rsautl.c

openssl加密例子

#ifndef OPENSSL_NO_RSA

#include "apps.h"
#include <string.h>
#include <openssl/err.h>
#include <openssl/pem.h>

#define RSA_SIGN 		1
#define RSA_VERIFY 	2
#define RSA_ENCRYPT 	3
#define RSA_DECRYPT 	4

#define KEY_PRIVKEY	1
#define KEY_PUBKEY	2
#define KEY_CERT		3

int rsautl_main(int argc, char **argv,char *inbuf,int *inlen,char *outbuf,int *outlen)
{
	ENGINE *e = NULL;
	BIO *in = NULL, *out = NULL;
	char *infile = NULL, *outfile = NULL;
#ifndef OPENSSL_NO_ENGINE
	char *engine = NULL;
#endif
	char *keyfile = NULL;
	char rsa_mode = RSA_VERIFY, key_type = KEY_PRIVKEY;
	int keyform = FORMAT_PEM;
	char need_priv = 0, badarg = 0, rev = 0;
	char hexdump = 0, asn1parse = 0;
	X509 *x;
	EVP_PKEY *pkey = NULL;
	RSA *rsa = NULL;
	unsigned char *rsa_in = NULL, *rsa_out = NULL, pad;
	char *passargin = NULL, *passin = NULL;
	int rsa_inlen, rsa_outlen = 0;
	int keysize;

	int ret = 1;

	if(!bio_err) bio_err = BIO_new_fp(stderr, BIO_NOCLOSE);

	if (!load_config(bio_err, NULL))
		goto end;

	ERR_load_crypto_strings();
	OpenSSL_add_all_algorithms();
	pad = RSA_PKCS1_PADDING;
	
	while(argc >= 1)
	{
		if (!strcmp(*argv,"-in")) 
		{
			if (--argc < 1) badarg = 1;
			infile= *(++argv);
		} 
		else if (!strcmp(*argv,"-out")) 
		{
			if (--argc < 1) badarg = 1;
			outfile= *(++argv);
		} 
		else if(!strcmp(*argv, "-inkey")) 
		{
			if (--argc < 1) badarg = 1;
			keyfile = *(++argv);
		} 
		else if (!strcmp(*argv,"-passin")) 
		{
			if (--argc < 1) badarg = 1;
			passargin= *(++argv);
		} 
		else if (strcmp(*argv,"-keyform") == 0) 
		{
			if (--argc < 1) badarg = 1;
			keyform=str2fmt(*(++argv));
#ifndef OPENSSL_NO_ENGINE
		} 
		else if(!strcmp(*argv, "-engine")) 
		{
			if (--argc < 1) badarg = 1;
			engine = *(++argv);
#endif
		} 
		else if(!strcmp(*argv, "-pubin")) 
		{
			key_type = KEY_PUBKEY;
		} 
		else if(!strcmp(*argv, "-certin")) 
		{
			key_type = KEY_CERT;
		} 
		else if(!strcmp(*argv, "-asn1parse")) asn1parse = 1;
		else if(!strcmp(*argv, "-hexdump")) hexdump = 1;
		else if(!strcmp(*argv, "-raw")) pad = RSA_NO_PADDING;
		else if(!strcmp(*argv, "-oaep")) pad = RSA_PKCS1_OAEP_PADDING;
		else if(!strcmp(*argv, "-ssl")) pad = RSA_SSLV23_PADDING;
		else if(!strcmp(*argv, "-pkcs")) pad = RSA_PKCS1_PADDING;
		else if(!strcmp(*argv, "-x931")) pad = RSA_X931_PADDING;
		else if(!strcmp(*argv, "-rev")) rev = 1;
		else if(!strcmp(*argv, "-sign")) 
		{
			rsa_mode = RSA_SIGN;
			need_priv = 1;
		} 
		else if(!strcmp(*argv, "-verify")) rsa_mode = RSA_VERIFY;
		else if(!strcmp(*argv, "-encrypt"))
		{
			rsa_mode = RSA_ENCRYPT;
		}
		else if(!strcmp(*argv, "-decrypt")) 
		{
			rsa_mode = RSA_DECRYPT;
			need_priv = 1;
		} 
		else badarg = 1;

		if(badarg) 
		{
			goto end;
		}

		argc--;
		argv++;
	}

	if(need_priv && (key_type != KEY_PRIVKEY)) {
		BIO_printf(bio_err, "A private key is needed for this operation\n");
		goto end;
	}

#ifndef OPENSSL_NO_ENGINE
        e = setup_engine(bio_err, engine, 0);
#endif
	if(!app_passwd(bio_err, passargin, NULL, &passin, NULL)) {
		BIO_printf(bio_err, "Error getting password\n");
		goto end;
	}

/* FIXME: seed PRNG only if needed */
	app_RAND_load_file(NULL, bio_err, 0);

	switch(key_type) 
	{
		case KEY_PRIVKEY:
		pkey = load_key(bio_err, keyfile, keyform, 0,
			passin, e, "Private Key");
		break;

		case KEY_PUBKEY:
		pkey = load_pubkey(bio_err, keyfile, keyform, 0,
			NULL, e, "Public Key");
		break;

		case KEY_CERT:
		x = load_cert(bio_err, keyfile, keyform,
			NULL, e, "Certificate");
		if(x) 
		{
			pkey = X509_get_pubkey(x);
			X509_free(x);
		}
		break;
	}

	if(!pkey) 
	{
		return 1;
	}

	rsa = EVP_PKEY_get1_RSA(pkey);
	EVP_PKEY_free(pkey);

	if(!rsa) 
	{
		BIO_printf(bio_err, "Error getting RSA key\n");
		ERR_print_errors(bio_err);
		goto end;
	}

	if(infile) 
	{
		if(!(in = BIO_new_file(infile, "rb"))) 
		{
			BIO_printf(bio_err, "Error Reading Input File\n");
			ERR_print_errors(bio_err);	
			goto end;
		}
	} 

	if(outfile) 
	{
		if(!(out = BIO_new_file(outfile, "wb"))) 
		{
			BIO_printf(bio_err, "Error Reading Output File\n");
			ERR_print_errors(bio_err);	
			goto end;
		}
	} 
/*	else 
	{
		out = BIO_new_fp(stdout, BIO_NOCLOSE);
#ifdef OPENSSL_SYS_VMS
		{
		    BIO *tmpbio = BIO_new(BIO_f_linebuffer());
		    out = BIO_push(tmpbio, out);
		}
#endif
	}
*/
	keysize = RSA_size(rsa);

	rsa_in = OPENSSL_malloc(keysize * 2);
	rsa_out = OPENSSL_malloc(keysize);

	/* Read the input data */
	if(infile) 
	{
		rsa_inlen = BIO_read(in, rsa_in, keysize * 2);
		if(rsa_inlen <= 0) 
		{
			BIO_printf(bio_err, "Error reading input Data\n");
			exit(1);
		}
	}
	else
	{
		rsa_inlen=*inlen;
		if(rsa_inlen <= 0 || rsa_inlen>keysize) 
		{
			BIO_printf(bio_err, "Error reading input Data\n");
			exit(1);
		}
		memmove(rsa_in,inbuf,rsa_inlen);
	}

	if(rev) 
	{
		int i;
		unsigned char ctmp;
		for(i = 0; i < rsa_inlen/2; i++) 
		{
			ctmp = rsa_in[i];
			rsa_in[i] = rsa_in[rsa_inlen - 1 - i];
			rsa_in[rsa_inlen - 1 - i] = ctmp;
		}
	}

	switch(rsa_mode) 
	{

		case RSA_VERIFY:
			rsa_outlen  = RSA_public_decrypt(rsa_inlen, rsa_in, rsa_out, rsa, pad);
		break;

		case RSA_SIGN:
			rsa_outlen  = RSA_private_encrypt(rsa_inlen, rsa_in, rsa_out, rsa, pad);
		break;

		case RSA_ENCRYPT:
			rsa_outlen  = RSA_public_encrypt(rsa_inlen, rsa_in, rsa_out, rsa, pad);
		break;

		case RSA_DECRYPT:
			rsa_outlen  = RSA_private_decrypt(rsa_inlen, rsa_in, rsa_out, rsa, pad);
		break;

	}

	if(rsa_outlen <= 0) 
	{
		BIO_printf(bio_err, "RSA operation error\n");
		ERR_print_errors(bio_err);
		goto end;
	}

	ret = 0;
	if(outfile) 
	{
		if(asn1parse) 
		{
			if(!ASN1_parse_dump(out, rsa_out, rsa_outlen, 1, -1)) 
			{
				ERR_print_errors(bio_err);
			}
		} 
		else if(hexdump) BIO_dump(out, (char *)rsa_out, rsa_outlen);
		else BIO_write(out, rsa_out, rsa_outlen);
	}
	else
	{
		*outlen=rsa_outlen;
		memmove(outbuf,rsa_out,rsa_outlen);
	}

end:
	RSA_free(rsa);
	BIO_free(in);
	BIO_free_all(out);
	if(rsa_in) OPENSSL_free(rsa_in);
	if(rsa_out) OPENSSL_free(rsa_out);
	if(passin) OPENSSL_free(passin);
	return ret;
}

#endif

int digest_func(char* in, unsigned int inlen, unsigned char* out, unsigned int* outlen)
{
	 EVP_MD_CTX mdctx; 
     const EVP_MD *md; 
     unsigned char md_value[EVP_MAX_MD_SIZE]; 
     int md_len, i,ret; 

     //使EVP_Digest系列函数支持所有有效的信息摘要算法 
     OpenSSL_add_all_digests(); 
     
     
     EVP_MD_CTX_init(&mdctx); 
     //使用md的算法结构设置mdctx结构，impl为NULL，即使用缺省实现的算法（open ssl本身提供的信息摘要算法） 
     ret = EVP_DigestInit_ex(&mdctx, EVP_md5(), NULL); 
	 if(ret <= 0)
	 {
		 return (-1);
	 }
     //开始真正进行信息摘要运算，可以多次调用该函数，处理更多的数据，这里只调用了一次 
     ret = EVP_DigestUpdate(&mdctx, in, inlen); 
	 if(ret <= 0)
	 {
		 return (-2);
	 }
     
     //完成信息摘要计算过程，将完成的摘要信息存储在out里面,长度信息存储在*out_len里面 
     ret = EVP_DigestFinal_ex(&mdctx, out, outlen); 
	 if(ret <= 0)
	 {
		 return (-3);
	 }
     //使用该函数释放mdctx占用的资源，如果使用_ex系列函数，这是必须调用的。 
     EVP_MD_CTX_cleanup(&mdctx); 
  	 return 0;
}