diff options
Diffstat (limited to 'src/math/numbertheory/powm_mnt.cpp')
| -rw-r--r-- | src/math/numbertheory/powm_mnt.cpp | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/src/math/numbertheory/powm_mnt.cpp b/src/math/numbertheory/powm_mnt.cpp index e356387c0..2d18ccdef 100644 --- a/src/math/numbertheory/powm_mnt.cpp +++ b/src/math/numbertheory/powm_mnt.cpp @@ -156,10 +156,9 @@ BigInt Montgomery_Exponentiator::execute() const Montgomery_Exponentiator::Montgomery_Exponentiator(const BigInt& mod, Power_Mod::Usage_Hints hints) { - if(!mod.is_positive()) - throw Exception("Montgomery_Exponentiator: modulus must be positive"); - if(mod.is_even()) - throw Exception("Montgomery_Exponentiator: modulus must be odd"); + // Montgomery reduction only works for positive odd moduli + if(!mod.is_positive() || mod.is_even()) + throw Invalid_Argument("Montgomery_Exponentiator: invalid modulus"); window_bits = 0; this->hints = hints; |