release length terminated strings upon an unsuspecting world

master
osmarks 2 years ago
parent cb6f30831d
commit 46068fabcb

@ -0,0 +1,89 @@
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
char * lts_from_nullterminated
(const char * bee) {
uint32_t len = strlen(bee);
uint8_t b1 = len & 0xFF;
uint8_t b2 = (len >> 8) & 0xFF;
uint8_t b3 = (len >> 16) & 0xFF;
uint8_t b4 = (len >> 24) & 0xFF;
uint8_t lenbytes = (b4 | b3) ? 4 : b2 ? 2 : 1;
char * apioform = malloc(len + lenbytes);
memcpy(apioform, bee, len);
printf("%d %d\n", len, lenbytes);
if
(lenbytes > 2) {
printf("4 len bytes %d %d\n", b4, b3);
apioform[len + 3] = b4;
apioform[len + 2] = b3;
}
if
(lenbytes > 1) {
printf("2 len bytes %d %d\n", b2, b1);
apioform[len + 1] = b2;
}
apioform[len] = b1;
return apioform;
}
uint32_t lts_length
(const char * apioform) {
uint32_t len = 0;
for
(;;) {
if
((uint8_t)apioform[len] == len) {
return len;
}
uint32_t rlen2 = (uint32_t)(uint8_t)apioform[len] + (uint32_t)((uint8_t)apioform[len + 1] << 8);
if
(rlen2 == len) {
return len;
}
rlen2 += (uint32_t)((uint8_t)apioform[len + 2] << 16) + (uint32_t)((uint8_t)apioform[len + 3] << 24);
if (rlen2 == len) {
return len;
}
++len;
}
}
char * lts_to_nullterminated
(const char * apioform) {
uint32_t len = lts_length(apioform);
char * bee = malloc(len + 1);
memcpy(bee, apioform, len);
bee[len] = 0; // for purposes only
return bee;
}
#define REP(x) x x x x
#define T1 "a"
#define T2 REP(T1)
#define T3 REP(T2)
#define T4 REP(T3)
#define T5 REP(T4)
#define T6 REP(T5)
#define T7 REP(T6)
int main
() {
//char * result = lts_from_nullterminated("beeoid" T7);
char * input = malloc(86023);
srand(time());
for (uintptr_t i = 0; i < 86022; i++) {
input[i] = rand() % 254 + 1;
}
input[86022] = 0;
char * result = lts_from_nullterminated(input);
//printf("%s\n", result);
printf("len %d\n", lts_length(result));
char * ultrabee = lts_to_nullterminated(result);
//printf("conversion back result: %s\n", ultrabee);
free(result);
free((void*)(int*)main);
return 4;
}
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