small refactor of cipher.c: make ciphercontext opaque to callers

feedback and ok markus@

1 files changed, 14 insertions, 23 deletions

diff --git a/usr.bin/ssh/sshkey.c b/usr.bin/ssh/sshkey.c
index 2c97cf23499..f570afb8b3e 100644
--- a/usr.bin/ssh/sshkey.c
+++ b/usr.bin/ssh/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.35 2016/06/19 07:48:02 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.36 2016/08/03 05:41:57 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -2979,13 +2979,11 @@ sshkey_private_to_blob2(const struct sshkey *prv, struct sshbuf *blob,
 	size_t i, pubkeylen, keylen, ivlen, blocksize, authlen;
 	u_int check;
 	int r = SSH_ERR_INTERNAL_ERROR;
-	struct sshcipher_ctx ciphercontext;
+	struct sshcipher_ctx *ciphercontext = NULL;
 	const struct sshcipher *cipher;
 	const char *kdfname = KDFNAME;
 	struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL;
 
-	memset(&ciphercontext, 0, sizeof(ciphercontext));
-
 	if (rounds <= 0)
 		rounds = DEFAULT_ROUNDS;
 	if (passphrase == NULL || !strlen(passphrase)) {
@@ -3072,7 +3070,7 @@ sshkey_private_to_blob2(const struct sshkey *prv, struct sshbuf *blob,
 	if ((r = sshbuf_reserve(encoded,
 	    sshbuf_len(encrypted) + authlen, &cp)) != 0)
 		goto out;
-	if ((r = cipher_crypt(&ciphercontext, 0, cp,
+	if ((r = cipher_crypt(ciphercontext, 0, cp,
 	    sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0)
 		goto out;
 
@@ -3104,7 +3102,7 @@ sshkey_private_to_blob2(const struct sshkey *prv, struct sshbuf *blob,
 	sshbuf_free(kdf);
 	sshbuf_free(encoded);
 	sshbuf_free(encrypted);
-	cipher_cleanup(&ciphercontext);
+	cipher_free(ciphercontext);
 	explicit_bzero(salt, sizeof(salt));
 	if (key != NULL) {
 		explicit_bzero(key, keylen + ivlen);
@@ -3133,12 +3131,11 @@ sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
 	size_t i, keylen = 0, ivlen = 0, authlen = 0, slen = 0;
 	struct sshbuf *encoded = NULL, *decoded = NULL;
 	struct sshbuf *kdf = NULL, *decrypted = NULL;
-	struct sshcipher_ctx ciphercontext;
+	struct sshcipher_ctx *ciphercontext = NULL;
 	struct sshkey *k = NULL;
 	u_char *key = NULL, *salt = NULL, *dp, pad, last;
 	u_int blocksize, rounds, nkeys, encrypted_len, check1, check2;
 
-	memset(&ciphercontext, 0, sizeof(ciphercontext));
 	if (keyp != NULL)
 		*keyp = NULL;
 	if (commentp != NULL)
@@ -3267,7 +3264,7 @@ sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
 	    (r = cipher_init(&ciphercontext, cipher, key, keylen,
 	    key + keylen, ivlen, 0)) != 0)
 		goto out;
-	if ((r = cipher_crypt(&ciphercontext, 0, dp, sshbuf_ptr(decoded),
+	if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded),
 	    encrypted_len, 0, authlen)) != 0) {
 		/* an integrity error here indicates an incorrect passphrase */
 		if (r == SSH_ERR_MAC_INVALID)
@@ -3321,7 +3318,7 @@ sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
 	}
  out:
 	pad = 0;
-	cipher_cleanup(&ciphercontext);
+	cipher_free(ciphercontext);
 	free(ciphername);
 	free(kdfname);
 	free(comment);
@@ -3355,7 +3352,7 @@ sshkey_private_rsa1_to_blob(struct sshkey *key, struct sshbuf *blob,
 	struct sshbuf *buffer = NULL, *encrypted = NULL;
 	u_char buf[8];
 	int r, cipher_num;
-	struct sshcipher_ctx ciphercontext;
+	struct sshcipher_ctx *ciphercontext = NULL;
 	const struct sshcipher *cipher;
 	u_char *cp;
 
@@ -3425,16 +3422,14 @@ sshkey_private_rsa1_to_blob(struct sshkey *key, struct sshbuf *blob,
 	if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase,
 	    CIPHER_ENCRYPT)) != 0)
 		goto out;
-	if ((r = cipher_crypt(&ciphercontext, 0, cp,
+	if ((r = cipher_crypt(ciphercontext, 0, cp,
 	    sshbuf_ptr(buffer), sshbuf_len(buffer), 0, 0)) != 0)
 		goto out;
-	if ((r = cipher_cleanup(&ciphercontext)) != 0)
-		goto out;
 
 	r = sshbuf_putb(blob, encrypted);
 
  out:
-	explicit_bzero(&ciphercontext, sizeof(ciphercontext));
+	cipher_free(ciphercontext);
 	explicit_bzero(buf, sizeof(buf));
 	sshbuf_free(buffer);
 	sshbuf_free(encrypted);
@@ -3598,7 +3593,7 @@ sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase,
 	struct sshbuf *decrypted = NULL, *copy = NULL;
 	u_char *cp;
 	char *comment = NULL;
-	struct sshcipher_ctx ciphercontext;
+	struct sshcipher_ctx *ciphercontext = NULL;
 	const struct sshcipher *cipher;
 	struct sshkey *prv = NULL;
 
@@ -3656,12 +3651,8 @@ sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase,
 	if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase,
 	    CIPHER_DECRYPT)) != 0)
 		goto out;
-	if ((r = cipher_crypt(&ciphercontext, 0, cp,
-	    sshbuf_ptr(copy), sshbuf_len(copy), 0, 0)) != 0) {
-		cipher_cleanup(&ciphercontext);
-		goto out;
-	}
-	if ((r = cipher_cleanup(&ciphercontext)) != 0)
+	if ((r = cipher_crypt(ciphercontext, 0, cp,
+	    sshbuf_ptr(copy), sshbuf_len(copy), 0, 0)) != 0)
 		goto out;
 
 	if ((r = sshbuf_get_u16(decrypted, &check1)) != 0 ||
@@ -3698,7 +3689,7 @@ sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase,
 		comment = NULL;
 	}
  out:
-	explicit_bzero(&ciphercontext, sizeof(ciphercontext));
+	cipher_free(ciphercontext);
 	free(comment);
 	sshkey_free(prv);
 	sshbuf_free(copy);