#include <stdio.h>
#include "asn1.h"
#include "bio.h"
#include "x509.h"
#include "pem.h"

int verify_callback(int ok, X509_STORE_CTX *ctx);

BIO *bio_err=NULL;

main(argc,argv)
int argc;
char *argv[];
	{
	X509 *x509,*x;
	PKCS7 *p7;
	PKCS7_SIGNED *s;
	PKCS7_SIGNER_INFO *si;
	PKCS7_ISSUER_AND_SERIAL *ias;
	X509_STORE_CTX cert_ctx;
	X509_STORE *cert_store=NULL;
	X509_LOOKUP *lookup=NULL;
	BIO *data,*detached=NULL,*p7bio=NULL;
	char buf[1024*4];
	unsigned char *p,*pp;
	int i,j,printit=0;
	STACK *sk;

	bio_err=BIO_new_fp(stderr,BIO_NOCLOSE);
	EVP_add_digest(EVP_md2());
	EVP_add_digest(EVP_md5());
	EVP_add_digest(EVP_sha1());
	EVP_add_digest(EVP_mdc2());

	data=BIO_new(BIO_s_file());
again:
	pp=NULL;
	while (argc > 1)
		{
		argc--;
		argv++;
		if (strcmp(argv[0],"-p") == 0)
			{
			printit=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--;
			argv++;
			}
		else
			{
			pp=argv[0];
			if (!BIO_read_filename(data,argv[0]))
				goto err;
			}
		}

	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) 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_errors();

	/* We need to process the data */
	if (PKCS7_get_detached(p7))
		{
		if (detached == NULL)
			{
			printf("no data to verify the signature on\n");
			exit(1);
			}
		else
			p7bio=PKCS7_dataInit(p7,detached);
		}
	else
		{
		p7bio=PKCS7_dataInit(p7,NULL);
		}

	/* 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;
		}

	/* We can now verify signatures */
	sk=PKCS7_get_signer_info(p7);
	if (sk == NULL)
		{
		printf("there are no signatures on this data\n");
		exit(1);
		}

	/* Ok, first we need to, for each subject entry, see if we can verify */
	for (i=0; i<sk_num(sk); i++)
		{
		si=(PKCS7_SIGNER_INFO *)sk_value(sk,i);
		i=PKCS7_dataVerify(cert_store,&cert_ctx,p7bio,p7,si);
		if (i <= 0)
			goto err;
		}

	X509_STORE_free(cert_store);

	printf("done\n");
	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(ok, ctx)
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);
	}
