upstream commit

avoid BIGNUM in KRL code by using a simple bitmap;
 feedback and ok markus

5 files changed, 87 insertions, 41 deletions

diff --git a/Makefile.in b/Makefile.in
index 9b485fba8..ebd48c303 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -70,7 +70,9 @@ LIBOPENSSH_OBJS=\
         sshkey.o \
         sshbuf-getput-basic.o \
         sshbuf-misc.o \
-        sshbuf-getput-crypto.o
+        sshbuf-getput-crypto.o \
+        krl.o \
+        bitmap.o
 
 LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
         authfd.o authfile.o bufaux.o bufbn.o buffer.o \
@@ -83,7 +85,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
         monitor_fdpass.o rijndael.o ssh-dss.o ssh-ecdsa.o ssh-rsa.o dh.o \
         kexdh.o kexgex.o kexdhc.o kexgexc.o bufec.o kexecdh.o kexecdhc.o \
         msg.o progressmeter.o dns.o entropy.o gss-genr.o umac.o umac128.o \
-        ssh-pkcs11.o krl.o smult_curve25519_ref.o \
+        ssh-pkcs11.o smult_curve25519_ref.o \
         kexc25519.o kexc25519c.o poly1305.o chacha.o cipher-chachapoly.o \
         ssh-ed25519.o digest-openssl.o hmac.o \
         sc25519.o ge25519.o fe25519.o ed25519.o verify.o hash.o blocks.o
diff --git a/krl.c b/krl.c
index d6bd10935..3917338f9 100644
--- a/krl.c
+++ b/krl.c
@@ -14,7 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $OpenBSD: krl.c,v 1.25 2015/01/13 19:04:35 djm Exp $ */
+/* $OpenBSD: krl.c,v 1.26 2015/01/14 15:02:39 djm Exp $ */
 
 #include "includes.h"
 
@@ -37,6 +37,7 @@
 #include "misc.h"
 #include "log.h"
 #include "digest.h"
+#include "bitmap.h"
 
 #include "krl.h"
 
@@ -519,6 +520,25 @@ choose_next_state(int current_state, u_int64_t contig, int final,
         return new_state;
 }
 
+static int
+put_bitmap(struct sshbuf *buf, struct bitmap *bitmap)
+{
+        size_t len;
+        u_char *blob;
+        int r;
+
+        len = bitmap_nbytes(bitmap);
+        if ((blob = malloc(len)) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        if (bitmap_to_string(bitmap, blob, len) != 0) {
+                free(blob);
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        r = sshbuf_put_bignum2_bytes(buf, blob, len);
+        free(blob);
+        return r;
+}
+
 /* Generate a KRL_SECTION_CERTIFICATES KRL section */
 static int
 revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
@@ -529,7 +549,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
         struct revoked_key_id *rki;
         int next_state, state = 0;
         struct sshbuf *sect;
-        BIGNUM *bitmap = NULL;
+        struct bitmap *bitmap = NULL;
 
         if ((sect = sshbuf_new()) == NULL)
                 return SSH_ERR_ALLOC_FAIL;
@@ -572,9 +592,9 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
                         case KRL_SECTION_CERT_SERIAL_RANGE:
                                 break;
                         case KRL_SECTION_CERT_SERIAL_BITMAP:
-                                if ((r = sshbuf_put_bignum2(sect, bitmap)) != 0)
+                                if ((r = put_bitmap(sect, bitmap)) != 0)
                                         goto out;
-                                BN_free(bitmap);
+                                bitmap_free(bitmap);
                                 bitmap = NULL;
                                 break;
                         }
@@ -595,7 +615,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
                         case KRL_SECTION_CERT_SERIAL_RANGE:
                                 break;
                         case KRL_SECTION_CERT_SERIAL_BITMAP:
-                                if ((bitmap = BN_new()) == NULL) {
+                                if ((bitmap = bitmap_new()) == NULL) {
                                         r = SSH_ERR_ALLOC_FAIL;
                                         goto out;
                                 }
@@ -626,8 +646,8 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
                                 goto out;
                         }
                         for (i = 0; i < contig; i++) {
-                                if (BN_set_bit(bitmap,
-                                    rs->lo + i - bitmap_start) != 1) {
+                                if (bitmap_set_bit(bitmap,
+                                    rs->lo + i - bitmap_start) != 0) {
                                         r = SSH_ERR_ALLOC_FAIL;
                                         goto out;
                                 }
@@ -645,9 +665,9 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
                 case KRL_SECTION_CERT_SERIAL_RANGE:
                         break;
                 case KRL_SECTION_CERT_SERIAL_BITMAP:
-                        if ((r = sshbuf_put_bignum2(sect, bitmap)) != 0)
+                        if ((r = put_bitmap(sect, bitmap)) != 0)
                                 goto out;
-                        BN_free(bitmap);
+                        bitmap_free(bitmap);
                         bitmap = NULL;
                         break;
                 }
@@ -671,8 +691,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
         }
         r = 0;
  out:
-        if (bitmap != NULL)
-                BN_free(bitmap);
+        bitmap_free(bitmap);
         sshbuf_free(sect);
         return r;
 }
@@ -784,13 +803,13 @@ format_timestamp(u_int64_t timestamp, char *ts, size_t nts)
 static int
 parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
 {
-        int r = SSH_ERR_INTERNAL_ERROR, nbits;
+        int r = SSH_ERR_INTERNAL_ERROR;
         u_char type;
         const u_char *blob;
-        size_t blen;
+        size_t blen, nbits;
         struct sshbuf *subsect = NULL;
         u_int64_t serial, serial_lo, serial_hi;
-        BIGNUM *bitmap = NULL;
+        struct bitmap *bitmap = NULL;
         char *key_id = NULL;
         struct sshkey *ca_key = NULL;
 
@@ -834,31 +853,32 @@ parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
                                 goto out;
                         break;
                 case KRL_SECTION_CERT_SERIAL_BITMAP:
-                        if ((bitmap = BN_new()) == NULL) {
+                        if ((bitmap = bitmap_new()) == NULL) {
                                 r = SSH_ERR_ALLOC_FAIL;
                                 goto out;
                         }
                         if ((r = sshbuf_get_u64(subsect, &serial_lo)) != 0 ||
-                            (r = sshbuf_get_bignum2(subsect, bitmap)) != 0)
+                            (r = sshbuf_get_bignum2_bytes_direct(subsect,
+                            &blob, &blen)) != 0)
                                 goto out;
-                        if ((nbits = BN_num_bits(bitmap)) < 0) {
-                                error("%s: bitmap bits < 0", __func__);
+                        if (bitmap_from_string(bitmap, blob, blen) != 0) {
                                 r = SSH_ERR_INVALID_FORMAT;
                                 goto out;
                         }
+                        nbits = bitmap_nbits(bitmap);
                         for (serial = 0; serial < (u_int64_t)nbits; serial++) {
                                 if (serial > 0 && serial_lo + serial == 0) {
                                         error("%s: bitmap wraps u64", __func__);
                                         r = SSH_ERR_INVALID_FORMAT;
                                         goto out;
                                 }
-                                if (!BN_is_bit_set(bitmap, serial))
+                                if (!bitmap_test_bit(bitmap, serial))
                                         continue;
                                 if ((r = ssh_krl_revoke_cert_by_serial(krl,
                                     ca_key, serial_lo + serial)) != 0)
                                         goto out;
                         }
-                        BN_free(bitmap);
+                        bitmap_free(bitmap);
                         bitmap = NULL;
                         break;
                 case KRL_SECTION_CERT_KEY_ID:
@@ -888,7 +908,7 @@ parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
         r = 0;
  out:
         if (bitmap != NULL)
-                BN_free(bitmap);
+                bitmap_free(bitmap);
         free(key_id);
         sshkey_free(ca_key);
         sshbuf_free(subsect);
diff --git a/sshbuf-getput-basic.c b/sshbuf-getput-basic.c
index 06d6cc492..8ff8a0a28 100644
--- a/sshbuf-getput-basic.c
+++ b/sshbuf-getput-basic.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf-getput-basic.c,v 1.3 2015/01/12 15:18:07 djm Exp $     */
+/*      $OpenBSD: sshbuf-getput-basic.c,v 1.4 2015/01/14 15:02:39 djm Exp $     */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -424,3 +424,39 @@ sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len)
                 memcpy(d + 4 + prepend, s, len);
         return 0;
 }
+
+int
+sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
+    const u_char **valp, size_t *lenp)
+{
+        const u_char *d;
+        size_t len, olen;
+        int r;
+
+        if ((r = sshbuf_peek_string_direct(buf, &d, &olen)) < 0)
+                return r;
+        len = olen;
+        /* Refuse negative (MSB set) bignums */
+        if ((len != 0 && (*d & 0x80) != 0))
+                return SSH_ERR_BIGNUM_IS_NEGATIVE;
+        /* Refuse overlong bignums, allow prepended \0 to avoid MSB set */
+        if (len > SSHBUF_MAX_BIGNUM + 1 ||
+            (len == SSHBUF_MAX_BIGNUM + 1 && *d != 0))
+                return SSH_ERR_BIGNUM_TOO_LARGE;
+        /* Trim leading zeros */
+        while (len > 0 && *d == 0x00) {
+                d++;
+                len--;
+        }
+        if (valp != 0)
+                *valp = d;
+        if (lenp != NULL)
+                *lenp = len;
+        if (sshbuf_consume(buf, olen + 4) != 0) {
+                /* Shouldn't happen */
+                SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+                SSHBUF_ABORT();
+                return SSH_ERR_INTERNAL_ERROR;
+        }
+        return 0;
+}
diff --git a/sshbuf-getput-crypto.c b/sshbuf-getput-crypto.c
index 7fad28bb7..e2e093c00 100644
--- a/sshbuf-getput-crypto.c
+++ b/sshbuf-getput-crypto.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf-getput-crypto.c,v 1.3 2015/01/12 15:18:07 djm Exp $    */
+/*      $OpenBSD: sshbuf-getput-crypto.c,v 1.4 2015/01/14 15:02:39 djm Exp $    */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -38,24 +38,10 @@ sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v)
         size_t len;
         int r;
 
-        if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0)
+        if ((r = sshbuf_get_bignum2_bytes_direct(buf, &d, &len)) != 0)
                 return r;
-        /* Refuse negative (MSB set) bignums */
-        if ((len != 0 && (*d & 0x80) != 0))
-                return SSH_ERR_BIGNUM_IS_NEGATIVE;
-        /* Refuse overlong bignums, allow prepended \0 to avoid MSB set */
-        if (len > SSHBUF_MAX_BIGNUM + 1 ||
-            (len == SSHBUF_MAX_BIGNUM + 1 && *d != 0))
-                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;
 }
 
diff --git a/sshbuf.h b/sshbuf.h
index 3602bc53f..ac0191936 100644
--- a/sshbuf.h
+++ b/sshbuf.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf.h,v 1.3 2014/06/24 01:13:21 djm Exp $  */
+/*      $OpenBSD: sshbuf.h,v 1.4 2015/01/14 15:02:39 djm Exp $  */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -212,6 +212,8 @@ int	sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len);
 #ifdef WITH_OPENSSL
 int     sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v);
 int     sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v);
+int     sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
+            const u_char **valp, size_t *lenp);
 int     sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v);
 int     sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v);
 # ifdef OPENSSL_HAS_ECC