diff options
| author | Jack Lloyd <[email protected]> | 2018-06-15 13:40:46 -0400 |
|---|---|---|
| committer | Jack Lloyd <[email protected]> | 2018-06-15 13:40:46 -0400 |
| commit | b434f6a7518b65fbe5eb1b8e042d2daf10d03671 (patch) | |
| tree | a6c143e2a700decaf91b8dbfe6b6367f6b18cbcd /src | |
| parent | a8bbba27e89a7d21dc39020d8abeb9f9aff6f603 (diff) | |
| parent | d7df2981d3bfa16c36b5651ef2958a75ead0811a (diff) | |
Merge GH #1609 Avoid small side channel in ECC field mul
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib/pubkey/ec_group/curve_gfp.cpp | 37 |
1 files changed, 15 insertions, 22 deletions
diff --git a/src/lib/pubkey/ec_group/curve_gfp.cpp b/src/lib/pubkey/ec_group/curve_gfp.cpp index 112213d6c..a9fa2d614 100644 --- a/src/lib/pubkey/ec_group/curve_gfp.cpp +++ b/src/lib/pubkey/ec_group/curve_gfp.cpp @@ -133,12 +133,9 @@ void CurveGFp_Montgomery::curve_mul(BigInt& z, const BigInt& x, const BigInt& y, BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words); BOTAN_DEBUG_ASSERT(y.sig_words() <= m_p_words); - const size_t x_words = (x.size() >= m_p_words) ? m_p_words : x.sig_words(); - const size_t y_words = (y.size() >= m_p_words) ? m_p_words : y.sig_words(); - bigint_mul(z.mutable_data(), z.size(), - x.data(), x.size(), x_words, - y.data(), y.size(), y_words, + x.data(), x.size(), std::min(m_p_words, x.size()), + y.data(), y.size(), std::min(m_p_words, y.size()), ws.data(), ws.size()); bigint_monty_redc(z.mutable_data(), @@ -161,12 +158,9 @@ void CurveGFp_Montgomery::curve_mul_words(BigInt& z, BOTAN_DEBUG_ASSERT(y.sig_words() <= m_p_words); - const size_t x_words = (x_size >= m_p_words) ? m_p_words : x_size; - const size_t y_words = (y.size() >= m_p_words) ? m_p_words : y.sig_words(); - bigint_mul(z.mutable_data(), z.size(), - x_w, x_size, x_words, - y.data(), y.size(), y_words, + x_w, x_size, std::min(m_p_words, x_size), + y.data(), y.size(), std::min(m_p_words, y.size()), ws.data(), ws.size()); bigint_monty_redc(z.mutable_data(), @@ -184,10 +178,10 @@ void CurveGFp_Montgomery::curve_sqr(BigInt& z, const BigInt& x, if(z.size() < output_size) z.grow_to(output_size); - const size_t x_words = (x.size() >= m_p_words) ? m_p_words : x.sig_words(); + BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words); bigint_sqr(z.mutable_data(), z.size(), - x.data(), x.size(), x_words, + x.data(), x.size(), std::min(m_p_words, x.size()), ws.data(), ws.size()); bigint_monty_redc(z.mutable_data(), @@ -279,12 +273,12 @@ void CurveGFp_NIST::curve_mul(BigInt& z, const BigInt& x, const BigInt& y, if(z.size() < output_size) z.grow_to(output_size); - const size_t x_words = (x.size() >= m_p_words) ? m_p_words : x.sig_words(); - const size_t y_words = (y.size() >= m_p_words) ? m_p_words : y.sig_words(); + BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words); + BOTAN_DEBUG_ASSERT(y.sig_words() <= m_p_words); bigint_mul(z.mutable_data(), z.size(), - x.data(), x.size(), x_words, - y.data(), y.size(), y_words, + x.data(), x.size(), std::min(m_p_words, x.size()), + y.data(), y.size(), std::min(m_p_words, y.size()), ws.data(), ws.size()); this->redc(z, ws); @@ -303,12 +297,11 @@ void CurveGFp_NIST::curve_mul_words(BigInt& z, if(z.size() < output_size) z.grow_to(output_size); - const size_t x_words = (x_size >= m_p_words) ? m_p_words : x_size; - const size_t y_words = (y.size() >= m_p_words) ? m_p_words : y.sig_words(); + BOTAN_DEBUG_ASSERT(y.sig_words() <= m_p_words); bigint_mul(z.mutable_data(), z.size(), - x_w, x_size, x_words, - y.data(), y.size(), y_words, + x_w, x_size, std::min(m_p_words, x_size), + y.data(), y.size(), std::min(m_p_words, y.size()), ws.data(), ws.size()); this->redc(z, ws); @@ -324,10 +317,10 @@ void CurveGFp_NIST::curve_sqr(BigInt& z, const BigInt& x, if(z.size() < output_size) z.grow_to(output_size); - const size_t x_words = (x.size() >= m_p_words) ? m_p_words : x.sig_words(); + BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words); bigint_sqr(z.mutable_data(), output_size, - x.data(), x.size(), x_words, + x.data(), x.size(), std::min(m_p_words, x.size()), ws.data(), ws.size()); this->redc(z, ws); |