/* crypto/pkcs7/verify.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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/bio.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#include <openssl/asn1.h>

int verify_callback(int ok, X509_STORE_CTX *ctx);

BIO *bio_err=NULL;

int main(argc,argv)
int argc;
char *argv[];
	{
	char *keyfile=NULL;
	BIO *in;
	EVP_PKEY *pkey;
	X509 *x509;
	PKCS7 *p7;
	PKCS7_SIGNER_INFO *si;
	X509_STORE_CTX cert_ctx;
	X509_STORE *cert_store=NULL;
	BIO *data,*detached=NULL,*p7bio=NULL;
	char buf[1024*4];
	unsigned char *pp;
	int i,printit=0;
	STACK_OF(PKCS7_SIGNER_INFO) *sk;

	OpenSSL_add_all_algorithms();
	bio_err=BIO_new_fp(stderr,BIO_NOCLOSE);

	data=BIO_new(BIO_s_file());
	pp=NULL;
	while (argc > 1)
		{
		argc--;
		argv++;
		if (strcmp(argv[0],"-p") == 0)
			{
			printit=1;
			}
		else if ((strcmp(argv[0],"-k") == 0) && (argc >= 2)) {
			keyfile = argv[1];
			argc-=1;
			argv+=1;
		} else if ((strcmp(argv[0],"-d") == 0) && (argc >= 2))
			{
			detached=BIO_new(BIO_s_file());
			if (!BIO_read_filename(detached,argv[1]))
				goto err;
			argc-=1;
			argv+=1;
			}
		else break;
		}

	 if (!BIO_read_filename(data,argv[0])) goto err; 

	if(!keyfile) {
		fprintf(stderr, "No private key file specified\n");
		goto err;
	}

        if ((in=BIO_new_file(keyfile,"r")) == NULL) goto err;
        if ((x509=PEM_read_bio_X509(in,NULL,NULL,NULL)) == NULL) goto err;
        BIO_reset(in);
        if ((pkey=PEM_read_bio_PrivateKey(in,NULL,NULL,NULL)) == NULL)
		goto err;
        BIO_free(in);

	if (pp == NULL)
		BIO_set_fp(data,stdin,BIO_NOCLOSE);


	/* Load the PKCS7 object from a file */
	if ((p7=PEM_read_bio_PKCS7(data,NULL,NULL,NULL)) == NULL) goto err;


	/* This stuff is being setup for certificate verification.
	 * When using SSL, it could be replaced with a 
	 * cert_stre=SSL_CTX_get_cert_store(ssl_ctx); */
	cert_store=X509_STORE_new();
	X509_STORE_set_default_paths(cert_store);
	X509_STORE_load_locations(cert_store,NULL,"../../certs");
	X509_STORE_set_verify_cb_func(cert_store,verify_callback);

	ERR_clear_error();

	/* We need to process the data */
	/* We cannot support detached encryption */
	p7bio=PKCS7_dataDecode(p7,pkey,detached,x509);

	if (p7bio == NULL)
		{
		printf("problems decoding\n");
		goto err;
		}

	/* We now have to 'read' from p7bio to calculate digests etc. */
	for (;;)
		{
		i=BIO_read(p7bio,buf,sizeof(buf));
		/* print it? */
		if (i <= 0) break;
		fwrite(buf,1, i, stdout);
		}

	/* We can now verify signatures */
	sk=PKCS7_get_signer_info(p7);
	if (sk == NULL)
		{
		fprintf(stderr, "there are no signatures on this data\n");
		}
	else
		{
		/* Ok, first we need to, for each subject entry,
		 * see if we can verify */
		ERR_clear_error();
		for (i=0; i<sk_PKCS7_SIGNER_INFO_num(sk); i++)
			{
			si=sk_PKCS7_SIGNER_INFO_value(sk,i);
			i=PKCS7_dataVerify(cert_store,&cert_ctx,p7bio,p7,si);
			if (i <= 0)
				goto err;
			else
				fprintf(stderr,"Signature verified\n");
			}
		}
	X509_STORE_free(cert_store);

	exit(0);
err:
	ERR_load_crypto_strings();
	ERR_print_errors_fp(stderr);
	exit(1);
	}

/* should be X509 * but we can just have them as char *. */
int verify_callback(int ok, X509_STORE_CTX *ctx)
	{
	char buf[256];
	X509 *err_cert;
	int err,depth;

	err_cert=X509_STORE_CTX_get_current_cert(ctx);
	err=	X509_STORE_CTX_get_error(ctx);
	depth=	X509_STORE_CTX_get_error_depth(ctx);

	X509_NAME_oneline(X509_get_subject_name(err_cert),buf,256);
	BIO_printf(bio_err,"depth=%d %s\n",depth,buf);
	if (!ok)
		{
		BIO_printf(bio_err,"verify error:num=%d:%s\n",err,
			X509_verify_cert_error_string(err));
		if (depth < 6)
			{
			ok=1;
			X509_STORE_CTX_set_error(ctx,X509_V_OK);
			}
		else
			{
			ok=0;
			X509_STORE_CTX_set_error(ctx,X509_V_ERR_CERT_CHAIN_TOO_LONG);
			}
		}
	switch (ctx->error)
		{
	case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
		X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert),buf,256);
		BIO_printf(bio_err,"issuer= %s\n",buf);
		break;
	case X509_V_ERR_CERT_NOT_YET_VALID:
	case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
		BIO_printf(bio_err,"notBefore=");
		ASN1_UTCTIME_print(bio_err,X509_get_notBefore(ctx->current_cert));
		BIO_printf(bio_err,"\n");
		break;
	case X509_V_ERR_CERT_HAS_EXPIRED:
	case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
		BIO_printf(bio_err,"notAfter=");
		ASN1_UTCTIME_print(bio_err,X509_get_notAfter(ctx->current_cert));
		BIO_printf(bio_err,"\n");
		break;
		}
	BIO_printf(bio_err,"verify return:%d\n",ok);
	return(ok);
	}