/src/botan/src/lib/stream/ofb/ofb.cpp
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * OFB Mode |
3 | | * (C) 1999-2007,2014 Jack Lloyd |
4 | | * |
5 | | * Botan is released under the Simplified BSD License (see license.txt) |
6 | | */ |
7 | | |
8 | | #include <botan/internal/ofb.h> |
9 | | |
10 | | #include <botan/exceptn.h> |
11 | | #include <botan/internal/fmt.h> |
12 | | |
13 | | namespace Botan { |
14 | | |
15 | | OFB::OFB(std::unique_ptr<BlockCipher> cipher) : |
16 | 0 | m_cipher(std::move(cipher)), m_buffer(m_cipher->block_size()), m_buf_pos(0) {} |
17 | | |
18 | 0 | void OFB::clear() { |
19 | 0 | m_cipher->clear(); |
20 | 0 | zeroise(m_buffer); |
21 | 0 | m_buf_pos = 0; |
22 | 0 | } |
23 | | |
24 | 0 | bool OFB::has_keying_material() const { return m_cipher->has_keying_material(); } |
25 | | |
26 | 0 | size_t OFB::buffer_size() const { |
27 | 0 | return m_buffer.size(); // block size |
28 | 0 | } |
29 | | |
30 | 0 | void OFB::key_schedule(const uint8_t key[], size_t key_len) { |
31 | 0 | m_cipher->set_key(key, key_len); |
32 | | |
33 | | // Set a default all-zeros IV |
34 | 0 | set_iv(nullptr, 0); |
35 | 0 | } |
36 | | |
37 | 0 | std::string OFB::name() const { return fmt("OFB({})", m_cipher->name()); } |
38 | | |
39 | 0 | size_t OFB::default_iv_length() const { return m_cipher->block_size(); } |
40 | | |
41 | 0 | bool OFB::valid_iv_length(size_t iv_len) const { return (iv_len <= m_cipher->block_size()); } |
42 | | |
43 | 0 | Key_Length_Specification OFB::key_spec() const { return m_cipher->key_spec(); } |
44 | | |
45 | 0 | std::unique_ptr<StreamCipher> OFB::new_object() const { return std::make_unique<OFB>(m_cipher->new_object()); } |
46 | | |
47 | 0 | void OFB::cipher_bytes(const uint8_t in[], uint8_t out[], size_t length) { |
48 | 0 | while(length >= m_buffer.size() - m_buf_pos) { |
49 | 0 | xor_buf(out, in, &m_buffer[m_buf_pos], m_buffer.size() - m_buf_pos); |
50 | 0 | length -= (m_buffer.size() - m_buf_pos); |
51 | 0 | in += (m_buffer.size() - m_buf_pos); |
52 | 0 | out += (m_buffer.size() - m_buf_pos); |
53 | 0 | m_cipher->encrypt(m_buffer); |
54 | 0 | m_buf_pos = 0; |
55 | 0 | } |
56 | 0 | xor_buf(out, in, &m_buffer[m_buf_pos], length); |
57 | 0 | m_buf_pos += length; |
58 | 0 | } |
59 | | |
60 | 0 | void OFB::set_iv_bytes(const uint8_t iv[], size_t iv_len) { |
61 | 0 | if(!valid_iv_length(iv_len)) { |
62 | 0 | throw Invalid_IV_Length(name(), iv_len); |
63 | 0 | } |
64 | | |
65 | 0 | zeroise(m_buffer); |
66 | 0 | buffer_insert(m_buffer, 0, iv, iv_len); |
67 | |
|
68 | 0 | m_cipher->encrypt(m_buffer); |
69 | 0 | m_buf_pos = 0; |
70 | 0 | } |
71 | | |
72 | 0 | void OFB::seek(uint64_t /*offset*/) { throw Not_Implemented("OFB does not support seeking"); } |
73 | | } // namespace Botan |