From 4ce5741703e2d49927c0b7934a6aed1711ab19fe Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Dec 08 2016 12:50:08 +0000
Subject: Properly deserialize received RSA certificates in ssh-agent (#1402029)


---

diff --git a/openssh-7.3p1-openssl-1.1.0.patch b/openssh-7.3p1-openssl-1.1.0.patch
index 87edc29..77bb7d1 100644
--- a/openssh-7.3p1-openssl-1.1.0.patch
+++ b/openssh-7.3p1-openssl-1.1.0.patch
@@ -3566,7 +3566,7 @@ diff -up openssh-7.3p1/sshkey.c.openssl openssh-7.3p1/sshkey.c
  		break;
  # ifdef OPENSSL_HAS_ECC
  	case KEY_ECDSA:
-@@ -2818,24 +2994,73 @@ sshkey_private_deserialize(struct sshbuf
+@@ -2818,24 +2994,81 @@ sshkey_private_deserialize(struct sshbuf
  			r = SSH_ERR_ALLOC_FAIL;
  			goto out;
  		}
@@ -3631,28 +3631,36 @@ diff -up openssh-7.3p1/sshkey.c.openssl openssh-7.3p1/sshkey.c
 +	case KEY_RSA_CERT: {
 +			BIGNUM *n, *e, *d, *iqmp, *p, *q;
 +
-+			/* XXX leave N, E as zero */
++			/* N can't be zero because it breaks blinding (seed). Count it now */
++			/* E is zero because it is not in the protocol, but needed for RSA structure */
 +			n = BN_new();
 +			e = BN_new();
 +			d = BN_new();
 +			iqmp = BN_new();
 +			p = BN_new();
 +			q = BN_new();
++			BN_CTX *ctx = BN_CTX_new();
 +
 +			if (n == NULL || e == NULL || d == NULL ||
 +			    iqmp == NULL || p == NULL || q == NULL ||
++			    ctx == NULL ||
 +			    (r = sshkey_froms(buf, &k)) != 0 ||
 +			    (r = sshkey_add_private(k)) != 0 ||
 +			    (r = sshbuf_get_bignum2(buf, d)) != 0 ||
 +			    (r = sshbuf_get_bignum2(buf, iqmp)) != 0 ||
 +			    (r = sshbuf_get_bignum2(buf, p)) != 0 ||
 +			    (r = sshbuf_get_bignum2(buf, q)) != 0 ||
++			    (r = ((BN_mul(n, p, q, ctx) == 0)           /* N = P * Q */
++			        ? SSH_ERR_LIBCRYPTO_ERROR : 0)) != 0 ||
 +			    (r = ((RSA_set0_key(k->rsa, n, e, d) == 0)
 +			        ? SSH_ERR_LIBCRYPTO_ERROR : 0)) != 0 ||
 +			    (r = ((RSA_set0_factors(k->rsa, p, q) == 0)
 +			        ? SSH_ERR_LIBCRYPTO_ERROR : 0)) != 0 ||
-+			    (r = rsa_generate_additional_parameters(k->rsa, iqmp)) != 0)
++			    (r = rsa_generate_additional_parameters(k->rsa, iqmp)) != 0) {
++				BN_CTX_free(ctx);
 +				goto out;
++			}
++			BN_CTX_free(ctx);
 +		}
  		break;
  #endif /* WITH_OPENSSL */