64 lines
1.7 KiB
C
64 lines
1.7 KiB
C
#include <stdio.h>
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#include <string.h>
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#include <sys/random.h>
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#include "epic_drm.h"
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#define log(what) printf("[client] " what "\n")
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#define logf(what, ...) printf("[client] " what "\n", __VA_ARGS__)
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// this code is untrusted
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// but don't worry, Epic DRM(tm) protections are unbreakable
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void* get_cmd(struct command_channel* chan) {
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// get the protected shell command from the DRM server
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void* dst = malloc(sizeof(chan->data));
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log("sending get_cmd");
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chan->command = GET_CMD;
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sem_post(&chan->sem_c2s);
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sem_wait(&chan->sem_s2c);
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logf("result: %s", chan->command == SUCCESS ? "success" : "error");
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if (chan->command == SUCCESS) {
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memcpy(dst, &chan->data, sizeof(chan->data));
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return dst;
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} else {
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return NULL;
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}
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}
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void send_cmd(struct command_channel* chan, void* data) {
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// send a protected shell command back to the server
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log("sending execute_cmd");
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memcpy(&chan->data, data, sizeof(chan->data));
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chan->command = EXECUTE_CMD;
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sem_post(&chan->sem_c2s);
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sem_wait(&chan->sem_s2c);
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logf("result: %s", chan->command == SUCCESS ? "success" : "error");
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}
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int main() {
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// perform a basic interaction with epic_drm
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log("opening drm");
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int shm = shm_open(SHM_NAME, O_RDWR, 0);
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struct command_channel* chan = mmap(NULL, SHM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm, 0);
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// get protected shell command
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void* data = get_cmd(chan);
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log("data");
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for (size_t i = 0; i < 64; i++) {
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uint8_t b = ((uint8_t*)data)[i];
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printf("%02x ", b);
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if (i % 16 == 15) {
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printf("\n");
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}
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}
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printf("...\n");
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// send back
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send_cmd(chan, data);
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log("done");
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}
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