Verify DM media record boundaries and corrupted artifacts

tests/test_dm.c

@@ -15,6 +15,85 @@
 #include <stdio.h>
 #include "../lib/mem.h"
 
+/* Потоковые файлы разного размера; результат доступен только после всех проверок. */
+static int test_media_stream(const uint8_t key1[32], const uint8_t key2[32], uint64_t author, size_t size) {
+    FILE* src = tmpfile();
+    FILE* cipher = tmpfile();
+    FILE* plain = tmpfile();
+    FILE* short_cipher = tmpfile();
+    if (!src || !cipher || !plain || !short_cipher) {
+        DEBUG_ERROR(DEBUG_CATEGORY_DM, "media test temporary file creation failed");
+        if (src) fclose(src);
+        if (cipher) fclose(cipher);
+        if (plain) fclose(plain);
+        if (short_cipher) fclose(short_cipher);
+        return 1;
+    }
+    uint8_t pattern[4096], actual[4096], id[16] = {1}, hash[32];
+    for (size_t i = 0; i < sizeof(pattern); i++) pattern[i] = (uint8_t)(i * 17 + 3);
+    int failed = 0;
+    size_t remaining = size;
+    while (remaining) {
+        size_t n = remaining > sizeof(pattern) ? sizeof(pattern) : remaining;
+        if (fwrite(pattern, 1, n, src) != n) { failed = 1; goto done; }
+        remaining -= n;
+    }
+    rewind(src);
+    uint64_t reported_size = 0;
+    if (dm_media_encrypt_stream(key1, author, id, src, cipher, &reported_size, hash) != 0 || reported_size != size) {
+        failed = 1;
+        goto done;
+    }
+    long cipher_size = ftell(cipher);
+    size_t records = size ? (size + DM_MEDIA_PLAIN_SIZE - 1) / DM_MEDIA_PLAIN_SIZE : 1;
+    if (cipher_size != (long)(size + records * DM_TAG_SIZE)) { failed = 1; goto done; }
+    rewind(cipher);
+    if (dm_media_decrypt_stream(key2, author, id, size, hash, cipher, plain) != 0 || ftell(plain) != (long)size) {
+        failed = 1;
+        goto done;
+    }
+    rewind(plain);
+    remaining = size;
+    while (remaining) {
+        size_t n = remaining > sizeof(actual) ? sizeof(actual) : remaining;
+        if (fread(actual, 1, n, plain) != n || memcmp(actual, pattern, n)) { failed = 1; goto done; }
+        remaining -= n;
+    }
+    /* Неправильный получатель, автор, ID и manifest hash не принимаются. */
+    uint8_t wrong_key[32] = {0};
+    rewind(cipher);
+    if (dm_media_decrypt_stream(wrong_key, author, id, size, hash, cipher, plain) == 0) failed = 1;
+    rewind(cipher);
+    if (dm_media_decrypt_stream(key2, author + 1, id, size, hash, cipher, plain) == 0) failed = 1;
+    id[1] = 1;
+    rewind(cipher);
+    if (dm_media_decrypt_stream(key2, author, id, size, hash, cipher, plain) == 0) failed = 1;
+    id[1] = 0;
+    hash[0] ^= 1;
+    rewind(cipher);
+    if (dm_media_decrypt_stream(key2, author, id, size, hash, cipher, plain) == 0) failed = 1;
+    hash[0] ^= 1;
+    /* Обрезанный файл и лишние байты обнаруживаются независимо от тегов порций. */
+    rewind(cipher);
+    for (long i = 0; i < cipher_size - 1; i++) {
+        int ch = fgetc(cipher);
+        if (ch == EOF || fputc(ch, short_cipher) == EOF) { failed = 1; goto done; }
+    }
+    rewind(short_cipher);
+    if (dm_media_decrypt_stream(key2, author, id, size, hash, short_cipher, plain) == 0) failed = 1;
+    fseek(cipher, 0, SEEK_END);
+    if (fputc(1, cipher) == EOF) { failed = 1; goto done; }
+    rewind(cipher);
+    if (dm_media_decrypt_stream(key2, author, id, size, hash, cipher, plain) == 0) failed = 1;
+done:
+    fclose(src);
+    fclose(cipher);
+    fclose(plain);
+    fclose(short_cipher);
+    if (failed) DEBUG_ERROR(DEBUG_CATEGORY_DM, "media stream test failed plain_size=%zu", size);
+    return failed;
+}
+
 int main(void) {
     debug_config_init();
     debug_set_level(DEBUG_LEVEL_ERROR);
@@ -131,6 +210,9 @@ int main(void) {
     u_free(large);
     u_free(cipher);
     u_free(restored);
+    const size_t file_sizes[] = {0, 1, DM_MEDIA_PLAIN_SIZE, DM_MEDIA_PLAIN_SIZE + 1, DM_MEDIA_PLAIN_SIZE * 3 + 77};
+    for (size_t i = 0; i < sizeof(file_sizes) / sizeof(file_sizes[0]); i++)
+        failures += test_media_stream(key1, key2, a, file_sizes[i]);
 
     if (failures == 0) {
         printf("TEST PASSED\n");