[cmm07]

Empezado por rretamar

No me resistí a colocar un trozo de código fuente en C++ (sacado de http://www.cprogramming.com ), creo que una imagen vale más que mil palabras:

//**************************************
    //INCLUDE files for :crypt.c
    //**************************************
    #include <stdio.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    //**************************************
    // Name: CryptCode.c
    // Description:Encrypts file and outputs it to a file or stdout
    // By:Praveena M
    //
    //
    // Inputs:CryptCode.exe <infile> <outfile> <key>
    //
    //**************************************
   
    #define cypherbits 256 /* encryption strength in bits */
    #define cypher cypherbits/(sizeof(int)*8)
    int seed[cypher];
    void modseed() {
    int x;
    for(x=1;x<cypher;x++)seed[x]=seed[x]*0x81772012+seed[x]+0x49122035+seed[x+1];
    for(x=1;x<cypher;x++)seed[0]=seed[0]^seed[x];
    }
    int seedsum() {
    int n,x;
    n=0x80379251;
    for(x=0;x<cypher;x++)n=n^seed[x];
    return((n>>24)^((n>>16)&255)^((n>>8)&255)^(n&255));
    }
    char strequ(char *s1,char *s2) {
    int p;
    p=0;
    while((s1[p]==s2[p])&&(s1[p]!=0)&&(s2[p]!=0))p++;
    if(s1[p]==s2[p])return(1); else return(0);
    }
    int main(int argc,char *argv[]) {
    char 
banner[]="\x43\x6f\x64\x65\x64\x20\x62\x79\x20\x50\x72\x61\x76\x65\x65\x6e\x61"
    "\x20\x6f\x66\x20\x49\x6e\x64\x69\x61"
    
"\x20\x28\x70\x76\x6e\x63\x61\x64\x40\x6b\x72\x65\x63\x2e\x65\x72\x6e\x65\x74\x2e\x69\x6e\x29";
    char buf[2048];
    int p,r,l,i,t,s,x;
    char b,c,pct,lpct;
    FILE *infile=NULL,*outfile=NULL;
    fprintf(stderr, "%s\n", banner);
    if(argc!=4){
    fprintf(stderr,"use: %s <infile> <outfile> <key>\n",argv[0]);
    return -1;
    }
    if(strequ(argv[1],"stdin"))infile=stdin; else
    if((infile=fopen(argv[1],"r"))==NULL){
    fprintf(stderr,"failed to open %s\n",argv[1]);
    return -1;
    }
    if(strequ(argv[2],"stdout"))outfile=stdout; else
    if((outfile=fopen(argv[2],"w"))==NULL){
    fprintf(stderr,"failed to create %s\n",argv[2]);
    return -1;
    }
    if(infile!=stdin) {
    fseek(infile,0,SEEK_END);
    l=ftell(infile);
    rewind(infile);
    } else l=0;
    s=l;
    t=0;
    pct=0;
    if(l<1)fprintf(stderr,"Encrypting data.. (%d bit cypher)\n",cypher*sizeof(int)*8);
    else fprintf(stderr,"Encrypting %d bytes.. (%d bit cypher)\n",l,cypher*sizeof(int)*8);
  /*  bzero(seed,sizeof(seed)); */
    modseed();
    p=0;
    while(argv[3][p]!=0){
    modseed();
    seed[0]=seed[0]+argv[3][p];
    modseed();
    p++;
    }
    i=0;
    if(l>0){
    fputc('[',stderr);
    x=(l/sizeof(buf));
    if(l-x*sizeof(buf)!=0)x+=1;
    if(x>38)x=38;
    for(p=0;p<x;p++) fputc(32,stderr);
    fputc(']',stderr);
    fputc(13,stderr);
    fputc('[',stderr);
    fflush(stderr);
    }
    c=1;
    while(c){
    r=fread(&buf,1,sizeof(buf),infile);
    if(r>0) {
         t+=r;
         if(l>0){
        lpct=pct;
        pct=t/(l/x);
        if(pct>lpct) {
        fputc(88+32*i,stderr);  
        fflush(stderr);
        i=1-i;
        }
         } else {
        fputc(88+32*i,stderr);
        fflush(stderr);
        i=1-i;
         }
         p=0;
         while(p<r) {
        modseed();
        buf[p]=buf[p]^seedsum();
        p++;
         }
         if(fwrite(&buf,1,r,outfile)!=r) {
        fprintf(stderr,"\nerror writing data\n");
        return -1;
         }
    } else c=0;
    }
    if(l>0)fputc(']',stderr);
    fprintf(stderr,"\nDone. Wrote %d bytes.\n",t);
    }

Una pesadilla. Realmente un trabajo para dar a un programador que uno quiere despedir.

Aquí otro código más legible:

/*
XOR.cpp
Matthew Costuros
snoborder420@yahoo.com
AIM: Rpi Matty
Proper usage is XOR.exe filename Key
Encrypt the file with a key 324
XOR.exe plain.txt 324
Decrypt that file
XOR.exe plain.enc  324
Encrypt a top secret file
XOR.exe keepsafe.txt 56765
Decrypt that secret file
XOR.exe keepsafe.end 56765
*/
#include <iostream.h>
#include <string.h>
#include <stdio.h>
int XOR(char * filename, unsigned long key);
int main(int argv, char ** argc)
{
    unsigned long key;
    char filename[100];
    //if they used command line arguments pass the filename and key to xor function
    if( argv == 3)
    {
        if( XOR(argc[1],(unsigned int)atol(argc[2]) ) )
        {
            cout << "There was an error trying to encrypt/decrypt the file " <<  argc[1] << endl;
        }
    }
    //other wise prompt for the key and filename
    else
    {
        cout << "What is the filename?" << endl;
        cin.getline(filename,99,'\n');
    
        cout << "What is the key?" << endl;
        cin >> key;
        
        //tell the user about command line then call xor function
        cout << "Next time you can use the command line, the format is " << argc[0] << " filename key" << endl;
        if( XOR(filename,key) )
        {
            cout << "There was an error trying encrypt/decrpyt the file " << filename << endl;
        }
    }
    return 0;
}
int XOR(char * filename, unsigned long key)
{
    FILE * input = NULL , *output = NULL;
    char * outfilename = NULL;
    int len = strlen(filename);
    unsigned char buffer;
    if( (filename[len-4] == '.') && (filename[len-3] == 'e') && (filename[len-2] == 'n') && (filename[len-1] == 'c') )
    {
        // our input file is encoded then we will create a file without the .end extension
        outfilename = new char[len+1]; //make room for the name+\0
        strcpy(outfilename,filename); //copy the string name
        outfilename[len-4] = '\0'; //put the \0 before the .enc extension to cut it off
    }
    else
    {
        outfilename = new char[len+5]; //make room for the name + .enc + \0
        strcpy(outfilename,filename); //copy the file name
        strncat(outfilename,".enc",4); //add the .enc extension
    }
    input =    fopen(filename,"rb");
    if( input == NULL)
    {
        cout << "Error opening file " << filename << endl;
        delete [] outfilename; //free the memory before leaving
        outfilename = NULL;
        return 1;
    }
    
    output = fopen(outfilename,"wb");
    if( output == NULL )
    {
        cout << "Error creating output file " << outfilename << endl;
        delete [] outfilename; //free the mem before leaving
        outfilename = NULL;
        return 1;
    }
    while( ! feof(input) )
    {
        //get some data
        if( fread(&buffer,sizeof(unsigned char),1,input) != 1 )
        {
            //if we didnt get any data, but we are not at the eof, then an error has occured
            if( ! feof(input) )
            {
                delete [] outfilename;
                outfilename = NULL;
                fclose(input);
                fclose(output);
                
                return 1;
            }
        }
        else
        {
            //xor that data
            buffer ^= key; 
        
            //write some data
            fwrite(&buffer,sizeof(unsigned char),1,output);
        }
    }
    //close the files and free that memory
    fclose(input);
    fclose(output);
    delete [] outfilename;
    return 0;
}

Mucho mejor.

(igual sigo prefiriendo la sintaxis de Object Pascal, la encuentro mucho más amigable "programación para seres humanos" ).

Lo ultimo, es como si yo colocara este código de delphi de un cripter y desordenado:

Código Delphi [-]
    
 FI := Y1[i]-State.X[0]*exp((-1)*((AP_Sqr(X1[i]-State.X[1])/(2*AP_Sqr(6.3)))))-State.X[2]*exp((-1)*((AP_Sqr(X1[i]-State.X[3])/(2*AP_Sqr(6.3)))));


                // dFi/dA = -exp^(-((x-Xk)^2)/2s^2)
                //
                State.J[I,0] := (-1)*exp((-1)*((AP_Sqr(X1[i]-State.X[1])/(2*AP_Sqr(6.3)))));
                //
                // dFi/dXk = (A*(xK-x)*exp(-(((x-Xk)^2)/(2*s^2))))))/(6.3^2))
               State.J[I,1] := (State.X[0]*(State.X[1]-X1[i])*exp((-1)*((AP_Sqr(X1[i]-State.X[1])/(2*AP_Sqr(6.3))))))/(AP_Sqr(6.3));

                //
                // dFi/dB = -exp^(-((x-XL)^2)/2s^2) 
                //
                State.J[I,2] := (-1)*exp((-1)*((AP_Sqr(X1[i]-State.X[3])/(2*AP_Sqr(6.3)))));

                //
                // dFi/dXLa = (B*(xL-x)*exp(-(((x-xL)^2)/(2*s^2))))))/(6.3^2))
                //
                State.J[I,3] := (State.X[2]*(State.X[3]-X1[i])*exp((-1)*((AP_Sqr(X1[i]-State.X[3])/(2*AP_Sqr(6.3))))))/(AP_Sqr(6.3));
    //
    Memo1.Lines.Add(Format('A = %4.2f'#13#10'',[
        S[0]]));
    Memo1.Lines.Add(Format('Xk = %4.2f'#13#10'',[
        S[1]]));
    Memo1.Lines.Add(Format('B = %4.2f'#13#10'',[
        S[2]]));
    Memo1.Lines.Add(Format('XLa = %4.2f'#13#10'',[
        S[3]]));
    Memo1.Lines.Add(Format('Tipo de terminación = %0d (debería ser 2 - parando cuando sea suficientemente pequeño)'#13#10'',[
        Rep.TerminationType]));

Se ve igual de feo y desordenado que el codigo de c++ que enviste :S, en fin, yo no estoy para hacer criticas a delphi, solo que no puede ser que cobren tanto por algo que tampoco es la "gran maravilla de aquiles", me gustaria ver un delphi con los precios mucho mas bajos y con más caracteristicas en el lenguaje en SI, no crear más herramientas como firemonkey, o firdeci... etc....

No estoy criticando a delphi...