Linux adds custom encryption algorithms to OpenSSL

Linux system OpenSSL is a set of password library system, so Linux system will use OpenSSL to add encryption algorithm to OpenSSL. This article will introduce Linux's skills for adding custom encryption algorithm to OpenSSL.

I. Introduction

This article introduces the custom algorithm EVP_ssf33 as an example to introduce the method of adding a custom encryption algorithm in OpenSSL

II. Steps

1, modify crypto /object /objects.txt, registration algorithm OID, as follows:

rsadsi 3 255: SSF33: ssf33

2, enter the directory: crypto /object /, execute the following command , the declaration of the generated algorithm

perl objects.pl objects.txt obj_mac.num obj_mac.h

3, add e_ssf33.c under crypto/evp/, the content is as follows

#include "stdio.h"

#include “cryptlib.h”

#ifndef OPENSSL_NO_RC4

#include 《openssl/evp.h》

#include 《openssl/objects.h》

#include 《openssl/rc4.h》

/* FIXME: surely this is available elsewhere? */

#define EVP_SSF33_KEY_SIZE 16

typedef struct

{

RC4_KEY ks; /* working key */

} EVP_SSF33_KEY ;

#define data(ctx) ((EVP_SSF33_KEY *)(ctx)-"cipher_data)

static int ssf33_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key, const unsigned char *iv , int enc);

static int ssf33_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, unsigned int inl);

static const EVP_CIPHER ssf33_evp_cipher=

{

NID_ssf33,

1,

EVP_SSF33_KEY_SIZE,

0,

EVP_CIPH_VARIABLE_LENGTH,

ssf33_init_key ,

ssf33_cipher,

NULL,

sizeof(EVP_SSF33_KEY),

NULL,

NULL,

NULL,

NULL

};

const EVP_CIPHER *EVP_ssf33(void)

{

return(&ssf33_evp_cipher);

}

static int ssf33_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key, const unsigned char *iv, int enc)

{

RC4_set_key(&data(ctx)-"ks,EVP_CIPHER_CTX_key_length(ctx), key);

return 1;

}< Br>

static int ssf33_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, unsigned int inl)

{

RC4(&data(ctx)- 》ks,inl,in,out);

return 1;

}

#endif Previous12Next Total 2 Pages