text: /* $OpenBSD: d2i_pr.c,v 1.10 2014/06/12 15:49:27 deraadt Exp $ */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  #include "cryptlib.h"
  #include <openssl/bn.h>
  #include <openssl/evp.h>
  #include <openssl/objects.h>
  #ifndef OPENSSL_NO_ENGINE
  #include <openssl/engine.h>
  #endif
  #include <openssl/x509.h>
  #include <openssl/asn1.h>
  #include "asn1_locl.h"
  
  EVP_PKEY *
  d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp, long length)
  {
  	EVP_PKEY *ret;
  
  	if ((a == NULL) || (*a == NULL)) {
  		if ((ret = EVP_PKEY_new()) == NULL) {
  			ASN1err(ASN1_F_D2I_PRIVATEKEY, ERR_R_EVP_LIB);
  			return (NULL);
  		}
  	} else {
  		ret = *a;
  #ifndef OPENSSL_NO_ENGINE
  		if (ret->engine) {
  			ENGINE_finish(ret->engine);
  			ret->engine = NULL;
  		}
  #endif
  	}
  
  	if (!EVP_PKEY_set_type(ret, type)) {
  		ASN1err(ASN1_F_D2I_PRIVATEKEY, ASN1_R_UNKNOWN_PUBLIC_KEY_TYPE);
  		goto err;
  	}
  
  	if (!ret->ameth->old_priv_decode ||
  	    !ret->ameth->old_priv_decode(ret, pp, length)) {
  		if (ret->ameth->priv_decode) {
  			PKCS8_PRIV_KEY_INFO *p8 = NULL;
  			p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, pp, length);
  			if (!p8)
  				goto err;
  			EVP_PKEY_free(ret);
  			ret = EVP_PKCS82PKEY(p8);
  			PKCS8_PRIV_KEY_INFO_free(p8);
  		} else {
  			ASN1err(ASN1_F_D2I_PRIVATEKEY, ERR_R_ASN1_LIB);
  			goto err;
  		}
  	}
  	if (a != NULL)
  		(*a) = ret;
  	return (ret);
  
  err:
  	if ((ret != NULL) && ((a == NULL) || (*a != ret)))
  		EVP_PKEY_free(ret);
  	return (NULL);
  }
  
  /* This works like d2i_PrivateKey() except it automatically works out the type */
  
  EVP_PKEY *
  d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp, long length)
  {
  	STACK_OF(ASN1_TYPE) *inkey;
  	const unsigned char *p;
  	int keytype;
  
  	p = *pp;
  	/* Dirty trick: read in the ASN1 data into a STACK_OF(ASN1_TYPE):
  	 * by analyzing it we can determine the passed structure: this
  	 * assumes the input is surrounded by an ASN1 SEQUENCE.
  	 */
  	inkey = d2i_ASN1_SEQUENCE_ANY(NULL, &p, length);
  	/* Since we only need to discern "traditional format" RSA and DSA
  	 * keys we can just count the elements.
           */
  	if (sk_ASN1_TYPE_num(inkey) == 6)
  		keytype = EVP_PKEY_DSA;
  	else if (sk_ASN1_TYPE_num(inkey) == 4)
  		keytype = EVP_PKEY_EC;
  	else if (sk_ASN1_TYPE_num(inkey) == 3)  {
  		/* This seems to be PKCS8, not traditional format */
  		PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(
  		    NULL, pp, length);
  		EVP_PKEY *ret;
  
  		sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
  		if (!p8) {
  			ASN1err(ASN1_F_D2I_AUTOPRIVATEKEY,
  			    ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
  			return NULL;
  		}
  		ret = EVP_PKCS82PKEY(p8);
  		PKCS8_PRIV_KEY_INFO_free(p8);
  		if (a) {
  			*a = ret;
  		}
  		return ret;
  	} else
  		keytype = EVP_PKEY_RSA;
  	sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
  	return d2i_PrivateKey(keytype, a, pp, length);
  }
  