3 files changed, 11 insertions, 1 deletions
diff --git a/crypto/modes/cfb128.c b/crypto/modes/cfb128.c
index fa94f047b5..f9c3c60536 100644
--- a/crypto/modes/cfb128.c
+++ b/crypto/modes/cfb128.c
@@ -30,6 +30,11 @@ void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
     unsigned int n;
     size_t l = 0;
 
+    if (*num < 0) {
+        /* There is no good way to signal an error return from here */
+        *num = -1;
+        return;
+    }
     n = *num;
 
     if (enc) {
diff --git a/crypto/modes/ctr128.c b/crypto/modes/ctr128.c
index b902ee9b0b..2147751c58 100644
--- a/crypto/modes/ctr128.c
+++ b/crypto/modes/ctr128.c
@@ -155,7 +155,7 @@ void CRYPTO_ctr128_encrypt_ctr32(const unsigned char *in, unsigned char *out,
 {
     unsigned int n, ctr32;
 
-    n = *num;
+   n = *num;
 
     while (n && len) {
         *(out++) = *(in++) ^ ecount_buf[n];
diff --git a/crypto/modes/ofb128.c b/crypto/modes/ofb128.c
index 829d724e2a..0b21380208 100644
--- a/crypto/modes/ofb128.c
+++ b/crypto/modes/ofb128.c
@@ -29,6 +29,11 @@ void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out,
     unsigned int n;
     size_t l = 0;
 
+    if (*num < 0) {
+        /* There is no good way to signal an error return from here */
+        *num = -1;
+        return;
+    }
     n = *num;
 
 #if !defined(OPENSSL_SMALL_FOOTPRINT)