pem_seal.c

/* crypto/pem/pem_seal.c */
/* 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 <openssl/opensslconf.h>	/* for OPENSSL_NO_RSA */
#ifndef OPENSSL_NO_RSA
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/rsa.h>

int PEM_SealInit(PEM_ENCODE_SEAL_CTX *ctx, EVP_CIPHER *type, EVP_MD *md_type,
	     unsigned char **ek, int *ekl, unsigned char *iv, EVP_PKEY **pubk,
	     int npubk)
	{
	unsigned char key[EVP_MAX_KEY_LENGTH];
	int ret= -1;
	int i,j,max=0;
	char *s=NULL;

	for (i=0; i<npubk; i++)
		{
		if (pubk[i]->type != EVP_PKEY_RSA)
			{
			PEMerr(PEM_F_PEM_SEALINIT,PEM_R_PUBLIC_KEY_NO_RSA);
			goto err;
			}
		j=RSA_size(pubk[i]->pkey.rsa);
		if (j > max) max=j;
		}
	s=(char *)OPENSSL_malloc(max*2);
	if (s == NULL)
		{
		PEMerr(PEM_F_PEM_SEALINIT,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	EVP_EncodeInit(&ctx->encode);

	EVP_MD_CTX_init(&ctx->md);
	if (!EVP_SignInit(&ctx->md,md_type))
		goto err;

	EVP_CIPHER_CTX_init(&ctx->cipher);
	ret=EVP_SealInit(&ctx->cipher,type,ek,ekl,iv,pubk,npubk);
	if (ret <= 0) goto err;

	/* base64 encode the keys */
	for (i=0; i<npubk; i++)
		{
		j=EVP_EncodeBlock((unsigned char *)s,ek[i],
			RSA_size(pubk[i]->pkey.rsa));
		ekl[i]=j;
		memcpy(ek[i],s,j+1);
		}

	ret=npubk;
err:
	if (s != NULL) OPENSSL_free(s);
	OPENSSL_cleanse(key,EVP_MAX_KEY_LENGTH);
	return(ret);
	}

void PEM_SealUpdate(PEM_ENCODE_SEAL_CTX *ctx, unsigned char *out, int *outl,
	     unsigned char *in, int inl)
	{
	unsigned char buffer[1600];
	int i,j;

	*outl=0;
	EVP_SignUpdate(&ctx->md,in,inl);
	for (;;)
		{
		if (inl <= 0) break;
		if (inl > 1200)
			i=1200;
		else
			i=inl;
		EVP_EncryptUpdate(&ctx->cipher,buffer,&j,in,i);
		EVP_EncodeUpdate(&ctx->encode,out,&j,buffer,j);
		*outl+=j;
		out+=j;
		in+=i;
		inl-=i;
		}
	}

int PEM_SealFinal(PEM_ENCODE_SEAL_CTX *ctx, unsigned char *sig, int *sigl,
	     unsigned char *out, int *outl, EVP_PKEY *priv)
	{
	unsigned char *s=NULL;
	int ret=0,j;
	unsigned int i;

	if (priv->type != EVP_PKEY_RSA)
		{
		PEMerr(PEM_F_PEM_SEALFINAL,PEM_R_PUBLIC_KEY_NO_RSA);
		goto err;
		}
	i=RSA_size(priv->pkey.rsa);
	if (i < 100) i=100;
	s=(unsigned char *)OPENSSL_malloc(i*2);
	if (s == NULL)
		{
		PEMerr(PEM_F_PEM_SEALFINAL,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	if (!EVP_EncryptFinal_ex(&ctx->cipher,s,(int *)&i))
		goto err;
	EVP_EncodeUpdate(&ctx->encode,out,&j,s,i);
	*outl=j;
	out+=j;
	EVP_EncodeFinal(&ctx->encode,out,&j);
	*outl+=j;

	if (!EVP_SignFinal(&ctx->md,s,&i,priv)) goto err;
	*sigl=EVP_EncodeBlock(sig,s,i);

	ret=1;
err:
	EVP_MD_CTX_cleanup(&ctx->md);
	EVP_CIPHER_CTX_cleanup(&ctx->cipher);
	if (s != NULL) OPENSSL_free(s);
	return(ret);
	}
#else /* !OPENSSL_NO_RSA */

# if PEDANTIC
static void *dummy=&dummy;
# endif

#endif