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authordjm@openbsd.org <djm@openbsd.org>2020-04-11 10:16:11 +0000
committerDamien Miller <djm@mindrot.org>2020-04-11 20:20:58 +1000
commit3779b50ee952078018a5d9e1df20977f4355df17 (patch)
tree4f21fc8fb3bdba5432e34064560f543479eee4ea /sshkey.c
parentb6a4013647db67ec622c144a9e05dd768f1966b3 (diff)
upstream: Refactor private key parsing. Eliminates a fair bit of
duplicated code and fixes oss-fuzz#20074 (NULL deref) caused by a missing key type check in the ECDSA_CERT parsing path. feedback and ok markus@ OpenBSD-Commit-ID: 4711981d88afb7196d228f7baad9be1d3b20f9c9
Diffstat (limited to 'sshkey.c')
-rw-r--r--sshkey.c187
1 files changed, 40 insertions, 147 deletions
diff --git a/sshkey.c b/sshkey.c
index d6cc6365f..1571e3d93 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
1/* $OpenBSD: sshkey.c,v 1.107 2020/04/08 00:08:46 djm Exp $ */ 1/* $OpenBSD: sshkey.c,v 1.108 2020/04/11 10:16:11 djm Exp $ */
2/* 2/*
3 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 3 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
4 * Copyright (c) 2008 Alexander von Gernler. All rights reserved. 4 * Copyright (c) 2008 Alexander von Gernler. All rights reserved.
@@ -3394,38 +3394,52 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3394 if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0) 3394 if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0)
3395 goto out; 3395 goto out;
3396 type = sshkey_type_from_name(tname); 3396 type = sshkey_type_from_name(tname);
3397 switch (type) { 3397 if (sshkey_type_is_cert(type)) {
3398#ifdef WITH_OPENSSL 3398 /*
3399 case KEY_DSA: 3399 * Certificate key private keys begin with the certificate
3400 * itself. Make sure this matches the type of the enclosing
3401 * private key.
3402 */
3403 if ((r = sshkey_froms(buf, &k)) != 0)
3404 goto out;
3405 if (k->type != type) {
3406 r = SSH_ERR_KEY_CERT_MISMATCH;
3407 goto out;
3408 }
3409 /* For ECDSA keys, the group must match too */
3410 if (k->type == KEY_ECDSA &&
3411 k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) {
3412 r = SSH_ERR_KEY_CERT_MISMATCH;
3413 goto out;
3414 }
3415 } else {
3400 if ((k = sshkey_new(type)) == NULL) { 3416 if ((k = sshkey_new(type)) == NULL) {
3401 r = SSH_ERR_ALLOC_FAIL; 3417 r = SSH_ERR_ALLOC_FAIL;
3402 goto out; 3418 goto out;
3403 } 3419 }
3420 }
3421 switch (type) {
3422#ifdef WITH_OPENSSL
3423 case KEY_DSA:
3404 if ((r = sshbuf_get_bignum2(buf, &dsa_p)) != 0 || 3424 if ((r = sshbuf_get_bignum2(buf, &dsa_p)) != 0 ||
3405 (r = sshbuf_get_bignum2(buf, &dsa_q)) != 0 || 3425 (r = sshbuf_get_bignum2(buf, &dsa_q)) != 0 ||
3406 (r = sshbuf_get_bignum2(buf, &dsa_g)) != 0 || 3426 (r = sshbuf_get_bignum2(buf, &dsa_g)) != 0 ||
3407 (r = sshbuf_get_bignum2(buf, &dsa_pub_key)) != 0 || 3427 (r = sshbuf_get_bignum2(buf, &dsa_pub_key)) != 0)
3408 (r = sshbuf_get_bignum2(buf, &dsa_priv_key)) != 0)
3409 goto out; 3428 goto out;
3410 if (!DSA_set0_pqg(k->dsa, dsa_p, dsa_q, dsa_g)) { 3429 if (!DSA_set0_pqg(k->dsa, dsa_p, dsa_q, dsa_g)) {
3411 r = SSH_ERR_LIBCRYPTO_ERROR; 3430 r = SSH_ERR_LIBCRYPTO_ERROR;
3412 goto out; 3431 goto out;
3413 } 3432 }
3414 dsa_p = dsa_q = dsa_g = NULL; /* transferred */ 3433 dsa_p = dsa_q = dsa_g = NULL; /* transferred */
3415 if (!DSA_set0_key(k->dsa, dsa_pub_key, dsa_priv_key)) { 3434 if (!DSA_set0_key(k->dsa, dsa_pub_key, NULL)) {
3416 r = SSH_ERR_LIBCRYPTO_ERROR; 3435 r = SSH_ERR_LIBCRYPTO_ERROR;
3417 goto out; 3436 goto out;
3418 } 3437 }
3419 dsa_pub_key = dsa_priv_key = NULL; /* transferred */ 3438 dsa_pub_key = NULL; /* transferred */
3420 break; 3439 /* FALLTHROUGH */
3421 case KEY_DSA_CERT: 3440 case KEY_DSA_CERT:
3422 if ((r = sshkey_froms(buf, &k)) != 0 || 3441 if ((r = sshbuf_get_bignum2(buf, &dsa_priv_key)) != 0)
3423 (r = sshbuf_get_bignum2(buf, &dsa_priv_key)) != 0)
3424 goto out; 3442 goto out;
3425 if (k->type != type) {
3426 r = SSH_ERR_INVALID_FORMAT;
3427 goto out;
3428 }
3429 if (!DSA_set0_key(k->dsa, NULL, dsa_priv_key)) { 3443 if (!DSA_set0_key(k->dsa, NULL, dsa_priv_key)) {
3430 r = SSH_ERR_LIBCRYPTO_ERROR; 3444 r = SSH_ERR_LIBCRYPTO_ERROR;
3431 goto out; 3445 goto out;
@@ -3434,10 +3448,6 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3434 break; 3448 break;
3435# ifdef OPENSSL_HAS_ECC 3449# ifdef OPENSSL_HAS_ECC
3436 case KEY_ECDSA: 3450 case KEY_ECDSA:
3437 if ((k = sshkey_new(type)) == NULL) {
3438 r = SSH_ERR_ALLOC_FAIL;
3439 goto out;
3440 }
3441 if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) { 3451 if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) {
3442 r = SSH_ERR_INVALID_ARGUMENT; 3452 r = SSH_ERR_INVALID_ARGUMENT;
3443 goto out; 3453 goto out;
@@ -3453,27 +3463,12 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3453 r = SSH_ERR_LIBCRYPTO_ERROR; 3463 r = SSH_ERR_LIBCRYPTO_ERROR;
3454 goto out; 3464 goto out;
3455 } 3465 }
3456 if ((r = sshbuf_get_eckey(buf, k->ecdsa)) != 0 || 3466 if ((r = sshbuf_get_eckey(buf, k->ecdsa)) != 0)
3457 (r = sshbuf_get_bignum2(buf, &exponent)))
3458 goto out;
3459 if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
3460 r = SSH_ERR_LIBCRYPTO_ERROR;
3461 goto out;
3462 }
3463 if ((r = sshkey_ec_validate_public(EC_KEY_get0_group(k->ecdsa),
3464 EC_KEY_get0_public_key(k->ecdsa))) != 0 ||
3465 (r = sshkey_ec_validate_private(k->ecdsa)) != 0)
3466 goto out; 3467 goto out;
3467 break; 3468 /* FALLTHROUGH */
3468 case KEY_ECDSA_CERT: 3469 case KEY_ECDSA_CERT:
3469 if ((r = sshkey_froms(buf, &k)) != 0 || 3470 if ((r = sshbuf_get_bignum2(buf, &exponent)) != 0)
3470 (r = sshbuf_get_bignum2(buf, &exponent)) != 0)
3471 goto out;
3472 if (k->type != type ||
3473 k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) {
3474 r = SSH_ERR_INVALID_FORMAT;
3475 goto out; 3471 goto out;
3476 }
3477 if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) { 3472 if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
3478 r = SSH_ERR_LIBCRYPTO_ERROR; 3473 r = SSH_ERR_LIBCRYPTO_ERROR;
3479 goto out; 3474 goto out;
@@ -3484,10 +3479,6 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3484 goto out; 3479 goto out;
3485 break; 3480 break;
3486 case KEY_ECDSA_SK: 3481 case KEY_ECDSA_SK:
3487 if ((k = sshkey_new(type)) == NULL) {
3488 r = SSH_ERR_ALLOC_FAIL;
3489 goto out;
3490 }
3491 if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) { 3482 if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) {
3492 r = SSH_ERR_INVALID_ARGUMENT; 3483 r = SSH_ERR_INVALID_ARGUMENT;
3493 goto out; 3484 goto out;
@@ -3520,8 +3511,6 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3520 goto out; 3511 goto out;
3521 break; 3512 break;
3522 case KEY_ECDSA_SK_CERT: 3513 case KEY_ECDSA_SK_CERT:
3523 if ((r = sshkey_froms(buf, &k)) != 0)
3524 goto out;
3525 if ((k->sk_key_handle = sshbuf_new()) == NULL || 3514 if ((k->sk_key_handle = sshbuf_new()) == NULL ||
3526 (k->sk_reserved = sshbuf_new()) == NULL) { 3515 (k->sk_reserved = sshbuf_new()) == NULL) {
3527 r = SSH_ERR_ALLOC_FAIL; 3516 r = SSH_ERR_ALLOC_FAIL;
@@ -3539,43 +3528,21 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3539 break; 3528 break;
3540# endif /* OPENSSL_HAS_ECC */ 3529# endif /* OPENSSL_HAS_ECC */
3541 case KEY_RSA: 3530 case KEY_RSA:
3542 if ((k = sshkey_new(type)) == NULL) {
3543 r = SSH_ERR_ALLOC_FAIL;
3544 goto out;
3545 }
3546 if ((r = sshbuf_get_bignum2(buf, &rsa_n)) != 0 || 3531 if ((r = sshbuf_get_bignum2(buf, &rsa_n)) != 0 ||
3547 (r = sshbuf_get_bignum2(buf, &rsa_e)) != 0 || 3532 (r = sshbuf_get_bignum2(buf, &rsa_e)) != 0)
3548 (r = sshbuf_get_bignum2(buf, &rsa_d)) != 0 ||
3549 (r = sshbuf_get_bignum2(buf, &rsa_iqmp)) != 0 ||
3550 (r = sshbuf_get_bignum2(buf, &rsa_p)) != 0 ||
3551 (r = sshbuf_get_bignum2(buf, &rsa_q)) != 0)
3552 goto out;
3553 if (!RSA_set0_key(k->rsa, rsa_n, rsa_e, rsa_d)) {
3554 r = SSH_ERR_LIBCRYPTO_ERROR;
3555 goto out; 3533 goto out;
3556 } 3534 if (!RSA_set0_key(k->rsa, rsa_n, rsa_e, NULL)) {
3557 rsa_n = rsa_e = rsa_d = NULL; /* transferred */
3558 if (!RSA_set0_factors(k->rsa, rsa_p, rsa_q)) {
3559 r = SSH_ERR_LIBCRYPTO_ERROR; 3535 r = SSH_ERR_LIBCRYPTO_ERROR;
3560 goto out; 3536 goto out;
3561 } 3537 }
3562 rsa_p = rsa_q = NULL; /* transferred */ 3538 rsa_n = rsa_e = NULL; /* transferred */
3563 if ((r = check_rsa_length(k->rsa)) != 0) 3539 /* FALLTHROUGH */
3564 goto out;
3565 if ((r = ssh_rsa_complete_crt_parameters(k, rsa_iqmp)) != 0)
3566 goto out;
3567 break;
3568 case KEY_RSA_CERT: 3540 case KEY_RSA_CERT:
3569 if ((r = sshkey_froms(buf, &k)) != 0 || 3541 if ((r = sshbuf_get_bignum2(buf, &rsa_d)) != 0 ||
3570 (r = sshbuf_get_bignum2(buf, &rsa_d)) != 0 ||
3571 (r = sshbuf_get_bignum2(buf, &rsa_iqmp)) != 0 || 3542 (r = sshbuf_get_bignum2(buf, &rsa_iqmp)) != 0 ||
3572 (r = sshbuf_get_bignum2(buf, &rsa_p)) != 0 || 3543 (r = sshbuf_get_bignum2(buf, &rsa_p)) != 0 ||
3573 (r = sshbuf_get_bignum2(buf, &rsa_q)) != 0) 3544 (r = sshbuf_get_bignum2(buf, &rsa_q)) != 0)
3574 goto out; 3545 goto out;
3575 if (k->type != type) {
3576 r = SSH_ERR_INVALID_FORMAT;
3577 goto out;
3578 }
3579 if (!RSA_set0_key(k->rsa, NULL, NULL, rsa_d)) { 3546 if (!RSA_set0_key(k->rsa, NULL, NULL, rsa_d)) {
3580 r = SSH_ERR_LIBCRYPTO_ERROR; 3547 r = SSH_ERR_LIBCRYPTO_ERROR;
3581 goto out; 3548 goto out;
@@ -3593,30 +3560,10 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3593 break; 3560 break;
3594#endif /* WITH_OPENSSL */ 3561#endif /* WITH_OPENSSL */
3595 case KEY_ED25519: 3562 case KEY_ED25519:
3596 if ((k = sshkey_new(type)) == NULL) {
3597 r = SSH_ERR_ALLOC_FAIL;
3598 goto out;
3599 }
3600 if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
3601 (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
3602 goto out;
3603 if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
3604 r = SSH_ERR_INVALID_FORMAT;
3605 goto out;
3606 }
3607 k->ed25519_pk = ed25519_pk;
3608 k->ed25519_sk = ed25519_sk;
3609 ed25519_pk = ed25519_sk = NULL;
3610 break;
3611 case KEY_ED25519_CERT: 3563 case KEY_ED25519_CERT:
3612 if ((r = sshkey_froms(buf, &k)) != 0 || 3564 if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
3613 (r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
3614 (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0) 3565 (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
3615 goto out; 3566 goto out;
3616 if (k->type != type) {
3617 r = SSH_ERR_INVALID_FORMAT;
3618 goto out;
3619 }
3620 if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) { 3567 if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
3621 r = SSH_ERR_INVALID_FORMAT; 3568 r = SSH_ERR_INVALID_FORMAT;
3622 goto out; 3569 goto out;
@@ -3626,38 +3573,9 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3626 ed25519_pk = ed25519_sk = NULL; /* transferred */ 3573 ed25519_pk = ed25519_sk = NULL; /* transferred */
3627 break; 3574 break;
3628 case KEY_ED25519_SK: 3575 case KEY_ED25519_SK:
3629 if ((k = sshkey_new(type)) == NULL) {
3630 r = SSH_ERR_ALLOC_FAIL;
3631 goto out;
3632 }
3633 if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0)
3634 goto out;
3635 if (pklen != ED25519_PK_SZ) {
3636 r = SSH_ERR_INVALID_FORMAT;
3637 goto out;
3638 }
3639 if ((k->sk_key_handle = sshbuf_new()) == NULL ||
3640 (k->sk_reserved = sshbuf_new()) == NULL) {
3641 r = SSH_ERR_ALLOC_FAIL;
3642 goto out;
3643 }
3644 if ((r = sshbuf_get_cstring(buf, &k->sk_application,
3645 NULL)) != 0 ||
3646 (r = sshbuf_get_u8(buf, &k->sk_flags)) != 0 ||
3647 (r = sshbuf_get_stringb(buf, k->sk_key_handle)) != 0 ||
3648 (r = sshbuf_get_stringb(buf, k->sk_reserved)) != 0)
3649 goto out;
3650 k->ed25519_pk = ed25519_pk;
3651 ed25519_pk = NULL;
3652 break;
3653 case KEY_ED25519_SK_CERT: 3576 case KEY_ED25519_SK_CERT:
3654 if ((r = sshkey_froms(buf, &k)) != 0 || 3577 if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0)
3655 (r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0)
3656 goto out;
3657 if (k->type != type) {
3658 r = SSH_ERR_INVALID_FORMAT;
3659 goto out; 3578 goto out;
3660 }
3661 if (pklen != ED25519_PK_SZ) { 3579 if (pklen != ED25519_PK_SZ) {
3662 r = SSH_ERR_INVALID_FORMAT; 3580 r = SSH_ERR_INVALID_FORMAT;
3663 goto out; 3581 goto out;
@@ -3678,10 +3596,7 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3678 break; 3596 break;
3679#ifdef WITH_XMSS 3597#ifdef WITH_XMSS
3680 case KEY_XMSS: 3598 case KEY_XMSS:
3681 if ((k = sshkey_new(type)) == NULL) { 3599 case KEY_XMSS_CERT:
3682 r = SSH_ERR_ALLOC_FAIL;
3683 goto out;
3684 }
3685 if ((r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 || 3600 if ((r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 ||
3686 (r = sshkey_xmss_init(k, xmss_name)) != 0 || 3601 (r = sshkey_xmss_init(k, xmss_name)) != 0 ||
3687 (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 || 3602 (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 ||
@@ -3699,28 +3614,6 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
3699 if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0) 3614 if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0)
3700 goto out; 3615 goto out;
3701 break; 3616 break;
3702 case KEY_XMSS_CERT:
3703 if ((r = sshkey_froms(buf, &k)) != 0 ||
3704 (r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 ||
3705 (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 ||
3706 (r = sshbuf_get_string(buf, &xmss_sk, &sklen)) != 0)
3707 goto out;
3708 if (k->type != type || strcmp(xmss_name, k->xmss_name) != 0) {
3709 r = SSH_ERR_INVALID_FORMAT;
3710 goto out;
3711 }
3712 if (pklen != sshkey_xmss_pklen(k) ||
3713 sklen != sshkey_xmss_sklen(k)) {
3714 r = SSH_ERR_INVALID_FORMAT;
3715 goto out;
3716 }
3717 k->xmss_pk = xmss_pk;
3718 k->xmss_sk = xmss_sk;
3719 xmss_pk = xmss_sk = NULL;
3720 /* optional internal state */
3721 if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0)
3722 goto out;
3723 break;
3724#endif /* WITH_XMSS */ 3617#endif /* WITH_XMSS */
3725 default: 3618 default:
3726 r = SSH_ERR_KEY_TYPE_UNKNOWN; 3619 r = SSH_ERR_KEY_TYPE_UNKNOWN;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-18 12:04:32 +0000