0703ef62d3
This commit changes the behavior of BitCurve.Add to be more inline with btcd. It fixes two different bugs: 1) When adding a point at infinity to another point, the other point should be returned. While this is undefined behavior, it is better to be more inline with the go standard library. Thus (0,0) + (a, b) = (a,b) 2) Adding the same point to itself produced the point at infinity. This is incorrect, now doubleJacobian is used to correctly calculate it. Thus (a,b) + (a,b) == 2* (a,b) and not (0,0) anymore. The change also adds a differential fuzzer for Add, testing it against btcd. Co-authored-by: Felix Lange <fjl@twurst.com> |
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|---|---|---|
| .. | ||
| abi | ||
| bitutil | ||
| bls12381 | ||
| bn256 | ||
| difficulty | ||
| keystore | ||
| les | ||
| rangeproof | ||
| rlp | ||
| runtime | ||
| secp256k1 | ||
| stacktrie | ||
| trie | ||
| txfetcher | ||
| vflux | ||
| README.md | ||
Fuzzers
To run a fuzzer locally, you need go-fuzz installed.
First build a fuzzing-binary out of the selected package:
(cd ./rlp && CGO_ENABLED=0 go-fuzz-build .)
That command should generate a rlp-fuzz.zip in the rlp/ directory. If you are already in that directory, you can do
[user@work rlp]$ go-fuzz
2019/11/26 13:36:54 workers: 6, corpus: 3 (3s ago), crashers: 0, restarts: 1/0, execs: 0 (0/sec), cover: 0, uptime: 3s
2019/11/26 13:36:57 workers: 6, corpus: 3 (6s ago), crashers: 0, restarts: 1/0, execs: 0 (0/sec), cover: 1054, uptime: 6s
2019/11/26 13:37:00 workers: 6, corpus: 3 (9s ago), crashers: 0, restarts: 1/8358, execs: 25074 (2786/sec), cover: 1054, uptime: 9s
2019/11/26 13:37:03 workers: 6, corpus: 3 (12s ago), crashers: 0, restarts: 1/8497, execs: 50986 (4249/sec), cover: 1054, uptime: 12s
2019/11/26 13:37:06 workers: 6, corpus: 3 (15s ago), crashers: 0, restarts: 1/9330, execs: 74640 (4976/sec), cover: 1054, uptime: 15s
2019/11/26 13:37:09 workers: 6, corpus: 3 (18s ago), crashers: 0, restarts: 1/9948, execs: 99482 (5527/sec), cover: 1054, uptime: 18s
2019/11/26 13:37:12 workers: 6, corpus: 3 (21s ago), crashers: 0, restarts: 1/9428, execs: 122568 (5836/sec), cover: 1054, uptime: 21s
2019/11/26 13:37:15 workers: 6, corpus: 3 (24s ago), crashers: 0, restarts: 1/9676, execs: 145152 (6048/sec), cover: 1054, uptime: 24s
2019/11/26 13:37:18 workers: 6, corpus: 3 (27s ago), crashers: 0, restarts: 1/9855, execs: 167538 (6205/sec), cover: 1054, uptime: 27s
2019/11/26 13:37:21 workers: 6, corpus: 3 (30s ago), crashers: 0, restarts: 1/9645, execs: 192901 (6430/sec), cover: 1054, uptime: 30s
2019/11/26 13:37:24 workers: 6, corpus: 3 (33s ago), crashers: 0, restarts: 1/9967, execs: 219294 (6645/sec), cover: 1054, uptime: 33s
Otherwise:
go-fuzz -bin ./rlp/rlp-fuzz.zip
Notes
Once a 'crasher' is found, the fuzzer tries to avoid reporting the same vector twice, so stores the fault in the suppressions folder. Thus, if you
e.g. make changes to fix a bug, you should remove all data from the suppressions-folder, to verify that the issue is indeed resolved.
Also, if you have only one and the same exit-point for multiple different types of test, the suppression can make the fuzzer hide different types of errors. So make
sure that each type of failure is unique (for an example, see the rlp fuzzer, where a counter i is used to differentiate between failures:
if !bytes.Equal(input, output) {
panic(fmt.Sprintf("case %d: encode-decode is not equal, \ninput : %x\noutput: %x", i, input, output))
}