void-packages/srcpkgs/botan/patches/CVE-2018-12435_part1.patch

From 2cfa191a940b7b884f24d23d94227ff382c672b4 Mon Sep 17 00:00:00 2001
From: Jack Lloyd <jack@randombit.net>
Date: Tue, 17 Apr 2018 18:06:34 -0400
Subject: [PATCH] Add EC_Group::inverse_mod_order

Centralizing this logic allows curve specific implementations such
as using a precomputed ladder for exponentiating by p - 2

GH #1479
---
 src/lib/pubkey/ec_group/ec_group.cpp | 10 ++++++++++
 src/lib/pubkey/ec_group/ec_group.h   |  5 +++++
 src/lib/pubkey/ecdh/ecdh.cpp         |  2 +-
 src/lib/pubkey/ecdsa/ecdsa.cpp       |  4 ++--
 src/lib/pubkey/ecgdsa/ecgdsa.cpp     |  2 +-
 src/lib/pubkey/sm2/sm2.cpp           |  4 ++--
 6 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/src/lib/pubkey/ec_group/ec_group.cpp b/src/lib/pubkey/ec_group/ec_group.cpp
index fc512b7332..ac23aa151e 100644
--- src/lib/pubkey/ec_group/ec_group.cpp
+++ src/lib/pubkey/ec_group/ec_group.cpp
@@ -87,6 +87,11 @@ class EC_Group_Data final
          return m_mod_order.multiply(x, y);
          }
 
+      BigInt inverse_mod_order(const BigInt& x) const
+         {
+         return inverse_mod(x, m_order);
+         }
+
       PointGFp blinded_base_point_multiply(const BigInt& k,
                                            RandomNumberGenerator& rng,
                                            std::vector<BigInt>& ws) const
@@ -469,6 +476,11 @@ BigInt EC_Group::multiply_mod_order(const BigInt& x, const BigInt& y) const
    return data().multiply_mod_order(x, y);
    }
 
+BigInt EC_Group::inverse_mod_order(const BigInt& x) const
+   {
+   return data().inverse_mod_order(x);
+   }
+
 const OID& EC_Group::get_curve_oid() const
    {
    return data().oid();
diff --git a/src/lib/pubkey/ec_group/ec_group.h b/src/lib/pubkey/ec_group/ec_group.h
index 8bb1a30448..f273108d2b 100644
--- src/lib/pubkey/ec_group/ec_group.h
+++ src/lib/pubkey/ec_group/ec_group.h
@@ -193,6 +193,11 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       */
       BigInt mod_order(const BigInt& x) const;
 
+      /*
+      * Return inverse of x modulo the order
+      */
+      BigInt inverse_mod_order(const BigInt& x) const;
+
       /*
       * Reduce (x*y) modulo the order
       */
diff --git a/src/lib/pubkey/ecdh/ecdh.cpp b/src/lib/pubkey/ecdh/ecdh.cpp
index adadb27036..59f245a00c 100644
--- src/lib/pubkey/ecdh/ecdh.cpp
+++ src/lib/pubkey/ecdh/ecdh.cpp
@@ -31,7 +31,7 @@ class ECDH_KA_Operation final : public PK_Ops::Key_Agreement_with_KDF
          m_group(key.domain()),
          m_rng(rng)
          {
-         m_l_times_priv = inverse_mod(m_group.get_cofactor(), m_group.get_order()) * key.private_value();
+         m_l_times_priv = m_group.inverse_mod_order(m_group.get_cofactor()) * key.private_value();
          }
 
       secure_vector<uint8_t> raw_agree(const uint8_t w[], size_t w_len) override
diff --git a/src/lib/pubkey/ecdsa/ecdsa.cpp b/src/lib/pubkey/ecdsa/ecdsa.cpp
index 03f5e57ab6..6e104f1641 100644
--- src/lib/pubkey/ecdsa/ecdsa.cpp
+++ src/lib/pubkey/ecdsa/ecdsa.cpp
@@ -89,7 +89,7 @@ ECDSA_Signature_Operation::raw_sign(const uint8_t msg[], size_t msg_len,
    const BigInt k = m_group.random_scalar(rng);
 #endif
 
-   const BigInt k_inv = inverse_mod(k, m_group.get_order());
+   const BigInt k_inv = m_group.inverse_mod_order(k);
    const BigInt r = m_group.mod_order(
       m_group.blinded_base_point_multiply_x(k, rng, m_ws));
 
@@ -142,7 +142,7 @@ bool ECDSA_Verification_Operation::verify(const uint8_t msg[], size_t msg_len,
    if(r <= 0 || r >= m_group.get_order() || s <= 0 || s >= m_group.get_order())
       return false;
 
-   const BigInt w = inverse_mod(s, m_group.get_order());
+   const BigInt w = m_group.inverse_mod_order(s);
 
    const BigInt u1 = m_group.multiply_mod_order(e, w);
    const BigInt u2 = m_group.multiply_mod_order(r, w);
diff --git a/src/lib/pubkey/ecgdsa/ecgdsa.cpp b/src/lib/pubkey/ecgdsa/ecgdsa.cpp
index 192d999a8e..61b7ae0558 100644
--- src/lib/pubkey/ecgdsa/ecgdsa.cpp
+++ src/lib/pubkey/ecgdsa/ecgdsa.cpp
@@ -115,7 +115,7 @@ bool ECGDSA_Verification_Operation::verify(const uint8_t msg[], size_t msg_len,
    if(r <= 0 || r >= m_group.get_order() || s <= 0 || s >= m_group.get_order())
       return false;
 
-   const BigInt w = inverse_mod(r, m_group.get_order());
+   const BigInt w = m_group.inverse_mod_order(r);
 
    const BigInt u1 = m_group.multiply_mod_order(e, w);
    const BigInt u2 = m_group.multiply_mod_order(s, w);
diff --git a/src/lib/pubkey/sm2/sm2.cpp b/src/lib/pubkey/sm2/sm2.cpp
index 95fe28f147..1096ea99f5 100644
--- src/lib/pubkey/sm2/sm2.cpp
+++ src/lib/pubkey/sm2/sm2.cpp
@@ -30,7 +30,7 @@ SM2_Signature_PrivateKey::SM2_Signature_PrivateKey(const AlgorithmIdentifier& al
                                                    const secure_vector<uint8_t>& key_bits) :
    EC_PrivateKey(alg_id, key_bits)
    {
-   m_da_inv = inverse_mod(m_private_key + 1, domain().get_order());
+   m_da_inv = domain().inverse_mod_order(m_private_key + 1);
    }
 
 SM2_Signature_PrivateKey::SM2_Signature_PrivateKey(RandomNumberGenerator& rng,
@@ -38,7 +38,7 @@ SM2_Signature_PrivateKey::SM2_Signature_PrivateKey(RandomNumberGenerator& rng,
                                                    const BigInt& x) :
    EC_PrivateKey(rng, domain, x)
    {
-   m_da_inv = inverse_mod(m_private_key + 1, domain.get_order());
+   m_da_inv = domain.inverse_mod_order(m_private_key + 1);
    }
 
 std::vector<uint8_t> sm2_compute_za(HashFunction& hash,