File size: 6,151 Bytes
2166d7e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | #include "cs_test.h"
#include "cs_sha256.h"
#include "l8_worm.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
static void witness(uint8_t out[32], int n) { cs_sha256(&n, sizeof n, out); }
static char *slurp(const char *path, size_t *len)
{
FILE *f = fopen(path, "rb");
if (!f) return NULL;
static char buf[1 << 16];
*len = fread(buf, 1, sizeof buf - 1, f);
fclose(f);
buf[*len] = '\0';
return buf;
}
static void spit(const char *path, const char *data, size_t len)
{
FILE *f = fopen(path, "wb");
fwrite(data, 1, len, f);
fclose(f);
}
TEST_MAIN_BEGIN("l8 worm")
uint8_t w[32];
worm_ledger l;
/* in-memory chain */
CHECK_EQ_STATUS(worm_open(&l, NULL), CS_OK);
CHECK(worm_count(&l) == 1);
const worm_seal genesis_copy = *worm_at(&l, 0); /* by value: appends may reallocate */
const worm_seal *g = &genesis_copy;
uint8_t expect_genesis[32];
cs_sha256("cstack-worm-genesis-v1", 22, expect_genesis);
CHECK(g->index == 0 && memcmp(g->seal, expect_genesis, 32) == 0);
CHECK_EQ_STATUS(worm_verify(&l), CS_OK);
for (int i = 1; i <= 100; i++) {
witness(w, i);
worm_seal s;
CHECK_EQ_STATUS(worm_append(&l, w, &s), CS_OK);
CHECK(s.index == (uint64_t)i);
}
CHECK(worm_count(&l) == 101 && worm_head(&l)->index == 100);
CHECK_EQ_STATUS(worm_verify(&l), CS_OK);
CHECK(worm_at(&l, 101) == NULL);
/* seal_i really chains seal_{i-1}: recompute independently */
{
cs_sha256_ctx c;
uint8_t want[32];
witness(w, 1);
cs_sha256_init(&c);
cs_sha256_update(&c, "cstack-worm-seal-v1", 19);
cs_sha256_update_u64(&c, 1);
cs_sha256_update(&c, g->seal, 32);
cs_sha256_update(&c, w, 32);
cs_sha256_final(&c, want);
CHECK(memcmp(worm_at(&l, 1)->seal, want, 32) == 0);
}
/* tamper detection on the chain: every kind of edit is caught */
worm_seal copy[101];
int caught = 0, tries = 0;
for (size_t i = 0; i < 101; i++) {
for (int field = 0; field < 3; field++) {
memcpy(copy, l.seals, sizeof copy);
if (field == 0) copy[i].index ^= 1;
else if (field == 1) copy[i].witness_digest[7] ^= 0x10;
else copy[i].seal[31] ^= 1;
tries++;
if (worm_verify_chain(copy, 101) == CS_ERR_TAMPER) caught++;
}
}
CHECK(caught == tries);
memcpy(copy, l.seals, sizeof copy); /* reordering */
worm_seal tmp = copy[5]; copy[5] = copy[6]; copy[6] = tmp;
CHECK_EQ_STATUS(worm_verify_chain(copy, 101), CS_ERR_TAMPER);
memcpy(copy, l.seals, sizeof copy); /* deleting a middle entry */
memmove(©[50], ©[51], 50 * sizeof copy[0]);
CHECK_EQ_STATUS(worm_verify_chain(copy, 100), CS_ERR_TAMPER);
CHECK_EQ_STATUS(worm_verify_chain(l.seals + 1, 100), CS_ERR_TAMPER); /* no genesis */
CHECK_EQ_STATUS(worm_verify_chain(l.seals, 50), CS_OK); /* a prefix is a valid chain */
CHECK_EQ_STATUS(worm_verify_chain(NULL, 0), CS_ERR_TAMPER);
worm_close(&l);
CHECK(worm_count(&l) == 0);
/* file-backed ledger: persistence across open/close */
const char *path = "build/worm_test.ledger";
remove(path);
CHECK_EQ_STATUS(worm_open(&l, path), CS_OK);
for (int i = 1; i <= 5; i++) { witness(w, i); CHECK_EQ_STATUS(worm_append(&l, w, NULL), CS_OK); }
uint8_t head[32];
memcpy(head, worm_head(&l)->seal, 32);
worm_close(&l);
CHECK_EQ_STATUS(worm_open(&l, path), CS_OK);
CHECK(worm_count(&l) == 6 && memcmp(worm_head(&l)->seal, head, 32) == 0);
witness(w, 6);
CHECK_EQ_STATUS(worm_append(&l, w, NULL), CS_OK); /* continues the same chain */
worm_close(&l);
CHECK_EQ_STATUS(worm_open(&l, path), CS_OK);
CHECK(worm_count(&l) == 7);
worm_close(&l);
size_t len = 0;
char *orig = slurp(path, &len);
char saved[1 << 12];
CHECK(orig != NULL && len < sizeof saved);
memcpy(saved, orig, len + 1);
size_t saved_len = len;
/* edit a witness digest on disk */
char mod[1 << 12];
memcpy(mod, saved, saved_len + 1);
char *p = strchr(mod, '\n'); /* start of line 1 */
p += 1 + 2 + 1; /* "1 " then first hex digit */
*p = (*p == '0') ? '1' : '0';
spit(path, mod, saved_len);
CHECK_EQ_STATUS(worm_open(&l, path), CS_ERR_TAMPER);
/* delete a middle line */
{
char *s1 = strchr(saved, '\n') + 1, *s2 = strchr(s1, '\n') + 1, *s3 = strchr(s2, '\n') + 1;
memcpy(mod, saved, (size_t)(s2 - saved));
memcpy(mod + (s2 - saved), s3, saved_len - (size_t)(s3 - saved));
spit(path, mod, saved_len - (size_t)(s3 - s2));
CHECK_EQ_STATUS(worm_open(&l, path), CS_ERR_TAMPER);
}
/* truncated last line (crash mid-write) */
spit(path, saved, saved_len - 10);
CHECK_EQ_STATUS(worm_open(&l, path), CS_ERR_TAMPER);
/* truncation at a line boundary yields a shorter but valid chain (documented limit: pair with an external head) */
{
char *last = saved + saved_len - 1;
while (last > saved && *(last - 1) != '\n') last--;
spit(path, saved, (size_t)(last - saved));
CHECK_EQ_STATUS(worm_open(&l, path), CS_OK);
CHECK(worm_count(&l) == 6);
worm_close(&l);
}
/* garbage */
spit(path, "not a ledger\n", 13);
CHECK_EQ_STATUS(worm_open(&l, path), CS_ERR_TAMPER);
/* a file that does not start at genesis */
{
char *s1 = strchr(saved, '\n') + 1;
spit(path, s1, saved_len - (size_t)(s1 - saved));
CHECK_EQ_STATUS(worm_open(&l, path), CS_ERR_TAMPER);
}
remove(path);
CHECK_EQ_STATUS(worm_open(&l, "build/no_such_dir/x.ledger"), CS_ERR_IO);
CHECK_EQ_STATUS(worm_open(NULL, NULL), CS_ERR_ARG);
worm_ledger z;
memset(&z, 0, sizeof z);
witness(w, 1);
CHECK_EQ_STATUS(worm_append(&z, w, NULL), CS_ERR_ARG); /* not opened */
TEST_MAIN_END
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