1 files changed, 26 insertions, 14 deletions

diff --git a/src/lib/libcrypto/asn1/a_bitstr.c b/src/lib/libcrypto/asn1/a_bitstr.c
index 7ea3e12b91..851a3a3d51 100644
--- a/src/lib/libcrypto/asn1/a_bitstr.c
+++ b/src/lib/libcrypto/asn1/a_bitstr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: a_bitstr.c,v 1.41 2023/07/28 10:33:13 tb Exp $ */
+/* $OpenBSD: a_bitstr.c,v 1.42 2023/12/25 22:02:59 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -120,20 +120,24 @@ ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
         int w, v, iv;
         unsigned char *c;
 
-        w = n/8;
+        if (a == NULL)
+                return 0;
+        if (n < 0)
+                return 0;
+
+        w = n / 8;
         v = 1 << (7 - (n & 0x07));
         iv = ~v;
-        if (!value)
-                v = 0;
 
-        if (a == NULL)
-                return 0;
+        if (value == 0)
+                v = 0;
 
         asn1_abs_clear_unused_bits(a);
 
-        if ((a->length < (w + 1)) || (a->data == NULL)) {
-                if (!value)
-                        return(1); /* Don't need to set */
+        if (a->length < w + 1 || a->data == NULL) {
+                /* Don't expand if there's no bit to set. */
+                if (value == 0)
+                        return 1;
                 if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) {
                         ASN1error(ERR_R_MALLOC_FAILURE);
                         return 0;
@@ -141,11 +145,12 @@ ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
                 a->data = c;
                 a->length = w + 1;
         }
+
         a->data[w] = ((a->data[w]) & iv) | v;
-        while ((a->length > 0) && (a->data[a->length - 1] == 0))
+        while (a->length > 0 && a->data[a->length - 1] == 0)
                 a->length--;
 
-        return (1);
+        return 1;
 }
 LCRYPTO_ALIAS(ASN1_BIT_STRING_set_bit);
 
@@ -154,11 +159,18 @@ ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n)
 {
         int w, v;
 
+        if (a == NULL)
+                return 0;
+        if (n < 0)
+                return 0;
+
         w = n / 8;
         v = 1 << (7 - (n & 0x07));
-        if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
-                return (0);
-        return ((a->data[w] & v) != 0);
+
+        if (a->length < w + 1 || a->data == NULL)
+                return 0;
+
+        return (a->data[w] & v) != 0;
 }
 LCRYPTO_ALIAS(ASN1_BIT_STRING_get_bit);