crypto/asn1/bio_asn1.c - third_party/openssl - Git at Google

 /*
  * Copyright 2006-2018 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
  */

 /*
  * Experimental ASN1 BIO. When written through the data is converted to an
  * ASN1 string type: default is OCTET STRING. Additional functions can be
  * provided to add prefix and suffix data.
  */

 #include <string.h>
 #include "internal/bio.h"
 #include <openssl/asn1.h>
 #include "internal/cryptlib.h"

 /* Must be large enough for biggest tag+length */
 #define DEFAULT_ASN1_BUF_SIZE 20

 typedef enum {
     ASN1_STATE_START,
     ASN1_STATE_PRE_COPY,
     ASN1_STATE_HEADER,
     ASN1_STATE_HEADER_COPY,
     ASN1_STATE_DATA_COPY,
     ASN1_STATE_POST_COPY,
     ASN1_STATE_DONE
 } asn1_bio_state_t;

 typedef struct BIO_ASN1_EX_FUNCS_st {
     asn1_ps_func *ex_func;
     asn1_ps_func *ex_free_func;
 } BIO_ASN1_EX_FUNCS;

 typedef struct BIO_ASN1_BUF_CTX_t {
     /* Internal state */
     asn1_bio_state_t state;
     /* Internal buffer */
     unsigned char *buf;
     /* Size of buffer */
     int bufsize;
     /* Current position in buffer */
     int bufpos;
     /* Current buffer length */
     int buflen;
     /* Amount of data to copy */
     int copylen;
     /* Class and tag to use */
     int asn1_class, asn1_tag;
     asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;
     /* Extra buffer for prefix and suffix data */
     unsigned char *ex_buf;
     int ex_len;
     int ex_pos;
     void *ex_arg;
 } BIO_ASN1_BUF_CTX;

 static int asn1_bio_write(BIO *h, const char *buf, int num);
 static int asn1_bio_read(BIO *h, char *buf, int size);
 static int asn1_bio_puts(BIO *h, const char *str);
 static int asn1_bio_gets(BIO *h, char *str, int size);
 static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);
 static int asn1_bio_new(BIO *h);
 static int asn1_bio_free(BIO *data);
 static long asn1_bio_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);

 static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
 static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
                              asn1_ps_func *cleanup, asn1_bio_state_t next);
 static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
                              asn1_ps_func *setup,
                              asn1_bio_state_t ex_state,
                              asn1_bio_state_t other_state);

 static const BIO_METHOD methods_asn1 = {
     BIO_TYPE_ASN1,
     "asn1",
     /* TODO: Convert to new style write function */
     bwrite_conv,
     asn1_bio_write,
     /* TODO: Convert to new style read function */
     bread_conv,
     asn1_bio_read,
     asn1_bio_puts,
     asn1_bio_gets,
     asn1_bio_ctrl,
     asn1_bio_new,
     asn1_bio_free,
     asn1_bio_callback_ctrl,
 };

 const BIO_METHOD *BIO_f_asn1(void)
 {
     return &methods_asn1;
 }

 static int asn1_bio_new(BIO *b)
 {
     BIO_ASN1_BUF_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));

     if (ctx == NULL)
         return 0;
     if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
         OPENSSL_free(ctx);
         return 0;
     }
     BIO_set_data(b, ctx);
     BIO_set_init(b, 1);

     return 1;
 }

 static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
 {
     if ((ctx->buf = OPENSSL_malloc(size)) == NULL) {
         ASN1err(ASN1_F_ASN1_BIO_INIT, ERR_R_MALLOC_FAILURE);
         return 0;
     }
     ctx->bufsize = size;
     ctx->asn1_class = V_ASN1_UNIVERSAL;
     ctx->asn1_tag = V_ASN1_OCTET_STRING;
     ctx->state = ASN1_STATE_START;
     return 1;
 }

 static int asn1_bio_free(BIO *b)
 {
     BIO_ASN1_BUF_CTX *ctx;

     if (b == NULL)
         return 0;

     ctx = BIO_get_data(b);
     if (ctx == NULL)
         return 0;

     OPENSSL_free(ctx->buf);
     OPENSSL_free(ctx);
     BIO_set_data(b, NULL);
     BIO_set_init(b, 0);

     return 1;
 }

 static int asn1_bio_write(BIO *b, const char *in, int inl)
 {
     BIO_ASN1_BUF_CTX *ctx;
     int wrmax, wrlen, ret;
     unsigned char *p;
     BIO *next;

     ctx = BIO_get_data(b);
     next = BIO_next(b);
     if (in == NULL || inl < 0 || ctx == NULL || next == NULL)
         return 0;

     wrlen = 0;
     ret = -1;

     for (;;) {
         switch (ctx->state) {
             /* Setup prefix data, call it */
         case ASN1_STATE_START:
             if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
                                    ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
                 return 0;
             break;

             /* Copy any pre data first */
         case ASN1_STATE_PRE_COPY:

             ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
                                     ASN1_STATE_HEADER);

             if (ret <= 0)
                 goto done;

             break;

         case ASN1_STATE_HEADER:
             ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
             if (!ossl_assert(ctx->buflen <= ctx->bufsize))
                 return 0;
             p = ctx->buf;
             ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);
             ctx->copylen = inl;
             ctx->state = ASN1_STATE_HEADER_COPY;

             break;

         case ASN1_STATE_HEADER_COPY:
             ret = BIO_write(next, ctx->buf + ctx->bufpos, ctx->buflen);
             if (ret <= 0)
                 goto done;

             ctx->buflen -= ret;
             if (ctx->buflen)
                 ctx->bufpos += ret;
             else {
                 ctx->bufpos = 0;
                 ctx->state = ASN1_STATE_DATA_COPY;
             }

             break;

         case ASN1_STATE_DATA_COPY:

             if (inl > ctx->copylen)
                 wrmax = ctx->copylen;
             else
                 wrmax = inl;
             ret = BIO_write(next, in, wrmax);
             if (ret <= 0)
                 goto done;
             wrlen += ret;
             ctx->copylen -= ret;
             in += ret;
             inl -= ret;

             if (ctx->copylen == 0)
                 ctx->state = ASN1_STATE_HEADER;

             if (inl == 0)
                 goto done;

             break;

         case ASN1_STATE_POST_COPY:
         case ASN1_STATE_DONE:
             BIO_clear_retry_flags(b);
             return 0;

         }

     }

  done:
     BIO_clear_retry_flags(b);
     BIO_copy_next_retry(b);

     return (wrlen > 0) ? wrlen : ret;

 }

 static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
                              asn1_ps_func *cleanup, asn1_bio_state_t next)
 {
     int ret;

     if (ctx->ex_len <= 0)
         return 1;
     for (;;) {
         ret = BIO_write(BIO_next(b), ctx->ex_buf + ctx->ex_pos, ctx->ex_len);
         if (ret <= 0)
             break;
         ctx->ex_len -= ret;
         if (ctx->ex_len > 0)
             ctx->ex_pos += ret;
         else {
             if (cleanup)
                 cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
             ctx->state = next;
             ctx->ex_pos = 0;
             break;
         }
     }
     return ret;
 }

 static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
                              asn1_ps_func *setup,
                              asn1_bio_state_t ex_state,
                              asn1_bio_state_t other_state)
 {
     if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
         BIO_clear_retry_flags(b);
         return 0;
     }
     if (ctx->ex_len > 0)
         ctx->state = ex_state;
     else
         ctx->state = other_state;
     return 1;
 }

 static int asn1_bio_read(BIO *b, char *in, int inl)
 {
     BIO *next = BIO_next(b);
     if (next == NULL)
         return 0;
     return BIO_read(next, in, inl);
 }

 static int asn1_bio_puts(BIO *b, const char *str)
 {
     return asn1_bio_write(b, str, strlen(str));
 }

 static int asn1_bio_gets(BIO *b, char *str, int size)
 {
     BIO *next = BIO_next(b);
     if (next == NULL)
         return 0;
     return BIO_gets(next, str, size);
 }

 static long asn1_bio_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 {
     BIO *next = BIO_next(b);
     if (next == NULL)
         return 0;
     return BIO_callback_ctrl(next, cmd, fp);
 }

 static long asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)
 {
     BIO_ASN1_BUF_CTX *ctx;
     BIO_ASN1_EX_FUNCS *ex_func;
     long ret = 1;
     BIO *next;

     ctx = BIO_get_data(b);
     if (ctx == NULL)
         return 0;
     next = BIO_next(b);
     switch (cmd) {

     case BIO_C_SET_PREFIX:
         ex_func = arg2;
         ctx->prefix = ex_func->ex_func;
         ctx->prefix_free = ex_func->ex_free_func;
         break;

     case BIO_C_GET_PREFIX:
         ex_func = arg2;
         ex_func->ex_func = ctx->prefix;
         ex_func->ex_free_func = ctx->prefix_free;
         break;

     case BIO_C_SET_SUFFIX:
         ex_func = arg2;
         ctx->suffix = ex_func->ex_func;
         ctx->suffix_free = ex_func->ex_free_func;
         break;

     case BIO_C_GET_SUFFIX:
         ex_func = arg2;
         ex_func->ex_func = ctx->suffix;
         ex_func->ex_free_func = ctx->suffix_free;
         break;

     case BIO_C_SET_EX_ARG:
         ctx->ex_arg = arg2;
         break;

     case BIO_C_GET_EX_ARG:
         *(void **)arg2 = ctx->ex_arg;
         break;

     case BIO_CTRL_FLUSH:
         if (next == NULL)
             return 0;

         /* Call post function if possible */
         if (ctx->state == ASN1_STATE_HEADER) {
             if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
                                    ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
                 return 0;
         }

         if (ctx->state == ASN1_STATE_POST_COPY) {
             ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
                                     ASN1_STATE_DONE);
             if (ret <= 0)
                 return ret;
         }

         if (ctx->state == ASN1_STATE_DONE)
             return BIO_ctrl(next, cmd, arg1, arg2);
         else {
             BIO_clear_retry_flags(b);
             return 0;
         }

     default:
         if (next == NULL)
             return 0;
         return BIO_ctrl(next, cmd, arg1, arg2);

     }

     return ret;
 }

 static int asn1_bio_set_ex(BIO *b, int cmd,
                            asn1_ps_func *ex_func, asn1_ps_func *ex_free_func)
 {
     BIO_ASN1_EX_FUNCS extmp;
     extmp.ex_func = ex_func;
     extmp.ex_free_func = ex_free_func;
     return BIO_ctrl(b, cmd, 0, &extmp);
 }

 static int asn1_bio_get_ex(BIO *b, int cmd,
                            asn1_ps_func **ex_func,
                            asn1_ps_func **ex_free_func)
 {
     BIO_ASN1_EX_FUNCS extmp;
     int ret;
     ret = BIO_ctrl(b, cmd, 0, &extmp);
     if (ret > 0) {
         *ex_func = extmp.ex_func;
         *ex_free_func = extmp.ex_free_func;
     }
     return ret;
 }

 int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix,
                         asn1_ps_func *prefix_free)
 {
     return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
 }

 int BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix,
                         asn1_ps_func **pprefix_free)
 {
     return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
 }

 int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix,
                         asn1_ps_func *suffix_free)
 {
     return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
 }

 int BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix,
                         asn1_ps_func **psuffix_free)
 {
     return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
 }
	/*
	* Copyright 2006-2018 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
	*/

	/*
	* Experimental ASN1 BIO. When written through the data is converted to an
	* ASN1 string type: default is OCTET STRING. Additional functions can be
	* provided to add prefix and suffix data.
	*/

	#include <string.h>
	#include "internal/bio.h"
	#include <openssl/asn1.h>
	#include "internal/cryptlib.h"

	/* Must be large enough for biggest tag+length */
	#define DEFAULT_ASN1_BUF_SIZE 20

	typedef enum {
	ASN1_STATE_START,
	ASN1_STATE_PRE_COPY,
	ASN1_STATE_HEADER,
	ASN1_STATE_HEADER_COPY,
	ASN1_STATE_DATA_COPY,
	ASN1_STATE_POST_COPY,
	ASN1_STATE_DONE
	} asn1_bio_state_t;

	typedef struct BIO_ASN1_EX_FUNCS_st {
	asn1_ps_func *ex_func;
	asn1_ps_func *ex_free_func;
	} BIO_ASN1_EX_FUNCS;

	typedef struct BIO_ASN1_BUF_CTX_t {
	/* Internal state */
	asn1_bio_state_t state;
	/* Internal buffer */
	unsigned char *buf;
	/* Size of buffer */
	int bufsize;
	/* Current position in buffer */
	int bufpos;
	/* Current buffer length */
	int buflen;
	/* Amount of data to copy */
	int copylen;
	/* Class and tag to use */
	int asn1_class, asn1_tag;
	asn1_ps_func prefix, prefix_free, suffix, suffix_free;
	/* Extra buffer for prefix and suffix data */
	unsigned char *ex_buf;
	int ex_len;
	int ex_pos;
	void *ex_arg;
	} BIO_ASN1_BUF_CTX;

	static int asn1_bio_write(BIO h, const char buf, int num);
	static int asn1_bio_read(BIO h, char buf, int size);
	static int asn1_bio_puts(BIO h, const char str);
	static int asn1_bio_gets(BIO h, char str, int size);
	static long asn1_bio_ctrl(BIO h, int cmd, long arg1, void arg2);
	static int asn1_bio_new(BIO *h);
	static int asn1_bio_free(BIO *data);
	static long asn1_bio_callback_ctrl(BIO h, int cmd, BIO_info_cb fp);

	static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
	static int asn1_bio_flush_ex(BIO b, BIO_ASN1_BUF_CTX ctx,
	asn1_ps_func *cleanup, asn1_bio_state_t next);
	static int asn1_bio_setup_ex(BIO b, BIO_ASN1_BUF_CTX ctx,
	asn1_ps_func *setup,
	asn1_bio_state_t ex_state,
	asn1_bio_state_t other_state);

	static const BIO_METHOD methods_asn1 = {
	BIO_TYPE_ASN1,
	"asn1",
	/* TODO: Convert to new style write function */
	bwrite_conv,
	asn1_bio_write,
	/* TODO: Convert to new style read function */
	bread_conv,
	asn1_bio_read,
	asn1_bio_puts,
	asn1_bio_gets,
	asn1_bio_ctrl,
	asn1_bio_new,
	asn1_bio_free,
	asn1_bio_callback_ctrl,
	};

	const BIO_METHOD *BIO_f_asn1(void)
	{
	return &methods_asn1;
	}

	static int asn1_bio_new(BIO *b)
	{
	BIO_ASN1_BUF_CTX ctx = OPENSSL_zalloc(sizeof(ctx));

	if (ctx == NULL)
	return 0;
	if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
	OPENSSL_free(ctx);
	return 0;
	}
	BIO_set_data(b, ctx);
	BIO_set_init(b, 1);

	return 1;
	}

	static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
	{
	if ((ctx->buf = OPENSSL_malloc(size)) == NULL) {
	ASN1err(ASN1_F_ASN1_BIO_INIT, ERR_R_MALLOC_FAILURE);
	return 0;
	}
	ctx->bufsize = size;
	ctx->asn1_class = V_ASN1_UNIVERSAL;
	ctx->asn1_tag = V_ASN1_OCTET_STRING;
	ctx->state = ASN1_STATE_START;
	return 1;
	}

	static int asn1_bio_free(BIO *b)
	{
	BIO_ASN1_BUF_CTX *ctx;

	if (b == NULL)
	return 0;

	ctx = BIO_get_data(b);
	if (ctx == NULL)
	return 0;

	OPENSSL_free(ctx->buf);
	OPENSSL_free(ctx);
	BIO_set_data(b, NULL);
	BIO_set_init(b, 0);

	return 1;
	}

	static int asn1_bio_write(BIO b, const char in, int inl)
	{
	BIO_ASN1_BUF_CTX *ctx;
	int wrmax, wrlen, ret;
	unsigned char *p;
	BIO *next;

	ctx = BIO_get_data(b);
	next = BIO_next(b);
	if (in == NULL \|\| inl < 0 \|\| ctx == NULL \|\| next == NULL)
	return 0;

	wrlen = 0;
	ret = -1;

	for (;;) {
	switch (ctx->state) {
	/* Setup prefix data, call it */
	case ASN1_STATE_START:
	if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
	ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
	return 0;
	break;

	/* Copy any pre data first */
	case ASN1_STATE_PRE_COPY:

	ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
	ASN1_STATE_HEADER);

	if (ret <= 0)
	goto done;

	break;

	case ASN1_STATE_HEADER:
	ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
	if (!ossl_assert(ctx->buflen <= ctx->bufsize))
	return 0;
	p = ctx->buf;
	ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);
	ctx->copylen = inl;
	ctx->state = ASN1_STATE_HEADER_COPY;

	break;

	case ASN1_STATE_HEADER_COPY:
	ret = BIO_write(next, ctx->buf + ctx->bufpos, ctx->buflen);
	if (ret <= 0)
	goto done;

	ctx->buflen -= ret;
	if (ctx->buflen)
	ctx->bufpos += ret;
	else {
	ctx->bufpos = 0;
	ctx->state = ASN1_STATE_DATA_COPY;
	}

	break;

	case ASN1_STATE_DATA_COPY:

	if (inl > ctx->copylen)
	wrmax = ctx->copylen;
	else
	wrmax = inl;
	ret = BIO_write(next, in, wrmax);
	if (ret <= 0)
	goto done;
	wrlen += ret;
	ctx->copylen -= ret;
	in += ret;
	inl -= ret;

	if (ctx->copylen == 0)
	ctx->state = ASN1_STATE_HEADER;

	if (inl == 0)
	goto done;

	break;

	case ASN1_STATE_POST_COPY:
	case ASN1_STATE_DONE:
	BIO_clear_retry_flags(b);
	return 0;

	}

	}

	done:
	BIO_clear_retry_flags(b);
	BIO_copy_next_retry(b);

	return (wrlen > 0) ? wrlen : ret;

	}

	static int asn1_bio_flush_ex(BIO b, BIO_ASN1_BUF_CTX ctx,
	asn1_ps_func *cleanup, asn1_bio_state_t next)
	{
	int ret;

	if (ctx->ex_len <= 0)
	return 1;
	for (;;) {
	ret = BIO_write(BIO_next(b), ctx->ex_buf + ctx->ex_pos, ctx->ex_len);
	if (ret <= 0)
	break;
	ctx->ex_len -= ret;
	if (ctx->ex_len > 0)
	ctx->ex_pos += ret;
	else {
	if (cleanup)
	cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
	ctx->state = next;
	ctx->ex_pos = 0;
	break;
	}
	}
	return ret;
	}

	static int asn1_bio_setup_ex(BIO b, BIO_ASN1_BUF_CTX ctx,
	asn1_ps_func *setup,
	asn1_bio_state_t ex_state,
	asn1_bio_state_t other_state)
	{
	if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
	BIO_clear_retry_flags(b);
	return 0;
	}
	if (ctx->ex_len > 0)
	ctx->state = ex_state;
	else
	ctx->state = other_state;
	return 1;
	}

	static int asn1_bio_read(BIO b, char in, int inl)
	{
	BIO *next = BIO_next(b);
	if (next == NULL)
	return 0;
	return BIO_read(next, in, inl);
	}

	static int asn1_bio_puts(BIO b, const char str)
	{
	return asn1_bio_write(b, str, strlen(str));
	}

	static int asn1_bio_gets(BIO b, char str, int size)
	{
	BIO *next = BIO_next(b);
	if (next == NULL)
	return 0;
	return BIO_gets(next, str, size);
	}

	static long asn1_bio_callback_ctrl(BIO b, int cmd, BIO_info_cb fp)
	{
	BIO *next = BIO_next(b);
	if (next == NULL)
	return 0;
	return BIO_callback_ctrl(next, cmd, fp);
	}

	static long asn1_bio_ctrl(BIO b, int cmd, long arg1, void arg2)
	{
	BIO_ASN1_BUF_CTX *ctx;
	BIO_ASN1_EX_FUNCS *ex_func;
	long ret = 1;
	BIO *next;

	ctx = BIO_get_data(b);
	if (ctx == NULL)
	return 0;
	next = BIO_next(b);
	switch (cmd) {

	case BIO_C_SET_PREFIX:
	ex_func = arg2;
	ctx->prefix = ex_func->ex_func;
	ctx->prefix_free = ex_func->ex_free_func;
	break;

	case BIO_C_GET_PREFIX:
	ex_func = arg2;
	ex_func->ex_func = ctx->prefix;
	ex_func->ex_free_func = ctx->prefix_free;
	break;

	case BIO_C_SET_SUFFIX:
	ex_func = arg2;
	ctx->suffix = ex_func->ex_func;
	ctx->suffix_free = ex_func->ex_free_func;
	break;

	case BIO_C_GET_SUFFIX:
	ex_func = arg2;
	ex_func->ex_func = ctx->suffix;
	ex_func->ex_free_func = ctx->suffix_free;
	break;

	case BIO_C_SET_EX_ARG:
	ctx->ex_arg = arg2;
	break;

	case BIO_C_GET_EX_ARG:
	(void *)arg2 = ctx->ex_arg;
	break;

	case BIO_CTRL_FLUSH:
	if (next == NULL)
	return 0;

	/* Call post function if possible */
	if (ctx->state == ASN1_STATE_HEADER) {
	if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
	ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
	return 0;
	}

	if (ctx->state == ASN1_STATE_POST_COPY) {
	ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
	ASN1_STATE_DONE);
	if (ret <= 0)
	return ret;
	}

	if (ctx->state == ASN1_STATE_DONE)
	return BIO_ctrl(next, cmd, arg1, arg2);
	else {
	BIO_clear_retry_flags(b);
	return 0;
	}

	default:
	if (next == NULL)
	return 0;
	return BIO_ctrl(next, cmd, arg1, arg2);

	}

	return ret;
	}

	static int asn1_bio_set_ex(BIO *b, int cmd,
	asn1_ps_func ex_func, asn1_ps_func ex_free_func)
	{
	BIO_ASN1_EX_FUNCS extmp;
	extmp.ex_func = ex_func;
	extmp.ex_free_func = ex_free_func;
	return BIO_ctrl(b, cmd, 0, &extmp);
	}

	static int asn1_bio_get_ex(BIO *b, int cmd,
	asn1_ps_func **ex_func,
	asn1_ps_func **ex_free_func)
	{
	BIO_ASN1_EX_FUNCS extmp;
	int ret;
	ret = BIO_ctrl(b, cmd, 0, &extmp);
	if (ret > 0) {
	*ex_func = extmp.ex_func;
	*ex_free_func = extmp.ex_free_func;
	}
	return ret;
	}

	int BIO_asn1_set_prefix(BIO b, asn1_ps_func prefix,
	asn1_ps_func *prefix_free)
	{
	return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
	}

	int BIO_asn1_get_prefix(BIO b, asn1_ps_func *pprefix,
	asn1_ps_func **pprefix_free)
	{
	return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
	}

	int BIO_asn1_set_suffix(BIO b, asn1_ps_func suffix,
	asn1_ps_func *suffix_free)
	{
	return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
	}

	int BIO_asn1_get_suffix(BIO b, asn1_ps_func *psuffix,
	asn1_ps_func **psuffix_free)
	{
	return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
	}