Remove all guards for calls to OpenSSL free functions - all of these

functions handle NULL, from at least OpenSSL 1.0.1g onwards.

Prompted by dtucker@ asking about guards for RSA_free(), when looking at
openssh-portable pr#84 on github.

ok deraadt@ dtucker@

13 files changed, 61 insertions, 109 deletions

diff --git a/usr.bin/ssh/cipher.c b/usr.bin/ssh/cipher.c
index ec6c138c4d6..cded43b2bb3 100644
--- a/usr.bin/ssh/cipher.c
+++ b/usr.bin/ssh/cipher.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cipher.c,v 1.108 2017/11/03 02:22:41 djm Exp $ */
+/* $OpenBSD: cipher.c,v 1.109 2018/02/07 02:06:50 jsing Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -304,8 +304,7 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
 	} else {
 		if (cc != NULL) {
 #ifdef WITH_OPENSSL
-			if (cc->evp != NULL)
-				EVP_CIPHER_CTX_free(cc->evp);
+			EVP_CIPHER_CTX_free(cc->evp);
 #endif /* WITH_OPENSSL */
 			explicit_bzero(cc, sizeof(*cc));
 			free(cc);
@@ -410,10 +409,8 @@ cipher_free(struct sshcipher_ctx *cc)
 	else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
 		explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx));
 #ifdef WITH_OPENSSL
-	if (cc->evp != NULL) {
-		EVP_CIPHER_CTX_free(cc->evp);
-		cc->evp = NULL;
-	}
+	EVP_CIPHER_CTX_free(cc->evp);
+	cc->evp = NULL;
 #endif
 	explicit_bzero(cc, sizeof(*cc));
 	free(cc);
diff --git a/usr.bin/ssh/dh.c b/usr.bin/ssh/dh.c
index 095f93b6c92..74b4135d4af 100644
--- a/usr.bin/ssh/dh.c
+++ b/usr.bin/ssh/dh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.c,v 1.62 2016/12/15 21:20:41 dtucker Exp $ */
+/* $OpenBSD: dh.c,v 1.63 2018/02/07 02:06:50 jsing Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  *
@@ -131,10 +131,8 @@ parse_prime(int linenum, char *line, struct dhgroup *dhg)
 	return 1;
 
  fail:
-	if (dhg->g != NULL)
-		BN_clear_free(dhg->g);
-	if (dhg->p != NULL)
-		BN_clear_free(dhg->p);
+	BN_clear_free(dhg->g);
+	BN_clear_free(dhg->p);
 	dhg->g = dhg->p = NULL;
 	return 0;
 }
diff --git a/usr.bin/ssh/kex.c b/usr.bin/ssh/kex.c
index f88fefcd2c3..44723db11e4 100644
--- a/usr.bin/ssh/kex.c
+++ b/usr.bin/ssh/kex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.135 2018/01/23 05:27:21 djm Exp $ */
+/* $OpenBSD: kex.c,v 1.136 2018/02/07 02:06:50 jsing Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -575,10 +575,8 @@ kex_free(struct kex *kex)
 	u_int mode;
 
 #ifdef WITH_OPENSSL
-	if (kex->dh)
-		DH_free(kex->dh);
-	if (kex->ec_client_key)
-		EC_KEY_free(kex->ec_client_key);
+	DH_free(kex->dh);
+	EC_KEY_free(kex->ec_client_key);
 #endif
 	for (mode = 0; mode < MODE_MAX; mode++) {
 		kex_free_newkeys(kex->newkeys[mode]);
diff --git a/usr.bin/ssh/kexdhc.c b/usr.bin/ssh/kexdhc.c
index 6b60f59da31..dc06b666ca4 100644
--- a/usr.bin/ssh/kexdhc.c
+++ b/usr.bin/ssh/kexdhc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexdhc.c,v 1.21 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: kexdhc.c,v 1.22 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -198,14 +198,12 @@ input_kex_dh(int type, u_int32_t seq, struct ssh *ssh)
 	explicit_bzero(hash, sizeof(hash));
 	DH_free(kex->dh);
 	kex->dh = NULL;
-	if (dh_server_pub)
-		BN_clear_free(dh_server_pub);
+	BN_clear_free(dh_server_pub);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	sshkey_free(server_host_key);
 	free(server_host_key_blob);
 	free(signature);
diff --git a/usr.bin/ssh/kexdhs.c b/usr.bin/ssh/kexdhs.c
index 6dae3b2db8e..20a061bf502 100644
--- a/usr.bin/ssh/kexdhs.c
+++ b/usr.bin/ssh/kexdhs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexdhs.c,v 1.25 2017/05/30 14:23:52 markus Exp $ */
+/* $OpenBSD: kexdhs.c,v 1.26 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -203,14 +203,12 @@ input_kex_dh_init(int type, u_int32_t seq, struct ssh *ssh)
 	explicit_bzero(hash, sizeof(hash));
 	DH_free(kex->dh);
 	kex->dh = NULL;
-	if (dh_client_pub)
-		BN_clear_free(dh_client_pub);
+	BN_clear_free(dh_client_pub);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	free(server_host_key_blob);
 	free(signature);
 	return r;
diff --git a/usr.bin/ssh/kexecdhc.c b/usr.bin/ssh/kexecdhc.c
index ee6f848cb27..0ff264b38e9 100644
--- a/usr.bin/ssh/kexecdhc.c
+++ b/usr.bin/ssh/kexecdhc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexecdhc.c,v 1.12 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: kexecdhc.c,v 1.13 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -85,8 +85,7 @@ kexecdh_client(struct ssh *ssh)
 	ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_ecdh_reply);
 	r = 0;
  out:
-	if (client_key)
-		EC_KEY_free(client_key);
+	EC_KEY_free(client_key);
 	return r;
 }
 
@@ -202,18 +201,14 @@ input_kex_ecdh_reply(int type, u_int32_t seq, struct ssh *ssh)
 		r = kex_send_newkeys(ssh);
  out:
 	explicit_bzero(hash, sizeof(hash));
-	if (kex->ec_client_key) {
-		EC_KEY_free(kex->ec_client_key);
-		kex->ec_client_key = NULL;
-	}
-	if (server_public)
-		EC_POINT_clear_free(server_public);
+	EC_KEY_free(kex->ec_client_key);
+	kex->ec_client_key = NULL;
+	EC_POINT_clear_free(server_public);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	sshkey_free(server_host_key);
 	free(server_host_key_blob);
 	free(signature);
diff --git a/usr.bin/ssh/kexecdhs.c b/usr.bin/ssh/kexecdhs.c
index 43921981711..89201c77e0b 100644
--- a/usr.bin/ssh/kexecdhs.c
+++ b/usr.bin/ssh/kexecdhs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexecdhs.c,v 1.16 2017/05/30 14:23:52 markus Exp $ */
+/* $OpenBSD: kexecdhs.c,v 1.17 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -183,18 +183,14 @@ input_kex_ecdh_init(int type, u_int32_t seq, struct ssh *ssh)
 		r = kex_send_newkeys(ssh);
  out:
 	explicit_bzero(hash, sizeof(hash));
-	if (kex->ec_client_key) {
-		EC_KEY_free(kex->ec_client_key);
-		kex->ec_client_key = NULL;
-	}
-	if (server_key)
-		EC_KEY_free(server_key);
+	EC_KEY_free(kex->ec_client_key);
+	kex->ec_client_key = NULL;
+	EC_KEY_free(server_key);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	free(server_host_key_blob);
 	free(signature);
 	return r;
diff --git a/usr.bin/ssh/kexgexc.c b/usr.bin/ssh/kexgexc.c
index 45a56827a74..bec49cedd00 100644
--- a/usr.bin/ssh/kexgexc.c
+++ b/usr.bin/ssh/kexgexc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexc.c,v 1.26 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: kexgexc.c,v 1.27 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -129,10 +129,8 @@ input_kex_dh_gex_group(int type, u_int32_t seq, struct ssh *ssh)
 	ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REPLY, &input_kex_dh_gex_reply);
 	r = 0;
 out:
-	if (p)
-		BN_clear_free(p);
-	if (g)
-		BN_clear_free(g);
+	BN_clear_free(p);
+	BN_clear_free(g);
 	return r;
 }
 
@@ -245,14 +243,12 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
 	explicit_bzero(hash, sizeof(hash));
 	DH_free(kex->dh);
 	kex->dh = NULL;
-	if (dh_server_pub)
-		BN_clear_free(dh_server_pub);
+	BN_clear_free(dh_server_pub);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	sshkey_free(server_host_key);
 	free(server_host_key_blob);
 	free(signature);
diff --git a/usr.bin/ssh/kexgexs.c b/usr.bin/ssh/kexgexs.c
index 7f9bce7a820..025ce9af4fa 100644
--- a/usr.bin/ssh/kexgexs.c
+++ b/usr.bin/ssh/kexgexs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexs.c,v 1.31 2017/05/30 14:23:52 markus Exp $ */
+/* $OpenBSD: kexgexs.c,v 1.32 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -232,14 +232,12 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
  out:
 	DH_free(kex->dh);
 	kex->dh = NULL;
-	if (dh_client_pub)
-		BN_clear_free(dh_client_pub);
+	BN_clear_free(dh_client_pub);
 	if (kbuf) {
 		explicit_bzero(kbuf, klen);
 		free(kbuf);
 	}
-	if (shared_secret)
-		BN_clear_free(shared_secret);
+	BN_clear_free(shared_secret);
 	free(server_host_key_blob);
 	free(signature);
 	return r;
diff --git a/usr.bin/ssh/ssh-dss.c b/usr.bin/ssh/ssh-dss.c
index 6c9604b3d9e..d742dee2899 100644
--- a/usr.bin/ssh/ssh-dss.c
+++ b/usr.bin/ssh/ssh-dss.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-dss.c,v 1.36 2018/01/23 05:27:21 djm Exp $ */
+/* $OpenBSD: ssh-dss.c,v 1.37 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -101,8 +101,7 @@ ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
 	ret = 0;
  out:
 	explicit_bzero(digest, sizeof(digest));
-	if (sig != NULL)
-		DSA_SIG_free(sig);
+	DSA_SIG_free(sig);
 	sshbuf_free(b);
 	return ret;
 }
@@ -180,8 +179,7 @@ ssh_dss_verify(const struct sshkey *key,
 
  out:
 	explicit_bzero(digest, sizeof(digest));
-	if (sig != NULL)
-		DSA_SIG_free(sig);
+	DSA_SIG_free(sig);
 	sshbuf_free(b);
 	free(ktype);
 	if (sigblob != NULL) {
diff --git a/usr.bin/ssh/ssh-ecdsa.c b/usr.bin/ssh/ssh-ecdsa.c
index b1272694417..fef0e006837 100644
--- a/usr.bin/ssh/ssh-ecdsa.c
+++ b/usr.bin/ssh/ssh-ecdsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ecdsa.c,v 1.13 2016/04/21 06:08:02 djm Exp $ */
+/* $OpenBSD: ssh-ecdsa.c,v 1.14 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2010 Damien Miller.  All rights reserved.
@@ -97,8 +97,7 @@ ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
 	explicit_bzero(digest, sizeof(digest));
 	sshbuf_free(b);
 	sshbuf_free(bb);
-	if (sig != NULL)
-		ECDSA_SIG_free(sig);
+	ECDSA_SIG_free(sig);
 	return ret;
 }
 
@@ -176,8 +175,7 @@ ssh_ecdsa_verify(const struct sshkey *key,
 	explicit_bzero(digest, sizeof(digest));
 	sshbuf_free(sigbuf);
 	sshbuf_free(b);
-	if (sig != NULL)
-		ECDSA_SIG_free(sig);
+	ECDSA_SIG_free(sig);
 	free(ktype);
 	return ret;
 }
diff --git a/usr.bin/ssh/ssh-pkcs11.c b/usr.bin/ssh/ssh-pkcs11.c
index 763997e05fc..64cff8c5c30 100644
--- a/usr.bin/ssh/ssh-pkcs11.c
+++ b/usr.bin/ssh/ssh-pkcs11.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-pkcs11.c,v 1.25 2017/05/31 09:15:42 deraadt Exp $ */
+/* $OpenBSD: ssh-pkcs11.c,v 1.26 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
  *
@@ -521,8 +521,7 @@ pkcs11_fetch_keys_filter(struct pkcs11_provider *p, CK_ULONG slotidx,
 			    == NULL) {
 				error("RSAPublicKey_dup");
 			}
-			if (x509)
-				X509_free(x509);
+			X509_free(x509);
 		}
 		if (rsa && rsa->n && rsa->e &&
 		    pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
diff --git a/usr.bin/ssh/sshkey.c b/usr.bin/ssh/sshkey.c
index 0f8769f2943..20f4fb2af26 100644
--- a/usr.bin/ssh/sshkey.c
+++ b/usr.bin/ssh/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.59 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.60 2018/02/07 02:06:51 jsing Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -449,8 +449,7 @@ sshkey_new(int type)
 		if ((rsa = RSA_new()) == NULL ||
 		    (rsa->n = BN_new()) == NULL ||
 		    (rsa->e = BN_new()) == NULL) {
-			if (rsa != NULL)
-				RSA_free(rsa);
+			RSA_free(rsa);
 			free(k);
 			return NULL;
 		}
@@ -463,8 +462,7 @@ sshkey_new(int type)
 		    (dsa->q = BN_new()) == NULL ||
 		    (dsa->g = BN_new()) == NULL ||
 		    (dsa->pub_key = BN_new()) == NULL) {
-			if (dsa != NULL)
-				DSA_free(dsa);
+			DSA_free(dsa);
 			free(k);
 			return NULL;
 		}
@@ -558,20 +556,17 @@ sshkey_free(struct sshkey *k)
 #ifdef WITH_OPENSSL
 	case KEY_RSA:
 	case KEY_RSA_CERT:
-		if (k->rsa != NULL)
-			RSA_free(k->rsa);
+		RSA_free(k->rsa);
 		k->rsa = NULL;
 		break;
 	case KEY_DSA:
 	case KEY_DSA_CERT:
-		if (k->dsa != NULL)
-			DSA_free(k->dsa);
+		DSA_free(k->dsa);
 		k->dsa = NULL;
 		break;
 	case KEY_ECDSA:
 	case KEY_ECDSA_CERT:
-		if (k->ecdsa != NULL)
-			EC_KEY_free(k->ecdsa);
+		EC_KEY_free(k->ecdsa);
 		k->ecdsa = NULL;
 		break;
 #endif /* WITH_OPENSSL */
@@ -1222,8 +1217,7 @@ sshkey_read(struct sshkey *ret, char **cpp)
 		switch (sshkey_type_plain(ret->type)) {
 #ifdef WITH_OPENSSL
 		case KEY_RSA:
-			if (ret->rsa != NULL)
-				RSA_free(ret->rsa);
+			RSA_free(ret->rsa);
 			ret->rsa = k->rsa;
 			k->rsa = NULL;
 #ifdef DEBUG_PK
@@ -1231,8 +1225,7 @@ sshkey_read(struct sshkey *ret, char **cpp)
 #endif
 			break;
 		case KEY_DSA:
-			if (ret->dsa != NULL)
-				DSA_free(ret->dsa);
+			DSA_free(ret->dsa);
 			ret->dsa = k->dsa;
 			k->dsa = NULL;
 #ifdef DEBUG_PK
@@ -1240,8 +1233,7 @@ sshkey_read(struct sshkey *ret, char **cpp)
 #endif
 			break;
 		case KEY_ECDSA:
-			if (ret->ecdsa != NULL)
-				EC_KEY_free(ret->ecdsa);
+			EC_KEY_free(ret->ecdsa);
 			ret->ecdsa = k->ecdsa;
 			ret->ecdsa_nid = k->ecdsa_nid;
 			k->ecdsa = NULL;
@@ -1382,10 +1374,8 @@ rsa_generate_private_key(u_int bits, RSA **rsap)
 	private = NULL;
 	ret = 0;
  out:
-	if (private != NULL)
-		RSA_free(private);
-	if (f4 != NULL)
-		BN_free(f4);
+	RSA_free(private);
+	BN_free(f4);
 	return ret;
 }
 
@@ -1413,8 +1403,7 @@ dsa_generate_private_key(u_int bits, DSA **dsap)
 	private = NULL;
 	ret = 0;
  out:
-	if (private != NULL)
-		DSA_free(private);
+	DSA_free(private);
 	return ret;
 }
 
@@ -1490,8 +1479,7 @@ ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap)
 	private = NULL;
 	ret = 0;
  out:
-	if (private != NULL)
-		EC_KEY_free(private);
+	EC_KEY_free(private);
 	return ret;
 }
 #endif /* WITH_OPENSSL */
@@ -1896,8 +1884,7 @@ sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
 			ret = SSH_ERR_EC_CURVE_MISMATCH;
 			goto out;
 		}
-		if (key->ecdsa != NULL)
-			EC_KEY_free(key->ecdsa);
+		EC_KEY_free(key->ecdsa);
 		if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid))
 		    == NULL) {
 			ret = SSH_ERR_EC_CURVE_INVALID;
@@ -1973,8 +1960,7 @@ sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
 	free(curve);
 	free(pk);
 #ifdef WITH_OPENSSL
-	if (q != NULL)
-		EC_POINT_free(q);
+	EC_POINT_free(q);
 #endif /* WITH_OPENSSL */
 	return ret;
 }
@@ -2715,8 +2701,7 @@ sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
 	free(tname);
 	free(curve);
 #ifdef WITH_OPENSSL
-	if (exponent != NULL)
-		BN_clear_free(exponent);
+	BN_clear_free(exponent);
 #endif /* WITH_OPENSSL */
 	sshkey_free(k);
 	if (ed25519_pk != NULL) {
@@ -2804,8 +2789,7 @@ sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
 	ret = 0;
  out:
 	BN_CTX_free(bnctx);
-	if (nq != NULL)
-		EC_POINT_free(nq);
+	EC_POINT_free(nq);
 	return ret;
 }
 
@@ -3496,8 +3480,7 @@ sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
 	}
  out:
 	BIO_free(bio);
-	if (pk != NULL)
-		EVP_PKEY_free(pk);
+	EVP_PKEY_free(pk);
 	sshkey_free(prv);
 	return r;
 }