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#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdint.h>
#include "encrypt.h"
#ifdef BIGENDIAN
#include <endian.h>
#elif LITTLEENDIAN
#define htole64(x) (x)
#endif
static int random_compare(const void *_x, const void *_y) { uint32_t i = _i; uint64_t a = _a; uint8_t x = *((uint8_t *) _x); uint8_t y = *((uint8_t*) _y); return (a % (x + i) - a % (y + i)); }
static void merge(uint8_t *left, int llength, uint8_t *right, int rlength) { /* Temporary memory locations for the 2 segments of the array to merge. */ uint8_t *ltmp = (uint8_t *) malloc(llength * sizeof(uint8_t)); uint8_t *rtmp = (uint8_t *) malloc(rlength * sizeof(uint8_t));
/*
* Pointers to the elements being sorted in the temporary memory locations. */ uint8_t *ll = ltmp; uint8_t *rr = rtmp;
uint8_t *result = left;
/*
* Copy the segment of the array to be merged into the temporary memory * locations. */ memcpy(ltmp, left, llength * sizeof(uint8_t)); memcpy(rtmp, right, rlength * sizeof(uint8_t));
while (llength > 0 && rlength > 0) { if (random_compare(ll, rr) <= 0) { /*
* Merge the first element from the left back into the main array * if it is smaller or equal to the one on the right. */ *result = *ll; ++ll; --llength; } else { /*
* Merge the first element from the right back into the main array * if it is smaller than the one on the left. */ *result = *rr; ++rr; --rlength; } ++result; } /*
* All the elements from either the left or the right temporary array * segment have been merged back into the main array. Append the remaining * elements from the other temporary array back into the main array. */ if (llength > 0) while (llength > 0) { /* Appending the rest of the left temporary array. */ *result = *ll; ++result; ++ll; --llength; } else while (rlength > 0) { /* Appending the rest of the right temporary array. */ *result = *rr; ++result; ++rr; --rlength; }
/* Release the memory used for the temporary arrays. */ free(ltmp); free(rtmp); }
static void merge_sort(uint8_t array[], int length) { /* This is the middle index and also the length of the right array. */ uint8_t middle;
/*
* Pointers to the beginning of the left and right segment of the array * to be merged. */ uint8_t *left, *right;
/* Length of the left segment of the array to be merged. */ int llength;
if (length <= 1) return;
/* Let integer division truncate the value. */ middle = length / 2;
llength = length - middle;
/*
* Set the pointers to the appropriate segments of the array to be merged. */ left = array; right = array + llength;
merge_sort(left, llength); merge_sort(right, middle); merge(left, llength, right, middle); }
void encrypt_ctx(char *buf, int len, EVP_CIPHER_CTX *ctx) { if (ctx != NULL) { int outlen; unsigned char mybuf[BUF_SIZE]; EVP_CipherUpdate(ctx, mybuf, &outlen, (unsigned char*)buf, len); memcpy(buf, mybuf, len); } else { char *end = buf + len; while (buf < end) { *buf = (char)encrypt_table[(uint8_t)*buf]; buf++; } } }
void decrypt_ctx(char *buf, int len, EVP_CIPHER_CTX *ctx) { if (ctx != NULL) { int outlen; unsigned char mybuf[BUF_SIZE]; EVP_CipherUpdate(ctx, mybuf, &outlen, (unsigned char*) buf, len); memcpy(buf, mybuf, len); } else { char *end = buf + len; while (buf < end) { *buf = (char)decrypt_table[(uint8_t)*buf]; buf++; } } }
void enc_ctx_init(EVP_CIPHER_CTX *ctx, const char *pass, int enc) { unsigned char key[EVP_MAX_KEY_LENGTH]; unsigned char iv[EVP_MAX_IV_LENGTH]; int key_len = EVP_BytesToKey(EVP_rc4(), EVP_md5(), NULL, (unsigned char*) pass, strlen(pass), 1, key, iv); EVP_CIPHER_CTX_init(ctx); EVP_CipherInit_ex(ctx, EVP_rc4(), NULL, NULL, NULL, enc); if (!EVP_CIPHER_CTX_set_key_length(ctx, key_len)) { LOGE("Invalid key length: %d", key_len); EVP_CIPHER_CTX_cleanup(ctx); exit(EXIT_FAILURE); } EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, enc); }
void get_table(const char *pass) { uint8_t *table = encrypt_table; uint8_t *tmp_hash = MD5((unsigned char *) pass, strlen(pass), NULL); _a = htole64(*(uint64_t *) tmp_hash); uint32_t i;
for(i = 0; i < 256; ++i) { table[i] = i; } for(i = 1; i < 1024; ++i) { _i = i; merge_sort(table, 256); } for(i = 0; i < 256; ++i) { // gen decrypt table from encrypt table
decrypt_table[encrypt_table[i]] = i; } }
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