_CTX *ctx, int selection)
{
if (!ossl_assert(ctx != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (!ossl_assert(selection != 0)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_INVALID_ARGUMENT);
return 0;
}
ctx->selection = selection;
return 1;
}
int OSSL_ENCODER_CTX_set_output_type(OSSL_ENCODER_CTX *ctx,
const char *output_type)
{
if (!ossl_assert(ctx != NULL) || !ossl_assert(output_type != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
ctx->output_type = output_type;
return 1;
}
int OSSL_ENCODER_CTX_set_output_structure(OSSL_ENCODER_CTX *ctx,
const char *output_structure)
{
if (!ossl_assert(ctx != NULL) || !ossl_assert(output_structure != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
ctx->output_structure = output_structure;
return 1;
}
static OSSL_ENCODER_INSTANCE *ossl_encoder_instance_new(OSSL_ENCODER *encoder,
void *encoderctx)
{
OSSL_ENCODER_INSTANCE *encoder_inst = NULL;
const OSSL_PROVIDER *prov;
OSSL_LIB_CTX *libctx;
const OSSL_PROPERTY_LIST *props;
const OSSL_PROPERTY_DEFINITION *prop;
if (!ossl_assert(encoder != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if ((encoder_inst = OPENSSL_zalloc(sizeof(*encoder_inst))) == NULL)
return 0;
if (!OSSL_ENCODER_up_ref(encoder)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_INTERNAL_ERROR);
goto err;
}
prov = OSSL_ENCODER_get0_provider(encoder);
libctx = ossl_provider_libctx(prov);
props = ossl_encoder_parsed_properties(encoder);
if (props == NULL) {
ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
"there are no property definitions with encoder %s",
OSSL_ENCODER_get0_name(encoder));
goto err;
}
/* The "output" property is mandatory */
prop = ossl_property_find_property(props, libctx, "output");
encoder_inst->output_type = ossl_property_get_string_value(libctx, prop);
if (encoder_inst->output_type == NULL) {
ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
"the mandatory 'output' property is missing "
"for encoder %s (properties: %s)",
OSSL_ENCODER_get0_name(encoder),
OSSL_ENCODER_get0_properties(encoder));
goto err;
}
/* The "structure" property is optional */
prop = ossl_property_find_property(props, libctx, "structure");
if (prop != NULL)
encoder_inst->output_structure
= ossl_property_get_string_value(libctx, prop);
encoder_inst->encoder = encoder;
encoder_inst->encoderctx = encoderctx;
return encoder_inst;
err:
ossl_encoder_instance_free(encoder_inst);
return NULL;
}
void ossl_encoder_instance_free(OSSL_ENCODER_INSTANCE *encoder_inst)
{
if (encoder_inst != NULL) {
if (encoder_inst->encoder != NULL)
encoder_inst->encoder->freectx(encoder_inst->encoderctx);
encoder_inst->encoderctx = NULL;
OSSL_ENCODER_free(encoder_inst->encoder);
encoder_inst->encoder = NULL;
OPENSSL_free(encoder_inst);
}
}
static int ossl_encoder_ctx_add_encoder_inst(OSSL_ENCODER_CTX *ctx,
OSSL_ENCODER_INSTANCE *ei)
{
int ok;
if (ctx->encoder_insts == NULL
&& (ctx->encoder_insts =
sk_OSSL_ENCODER_INSTANCE_new_null()) == NULL) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_CRYPTO_LIB);
return 0;
}
ok = (sk_OSSL_ENCODER_INSTANCE_push(ctx->encoder_insts, ei) > 0);
if (ok) {
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"(ctx %p) Added encoder instance %p (encoder %p):\n"
" %s with %s\n",
(void *)ctx, (void *)ei, (void *)ei->encoder,
OSSL_ENCODER_get0_name(ei->encoder),
OSSL_ENCODER_get0_properties(ei->encoder));
} OSSL_TRACE_END(ENCODER);
}
return ok;
}
int OSSL_ENCODER_CTX_add_encoder(OSSL_ENCODER_CTX *ctx, OSSL_ENCODER *encoder)
{
OSSL_ENCODER_INSTANCE *encoder_inst = NULL;
const OSSL_PROVIDER *prov = NULL;
void *encoderctx = NULL;
void *provctx = NULL;
if (!ossl_assert(ctx != NULL) || !ossl_assert(encoder != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
prov = OSSL_ENCODER_get0_provider(encoder);
provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
if ((encoderctx = encoder->newctx(provctx)) == NULL
|| (encoder_inst =
ossl_encoder_instance_new(encoder, encoderctx)) == NULL)
goto err;
/* Avoid double free of encoderctx on further errors */
encoderctx = NULL;
if (!ossl_encoder_ctx_add_encoder_inst(ctx, encoder_inst))
goto err;
return 1;
err:
ossl_encoder_instance_free(encoder_inst);
if (encoderctx != NULL)
encoder->freectx(encoderctx);
return 0;
}
int OSSL_ENCODER_CTX_add_extra(OSSL_ENCODER_CTX *ctx,
OSSL_LIB_CTX *libctx, const char *propq)
{
return 1;
}
int OSSL_ENCODER_CTX_get_num_encoders(OSSL_ENCODER_CTX *ctx)
{
if (ctx == NULL || ctx->encoder_insts == NULL)
return 0;
return sk_OSSL_ENCODER_INSTANCE_num(ctx->encoder_insts);
}
int OSSL_ENCODER_CTX_set_construct(OSSL_ENCODER_CTX *ctx,
OSSL_ENCODER_CONSTRUCT *construct)
{
if (!ossl_assert(ctx != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
ctx->construct = construct;
return 1;
}
int OSSL_ENCODER_CTX_set_construct_data(OSSL_ENCODER_CTX *ctx,
void *construct_data)
{
if (!ossl_assert(ctx != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
ctx->construct_data = construct_data;
return 1;
}
int OSSL_ENCODER_CTX_set_cleanup(OSSL_ENCODER_CTX *ctx,
OSSL_ENCODER_CLEANUP *cleanup)
{
if (!ossl_assert(ctx != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
ctx->cleanup = cleanup;
return 1;
}
OSSL_ENCODER *
OSSL_ENCODER_INSTANCE_get_encoder(OSSL_ENCODER_INSTANCE *encoder_inst)
{
if (encoder_inst == NULL)
return NULL;
return encoder_inst->encoder;
}
void *
OSSL_ENCODER_INSTANCE_get_encoder_ctx(OSSL_ENCODER_INSTANCE *encoder_inst)
{
if (encoder_inst == NULL)
return NULL;
return encoder_inst->encoderctx;
}
const char *
OSSL_ENCODER_INSTANCE_get_output_type(OSSL_ENCODER_INSTANCE *encoder_inst)
{
if (encoder_inst == NULL)
return NULL;
return encoder_inst->output_type;
}
const char *
OSSL_ENCODER_INSTANCE_get_output_structure(OSSL_ENCODER_INSTANCE *encoder_inst)
{
if (encoder_inst == NULL)
return NULL;
return encoder_inst->output_structure;
}
static int encoder_process(struct encoder_process_data_st *data)
{
OSSL_ENCODER_INSTANCE *current_encoder_inst = NULL;
OSSL_ENCODER *current_encoder = NULL;
OSSL_ENCODER_CTX *current_encoder_ctx = NULL;
BIO *allocated_out = NULL;
const void *original_data = NULL;
OSSL_PARAM abstract[10];
const OSSL_PARAM *current_abstract = NULL;
int i;
int ok = -1; /* -1 signifies that the lookup loop gave nothing */
int top = 0;
if (data->next_encoder_inst == NULL) {
/* First iteration, where we prepare for what is to come */
data->count_output_structure =
data->ctx->output_structure == NULL ? -1 : 0;
top = 1;
}
for (i = data->current_encoder_inst_index; i-- > 0;) {
OSSL_ENCODER *next_encoder = NULL;
const char *current_output_type;
const char *current_output_structure;
struct encoder_process_data_st new_data;
if (!top)
next_encoder =
OSSL_ENCODER_INSTANCE_get_encoder(data->next_encoder_inst);
current_encoder_inst =
sk_OSSL_ENCODER_INSTANCE_value(data->ctx->encoder_insts, i);
current_encoder =
OSSL_ENCODER_INSTANCE_get_encoder(current_encoder_inst);
current_encoder_ctx =
OSSL_ENCODER_INSTANCE_get_encoder_ctx(current_encoder_inst);
current_output_type =
OSSL_ENCODER_INSTANCE_get_output_type(current_encoder_inst);
current_output_structure =
OSSL_ENCODER_INSTANCE_get_output_structure(current_encoder_inst);
memset(&new_data, 0, sizeof(new_data));
new_data.ctx = data->ctx;
new_data.current_encoder_inst_index = i;
new_data.next_encoder_inst = current_encoder_inst;
new_data.count_output_structure = data->count_output_structure;
new_data.level = data->level + 1;
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] (ctx %p) Considering encoder instance %p (encoder %p)\n",
data->level, (void *)data->ctx,
(void *)current_encoder_inst, (void *)current_encoder);
} OSSL_TRACE_END(ENCODER);
/*
* If this is the top call, we check if the output type of the current
* encoder matches the desired output type.
* If this isn't the top call, i.e. this is deeper in the recursion,
* we instead check if the output type of the current encoder matches
* the name of the next encoder (the one found by the parent call).
*/
if (top) {
if (data->ctx->output_type != NULL
&& OPENSSL_strcasecmp(current_output_type,
data->ctx->output_type) != 0) {
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] Skipping because current encoder output type (%s) != desired output type (%s)\n",
data->level,
current_output_type, data->ctx->output_type);
} OSSL_TRACE_END(ENCODER);
continue;
}
} else {
if (!OSSL_ENCODER_is_a(next_encoder, current_output_type)) {
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] Skipping because current encoder output type (%s) != name of encoder %p\n",
data->level,
current_output_type, (void *)next_encoder);
} OSSL_TRACE_END(ENCODER);
continue;
}
}
/*
* If the caller and the current encoder specify an output structure,
* Check if they match. If they do, count the match, otherwise skip
* the current encoder.
*/
if (data->ctx->output_structure != NULL
&& current_output_structure != NULL) {
if (OPENSSL_strcasecmp(data->ctx->output_structure,
current_output_structure) != 0) {
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] Skipping because current encoder output structure (%s) != ctx output structure (%s)\n",
data->level,
current_output_structure,
data->ctx->output_structure);
} OSSL_TRACE_END(ENCODER);
continue;
}
data->count_output_structure++;
}
/*
* Recurse to process the encoder implementations before the current
* one.
*/
ok = encoder_process(&new_data);
data->prev_encoder_inst = new_data.prev_encoder_inst;
data->running_output = new_data.running_output;
data->running_output_length = new_data.running_output_length;
/*
* ok == -1 means that the recursion call above gave no further
* encoders, and that the one we're currently at should
* be tried.
* ok == 0 means that something failed in the recursion call
* above, making the result unsuitable for a chain.
* In this case, we simply continue to try finding a
* suitable encoder at this recursion level.
* ok == 1 means that the recursion call was successful, and we
* try to use the result at this recursion level.
*/
if (ok != 0)
break;
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] Skipping because recursion level %d failed\n",
data->level, new_data.level);
} OSSL_TRACE_END(ENCODER);
}
/*
* If |i < 0|, we didn't find any useful encoder in this recursion, so
* we do the rest of the process only if |i >= 0|.
*/
if (i < 0) {
ok = -1;
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] (ctx %p) No suitable encoder found\n",
data->level, (void *)data->ctx);
} OSSL_TRACE_END(ENCODER);
} else {
/* Preparations */
switch (ok) {
case 0:
break;
case -1:
/*
* We have reached the beginning of the encoder instance sequence,
* so we prepare the object to be encoded.
*/
/*
* |data->count_output_structure| is one of these values:
*
* -1 There is no desired output structure
* 0 There is a desired output structure, and it wasn't
* matched by any of the encoder instances that were
* considered
* >0 There is a desired output structure, and at least one
* of the encoder instances matched it
*/
if (data->count_output_structure == 0)
return 0;
original_data =
data->ctx->construct(current_encoder_inst,
data->ctx->construct_data);
/* Also set the data type, using the encoder implementation name */
data->data_type = OSSL_ENCODER_get0_name(current_encoder);
/* Assume that the constructor recorded an error */
if (original_data != NULL)
ok = 1;
else
ok = 0;
break;
case 1:
if (!ossl_assert(data->running_output != NULL)) {
ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_INTERNAL_ERROR);
ok = 0;
break;
}
{
/*
* Create an object abstraction from the latest output, which
* was stolen from the previous round.
*/
OSSL_PARAM *abstract_p = abstract;
const char *prev_output_structure =
OSSL_ENCODER_INSTANCE_get_output_structure(data->prev_encoder_inst);
*abstract_p++ =
OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,
(char *)data->data_type, 0);
if (prev_output_structure != NULL)
*abstract_p++ =
OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,
(char *)prev_output_structure,
0);
*abstract_p++ =
OSSL_PARAM_construct_octet_string(OSSL_OBJECT_PARAM_DATA,
data->running_output,
data->running_output_length);
*abstract_p = OSSL_PARAM_construct_end();
current_abstract = abstract;
}
break;
}
/* Calling the encoder implementation */
if (ok) {
OSSL_CORE_BIO *cbio = NULL;
BIO *current_out = NULL;
/*
* If we're at the last encoder instance to use, we're setting up
* final output. Otherwise, set up an intermediary memory output.
*/
if (top)
current_out = data->bio;
else if ((current_out = allocated_out = BIO_new(BIO_s_mem()))
== NULL)
ok = 0; /* Assume BIO_new() recorded an error */
if (ok)
ok = (cbio = ossl_core_bio_new_from_bio(current_out)) != NULL;
if (ok) {
ok = current_encoder->encode(current_encoder_ctx, cbio,
original_data, current_abstract,
data->ctx->selection,
ossl_pw_passphrase_callback_enc,
&data->ctx->pwdata);
OSSL_TRACE_BEGIN(ENCODER) {
BIO_printf(trc_out,
"[%d] (ctx %p) Running encoder instance %p => %d\n",
data->level, (void *)data->ctx,
(void *)current_encoder_inst, ok);
} OSSL_TRACE_END(ENCODER);
}
ossl_core_bio_free(cbio);
data->prev_encoder_inst = current_encoder_inst;
}
}
/* Cleanup and collecting the result */
OPENSSL_free(data->running_output);
data->running_output = NULL;
/*
* Steal the output from the BIO_s_mem, if we did allocate one.
* That'll be the data for an object abstraction in the next round.
*/
if (allocated_out != NULL) {
BUF_MEM *buf;
BIO_get_mem_ptr(allocated_out, &buf);
data->running_output = (unsigned char *)buf->data;
data->running_output_length = buf->length;
memset(buf, 0, sizeof(*buf));
}
BIO_free(allocated_out);
if (original_data != NULL)
data->ctx->cleanup(data->ctx->construct_data);
return ok;
}
