diff options
| author | djm@openbsd.org <djm@openbsd.org> | 2021-05-31 06:48:42 +0000 |
|---|---|---|
| committer | Damien Miller <djm@mindrot.org> | 2021-05-31 16:50:00 +1000 |
| commit | 59a194825f12fff8a7f75d91bf751ea17645711b (patch) | |
| tree | cadbf3bb984bdf4eeed536150a550f1aa59b23dc | |
| parent | eb68e669bc8ab968d4cca5bf1357baca7136a826 (diff) | |
upstream: Hash challenge supplied by client during FIDO key enrollment
prior to passing it to libfido2, which does expect a hash.
There is no effect for users who are simply generating FIDO keys using
ssh-keygen - by default we generate a random 256 bit challenge, but
people building attestation workflows around our tools should now have
a more consistent experience (esp. fewer failures when they fail to
guess the magic 32-byte challenge length requirement).
ok markus@
OpenBSD-Commit-ID: b8d5363a6a7ca3b23dc28f3ca69470472959f2b5
| -rw-r--r-- | sk-usbhid.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/sk-usbhid.c b/sk-usbhid.c index c85b9857..43898088 100644 --- a/sk-usbhid.c +++ b/sk-usbhid.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sk-usbhid.c,v 1.29 2021/02/18 02:15:07 djm Exp $ */ +/* $OpenBSD: sk-usbhid.c,v 1.30 2021/05/31 06:48:42 djm Exp $ */ /* * Copyright (c) 2019 Markus Friedl * Copyright (c) 2020 Pedro Martelletto @@ -669,7 +669,7 @@ sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, { fido_cred_t *cred = NULL; const uint8_t *ptr; - uint8_t user_id[32]; + uint8_t user_id[32], chall_hash[32]; struct sk_usbhid *sk = NULL; struct sk_enroll_response *response = NULL; size_t len; @@ -721,8 +721,13 @@ sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, skdebug(__func__, "fido_cred_set_type: %s", fido_strerr(r)); goto out; } - if ((r = fido_cred_set_clientdata_hash(cred, challenge, - challenge_len)) != FIDO_OK) { + if (sha256_mem(challenge, challenge_len, + chall_hash, sizeof(chall_hash)) != 0) { + skdebug(__func__, "hash challenge failed"); + goto out; + } + if ((r = fido_cred_set_clientdata_hash(cred, chall_hash, + sizeof(chall_hash))) != FIDO_OK) { skdebug(__func__, "fido_cred_set_clientdata_hash: %s", fido_strerr(r)); goto out; |