upstream: make Chacha20-POLY1305 context struct opaque; ok tb@ as

part of a larger diff at a2k20

OpenBSD-Commit-ID: a4609b7263284f95c9417ef60ed7cdbb7bf52cfd

4 files changed, 37 insertions, 22 deletions

diff --git a/cipher-chachapoly.c b/cipher-chachapoly.c
index 0899c5ad5..42e8d40b7 100644
--- a/cipher-chachapoly.c
+++ b/cipher-chachapoly.c
@@ -14,7 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $OpenBSD: cipher-chachapoly.c,v 1.8 2016/08/03 05:41:57 djm Exp $ */
+/* $OpenBSD: cipher-chachapoly.c,v 1.9 2020/04/03 04:27:03 djm Exp $ */
 
 #include "includes.h"
 
@@ -28,15 +28,28 @@
 #include "ssherr.h"
 #include "cipher-chachapoly.h"
 
-int
-chachapoly_init(struct chachapoly_ctx *ctx,
-    const u_char *key, u_int keylen)
+struct chachapoly_ctx {
+        struct chacha_ctx main_ctx, header_ctx;
+};
+
+struct chachapoly_ctx *
+chachapoly_new(const u_char *key, u_int keylen)
 {
+        struct chachapoly_ctx *ctx;
+
         if (keylen != (32 + 32)) /* 2 x 256 bit keys */
-                return SSH_ERR_INVALID_ARGUMENT;
+                return NULL;
+        if ((ctx = calloc(1, sizeof(*ctx))) == NULL)
+                return NULL;
         chacha_keysetup(&ctx->main_ctx, key, 256);
         chacha_keysetup(&ctx->header_ctx, key + 32, 256);
-        return 0;
+        return ctx;
+}
+
+void
+chachapoly_free(struct chachapoly_ctx *cpctx)
+{
+        freezero(cpctx, sizeof(*cpctx));
 }
 
 /*
diff --git a/cipher-chachapoly.h b/cipher-chachapoly.h
index b7072be7d..026d2de93 100644
--- a/cipher-chachapoly.h
+++ b/cipher-chachapoly.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cipher-chachapoly.h,v 1.4 2014/06/24 01:13:21 djm Exp $ */
+/* $OpenBSD: cipher-chachapoly.h,v 1.5 2020/04/03 04:27:03 djm Exp $ */
 
 /*
  * Copyright (c) Damien Miller 2013 <djm@mindrot.org>
@@ -24,13 +24,12 @@
 
 #define CHACHA_KEYLEN   32 /* Only 256 bit keys used here */
 
-struct chachapoly_ctx {
-        struct chacha_ctx main_ctx, header_ctx;
-};
+struct chachapoly_ctx;
+
+struct chachapoly_ctx *chachapoly_new(const u_char *key, u_int keylen)
+    __attribute__((__bounded__(__buffer__, 1, 2)));
+void chachapoly_free(struct chachapoly_ctx *cpctx);
 
-int     chachapoly_init(struct chachapoly_ctx *cpctx,
-    const u_char *key, u_int keylen)
-    __attribute__((__bounded__(__buffer__, 2, 3)));
 int     chachapoly_crypt(struct chachapoly_ctx *cpctx, u_int seqnr,
     u_char *dest, const u_char *src, u_int len, u_int aadlen, u_int authlen,
     int do_encrypt);
diff --git a/cipher.c b/cipher.c
index cd6e6def0..8195199b3 100644
--- a/cipher.c
+++ b/cipher.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cipher.c,v 1.116 2020/03/13 03:17:07 djm Exp $ */
+/* $OpenBSD: cipher.c,v 1.117 2020/04/03 04:27:03 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -59,7 +59,7 @@ struct sshcipher_ctx {
         int     plaintext;
         int     encrypt;
         EVP_CIPHER_CTX *evp;
-        struct chachapoly_ctx cp_ctx; /* XXX union with evp? */
+        struct chachapoly_ctx *cp_ctx;
         struct aesctr_ctx ac_ctx; /* XXX union with evp? */
         const struct sshcipher *cipher;
 };
@@ -273,7 +273,8 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
 
         cc->cipher = cipher;
         if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
-                ret = chachapoly_init(&cc->cp_ctx, key, keylen);
+                cc->cp_ctx = chachapoly_new(key, keylen);
+                ret = cc->cp_ctx != NULL ? 0 : SSH_ERR_INVALID_ARGUMENT;
                 goto out;
         }
         if ((cc->cipher->flags & CFLAG_NONE) != 0) {
@@ -349,7 +350,7 @@ cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
    const u_char *src, u_int len, u_int aadlen, u_int authlen)
 {
         if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
-                return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src,
+                return chachapoly_crypt(cc->cp_ctx, seqnr, dest, src,
                     len, aadlen, authlen, cc->encrypt);
         }
         if ((cc->cipher->flags & CFLAG_NONE) != 0) {
@@ -412,7 +413,7 @@ cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr,
     const u_char *cp, u_int len)
 {
         if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
-                return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr,
+                return chachapoly_get_length(cc->cp_ctx, plenp, seqnr,
                     cp, len);
         if (len < 4)
                 return SSH_ERR_MESSAGE_INCOMPLETE;
@@ -425,9 +426,10 @@ cipher_free(struct sshcipher_ctx *cc)
 {
         if (cc == NULL)
                 return;
-        if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
-                explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx));
-        else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
+        if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
+                chachapoly_free(cc->cp_ctx);
+                cc->cp_ctx = NULL;
+        } else if ((cc->cipher->flags & CFLAG_AESCTR) != 0)
                 explicit_bzero(&cc->ac_ctx, sizeof(cc->ac_ctx));
 #ifdef WITH_OPENSSL
         EVP_CIPHER_CTX_free(cc->evp);
diff --git a/regress/Makefile b/regress/Makefile
index 774c10d41..8f7b5aa99 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -1,4 +1,4 @@
-#       $OpenBSD: Makefile,v 1.106 2020/01/31 23:25:08 djm Exp $
+#       $OpenBSD: Makefile,v 1.107 2020/04/03 02:33:31 dtucker Exp $
 
 tests:          prep file-tests t-exec unit
 
@@ -66,6 +66,7 @@ LTESTS= 	connect \
                 cfgparse \
                 cfgmatch \
                 cfgmatchlisten \
+                percent \
                 addrmatch \
                 localcommand \
                 forcecommand \