1 files changed, 16 insertions, 48 deletions

diff --git a/src/lib/libcrypto/bn/bn_convert.c b/src/lib/libcrypto/bn/bn_convert.c
index 5c3c98b787..0bfb00e958 100644
--- a/src/lib/libcrypto/bn/bn_convert.c
+++ b/src/lib/libcrypto/bn/bn_convert.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_convert.c,v 1.18 2024/04/16 13:14:46 jsing Exp $ */
+/* $OpenBSD: bn_convert.c,v 1.19 2024/04/17 14:45:46 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -154,7 +154,7 @@ BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen)
 LCRYPTO_ALIAS(BN_bn2binpad);
 
 static int
-bn_bin2bn_cbs(BIGNUM **bnp, CBS *cbs)
+bn_bin2bn_cbs(BIGNUM **bnp, CBS *cbs, int lebin)
 {
         BIGNUM *bn = NULL;
         BN_ULONG w;
@@ -173,8 +173,13 @@ bn_bin2bn_cbs(BIGNUM **bnp, CBS *cbs)
         w = 0;
 
         while (CBS_len(cbs) > 0) {
-                if (!CBS_get_last_u8(cbs, &v))
-                        goto err;
+                if (lebin) {
+                        if (!CBS_get_u8(cbs, &v))
+                                goto err;
+                } else {
+                        if (!CBS_get_last_u8(cbs, &v))
+                                goto err;
+                }
 
                 w |= (BN_ULONG)v << b;
                 b += 8;
@@ -212,7 +217,7 @@ BN_bin2bn(const unsigned char *d, int len, BIGNUM *bn)
 
         CBS_init(&cbs, d, len);
 
-        if (!bn_bin2bn_cbs(&bn, &cbs))
+        if (!bn_bin2bn_cbs(&bn, &cbs, 0))
                 return NULL;
 
         return bn;
@@ -230,56 +235,19 @@ BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen)
 LCRYPTO_ALIAS(BN_bn2lebinpad);
 
 BIGNUM *
-BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret)
+BN_lebin2bn(const unsigned char *d, int len, BIGNUM *bn)
 {
-        unsigned int i, m, n;
-        BN_ULONG l;
-        BIGNUM *bn = NULL;
+        CBS cbs;
 
-        if (ret == NULL)
-                ret = bn = BN_new();
-        if (ret == NULL)
+        if (len < 0)
                 return NULL;
 
+        CBS_init(&cbs, d, len);
 
-        s += len;
-        /* Skip trailing zeroes. */
-        for (; len > 0 && s[-1] == 0; s--, len--)
-                continue;
-
-        n = len;
-        if (n == 0) {
-                ret->top = 0;
-                return ret;
-        }
-
-        i = ((n - 1) / BN_BYTES) + 1;
-        m = (n - 1) % BN_BYTES;
-        if (!bn_wexpand(ret, (int)i)) {
-                BN_free(bn);
+        if (!bn_bin2bn_cbs(&bn, &cbs, 1))
                 return NULL;
-        }
-
-        ret->top = i;
-        ret->neg = 0;
-        l = 0;
-        while (n-- > 0) {
-                s--;
-                l = (l << 8L) | *s;
-                if (m-- == 0) {
-                        ret->d[--i] = l;
-                        l = 0;
-                        m = BN_BYTES - 1;
-                }
-        }
 
-        /*
-         * need to call this due to clear byte at top if avoiding having the
-         * top bit set (-ve number)
-         */
-        bn_correct_top(ret);
-
-        return ret;
+        return bn;
 }
 LCRYPTO_ALIAS(BN_lebin2bn);