diff options
| -rw-r--r-- | src/tls/c_kex.cpp | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/src/tls/c_kex.cpp b/src/tls/c_kex.cpp index 22c0253c1..f95f74931 100644 --- a/src/tls/c_kex.cpp +++ b/src/tls/c_kex.cpp @@ -16,6 +16,26 @@ namespace Botan { +namespace { + +SecureVector<byte> strip_leading_zeros(const MemoryRegion<byte>& input) + { + size_t leading_zeros = 0; + + for(size_t i = 0; i != input.size(); ++i) + { + if(input[i] != 0) + break; + ++leading_zeros; + } + + SecureVector<byte> output(&input[leading_zeros], + input.size() - leading_zeros); + return output; + } + +} + /* * Create a new Client Key Exchange message */ @@ -34,7 +54,8 @@ Client_Key_Exchange::Client_Key_Exchange(Record_Writer& writer, PK_Key_Agreement ka(priv_key, "Raw"); - pre_master = ka.derive_key(0, dh_pub->public_value()).bits_of(); + pre_master = strip_leading_zeros( + ka.derive_key(0, dh_pub->public_value()).bits_of()); key_material = priv_key.public_value(); } @@ -115,7 +136,7 @@ Client_Key_Exchange::pre_master_secret(RandomNumberGenerator& rng, try { PK_Key_Agreement ka(*dh_priv, "Raw"); - pre_master = ka.derive_key(0, key_material).bits_of(); + pre_master = strip_leading_zeros(ka.derive_key(0, key_material).bits_of()); } catch(...) { |