Add CT::Mask type

1 files changed, 16 insertions, 8 deletions

diff --git a/src/lib/math/bigint/bigint.cpp b/src/lib/math/bigint/bigint.cpp
index 2cb9394ce..667035686 100644
--- a/src/lib/math/bigint/bigint.cpp
+++ b/src/lib/math/bigint/bigint.cpp
@@ -146,7 +146,7 @@ bool BigInt::is_equal(const BigInt& other) const
       return false;
 
    return bigint_ct_is_eq(this->data(), this->sig_words(),
-                          other.data(), other.sig_words());
+                          other.data(), other.sig_words()).is_set();
    }
 
 bool BigInt::is_less_than(const BigInt& other) const
@@ -160,11 +160,11 @@ bool BigInt::is_less_than(const BigInt& other) const
    if(other.is_negative() && this->is_negative())
       {
       return !bigint_ct_is_lt(other.data(), other.sig_words(),
-                              this->data(), this->sig_words(), true);
+                              this->data(), this->sig_words(), true).is_set();
       }
 
    return bigint_ct_is_lt(this->data(), this->sig_words(),
-                          other.data(), other.sig_words());
+                          other.data(), other.sig_words()).is_set();
    }
 
 void BigInt::encode_words(word out[], size_t size) const
@@ -187,7 +187,7 @@ size_t BigInt::Data::calc_sig_words() const
    for(size_t i = 0; i != m_reg.size(); ++i)
       {
       const word w = m_reg[m_reg.size() - i - 1];
-      sub &= CT::is_zero(w);
+      sub &= CT::Mask<word>::is_zero(w).value();
       sig -= sub;
       }
 
@@ -393,13 +393,18 @@ void BigInt::ct_cond_assign(bool predicate, BigInt& other)
    const size_t t_words = size();
    const size_t o_words = other.size();
 
+   if(o_words < t_words)
+      grow_to(o_words);
+
    const size_t r_words = std::max(t_words, o_words);
 
-   const word mask = CT::expand_mask<word>(predicate);
+   const auto mask = CT::Mask<word>::expand(predicate);
 
    for(size_t i = 0; i != r_words; ++i)
       {
-      this->set_word_at(i, CT::select<word>(mask, other.word_at(i), this->word_at(i)));
+      const word o_word = other.word_at(i);
+      const word t_word = this->word_at(i);
+      this->set_word_at(i, mask.select(o_word, t_word));
       }
    }
 
@@ -430,10 +435,13 @@ void BigInt::const_time_lookup(secure_vector<word>& output,
       BOTAN_ASSERT(vec[i].size() >= words,
                    "Word size as expected in const_time_lookup");
 
-      const word mask = CT::is_equal(i, idx);
+      const auto mask = CT::Mask<word>::is_equal(i, idx);
 
       for(size_t w = 0; w != words; ++w)
-         output[w] |= CT::select<word>(mask, vec[i].word_at(w), 0);
+         {
+         const word viw = vec[i].word_at(w);
+         output[w] = mask.if_set_return(viw);
+         }
       }
 
    CT::unpoison(idx);