diff options
author | Damien Miller <djm@mindrot.org> | 2010-11-05 10:19:49 +1100 |
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committer | Damien Miller <djm@mindrot.org> | 2010-11-05 10:19:49 +1100 |
commit | b472a90d4ceca15620aa525099bf4b2d5ba8a59b (patch) | |
tree | f4b9c97b1c3d78f68da5159852b7593a280edcf5 /key.c | |
parent | 3a0e9f6479d50a95b5ccd7d7668b0ff45571de9c (diff) |
- djm@cvs.openbsd.org 2010/10/28 11:22:09
[authfile.c key.c key.h ssh-keygen.c]
fix a possible NULL deref on loading a corrupt ECDH key
store ECDH group information in private keys files as "named groups"
rather than as a set of explicit group parameters (by setting
the OPENSSL_EC_NAMED_CURVE flag). This makes for shorter key files and
retrieves the group's OpenSSL NID that we need for various things.
Diffstat (limited to 'key.c')
-rw-r--r-- | key.c | 31 |
1 files changed, 22 insertions, 9 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: key.c,v 1.93 2010/09/09 10:45:45 djm Exp $ */ +/* $OpenBSD: key.c,v 1.94 2010/10/28 11:22:09 djm Exp $ */ /* * read_bignum(): * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -1053,12 +1053,8 @@ key_ecdsa_bits_to_nid(int bits) } #ifdef OPENSSL_HAS_ECC -/* - * This is horrid, but OpenSSL's PEM_read_PrivateKey seems not to restore - * the EC_GROUP nid when loading a key... - */ int -key_ecdsa_group_to_nid(const EC_GROUP *g) +key_ecdsa_key_to_nid(EC_KEY *k) { EC_GROUP *eg; int nids[] = { @@ -1067,23 +1063,39 @@ key_ecdsa_group_to_nid(const EC_GROUP *g) NID_secp521r1, -1 }; + int nid; u_int i; BN_CTX *bnctx; + const EC_GROUP *g = EC_KEY_get0_group(k); + /* + * The group may be stored in a ASN.1 encoded private key in one of two + * ways: as a "named group", which is reconstituted by ASN.1 object ID + * or explicit group parameters encoded into the key blob. Only the + * "named group" case sets the group NID for us, but we can figure + * it out for the other case by comparing against all the groups that + * are supported. + */ + if ((nid = EC_GROUP_get_curve_name(g)) > 0) + return nid; if ((bnctx = BN_CTX_new()) == NULL) fatal("%s: BN_CTX_new() failed", __func__); for (i = 0; nids[i] != -1; i++) { if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) fatal("%s: EC_GROUP_new_by_curve_name failed", __func__); - if (EC_GROUP_cmp(g, eg, bnctx) == 0) { - EC_GROUP_free(eg); + if (EC_GROUP_cmp(g, eg, bnctx) == 0) break; - } EC_GROUP_free(eg); } BN_CTX_free(bnctx); debug3("%s: nid = %d", __func__, nids[i]); + if (nids[i] != -1) { + /* Use the group with the NID attached */ + EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); + if (EC_KEY_set_group(k, eg) != 1) + fatal("%s: EC_KEY_set_group", __func__); + } return nids[i]; } @@ -1098,6 +1110,7 @@ ecdsa_generate_private_key(u_int bits, int *nid) fatal("%s: EC_KEY_new_by_curve_name failed", __func__); if (EC_KEY_generate_key(private) != 1) fatal("%s: EC_KEY_generate_key failed", __func__); + EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); return private; } #endif /* OPENSSL_HAS_ECC */ |