2 files changed, 14 insertions, 16 deletions

diff --git a/src/lib/libcrypto/bn/bn_gf2m.c b/src/lib/libcrypto/bn/bn_gf2m.c
index 1fd7105a31..b9e3ba8566 100644
--- a/src/lib/libcrypto/bn/bn_gf2m.c
+++ b/src/lib/libcrypto/bn/bn_gf2m.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_gf2m.c,v 1.24 2022/11/20 22:23:43 schwarze Exp $ */
+/* $OpenBSD: bn_gf2m.c,v 1.25 2022/11/20 23:35:00 schwarze Exp $ */
 /* ====================================================================
  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  *
@@ -464,17 +464,23 @@ int
 BN_GF2m_mod(BIGNUM *r, const BIGNUM *a, const BIGNUM *p)
 {
         int ret = 0;
-        int arr[6];
+        const int max = BN_num_bits(p) + 1;
+        int *arr = NULL;
 
         bn_check_top(a);
         bn_check_top(p);
-        ret = BN_GF2m_poly2arr(p, arr, sizeof(arr) / sizeof(arr[0]));
-        if (!ret || ret > (int)(sizeof(arr) / sizeof(arr[0]))) {
+        if ((arr = reallocarray(NULL, max, sizeof(int))) == NULL)
+                goto err;
+        ret = BN_GF2m_poly2arr(p, arr, max);
+        if (!ret || ret > max) {
                 BNerror(BN_R_INVALID_LENGTH);
-                return 0;
+                goto err;
         }
         ret = BN_GF2m_mod_arr(r, a, arr);
         bn_check_top(r);
+
+ err:
+        free(arr);
         return ret;
 }
 
diff --git a/src/lib/libcrypto/man/BN_GF2m_add.3 b/src/lib/libcrypto/man/BN_GF2m_add.3
index 170a7df18a..60a2a5eed4 100644
--- a/src/lib/libcrypto/man/BN_GF2m_add.3
+++ b/src/lib/libcrypto/man/BN_GF2m_add.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: BN_GF2m_add.3,v 1.3 2022/11/18 07:28:34 tb Exp $
+.\" $OpenBSD: BN_GF2m_add.3,v 1.4 2022/11/20 23:35:00 schwarze Exp $
 .\"
 .\" Copyright (c) 2022 Ingo Schwarze <schwarze@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 18 2022 $
+.Dd $Mdocdate: November 20 2022 $
 .Dt BN_GF2M_ADD 3
 .Os
 .Sh NAME
@@ -480,9 +480,7 @@ In one of the functions wrapping an
 .Fn *_arr
 variant, the
 .Fa "BIGNUM *p"
-argument had a value of zero, or in
-.Fn BN_GF2m_mod ,
-it contained more than five non-zero coefficients.
+argument had a value of zero.
 .El
 .Sh SEE ALSO
 .Xr BN_add 3 ,
@@ -514,9 +512,3 @@ it contained more than five non-zero coefficients.
  exponentiation algorithm A.4.1 for square roots, and\
  algorithms A.4.7 and A.4.6 for the quadratic equation
 .Re
-.Sh BUGS
-.Fn BN_GF2m_mod
-is arbitrarily limited to reducing polynomials containing at most five
-non-zero coefficients and returns failure if
-.Fa p
-contains six or more non-zero coefficients.