- 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, 233 insertions, 0 deletions

diff --git a/sshbuf-getput-crypto.c b/sshbuf-getput-crypto.c
new file mode 100644
index 000000000..9c801a45f
--- /dev/null
+++ b/sshbuf-getput-crypto.c
@@ -0,0 +1,233 @@
+/*      $OpenBSD: sshbuf-getput-crypto.c,v 1.1 2014/04/30 05:29:56 djm Exp $    */
+/*
+ * Copyright (c) 2011 Damien Miller
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+
+#include "ssherr.h"
+#define SSHBUF_INTERNAL
+#include "sshbuf.h"
+
+int
+sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v)
+{
+        const u_char *d;
+        size_t len;
+        int r;
+
+        if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0)
+                return r;
+        /* Refuse negative (MSB set) and overlong bignums */
+        if ((len != 0 && (*d & 0x80) != 0))
+                return SSH_ERR_BIGNUM_IS_NEGATIVE;
+        if (len > SSHBUF_MAX_BIGNUM)
+                return SSH_ERR_BIGNUM_TOO_LARGE;
+        if (v != NULL && BN_bin2bn(d, len, v) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        /* Consume the string */
+        if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
+                /* Shouldn't happen */
+                SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+                SSHBUF_ABORT();
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        return 0;
+}
+
+int
+sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v)
+{
+        const u_char *d = sshbuf_ptr(buf);
+        u_int16_t len_bits;
+        size_t len_bytes;
+
+        /* Length in bits */
+        if (sshbuf_len(buf) < 2)
+                return SSH_ERR_MESSAGE_INCOMPLETE;
+        len_bits = PEEK_U16(d);
+        len_bytes = (len_bits + 7) >> 3;
+        if (len_bytes > SSHBUF_MAX_BIGNUM + 1)
+                return SSH_ERR_BIGNUM_TOO_LARGE;
+        if (sshbuf_len(buf) < 2 + len_bytes)
+                return SSH_ERR_MESSAGE_INCOMPLETE;
+        if (v != NULL && BN_bin2bn(d + 2, len_bytes, v) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        if (sshbuf_consume(buf, 2 + len_bytes) != 0) {
+                SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+                SSHBUF_ABORT();
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        return 0;
+}
+
+#ifdef OPENSSL_HAS_ECC
+static int
+get_ec(const u_char *d, size_t len, EC_POINT *v, const EC_GROUP *g)
+{
+        /* Refuse overlong bignums */
+        if (len == 0 || len > SSHBUF_MAX_ECPOINT)
+                return SSH_ERR_ECPOINT_TOO_LARGE;
+        /* Only handle uncompressed points */
+        if (*d != POINT_CONVERSION_UNCOMPRESSED)
+                return SSH_ERR_INVALID_FORMAT;
+        if (v != NULL && EC_POINT_oct2point(g, v, d, len, NULL) != 1)
+                return SSH_ERR_INVALID_FORMAT; /* XXX assumption */
+        return 0;
+}
+
+int
+sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g)
+{
+        const u_char *d;
+        size_t len;
+        int r;
+
+        if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0)
+                return r;
+        if ((r = get_ec(d, len, v, g)) != 0)
+                return r;
+        /* Skip string */
+        if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
+                /* Shouldn't happen */
+                SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+                SSHBUF_ABORT();
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        return 0;
+}
+
+int
+sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v)
+{
+        EC_POINT *pt = EC_POINT_new(EC_KEY_get0_group(v));
+        int r;
+        const u_char *d;
+        size_t len;
+
+        if (pt == NULL) {
+                SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
+                return SSH_ERR_ALLOC_FAIL;
+        }
+        if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) {
+                EC_POINT_free(pt);
+                return r;
+        }
+        if ((r = get_ec(d, len, pt, EC_KEY_get0_group(v))) != 0) {
+                EC_POINT_free(pt);
+                return r;
+        }
+        if (EC_KEY_set_public_key(v, pt) != 1) {
+                EC_POINT_free(pt);
+                return SSH_ERR_ALLOC_FAIL; /* XXX assumption */
+        }
+        EC_POINT_free(pt);
+        /* Skip string */
+        if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) {
+                /* Shouldn't happen */
+                SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+                SSHBUF_ABORT();
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        return 0;       
+}
+#endif /* OPENSSL_HAS_ECC */
+
+int
+sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v)
+{
+        u_char d[SSHBUF_MAX_BIGNUM + 1];
+        int len = BN_num_bytes(v), prepend = 0, r;
+
+        if (len < 0 || len > SSHBUF_MAX_BIGNUM)
+                return SSH_ERR_INVALID_ARGUMENT;
+        *d = '\0';
+        if (BN_bn2bin(v, d + 1) != len)
+                return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
+        /* If MSB is set, prepend a \0 */
+        if (len > 0 && (d[1] & 0x80) != 0)
+                prepend = 1;
+        if ((r = sshbuf_put_string(buf, d + 1 - prepend, len + prepend)) < 0) {
+                bzero(d, sizeof(d));
+                return r;
+        }
+        bzero(d, sizeof(d));
+        return 0;
+}
+
+int
+sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v)
+{
+        int r, len_bits = BN_num_bits(v);
+        size_t len_bytes = (len_bits + 7) / 8;
+        u_char d[SSHBUF_MAX_BIGNUM], *dp;
+
+        if (len_bits < 0 || len_bytes > SSHBUF_MAX_BIGNUM)
+                return SSH_ERR_INVALID_ARGUMENT;
+        if (BN_bn2bin(v, d) != (int)len_bytes)
+                return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
+        if ((r = sshbuf_reserve(buf, len_bytes + 2, &dp)) < 0) {
+                bzero(d, sizeof(d));
+                return r;
+        }
+        POKE_U16(dp, len_bits);
+        memcpy(dp + 2, d, len_bytes);
+        bzero(d, sizeof(d));
+        return 0;
+}
+
+#ifdef OPENSSL_HAS_ECC
+int
+sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g)
+{
+        u_char d[SSHBUF_MAX_ECPOINT];
+        BN_CTX *bn_ctx;
+        size_t len;
+        int ret;
+
+        if ((bn_ctx = BN_CTX_new()) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        if ((len = EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED,
+            NULL, 0, bn_ctx)) > SSHBUF_MAX_ECPOINT) {
+                BN_CTX_free(bn_ctx);
+                return SSH_ERR_INVALID_ARGUMENT;
+        }
+        if (EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED,
+            d, len, bn_ctx) != len) {
+                BN_CTX_free(bn_ctx);
+                return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */
+        }
+        BN_CTX_free(bn_ctx);
+        ret = sshbuf_put_string(buf, d, len);
+        bzero(d, len);
+        return ret;
+}
+
+int
+sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v)
+{
+        return sshbuf_put_ec(buf, EC_KEY_get0_public_key(v),
+            EC_KEY_get0_group(v));
+}
+#endif /* OPENSSL_HAS_ECC */
+