crypto/trace.c - third_party/openssl - Git at Google

 /*
  * Copyright 2019-2021 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 <stdio.h>
 #include <string.h>

 #include "internal/thread_once.h"
 #include <openssl/bio.h>
 #include <openssl/crypto.h>
 #include <openssl/trace.h>
 #include "internal/bio.h"
 #include "internal/nelem.h"
 #include "internal/refcount.h"
 #include "crypto/cryptlib.h"

 #include "internal/e_os.h"                /* strcasecmp for Windows */

 #ifndef OPENSSL_NO_TRACE

 static CRYPTO_RWLOCK *trace_lock = NULL;

 static const BIO  *current_channel = NULL;

 /*-
  * INTERNAL TRACE CHANNEL IMPLEMENTATION
  *
  * For our own flexibility, all trace categories are associated with a
  * BIO sink object, also called the trace channel. Instead of a BIO object,
  * the application can also provide a callback function, in which case an
  * internal trace channel is attached, which simply calls the registered
  * callback function.
  */
 static int trace_write(BIO *b, const char *buf,
                                size_t num, size_t *written);
 static int trace_puts(BIO *b, const char *str);
 static long trace_ctrl(BIO *channel, int cmd, long argl, void *argp);
 static int trace_free(BIO *b);

 static const BIO_METHOD trace_method = {
     BIO_TYPE_SOURCE_SINK,
     "trace",
     trace_write,
     NULL,                        /* old write */
     NULL,                        /* read_ex */
     NULL,                        /* read */
     trace_puts,
     NULL,                        /* gets */
     trace_ctrl,                  /* ctrl */
     NULL,                        /* create */
     trace_free,                  /* free */
     NULL,                        /* callback_ctrl */
 };

 struct trace_data_st {
     OSSL_trace_cb callback;
     int category;
     void *data;
 };

 static int trace_write(BIO *channel,
                        const char *buf, size_t num, size_t *written)
 {
     struct trace_data_st *ctx = BIO_get_data(channel);
     size_t cnt = ctx->callback(buf, num, ctx->category, OSSL_TRACE_CTRL_WRITE,
                                ctx->data);

     *written = cnt;
     return cnt != 0;
 }

 static int trace_puts(BIO *channel, const char *str)
 {
     size_t written;

     if (trace_write(channel, str, strlen(str), &written))
         return (int)written;

     return EOF;
 }

 static long trace_ctrl(BIO *channel, int cmd, long argl, void *argp)
 {
     struct trace_data_st *ctx = BIO_get_data(channel);

     switch (cmd) {
     case OSSL_TRACE_CTRL_BEGIN:
     case OSSL_TRACE_CTRL_END:
         /* We know that the callback is likely to return 0 here */
         ctx->callback("", 0, ctx->category, cmd, ctx->data);
         return 1;
     default:
         break;
     }
     return -2;                   /* Unsupported */
 }

 static int trace_free(BIO *channel)
 {
     if (channel == NULL)
         return 0;
     OPENSSL_free(BIO_get_data(channel));
     return 1;
 }
 #endif

 /*-
  * TRACE
  */

 /* Helper struct and macro to get name string to number mapping */
 struct trace_category_st {
     const char * const name;
     const int num;
 };
 #define TRACE_CATEGORY_(name)       { #name, OSSL_TRACE_CATEGORY_##name }

 static const struct trace_category_st trace_categories[] = {
     TRACE_CATEGORY_(ALL),
     TRACE_CATEGORY_(TRACE),
     TRACE_CATEGORY_(INIT),
     TRACE_CATEGORY_(TLS),
     TRACE_CATEGORY_(TLS_CIPHER),
     TRACE_CATEGORY_(CONF),
 #ifndef OPENSSL_NO_ENGINE
     TRACE_CATEGORY_(ENGINE_TABLE),
     TRACE_CATEGORY_(ENGINE_REF_COUNT),
 #endif
     TRACE_CATEGORY_(PKCS5V2),
     TRACE_CATEGORY_(PKCS12_KEYGEN),
     TRACE_CATEGORY_(PKCS12_DECRYPT),
     TRACE_CATEGORY_(X509V3_POLICY),
     TRACE_CATEGORY_(BN_CTX),
     TRACE_CATEGORY_(CMP),
     TRACE_CATEGORY_(STORE),
     TRACE_CATEGORY_(DECODER),
     TRACE_CATEGORY_(ENCODER),
     TRACE_CATEGORY_(REF_COUNT)
 };

 const char *OSSL_trace_get_category_name(int num)
 {
     size_t i;

     for (i = 0; i < OSSL_NELEM(trace_categories); i++)
         if (trace_categories[i].num == num)
             return trace_categories[i].name;
     return NULL; /* not found */
 }

 int OSSL_trace_get_category_num(const char *name)
 {
     size_t i;

     for (i = 0; i < OSSL_NELEM(trace_categories); i++)
         if (strcasecmp(name, trace_categories[i].name) == 0)
             return trace_categories[i].num;
     return -1; /* not found */
 }

 #ifndef OPENSSL_NO_TRACE

 /* We use one trace channel for each trace category */
 static struct {
     enum { SIMPLE_CHANNEL, CALLBACK_CHANNEL } type;
     BIO *bio;
     char *prefix;
     char *suffix;
 } trace_channels[OSSL_TRACE_CATEGORY_NUM] = {
     { 0, NULL, NULL, NULL },
 };

 #endif

 #ifndef OPENSSL_NO_TRACE

 enum {
     CHANNEL,
     PREFIX,
     SUFFIX
 };

 static int trace_attach_cb(int category, int type, const void *data)
 {
     switch (type) {
     case CHANNEL:
         OSSL_TRACE2(TRACE, "Attach channel %p to category '%s'\n",
                     data, trace_categories[category].name);
         break;
     case PREFIX:
         OSSL_TRACE2(TRACE, "Attach prefix \"%s\" to category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     case SUFFIX:
         OSSL_TRACE2(TRACE, "Attach suffix \"%s\" to category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     default:                     /* No clue */
         break;
     }
     return 1;
 }

 static int trace_detach_cb(int category, int type, const void *data)
 {
     switch (type) {
     case CHANNEL:
         OSSL_TRACE2(TRACE, "Detach channel %p from category '%s'\n",
                     data, trace_categories[category].name);
         break;
     case PREFIX:
         OSSL_TRACE2(TRACE, "Detach prefix \"%s\" from category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     case SUFFIX:
         OSSL_TRACE2(TRACE, "Detach suffix \"%s\" from category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     default:                     /* No clue */
         break;
     }
     return 1;
 }

 static int do_ossl_trace_init(void);
 static CRYPTO_ONCE trace_inited = CRYPTO_ONCE_STATIC_INIT;
 DEFINE_RUN_ONCE_STATIC(ossl_trace_init)
 {
     return do_ossl_trace_init();
 }

 static int set_trace_data(int category, int type, BIO **channel,
                           const char **prefix, const char **suffix,
                           int (*attach_cb)(int, int, const void *),
                           int (*detach_cb)(int, int, const void *))
 {
     BIO *curr_channel = NULL;
     char *curr_prefix = NULL;
     char *curr_suffix = NULL;

     /* Ensure do_ossl_trace_init() is called once */
     if (!RUN_ONCE(&trace_inited, ossl_trace_init))
         return 0;

     curr_channel = trace_channels[category].bio;
     curr_prefix = trace_channels[category].prefix;
     curr_suffix = trace_channels[category].suffix;

     /* Make sure to run the detach callback first on all data */
     if (prefix != NULL && curr_prefix != NULL) {
         detach_cb(category, PREFIX, curr_prefix);
     }

     if (suffix != NULL && curr_suffix != NULL) {
         detach_cb(category, SUFFIX, curr_suffix);
     }

     if (channel != NULL && curr_channel != NULL) {
         detach_cb(category, CHANNEL, curr_channel);
     }

     /* After detach callbacks are done, clear data where appropriate */
     if (prefix != NULL && curr_prefix != NULL) {
         OPENSSL_free(curr_prefix);
         trace_channels[category].prefix = NULL;
     }

     if (suffix != NULL && curr_suffix != NULL) {
         OPENSSL_free(curr_suffix);
         trace_channels[category].suffix = NULL;
     }

     if (channel != NULL && curr_channel != NULL) {
         BIO_free(curr_channel);
         trace_channels[category].type = 0;
         trace_channels[category].bio = NULL;
     }

     /* Before running callbacks are done, set new data where appropriate */
     if (channel != NULL && *channel != NULL) {
         trace_channels[category].type = type;
         trace_channels[category].bio = *channel;
     }

     if (prefix != NULL && *prefix != NULL) {
         if ((curr_prefix = OPENSSL_strdup(*prefix)) == NULL)
             return 0;
         trace_channels[category].prefix = curr_prefix;
     }

     if (suffix != NULL && *suffix != NULL) {
         if ((curr_suffix = OPENSSL_strdup(*suffix)) == NULL)
             return 0;
         trace_channels[category].suffix = curr_suffix;
     }

     /* Finally, run the attach callback on the new data */
     if (channel != NULL && *channel != NULL) {
         attach_cb(category, CHANNEL, *channel);
     }

     if (prefix != NULL && *prefix != NULL) {
         attach_cb(category, PREFIX, *prefix);
     }

     if (suffix != NULL && *suffix != NULL) {
         attach_cb(category, SUFFIX, *suffix);
     }

     return 1;
 }

 static int do_ossl_trace_init(void)
 {
     trace_lock = CRYPTO_THREAD_lock_new();
     return trace_lock != NULL;
 }

 #endif

 void ossl_trace_cleanup(void)
 {
 #ifndef OPENSSL_NO_TRACE
     int category;
     BIO *channel = NULL;
     const char *prefix = NULL;
     const char *suffix = NULL;

     for (category = 0; category < OSSL_TRACE_CATEGORY_NUM; category++) {
         /* We force the TRACE category to be treated last */
         if (category == OSSL_TRACE_CATEGORY_TRACE)
             continue;
         set_trace_data(category, 0, &channel, &prefix, &suffix,
                        trace_attach_cb, trace_detach_cb);
     }
     set_trace_data(OSSL_TRACE_CATEGORY_TRACE, 0, &channel,
                    &prefix, &suffix,
                    trace_attach_cb, trace_detach_cb);
     CRYPTO_THREAD_lock_free(trace_lock);
 #endif
 }

 int OSSL_trace_set_channel(int category, BIO *channel)
 {
 #ifndef OPENSSL_NO_TRACE
     if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
         return set_trace_data(category, SIMPLE_CHANNEL, &channel, NULL, NULL,
                               trace_attach_cb, trace_detach_cb);
 #endif
     return 0;
 }

 #ifndef OPENSSL_NO_TRACE
 static int trace_attach_w_callback_cb(int category, int type, const void *data)
 {
     switch (type) {
     case CHANNEL:
         OSSL_TRACE2(TRACE,
                     "Attach channel %p to category '%s' (with callback)\n",
                     data, trace_categories[category].name);
         break;
     case PREFIX:
         OSSL_TRACE2(TRACE, "Attach prefix \"%s\" to category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     case SUFFIX:
         OSSL_TRACE2(TRACE, "Attach suffix \"%s\" to category '%s'\n",
                     (const char *)data, trace_categories[category].name);
         break;
     default:                     /* No clue */
         break;
     }
     return 1;
 }
 #endif

 int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data)
 {
 #ifndef OPENSSL_NO_TRACE
     BIO *channel = NULL;
     struct trace_data_st *trace_data = NULL;

     if (category < 0 || category >= OSSL_TRACE_CATEGORY_NUM)
         return 0;

     if (callback != NULL) {
         if ((channel = BIO_new(&trace_method)) == NULL
             || (trace_data =
                 OPENSSL_zalloc(sizeof(struct trace_data_st))) == NULL)
             goto err;

         trace_data->callback = callback;
         trace_data->category = category;
         trace_data->data = data;

         BIO_set_data(channel, trace_data);
     }

     if (!set_trace_data(category, CALLBACK_CHANNEL, &channel, NULL, NULL,
                         trace_attach_w_callback_cb, trace_detach_cb))
         goto err;

     return 1;

  err:
     BIO_free(channel);
     OPENSSL_free(trace_data);
 #endif

     return 0;
 }

 int OSSL_trace_set_prefix(int category, const char *prefix)
 {
 #ifndef OPENSSL_NO_TRACE
     if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
         return set_trace_data(category, 0, NULL, &prefix, NULL,
                               trace_attach_cb, trace_detach_cb);
 #endif
     return 0;
 }

 int OSSL_trace_set_suffix(int category, const char *suffix)
 {
 #ifndef OPENSSL_NO_TRACE
     if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
         return set_trace_data(category, 0, NULL, NULL, &suffix,
                               trace_attach_cb, trace_detach_cb);
 #endif
     return 0;
 }

 #ifndef OPENSSL_NO_TRACE
 static int ossl_trace_get_category(int category)
 {
     if (category < 0 || category >= OSSL_TRACE_CATEGORY_NUM)
         return -1;
     if (trace_channels[category].bio != NULL)
         return category;
     return OSSL_TRACE_CATEGORY_ALL;
 }
 #endif

 int OSSL_trace_enabled(int category)
 {
     int ret = 0;
 #ifndef OPENSSL_NO_TRACE
     category = ossl_trace_get_category(category);
     if (category >= 0)
         ret = trace_channels[category].bio != NULL;
 #endif
     return ret;
 }

 BIO *OSSL_trace_begin(int category)
 {
     BIO *channel = NULL;
 #ifndef OPENSSL_NO_TRACE
     char *prefix = NULL;

     category = ossl_trace_get_category(category);
     if (category < 0)
         return NULL;

     channel = trace_channels[category].bio;
     prefix = trace_channels[category].prefix;

     if (channel != NULL) {
         if (!CRYPTO_THREAD_write_lock(trace_lock))
             return NULL;
         current_channel = channel;
         switch (trace_channels[category].type) {
         case SIMPLE_CHANNEL:
             if (prefix != NULL) {
                 (void)BIO_puts(channel, prefix);
                 (void)BIO_puts(channel, "\n");
             }
             break;
         case CALLBACK_CHANNEL:
             (void)BIO_ctrl(channel, OSSL_TRACE_CTRL_BEGIN,
                            prefix == NULL ? 0 : strlen(prefix), prefix);
             break;
         }
     }
 #endif
     return channel;
 }

 void OSSL_trace_end(int category, BIO * channel)
 {
 #ifndef OPENSSL_NO_TRACE
     char *suffix = NULL;

     category = ossl_trace_get_category(category);
     if (category < 0)
         return;
     suffix = trace_channels[category].suffix;
     if (channel != NULL
         && ossl_assert(channel == current_channel)) {
         (void)BIO_flush(channel);
         switch (trace_channels[category].type) {
         case SIMPLE_CHANNEL:
             if (suffix != NULL) {
                 (void)BIO_puts(channel, suffix);
                 (void)BIO_puts(channel, "\n");
             }
             break;
         case CALLBACK_CHANNEL:
             (void)BIO_ctrl(channel, OSSL_TRACE_CTRL_END,
                            suffix == NULL ? 0 : strlen(suffix), suffix);
             break;
         }
         current_channel = NULL;
         CRYPTO_THREAD_unlock(trace_lock);
     }
 #endif
 }
	/*
	* Copyright 2019-2021 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 <stdio.h>
	#include <string.h>

	#include "internal/thread_once.h"
	#include <openssl/bio.h>
	#include <openssl/crypto.h>
	#include <openssl/trace.h>
	#include "internal/bio.h"
	#include "internal/nelem.h"
	#include "internal/refcount.h"
	#include "crypto/cryptlib.h"

	#include "internal/e_os.h" /* strcasecmp for Windows */

	#ifndef OPENSSL_NO_TRACE

	static CRYPTO_RWLOCK *trace_lock = NULL;

	static const BIO *current_channel = NULL;

	/*-
	* INTERNAL TRACE CHANNEL IMPLEMENTATION
	*
	* For our own flexibility, all trace categories are associated with a
	* BIO sink object, also called the trace channel. Instead of a BIO object,
	* the application can also provide a callback function, in which case an
	* internal trace channel is attached, which simply calls the registered
	* callback function.
	*/
	static int trace_write(BIO b, const char buf,
	size_t num, size_t *written);
	static int trace_puts(BIO b, const char str);
	static long trace_ctrl(BIO channel, int cmd, long argl, void argp);
	static int trace_free(BIO *b);

	static const BIO_METHOD trace_method = {
	BIO_TYPE_SOURCE_SINK,
	"trace",
	trace_write,
	NULL, /* old write */
	NULL, /* read_ex */
	NULL, /* read */
	trace_puts,
	NULL, /* gets */
	trace_ctrl, /* ctrl */
	NULL, /* create */
	trace_free, /* free */
	NULL, /* callback_ctrl */
	};

	struct trace_data_st {
	OSSL_trace_cb callback;
	int category;
	void *data;
	};

	static int trace_write(BIO *channel,
	const char buf, size_t num, size_t written)
	{
	struct trace_data_st *ctx = BIO_get_data(channel);
	size_t cnt = ctx->callback(buf, num, ctx->category, OSSL_TRACE_CTRL_WRITE,
	ctx->data);

	*written = cnt;
	return cnt != 0;
	}

	static int trace_puts(BIO channel, const char str)
	{
	size_t written;

	if (trace_write(channel, str, strlen(str), &written))
	return (int)written;

	return EOF;
	}

	static long trace_ctrl(BIO channel, int cmd, long argl, void argp)
	{
	struct trace_data_st *ctx = BIO_get_data(channel);

	switch (cmd) {
	case OSSL_TRACE_CTRL_BEGIN:
	case OSSL_TRACE_CTRL_END:
	/* We know that the callback is likely to return 0 here */
	ctx->callback("", 0, ctx->category, cmd, ctx->data);
	return 1;
	default:
	break;
	}
	return -2; /* Unsupported */
	}

	static int trace_free(BIO *channel)
	{
	if (channel == NULL)
	return 0;
	OPENSSL_free(BIO_get_data(channel));
	return 1;
	}
	#endif

	/*-
	* TRACE
	*/

	/* Helper struct and macro to get name string to number mapping */
	struct trace_category_st {
	const char * const name;
	const int num;
	};
	#define TRACE_CATEGORY_(name) { #name, OSSL_TRACE_CATEGORY_##name }

	static const struct trace_category_st trace_categories[] = {
	TRACE_CATEGORY_(ALL),
	TRACE_CATEGORY_(TRACE),
	TRACE_CATEGORY_(INIT),
	TRACE_CATEGORY_(TLS),
	TRACE_CATEGORY_(TLS_CIPHER),
	TRACE_CATEGORY_(CONF),
	#ifndef OPENSSL_NO_ENGINE
	TRACE_CATEGORY_(ENGINE_TABLE),
	TRACE_CATEGORY_(ENGINE_REF_COUNT),
	#endif
	TRACE_CATEGORY_(PKCS5V2),
	TRACE_CATEGORY_(PKCS12_KEYGEN),
	TRACE_CATEGORY_(PKCS12_DECRYPT),
	TRACE_CATEGORY_(X509V3_POLICY),
	TRACE_CATEGORY_(BN_CTX),
	TRACE_CATEGORY_(CMP),
	TRACE_CATEGORY_(STORE),
	TRACE_CATEGORY_(DECODER),
	TRACE_CATEGORY_(ENCODER),
	TRACE_CATEGORY_(REF_COUNT)
	};

	const char *OSSL_trace_get_category_name(int num)
	{
	size_t i;

	for (i = 0; i < OSSL_NELEM(trace_categories); i++)
	if (trace_categories[i].num == num)
	return trace_categories[i].name;
	return NULL; /* not found */
	}

	int OSSL_trace_get_category_num(const char *name)
	{
	size_t i;

	for (i = 0; i < OSSL_NELEM(trace_categories); i++)
	if (strcasecmp(name, trace_categories[i].name) == 0)
	return trace_categories[i].num;
	return -1; /* not found */
	}

	#ifndef OPENSSL_NO_TRACE

	/* We use one trace channel for each trace category */
	static struct {
	enum { SIMPLE_CHANNEL, CALLBACK_CHANNEL } type;
	BIO *bio;
	char *prefix;
	char *suffix;
	} trace_channels[OSSL_TRACE_CATEGORY_NUM] = {
	{ 0, NULL, NULL, NULL },
	};

	#endif

	#ifndef OPENSSL_NO_TRACE

	enum {
	CHANNEL,
	PREFIX,
	SUFFIX
	};

	static int trace_attach_cb(int category, int type, const void *data)
	{
	switch (type) {
	case CHANNEL:
	OSSL_TRACE2(TRACE, "Attach channel %p to category '%s'\n",
	data, trace_categories[category].name);
	break;
	case PREFIX:
	OSSL_TRACE2(TRACE, "Attach prefix \"%s\" to category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	case SUFFIX:
	OSSL_TRACE2(TRACE, "Attach suffix \"%s\" to category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	default: /* No clue */
	break;
	}
	return 1;
	}

	static int trace_detach_cb(int category, int type, const void *data)
	{
	switch (type) {
	case CHANNEL:
	OSSL_TRACE2(TRACE, "Detach channel %p from category '%s'\n",
	data, trace_categories[category].name);
	break;
	case PREFIX:
	OSSL_TRACE2(TRACE, "Detach prefix \"%s\" from category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	case SUFFIX:
	OSSL_TRACE2(TRACE, "Detach suffix \"%s\" from category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	default: /* No clue */
	break;
	}
	return 1;
	}

	static int do_ossl_trace_init(void);
	static CRYPTO_ONCE trace_inited = CRYPTO_ONCE_STATIC_INIT;
	DEFINE_RUN_ONCE_STATIC(ossl_trace_init)
	{
	return do_ossl_trace_init();
	}

	static int set_trace_data(int category, int type, BIO **channel,
	const char prefix, const char suffix,
	int (attach_cb)(int, int, const void ),
	int (detach_cb)(int, int, const void ))
	{
	BIO *curr_channel = NULL;
	char *curr_prefix = NULL;
	char *curr_suffix = NULL;

	/* Ensure do_ossl_trace_init() is called once */
	if (!RUN_ONCE(&trace_inited, ossl_trace_init))
	return 0;

	curr_channel = trace_channels[category].bio;
	curr_prefix = trace_channels[category].prefix;
	curr_suffix = trace_channels[category].suffix;

	/* Make sure to run the detach callback first on all data */
	if (prefix != NULL && curr_prefix != NULL) {
	detach_cb(category, PREFIX, curr_prefix);
	}

	if (suffix != NULL && curr_suffix != NULL) {
	detach_cb(category, SUFFIX, curr_suffix);
	}

	if (channel != NULL && curr_channel != NULL) {
	detach_cb(category, CHANNEL, curr_channel);
	}

	/* After detach callbacks are done, clear data where appropriate */
	if (prefix != NULL && curr_prefix != NULL) {
	OPENSSL_free(curr_prefix);
	trace_channels[category].prefix = NULL;
	}

	if (suffix != NULL && curr_suffix != NULL) {
	OPENSSL_free(curr_suffix);
	trace_channels[category].suffix = NULL;
	}

	if (channel != NULL && curr_channel != NULL) {
	BIO_free(curr_channel);
	trace_channels[category].type = 0;
	trace_channels[category].bio = NULL;
	}

	/* Before running callbacks are done, set new data where appropriate */
	if (channel != NULL && *channel != NULL) {
	trace_channels[category].type = type;
	trace_channels[category].bio = *channel;
	}

	if (prefix != NULL && *prefix != NULL) {
	if ((curr_prefix = OPENSSL_strdup(*prefix)) == NULL)
	return 0;
	trace_channels[category].prefix = curr_prefix;
	}

	if (suffix != NULL && *suffix != NULL) {
	if ((curr_suffix = OPENSSL_strdup(*suffix)) == NULL)
	return 0;
	trace_channels[category].suffix = curr_suffix;
	}

	/* Finally, run the attach callback on the new data */
	if (channel != NULL && *channel != NULL) {
	attach_cb(category, CHANNEL, *channel);
	}

	if (prefix != NULL && *prefix != NULL) {
	attach_cb(category, PREFIX, *prefix);
	}

	if (suffix != NULL && *suffix != NULL) {
	attach_cb(category, SUFFIX, *suffix);
	}

	return 1;
	}

	static int do_ossl_trace_init(void)
	{
	trace_lock = CRYPTO_THREAD_lock_new();
	return trace_lock != NULL;
	}

	#endif

	void ossl_trace_cleanup(void)
	{
	#ifndef OPENSSL_NO_TRACE
	int category;
	BIO *channel = NULL;
	const char *prefix = NULL;
	const char *suffix = NULL;

	for (category = 0; category < OSSL_TRACE_CATEGORY_NUM; category++) {
	/* We force the TRACE category to be treated last */
	if (category == OSSL_TRACE_CATEGORY_TRACE)
	continue;
	set_trace_data(category, 0, &channel, &prefix, &suffix,
	trace_attach_cb, trace_detach_cb);
	}
	set_trace_data(OSSL_TRACE_CATEGORY_TRACE, 0, &channel,
	&prefix, &suffix,
	trace_attach_cb, trace_detach_cb);
	CRYPTO_THREAD_lock_free(trace_lock);
	#endif
	}

	int OSSL_trace_set_channel(int category, BIO *channel)
	{
	#ifndef OPENSSL_NO_TRACE
	if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
	return set_trace_data(category, SIMPLE_CHANNEL, &channel, NULL, NULL,
	trace_attach_cb, trace_detach_cb);
	#endif
	return 0;
	}

	#ifndef OPENSSL_NO_TRACE
	static int trace_attach_w_callback_cb(int category, int type, const void *data)
	{
	switch (type) {
	case CHANNEL:
	OSSL_TRACE2(TRACE,
	"Attach channel %p to category '%s' (with callback)\n",
	data, trace_categories[category].name);
	break;
	case PREFIX:
	OSSL_TRACE2(TRACE, "Attach prefix \"%s\" to category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	case SUFFIX:
	OSSL_TRACE2(TRACE, "Attach suffix \"%s\" to category '%s'\n",
	(const char *)data, trace_categories[category].name);
	break;
	default: /* No clue */
	break;
	}
	return 1;
	}
	#endif

	int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data)
	{
	#ifndef OPENSSL_NO_TRACE
	BIO *channel = NULL;
	struct trace_data_st *trace_data = NULL;

	if (category < 0 \|\| category >= OSSL_TRACE_CATEGORY_NUM)
	return 0;

	if (callback != NULL) {
	if ((channel = BIO_new(&trace_method)) == NULL
	\|\| (trace_data =
	OPENSSL_zalloc(sizeof(struct trace_data_st))) == NULL)
	goto err;

	trace_data->callback = callback;
	trace_data->category = category;
	trace_data->data = data;

	BIO_set_data(channel, trace_data);
	}

	if (!set_trace_data(category, CALLBACK_CHANNEL, &channel, NULL, NULL,
	trace_attach_w_callback_cb, trace_detach_cb))
	goto err;

	return 1;

	err:
	BIO_free(channel);
	OPENSSL_free(trace_data);
	#endif

	return 0;
	}

	int OSSL_trace_set_prefix(int category, const char *prefix)
	{
	#ifndef OPENSSL_NO_TRACE
	if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
	return set_trace_data(category, 0, NULL, &prefix, NULL,
	trace_attach_cb, trace_detach_cb);
	#endif
	return 0;
	}

	int OSSL_trace_set_suffix(int category, const char *suffix)
	{
	#ifndef OPENSSL_NO_TRACE
	if (category >= 0 && category < OSSL_TRACE_CATEGORY_NUM)
	return set_trace_data(category, 0, NULL, NULL, &suffix,
	trace_attach_cb, trace_detach_cb);
	#endif
	return 0;
	}

	#ifndef OPENSSL_NO_TRACE
	static int ossl_trace_get_category(int category)
	{
	if (category < 0 \|\| category >= OSSL_TRACE_CATEGORY_NUM)
	return -1;
	if (trace_channels[category].bio != NULL)
	return category;
	return OSSL_TRACE_CATEGORY_ALL;
	}
	#endif

	int OSSL_trace_enabled(int category)
	{
	int ret = 0;
	#ifndef OPENSSL_NO_TRACE
	category = ossl_trace_get_category(category);
	if (category >= 0)
	ret = trace_channels[category].bio != NULL;
	#endif
	return ret;
	}

	BIO *OSSL_trace_begin(int category)
	{
	BIO *channel = NULL;
	#ifndef OPENSSL_NO_TRACE
	char *prefix = NULL;

	category = ossl_trace_get_category(category);
	if (category < 0)
	return NULL;

	channel = trace_channels[category].bio;
	prefix = trace_channels[category].prefix;

	if (channel != NULL) {
	if (!CRYPTO_THREAD_write_lock(trace_lock))
	return NULL;
	current_channel = channel;
	switch (trace_channels[category].type) {
	case SIMPLE_CHANNEL:
	if (prefix != NULL) {
	(void)BIO_puts(channel, prefix);
	(void)BIO_puts(channel, "\n");
	}
	break;
	case CALLBACK_CHANNEL:
	(void)BIO_ctrl(channel, OSSL_TRACE_CTRL_BEGIN,
	prefix == NULL ? 0 : strlen(prefix), prefix);
	break;
	}
	}
	#endif
	return channel;
	}

	void OSSL_trace_end(int category, BIO * channel)
	{
	#ifndef OPENSSL_NO_TRACE
	char *suffix = NULL;

	category = ossl_trace_get_category(category);
	if (category < 0)
	return;
	suffix = trace_channels[category].suffix;
	if (channel != NULL
	&& ossl_assert(channel == current_channel)) {
	(void)BIO_flush(channel);
	switch (trace_channels[category].type) {
	case SIMPLE_CHANNEL:
	if (suffix != NULL) {
	(void)BIO_puts(channel, suffix);
	(void)BIO_puts(channel, "\n");
	}
	break;
	case CALLBACK_CHANNEL:
	(void)BIO_ctrl(channel, OSSL_TRACE_CTRL_END,
	suffix == NULL ? 0 : strlen(suffix), suffix);
	break;
	}
	current_channel = NULL;
	CRYPTO_THREAD_unlock(trace_lock);
	}
	#endif
	}