/*
** rigol keygen / cybernet & the-eevblog-users
**
** to compile this you need MIRACL from [url]https://github.com/CertiVox/MIRACL[/url]
** download the master.zip into a new folder and run 'unzip -j -aa -L master.zip'
** then run 'bash linux' to build the miracle.a library
**
** BUILD WITH:
**
** gcc riglol.c -I../MIRACL ../MIRACL/miracl.a -o riglol
**
** adapt -I and path to miracl.a to your environment
**
** more info: http://www.eevblog.com/forum/testgear/sniffing-the-rigol's-internal-i2c-bus/
*/

// #define DEBUG

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include "miracl.h"

// ECC SETTINGS
char DP832_private_key[]  = "5C393C30FACCF4";
char DS2000_private_key[] = "8EEBD4D04C3771";
char DSA815_private_key[] = "80444DFECE903E";
char private_key[]        = "";
char prime1[]  = "AEBF94CEE3E707";
char prime2[]  = "AEBF94D5C6AA71";
char curve_a[] = "2982";
char curve_b[] = "3408";
char point1[]  = "7A3E808599A525";
char point2[]  = "28BE7FAFD2A052";


/*
** take serial and options make sha1 hash out of it
*/
static void hashing(char *opt_str, big hash) {
    char *p;
    char h[20];
    int ch;
    sha sh;
    shs_init(&sh);
    p = opt_str;

    while(*p) {
        shs_process(&sh, *p);
        p++;
    }

    shs_hash(&sh, h);
    bytes_to_big(20, h, hash);
}

/*
** sign the secret message (serial + opts) with the private key
*/
void ecssign(char *serial, char *options, char *privk, char *lic1, char *lic2) {
    int k_offset = 0; // optionally change ecssign starting offset (changes lic1; makes different licenses)
    mirsys(800, 16)->IOBASE = 16;

    sha sha1;
    shs_init(&sha1);

    char *ptr = serial;
    while(*ptr) shs_process(&sha1, *ptr++);
    ptr = options;
    while(*ptr) shs_process(&sha1, *ptr++);

    char h[20];
    shs_hash(&sha1, h);
    big hash = mirvar(0);
    bytes_to_big(20, h, hash);

    big a = mirvar(0);
    instr(a, curve_a);
    big b = mirvar(0);
    instr(b, curve_b);
    big p = mirvar(0);
    instr(p, prime1);
    big q = mirvar(0);
    instr(q, prime2);
    big Gx = mirvar(0);
    instr(Gx, point1);
    big Gy = mirvar(0);
    instr(Gy, point2);
    big d = mirvar(0);
    instr(d, privk);
    big k = mirvar(0);
    big r = mirvar(0);
    big s = mirvar(0);
    big k1 = mirvar(0);
    big zero = mirvar(0);

    big f1 = mirvar(17);
    big f2 = mirvar(53);
    big f3 = mirvar(905461);
    big f4 = mirvar(60291817);

    incr(k, k_offset, k);

    epoint *G = epoint_init();
    epoint *kG = epoint_init();
    ecurve_init(a, b, p, MR_PROJECTIVE);
    epoint_set(Gx, Gy, 0, G);

    for(;;) {
        incr(k, 1, k);

        if(divisible(k, f1) || divisible(k, f2) || divisible(k, f3) || divisible(k, f4))
            continue;

        ecurve_mult(k, G, kG);
        epoint_get(kG, r, r);
        divide(r, q, q);

        if(mr_compare(r, zero) == 0)
            continue;

        xgcd(k, q, k1, k1, k1);
        mad(d, r, hash, q, q, s);
        mad(s, k1, k1, q, q, s);

        if(!divisible(s, f1) && !divisible(s, f2) && !divisible(s, f3) && !divisible(s, f4))
            break;
    }

    cotstr(r, lic1);
    cotstr(s, lic2);
}

/*
** convert string to uppercase chars
*/
char * strtoupper(char *str) {
    char *newstr, *p;
    p = newstr = (char*) strdup((char*)str);
    while ((*p++ = toupper(*p)));
    return newstr;
}

/*
** prepend a char to a string
*/
char * prepend(char *c, char *str) {
    int i;

    for (i = strlen(str); i >= 0; i--) {
        str[i + 1] = str[i];
    }

    str[0] = *c;
    return c;
}

/*
** convert hex-ascii-string to rigol license format
*/
void map_hex_to_rigol(char *io) {
    unsigned long long b = 0;
    int i = 0;
    char map[] = {
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
        'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R',
        'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
        '2', '3', '4', '5', '6', '7', '8', '9'
    };

    /* hex2dez */
    while (io[i] != '\0') {
        if (io[i] >= '0' && io[i] <= '9') {
            b = b * 16 + io[i] - '0';
        } else if (io[i] >= 'A' && io[i] <= 'F') {
            b = b * 16 + io[i] - 'A' + 10;
        } else if (io[i] >= 'a' && io[i] <= 'f') {
            b = b * 16 + io[i] - 'a' + 10;
        }

        i++;
    }

    for (i = 3; ; i--) {
        io[i] = map[b & 0x1F];
        if (i == 0) break;
        b >>= 5;
    }

    io[4] = '\0';
}

void show_help(char *cmd) {
    printf("Usage: %s <sn> <opts> <privkey>\n", cmd);
    printf("  <sn>       serial number of device (D............)\n");
    printf("  <opts>     device options, 4 characters, see below\n");
    printf("  <privkey>  private key (optional)\n");
    printf("\n");
    printf("DS2000 and DS4000 device options:\n");
    printf("  first character:  D = official, V = trial\n");
    printf("  second character: S\n");
    printf("  third character:  A = DS2000, H = DS4000\n");
    printf("  last character :  your options, use the following table to generate for DS2000:\n");
    printf("  --------- A B C D E F G H J K L M N P Q R S T U V W X Y Z 2 3 4 5 6 7 8 9\n");
    printf("  100MHz    ' ' ' ' ' ' ' ' * * * * * * * * ' ' ' ' ' ' ' ' * * * * * * * *\n");
    printf("  200MHz    ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' * * * * * * * * * * * * * * * *\n");
    printf("  Memory56M ' ' ' ' * * * * ' ' ' ' * * * * ' ' ' ' * * * * ' ' ' ' * * * *\n");
    printf("  Decode    ' ' * * ' ' * * ' ' * * ' ' * * ' ' * * ' ' * * ' ' * * ' ' * *\n");
    printf("  Triggers  ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' * ' *\n");
    printf("  For DS4000, try DSH9, VSH9 to enable all options.\n");
    printf("\n");
    printf("DP832 device options:\n");
    printf("  first character:  M = official, 5 = trial\n");
    printf("  MWSS - Trigger\n");
    printf("  MWTB - Accuracy\n");
    printf("  MWTC - LAN and RS232\n");
    printf("  MWTE - Analyzer and Monitor\n");
    printf("\n");
    printf("DSA815 device options:\n");
    printf("  first character:  A = official, S = trial\n");
    printf("  AAAB - tracking generator\n");
    printf("  AAAC - adv measurement kit\n");
    printf("  AAAD - 10Hz RBW\n");
    printf("  AAAE - EMI/Quasi Peak\n");
    printf("  AAAF - VSWR\n");
    printf("\n");
    printf("MAKE SURE YOUR FIRMWARE IS UP TO DATE BEFORE APPLYING ANY KEYS\n");
}

/*
** the world ends here
*/
int main(int argc, char *argv[0]) {
    char *options, *lic1_code, *lic2_code, *lic_all;
    char *chunk, *temp, *final;
    char *priv_key;
    char *serial;
    int            i = 0, j = 0;

    /* parse input */
    if (!((argc == 3 || argc == 4))) {
        show_help(argv[0]);
        exit(-1);
    }
    serial = strtoupper((char*)argv[1]);
    options = strtoupper((char*)argv[2]);
    if (argc == 4) priv_key = (char*)argv[3];
    else if (!strncmp(serial, "DS2", 3)) priv_key = DS2000_private_key;
    else if (!strncmp(serial, "DS4", 3)) priv_key = DS2000_private_key;
    else if (!strncmp(serial, "DS6", 3)) priv_key = DS2000_private_key;
    else if (!strncmp(serial, "DSA", 3)) priv_key = DSA815_private_key;
    else if (!strncmp(serial, "DP8", 3)) priv_key = DP832_private_key;
    else {
        show_help(argv[0]);
        printf("\nERROR: UNKNOW DEVICE WITHOUT PRIVATKEY\n");
        exit(-1);
    }

    strtoupper(priv_key);
    if (strlen(priv_key) != 14) {
        show_help(argv[0]);
        printf("\nERROR: INVALID PRIVATE KEY LENGTH\n");
        exit(-1);
    }
    if (strlen(serial) < 13) {
        show_help(argv[0]);
        printf("\nERROR: INVALID SERIAL LENGTH\n");
        exit(-1);
    }
    if (strlen(options) != 4) {
        show_help(argv[0]);
        printf("\nERROR: INVALID OPTIONS LENGTH\n");
        exit(-1);
    }
#ifdef DEBUG
    printf("private-key:      %s\n", priv_key);
    printf("serial:           %s\n", serial);
    printf("options:          %s\n", options);
#endif

    /* sign the message */
    lic1_code = calloc(64, 1);
    lic2_code = calloc(64, 1);
    ecssign(serial, options, priv_key, lic1_code, lic2_code);

    /* fix missing zeroes */
    while (strlen(lic1_code) < 14) {
        prepend("0", lic1_code);
    }
    while (strlen(lic2_code) < 14) {
        prepend("0", lic2_code);
    }
#ifdef DEBUG
    printf("lic1-code:        %s\n", lic1_code);
    printf("lic2-code:        %s\n", lic2_code);
#endif

    /* combine lic1 and lic2 */
    lic_all = calloc(128, 1);
    temp = calloc(128, 1);
    chunk = calloc(6, 1);
    final = calloc(128, 1);
    strcpy(lic_all, lic1_code);
    strcat(lic_all, "0");
    strcat(lic_all, lic2_code);
    strcat(lic_all, "0");
#ifdef DEBUG
    printf("target-code:      %s\n", lic_all);
#endif

    /* generate serial */
    while (i < strlen(lic_all)) {
        memcpy(chunk, lic_all + i, 5);
        map_hex_to_rigol(chunk);
        strcat(temp, chunk);
        i = i + 5;
    }

    /* now add the options */
    memcpy(final,      temp     , 1);
    final[1] = options[0];
    memcpy(final +  2, temp +  1, 7);
    final[9] = options[1];
    memcpy(final + 10, temp +  8, 7);
    final[17] = options[2];
    memcpy(final + 18, temp + 15, 7);
    final[25] = options[3];
    memcpy(final + 26, temp + 22, 4);
#ifdef DEBUG
    printf("----------------------------------------------------\n");
    printf("your-license-key: ");
#endif
    for(i = 0; i < strlen(final); i++) {
        if (i % 7 == 0 && i > 0) printf("-");
        printf("%c", final[i]);
    }
    printf("\n");
#ifdef DEBUG
    printf("----------------------------------------------------\n");
#endif
}