#include <stdio.h>
#include <openssl/evp.h>

int main(int argc, char *argv[]) {
	FILE *in;
	FILE *out;
	unsigned char buffer_in[100];
	unsigned char buffer_out[100];
	int r,w;	
	EVP_CIPHER_CTX ctx;
	
	OpenSSL_add_all_algorithms();
	
	unsigned char data[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};

	EVP_CIPHER_CTX_init(&ctx);
	EVP_EncryptInit_ex(&ctx, EVP_rc4(), NULL,data,data);

	in = fopen("texto_limpo","r");
	out=fopen("criptograma","w");


	r=fread(buffer_in,1,100,in);
	while(r>0) {
		EVP_EncryptUpdate(&ctx,buffer_out,&w,buffer_in,r);
		fwrite(buffer_out,1,w,out);
		r=fread(buffer_in,1,100,in);
	}
	
	EVP_cleanup();
}