1 files changed, 3 insertions, 2 deletions

diff --git a/src/lib/libcrypto/bn/bn_print.c b/src/lib/libcrypto/bn/bn_print.c
index 5f46b1826c..e3b6aa235b 100644
--- a/src/lib/libcrypto/bn/bn_print.c
+++ b/src/lib/libcrypto/bn/bn_print.c
@@ -119,6 +119,7 @@ char *BN_bn2dec(const BIGNUM *a)
                 }
         if ((t=BN_dup(a)) == NULL) goto err;
 
+#define BUF_REMAIN (num+3 - (size_t)(p - buf))
         p=buf;
         lp=bn_data;
         if (t->neg) *(p++)='-';
@@ -139,12 +140,12 @@ char *BN_bn2dec(const BIGNUM *a)
                 /* We now have a series of blocks, BN_DEC_NUM chars
                  * in length, where the last one needs truncation.
                  * The blocks need to be reversed in order. */
-                sprintf(p,BN_DEC_FMT1,*lp);
+                snprintf(p,BUF_REMAIN,BN_DEC_FMT1,*lp);
                 while (*p) p++;
                 while (lp != bn_data)
                         {
                         lp--;
-                        sprintf(p,BN_DEC_FMT2,*lp);
+                        snprintf(p,BUF_REMAIN,BN_DEC_FMT2,*lp);
                         while (*p) p++;
                         }
                 }