diff options
| author | djm@openbsd.org <djm@openbsd.org> | 2020-06-22 05:56:23 +0000 |
|---|---|---|
| committer | Damien Miller <djm@mindrot.org> | 2020-06-22 16:11:14 +1000 |
| commit | 64bc121097f377142f1387ffb2df7592c49935af (patch) | |
| tree | db3bc091dda590eba65eb57ebead71224a0d2401 /ssh-ecdsa-sk.c | |
| parent | 12848191f8fe725af4485d3600e0842d92f8637f (diff) | |
| download | openssh-git-64bc121097f377142f1387ffb2df7592c49935af.tar.gz | |
upstream: refactor ECDSA-SK verification a little ahead of adding
support for FIDO webauthn signature verification support; ok markus@
OpenBSD-Commit-ID: c9f478fd8e0c1bd17e511ce8694f010d8e32043e
Diffstat (limited to 'ssh-ecdsa-sk.c')
| -rw-r--r-- | ssh-ecdsa-sk.c | 44 |
1 files changed, 23 insertions, 21 deletions
diff --git a/ssh-ecdsa-sk.c b/ssh-ecdsa-sk.c index 981d60d7..dcf605ba 100644 --- a/ssh-ecdsa-sk.c +++ b/ssh-ecdsa-sk.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-ecdsa-sk.c,v 1.5 2019/11/26 03:04:27 djm Exp $ */ +/* $OpenBSD: ssh-ecdsa-sk.c,v 1.6 2020/06/22 05:56:23 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -83,15 +83,22 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, /* fetch signature */ if ((b = sshbuf_from(signature, signaturelen)) == NULL) return SSH_ERR_ALLOC_FAIL; - if (sshbuf_get_cstring(b, &ktype, NULL) != 0 || - sshbuf_froms(b, &sigbuf) != 0 || - sshbuf_get_u8(b, &sig_flags) != 0 || - sshbuf_get_u32(b, &sig_counter) != 0) { + if ((details = calloc(1, sizeof(*details))) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } + if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { + ret = SSH_ERR_INVALID_FORMAT; + goto out; + } + if (strcmp(ktype, "sk-ecdsa-sha2-nistp256@openssh.com") != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } - if (strcmp(sshkey_ssh_name_plain(key), ktype) != 0) { - ret = SSH_ERR_KEY_TYPE_MISMATCH; + if (sshbuf_froms(b, &sigbuf) != 0 || + sshbuf_get_u8(b, &sig_flags) != 0 || + sshbuf_get_u32(b, &sig_counter) != 0) { + ret = SSH_ERR_INVALID_FORMAT; goto out; } if (sshbuf_len(b) != 0) { @@ -105,12 +112,8 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, ret = SSH_ERR_INVALID_FORMAT; goto out; } - if ((sig = ECDSA_SIG_new()) == NULL) { - ret = SSH_ERR_ALLOC_FAIL; - goto out; - } - if (!ECDSA_SIG_set0(sig, sig_r, sig_s)) { - ret = SSH_ERR_LIBCRYPTO_ERROR; + if (sshbuf_len(sigbuf) != 0) { + ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } #ifdef DEBUG_SK @@ -123,12 +126,15 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, fprintf(stderr, "%s: sig_flags = 0x%02x, sig_counter = %u\n", __func__, sig_flags, sig_counter); #endif - sig_r = sig_s = NULL; /* transferred */ - - if (sshbuf_len(sigbuf) != 0) { - ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; + if ((sig = ECDSA_SIG_new()) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; goto out; } + if (!ECDSA_SIG_set0(sig, sig_r, sig_s)) { + ret = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } + sig_r = sig_s = NULL; /* transferred */ /* Reconstruct data that was supposedly signed */ if ((original_signed = sshbuf_new()) == NULL) { @@ -158,10 +164,6 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, if ((ret = ssh_digest_buffer(SSH_DIGEST_SHA256, original_signed, sighash, sizeof(sighash))) != 0) goto out; - if ((details = calloc(1, sizeof(*details))) == NULL) { - ret = SSH_ERR_ALLOC_FAIL; - goto out; - } details->sk_counter = sig_counter; details->sk_flags = sig_flags; #ifdef DEBUG_SK |