i2d_ASN1_BOOLEAN(): allocate memory if the user didn't provide a buffer

Just as was done recently for i2d_ASN1_OBJECT, we also make
i2d_ASN1_BOOLEAN comply with the documentation.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6943)

1 files changed, 19 insertions, 5 deletions

diff --git a/crypto/asn1/a_bool.c b/crypto/asn1/a_bool.c
index 1b85bc9e61..98454f3b40 100644
--- a/crypto/asn1/a_bool.c
+++ b/crypto/asn1/a_bool.c
@@ -63,17 +63,31 @@
 int i2d_ASN1_BOOLEAN(int a, unsigned char **pp)
 {
     int r;
-    unsigned char *p;
+    unsigned char *p, *allocated = NULL;
 
     r = ASN1_object_size(0, 1, V_ASN1_BOOLEAN);
     if (pp == NULL)
         return (r);
-    p = *pp;
+
+    if (*pp == NULL) {
+        if ((p = allocated = OPENSSL_malloc(r)) == NULL) {
+            ASN1err(ASN1_F_I2D_ASN1_OBJECT, ERR_R_MALLOC_FAILURE);
+            return 0;
+        }
+    } else {
+        p = *pp;
+    }
 
     ASN1_put_object(&p, 0, 1, V_ASN1_BOOLEAN, V_ASN1_UNIVERSAL);
-    *(p++) = (unsigned char)a;
-    *pp = p;
-    return (r);
+    *p = (unsigned char)a;
+
+
+    /*
+     * If a new buffer was allocated, just return it back.
+     * If not, return the incremented buffer pointer.
+     */
+    *pp = allocated != NULL ? allocated : p + 1;
+    return r;
 }
 
 int d2i_ASN1_BOOLEAN(int *a, const unsigned char **pp, long length)