diff options
Diffstat (limited to 'src/lib/stream/ctr/ctr.cpp')
| -rw-r--r-- | src/lib/stream/ctr/ctr.cpp | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/src/lib/stream/ctr/ctr.cpp b/src/lib/stream/ctr/ctr.cpp index 88c7a8d8e..43609ba2d 100644 --- a/src/lib/stream/ctr/ctr.cpp +++ b/src/lib/stream/ctr/ctr.cpp @@ -23,10 +23,23 @@ CTR_BE::CTR_BE(BlockCipher* ciph) : m_cipher(ciph), m_counter(m_cipher->parallel_bytes()), m_pad(m_counter.size()), + m_ctr_size(m_cipher->block_size()), m_pad_pos(0) { } +CTR_BE::CTR_BE(BlockCipher* cipher, size_t ctr_size) : + m_cipher(cipher), + m_counter(m_cipher->parallel_bytes()), + m_pad(m_counter.size()), + m_ctr_size(ctr_size), + m_pad_pos(0) + { + //BOTAN_CHECK_ARG(m_ctr_size > 0 && m_ctr_size <= cipher->block_size(), "Invalid CTR size"); + if(m_ctr_size == 0 || m_ctr_size > m_cipher->block_size()) + throw Invalid_Argument("Invalid CTR-BE counter size"); + } + void CTR_BE::clear() { m_cipher->clear(); @@ -79,7 +92,7 @@ void CTR_BE::set_iv(const byte iv[], size_t iv_len) { buffer_insert(m_counter, i*bs, &m_counter[(i-1)*bs], bs); - for(size_t j = 0; j != bs; ++j) + for(size_t j = 0; j != m_ctr_size; ++j) if(++m_counter[i*bs + (bs - 1 - j)]) break; } @@ -99,7 +112,7 @@ void CTR_BE::increment_counter() for(size_t i = 0; i != n_wide; ++i) { uint16_t carry = static_cast<uint16_t>(n_wide); - for(size_t j = 0; carry && j != bs; ++j) + for(size_t j = 0; carry && j != m_ctr_size; ++j) { const size_t off = i*bs + (bs-1-j); const uint16_t cnt = static_cast<uint16_t>(m_counter[off]) + carry; @@ -112,4 +125,8 @@ void CTR_BE::increment_counter() m_pad_pos = 0; } +void CTR_BE::seek(u64bit) + { + throw Not_Implemented("CTR_BE::seek"); + } } |