upstream commit

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@

OpenBSD-Commit-ID: 954f1c51b94297d0ae1f749271e184141e0cadae

13 files changed, 61 insertions, 109 deletions

diff --git a/cipher.c b/cipher.c
index aa8cfcf67..f3d4f69a5 100644
--- a/cipher.c
+++ b/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
@@ -310,8 +310,7 @@ 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);
@@ -416,10 +415,8 @@ 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/dh.c b/dh.c
index eebee2377..46afba033 100644
--- a/dh.c
+++ b/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.
  *
@@ -135,10 +135,8 @@ 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/kex.c b/kex.c
index 83c6199f3..15ea28b07 100644
--- a/kex.c
+++ b/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.
  *
@@ -587,11 +587,9 @@ kex_free(struct kex *kex)
         u_int mode;
 
 #ifdef WITH_OPENSSL
-        if (kex->dh)
-                DH_free(kex->dh);
+        DH_free(kex->dh);
 #ifdef OPENSSL_HAS_ECC
-        if (kex->ec_client_key)
-                EC_KEY_free(kex->ec_client_key);
+        EC_KEY_free(kex->ec_client_key);
 #endif /* OPENSSL_HAS_ECC */
 #endif /* WITH_OPENSSL */
         for (mode = 0; mode < MODE_MAX; mode++) {
diff --git a/kexdhc.c b/kexdhc.c
index 5e1a353a5..9a9f1ea78 100644
--- a/kexdhc.c
+++ b/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.
  *
@@ -203,14 +203,12 @@ 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/kexdhs.c b/kexdhs.c
index 81ce56d7a..da8f4c439 100644
--- a/kexdhs.c
+++ b/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.
  *
@@ -208,14 +208,12 @@ 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/kexecdhc.c b/kexecdhc.c
index 67669b3bf..ac146a362 100644
--- a/kexecdhc.c
+++ b/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.
@@ -89,8 +89,7 @@ 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;
 }
 
@@ -206,18 +205,14 @@ 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/kexecdhs.c b/kexecdhs.c
index dc24a3af6..af4f30309 100644
--- a/kexecdhs.c
+++ b/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.
@@ -187,18 +187,14 @@ 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/kexgexc.c b/kexgexc.c
index 6f8cf48a6..762a9a322 100644
--- a/kexgexc.c
+++ b/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.
@@ -134,10 +134,8 @@ 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;
 }
 
@@ -250,14 +248,12 @@ 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/kexgexs.c b/kexgexs.c
index c5dd00578..d7b48ea88 100644
--- a/kexgexs.c
+++ b/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.
@@ -237,14 +237,12 @@ 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/ssh-dss.c b/ssh-dss.c
index cda498a87..9f832ee2b 100644
--- a/ssh-dss.c
+++ b/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.
  *
@@ -107,8 +107,7 @@ 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;
 }
@@ -186,8 +185,7 @@ 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/ssh-ecdsa.c b/ssh-ecdsa.c
index d7bf3c69b..3d3b78d7b 100644
--- a/ssh-ecdsa.c
+++ b/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.
@@ -101,8 +101,7 @@ 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;
 }
 
@@ -180,8 +179,7 @@ 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/ssh-pkcs11.c b/ssh-pkcs11.c
index b37491c5d..65a7b5897 100644
--- a/ssh-pkcs11.c
+++ b/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.
  *
@@ -532,8 +532,7 @@ 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/sshkey.c b/sshkey.c
index 91e0073ff..fb987d6b7 100644
--- a/sshkey.c
+++ b/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.
@@ -469,8 +469,7 @@ 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;
                 }
@@ -483,8 +482,7 @@ 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;
                 }
@@ -578,21 +576,18 @@ 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;
 # ifdef OPENSSL_HAS_ECC
         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 /* OPENSSL_HAS_ECC */
@@ -1248,8 +1243,7 @@ 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
@@ -1257,8 +1251,7 @@ 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
@@ -1267,8 +1260,7 @@ sshkey_read(struct sshkey *ret, char **cpp)
                         break;
 # ifdef OPENSSL_HAS_ECC
                 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;
@@ -1410,10 +1402,8 @@ 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;
 }
 
@@ -1441,8 +1431,7 @@ 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;
 }
 
@@ -1521,8 +1510,7 @@ 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 /* OPENSSL_HAS_ECC */
@@ -1933,8 +1921,7 @@ 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;
@@ -2011,8 +1998,7 @@ sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
         free(curve);
         free(pk);
 #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
-        if (q != NULL)
-                EC_POINT_free(q);
+        EC_POINT_free(q);
 #endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
         return ret;
 }
@@ -2765,8 +2751,7 @@ 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) {
@@ -2854,8 +2839,7 @@ 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;
 }
 
@@ -3550,8 +3534,7 @@ 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;
 }