1 files changed, 18 insertions, 13 deletions

diff --git a/cipher-chachapoly.c b/cipher-chachapoly.c
index 251b94ec8..8665b41a3 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 1.4 2014/01/31 16:39:19 tedu Exp $ */
+/* $OpenBSD: cipher-chachapoly.c,v 1.6 2014/07/03 12:42:16 jsing Exp $ */
 
 #include "includes.h"
 
@@ -24,16 +24,18 @@
 #include <stdio.h>  /* needed for misc.h */
 
 #include "log.h"
-#include "misc.h"
+#include "sshbuf.h"
+#include "ssherr.h"
 #include "cipher-chachapoly.h"
 
-void chachapoly_init(struct chachapoly_ctx *ctx,
+int chachapoly_init(struct chachapoly_ctx *ctx,
     const u_char *key, u_int keylen)
 {
         if (keylen != (32 + 32)) /* 2 x 256 bit keys */
-                fatal("%s: invalid keylen %u", __func__, keylen);
+                return SSH_ERR_INVALID_ARGUMENT;
         chacha_keysetup(&ctx->main_ctx, key, 256);
         chacha_keysetup(&ctx->header_ctx, key + 32, 256);
+        return 0;
 }
 
 /*
@@ -52,33 +54,37 @@ chachapoly_crypt(struct chachapoly_ctx *ctx, u_int seqnr, u_char *dest,
         u_char seqbuf[8];
         const u_char one[8] = { 1, 0, 0, 0, 0, 0, 0, 0 }; /* NB little-endian */
         u_char expected_tag[POLY1305_TAGLEN], poly_key[POLY1305_KEYLEN];
-        int r = -1;
+        int r = SSH_ERR_INTERNAL_ERROR;
 
         /*
          * Run ChaCha20 once to generate the Poly1305 key. The IV is the
          * packet sequence number.
          */
         memset(poly_key, 0, sizeof(poly_key));
-        put_u64(seqbuf, seqnr);
+        POKE_U64(seqbuf, seqnr);
         chacha_ivsetup(&ctx->main_ctx, seqbuf, NULL);
         chacha_encrypt_bytes(&ctx->main_ctx,
             poly_key, poly_key, sizeof(poly_key));
-        /* Set Chacha's block counter to 1 */
-        chacha_ivsetup(&ctx->main_ctx, seqbuf, one);
 
         /* If decrypting, check tag before anything else */
         if (!do_encrypt) {
                 const u_char *tag = src + aadlen + len;
 
                 poly1305_auth(expected_tag, src, aadlen + len, poly_key);
-                if (timingsafe_bcmp(expected_tag, tag, POLY1305_TAGLEN) != 0)
+                if (timingsafe_bcmp(expected_tag, tag, POLY1305_TAGLEN) != 0) {
+                        r = SSH_ERR_MAC_INVALID;
                         goto out;
+                }
         }
+
         /* Crypt additional data */
         if (aadlen) {
                 chacha_ivsetup(&ctx->header_ctx, seqbuf, NULL);
                 chacha_encrypt_bytes(&ctx->header_ctx, src, dest, aadlen);
         }
+
+        /* Set Chacha's block counter to 1 */
+        chacha_ivsetup(&ctx->main_ctx, seqbuf, one);
         chacha_encrypt_bytes(&ctx->main_ctx, src + aadlen,
             dest + aadlen, len);
 
@@ -88,7 +94,6 @@ chachapoly_crypt(struct chachapoly_ctx *ctx, u_int seqnr, u_char *dest,
                     poly_key);
         }
         r = 0;
-
  out:
         explicit_bzero(expected_tag, sizeof(expected_tag));
         explicit_bzero(seqbuf, sizeof(seqbuf));
@@ -104,11 +109,11 @@ chachapoly_get_length(struct chachapoly_ctx *ctx,
         u_char buf[4], seqbuf[8];
 
         if (len < 4)
-                return -1; /* Insufficient length */
-        put_u64(seqbuf, seqnr);
+                return SSH_ERR_MESSAGE_INCOMPLETE;
+        POKE_U64(seqbuf, seqnr);
         chacha_ivsetup(&ctx->header_ctx, seqbuf, NULL);
         chacha_encrypt_bytes(&ctx->header_ctx, cp, buf, 4);
-        *plenp = get_u32(buf);
+        *plenp = PEEK_U32(buf);
         return 0;
 }