[#BN_sub]
= BN_sub
:mrdocs:

Subtract signed BIGNUMs: `r` = `a` ‐ `b.`

== Synopsis

Declared in `<openssl/bn.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
BN_sub(
    xref:BIGNUM.adoc[BIGNUM]* r,
    xref:BIGNUM.adoc[BIGNUM] const* a,
    xref:BIGNUM.adoc[BIGNUM] const* b);
----

== Return Value

1 on success, or 0 on error.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *r*
| Destination difference.
| *a*
| Minuend.
| *b*
| Subtrahend.
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#