From 7e1d116d70c8188be4b96620d636d3b879810df7 Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Wed, 8 Aug 2018 22:56:23 +0300
Subject: [PATCH] Add BigNum::mod_inv.

GitOrigin-RevId: 98733421e0b8a6924724a4c13f2cd9ad937e3b0d
---
 tdutils/td/utils/BigNum.cpp | 5 +++++
 tdutils/td/utils/BigNum.h   | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/tdutils/td/utils/BigNum.cpp b/tdutils/td/utils/BigNum.cpp
index f553661d4..6e21b435b 100644
--- a/tdutils/td/utils/BigNum.cpp
+++ b/tdutils/td/utils/BigNum.cpp
@@ -220,6 +220,11 @@ void BigNum::mod_mul(BigNum &r, BigNum &a, BigNum &b, const BigNum &m, BigNumCon
   LOG_IF(FATAL, result != 1);
 }
 
+void BigNum::mod_inv(BigNum &r, BigNum &a, const BigNum &m, BigNumContext &context) {
+  BIGNUM *result = BN_mod_inverse(r.impl_->big_num, a.impl_->big_num, m.impl_->big_num, context.impl_->big_num_context);
+  LOG_IF(FATAL, result == nullptr);
+}
+
 void BigNum::div(BigNum *quotient, BigNum *remainder, const BigNum &dividend, const BigNum &divisor,
                  BigNumContext &context) {
   auto q = quotient == nullptr ? nullptr : quotient->impl_->big_num;
diff --git a/tdutils/td/utils/BigNum.h b/tdutils/td/utils/BigNum.h
index 6eecdeab0..8de4e5871 100644
--- a/tdutils/td/utils/BigNum.h
+++ b/tdutils/td/utils/BigNum.h
@@ -87,6 +87,8 @@ class BigNum {
 
   static void mod_mul(BigNum &r, BigNum &a, BigNum &b, const BigNum &m, BigNumContext &context);
 
+  static void mod_inv(BigNum &r, BigNum &a, const BigNum &m, BigNumContext &context);
+
   static void div(BigNum *quotient, BigNum *remainder, const BigNum &dividend, const BigNum &divisor,
                   BigNumContext &context);