- djm@cvs.openbsd.org 2014/04/30 05:29:56

     [bufaux.c bufbn.c bufec.c buffer.c buffer.h sshbuf-getput-basic.c]
     [sshbuf-getput-crypto.c sshbuf-misc.c sshbuf.c sshbuf.h ssherr.c]
     [ssherr.h]
     New buffer API; the first installment of the conversion/replacement
     of OpenSSH's internals to make them usable as a standalone library.

     This includes a set of wrappers to make it compatible with the
     existing buffer API so replacement can occur incrementally.

     With and ok markus@

     Thanks also to Ben Hawkes, David Tomaschik, Ivan Fratric, Matthew
     Dempsky and Ron Bowes for a detailed review.

1 files changed, 15 insertions, 92 deletions

diff --git a/bufec.c b/bufec.c
index 89482b906..b33ede385 100644
--- a/bufec.c
+++ b/bufec.c
@@ -1,6 +1,7 @@
-/* $OpenBSD: bufec.c,v 1.3 2014/01/31 16:39:19 tedu Exp $ */
+/* $OpenBSD: bufec.c,v 1.4 2014/04/30 05:29:56 djm Exp $ */
+
 /*
- * Copyright (c) 2010 Damien Miller <djm@mindrot.org>
+ * Copyright (c) 2012 Damien Miller <djm@mindrot.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -15,73 +16,25 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include "includes.h"
-
-#ifdef OPENSSL_HAS_ECC
+/* Emulation wrappers for legacy OpenSSH buffer API atop sshbuf */
 
 #include <sys/types.h>
 
-#include <openssl/bn.h>
-#include <openssl/ec.h>
-
-#include <string.h>
-#include <stdarg.h>
-
-#include "xmalloc.h"
 #include "buffer.h"
 #include "log.h"
-#include "misc.h"
+#include "ssherr.h"
 
-/*
- * Maximum supported EC GFp field length is 528 bits. SEC1 uncompressed
- * encoding represents this as two bitstring points that should each
- * be no longer than the field length, SEC1 specifies a 1 byte
- * point type header.
- * Being paranoid here may insulate us to parsing problems in
- * EC_POINT_oct2point.
- */
-#define BUFFER_MAX_ECPOINT_LEN ((528*2 / 8) + 1)
-
-/*
- * Append an EC_POINT to the buffer as a string containing a SEC1 encoded
- * uncompressed point. Fortunately OpenSSL handles the gory details for us.
- */
 int
 buffer_put_ecpoint_ret(Buffer *buffer, const EC_GROUP *curve,
     const EC_POINT *point)
 {
-	u_char *buf = NULL;
-	size_t len;
-	BN_CTX *bnctx;
-	int ret = -1;
+	int ret;
 
-	/* Determine length */
-	if ((bnctx = BN_CTX_new()) == NULL)
-		fatal("%s: BN_CTX_new failed", __func__);
-	len = EC_POINT_point2oct(curve, point, POINT_CONVERSION_UNCOMPRESSED,
-	    NULL, 0, bnctx);
-	if (len > BUFFER_MAX_ECPOINT_LEN) {
-		error("%s: giant EC point: len = %lu (max %u)",
-		    __func__, (u_long)len, BUFFER_MAX_ECPOINT_LEN);
-		goto out;
-	}
-	/* Convert */
-	buf = xmalloc(len);
-	if (EC_POINT_point2oct(curve, point, POINT_CONVERSION_UNCOMPRESSED,
-	    buf, len, bnctx) != len) {
-		error("%s: EC_POINT_point2oct length mismatch", __func__);
-		goto out;
-	}
-	/* Append */
-	buffer_put_string(buffer, buf, len);
-	ret = 0;
- out:
-	if (buf != NULL) {
-		explicit_bzero(buf, len);
-		free(buf);
+	if ((ret = sshbuf_put_ec(buffer, point, curve)) != 0) {
+		error("%s: %s", __func__, ssh_err(ret));
+		return -1;
 	}
-	BN_CTX_free(bnctx);
-	return ret;
+	return 0;
 }
 
 void
@@ -96,43 +49,13 @@ int
 buffer_get_ecpoint_ret(Buffer *buffer, const EC_GROUP *curve,
     EC_POINT *point)
 {
-	u_char *buf;
-	u_int len;
-	BN_CTX *bnctx;
-	int ret = -1;
+	int ret;
 
-	if ((buf = buffer_get_string_ret(buffer, &len)) == NULL) {
-		error("%s: invalid point", __func__);
+	if ((ret = sshbuf_get_ec(buffer, point, curve)) != 0) {
+		error("%s: %s", __func__, ssh_err(ret));
 		return -1;
 	}
-	if ((bnctx = BN_CTX_new()) == NULL)
-		fatal("%s: BN_CTX_new failed", __func__);
-	if (len > BUFFER_MAX_ECPOINT_LEN) {
-		error("%s: EC_POINT too long: %u > max %u", __func__,
-		    len, BUFFER_MAX_ECPOINT_LEN);
-		goto out;
-	}
-	if (len == 0) {
-		error("%s: EC_POINT buffer is empty", __func__);
-		goto out;
-	}
-	if (buf[0] != POINT_CONVERSION_UNCOMPRESSED) {
-		error("%s: EC_POINT is in an incorrect form: "
-		    "0x%02x (want 0x%02x)", __func__, buf[0],
-		    POINT_CONVERSION_UNCOMPRESSED);
-		goto out;
-	}
-	if (EC_POINT_oct2point(curve, point, buf, len, bnctx) != 1) {
-		error("buffer_get_bignum2_ret: BN_bin2bn failed");
-		goto out;
-	}
-	/* EC_POINT_oct2point verifies that the point is on the curve for us */
-	ret = 0;
- out:
-	BN_CTX_free(bnctx);
-	explicit_bzero(buf, len);
-	free(buf);
-	return ret;
+	return 0;
 }
 
 void
@@ -143,4 +66,4 @@ buffer_get_ecpoint(Buffer *buffer, const EC_GROUP *curve,
 		fatal("%s: buffer error", __func__);
 }
 
-#endif /* OPENSSL_HAS_ECC */
+