[#BN_reciprocal]
= BN_reciprocal
:mrdocs:

Compute a reciprocal `r` = 2ˆ`len` / `m` for BN_div‐style quotient estimation.

== Synopsis

Declared in `<openssl/bn.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
BN_reciprocal(
    xref:BIGNUM.adoc[BIGNUM]* r,
    xref:BIGNUM.adoc[BIGNUM] const* m,
    int len,
    xref:BN_CTX.adoc[BN_CTX]* ctx);
----

== Return Value

`len` on success, or ‐1 on error.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *r*
| Destination reciprocal.
| *m*
| Divisor.
| *len*
| Bit precision of the reciprocal.
| *ctx*
| BN_CTX scratch space.
|===


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