Botan  2.1.0
Crypto and TLS for C++11
Public Member Functions | Protected Member Functions | List of all members
Botan::SIV_Encryption Class Referencefinal

#include <siv.h>

Inheritance diagram for Botan::SIV_Encryption:
Botan::SIV_Mode Botan::AEAD_Mode Botan::Cipher_Mode

Public Member Functions

bool authenticated () const override
 
void clear () override
 
size_t default_nonce_length () const override
 
void finish (secure_vector< uint8_t > &final_block, size_t offset=0) override
 
Key_Length_Specification key_spec () const override
 
size_t minimum_final_size () const override
 
std::string name () const override
 
size_t output_length (size_t input_length) const override
 
size_t process (uint8_t buf[], size_t size) override
 
virtual std::string provider () const
 
void reset () override
 
template<typename Alloc >
void set_ad (const std::vector< uint8_t, Alloc > &ad)
 
void set_associated_data (const uint8_t ad[], size_t ad_len) override
 
void set_associated_data_n (size_t n, const uint8_t ad[], size_t ad_len)
 
template<typename Alloc >
void set_associated_data_vec (const std::vector< uint8_t, Alloc > &ad)
 
template<typename Alloc >
void set_key (const std::vector< uint8_t, Alloc > &key)
 
void set_key (const SymmetricKey &key)
 
void set_key (const uint8_t key[], size_t length)
 
 SIV_Encryption (BlockCipher *cipher)
 
template<typename Alloc >
void start (const std::vector< uint8_t, Alloc > &nonce)
 
void start (const uint8_t nonce[], size_t nonce_len)
 
void start ()
 
size_t tag_size () const override
 
void update (secure_vector< uint8_t > &buffer, size_t offset=0)
 
size_t update_granularity () const override
 
bool valid_keylength (size_t length) const
 
bool valid_nonce_length (size_t) const override
 

Protected Member Functions

StreamCipherctr ()
 
secure_vector< uint8_t > & msg_buf ()
 
secure_vector< uint8_t > S2V (const uint8_t text[], size_t text_len)
 
void set_ctr_iv (secure_vector< uint8_t > V)
 

Detailed Description

SIV Encryption

Definition at line 79 of file siv.h.

Constructor & Destructor Documentation

Botan::SIV_Encryption::SIV_Encryption ( BlockCipher cipher)
inlineexplicit
Parameters
ciphera block cipher

Definition at line 85 of file siv.h.

85 : SIV_Mode(cipher) {}
SIV_Mode(BlockCipher *cipher)
Definition: siv.cpp:16

Member Function Documentation

bool Botan::AEAD_Mode::authenticated ( ) const
inlineoverridevirtualinherited
Returns
true iff this mode provides authentication as well as confidentiality.

Reimplemented from Botan::Cipher_Mode.

Definition at line 25 of file aead.h.

25 { return true; }
void Botan::SIV_Mode::clear ( )
overridevirtualinherited

Zeroise all state See also reset_msg()

Implements Botan::Cipher_Mode.

Definition at line 25 of file siv.cpp.

References Botan::SIV_Mode::reset().

26  {
27  m_ctr->clear();
28  m_cmac->clear();
29  reset();
30  }
void reset() override
Definition: siv.cpp:32
StreamCipher& Botan::SIV_Mode::ctr ( )
inlineprotectedinherited

Definition at line 57 of file siv.h.

Referenced by finish(), Botan::SIV_Decryption::finish(), and Botan::SIV_Mode::set_ctr_iv().

57 { return *m_ctr; }
size_t Botan::AEAD_Mode::default_nonce_length ( ) const
inlineoverridevirtualinherited
Returns
default AEAD nonce size (a commonly supported value among AEAD modes, and large enough that random collisions are unlikely)

Implements Botan::Cipher_Mode.

Reimplemented in Botan::TLS::TLS_CBC_HMAC_AEAD_Mode, and Botan::CCM_Mode.

Definition at line 75 of file aead.h.

75 { return 12; }
void Botan::SIV_Encryption::finish ( secure_vector< uint8_t > &  final_block,
size_t  offset = 0 
)
overridevirtual

Complete processing of a message.

Parameters
final_blockin/out parameter which must be at least minimum_final_size() bytes, and will be set to any final output
offsetan offset into final_block to begin processing

Implements Botan::Cipher_Mode.

Definition at line 142 of file siv.cpp.

References BOTAN_ASSERT, Botan::StreamCipher::cipher1(), Botan::SIV_Mode::ctr(), Botan::SIV_Mode::msg_buf(), Botan::SIV_Mode::S2V(), and Botan::SIV_Mode::set_ctr_iv().

143  {
144  BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
145 
146  buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
147 
148  secure_vector<uint8_t> V = S2V(buffer.data() + offset, buffer.size() - offset);
149 
150  buffer.insert(buffer.begin() + offset, V.begin(), V.end());
151 
152  set_ctr_iv(V);
153  ctr().cipher1(&buffer[offset + V.size()], buffer.size() - offset - V.size());
154  }
secure_vector< uint8_t > & msg_buf()
Definition: siv.h:61
void cipher1(uint8_t buf[], size_t len)
Definition: stream_cipher.h:65
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:27
secure_vector< uint8_t > S2V(const uint8_t text[], size_t text_len)
Definition: siv.cpp:101
StreamCipher & ctr()
Definition: siv.h:57
void set_ctr_iv(secure_vector< uint8_t > V)
Definition: siv.cpp:134
Key_Length_Specification Botan::SIV_Mode::key_spec ( ) const
overridevirtualinherited
Returns
object describing limits on key size

Implements Botan::Cipher_Mode.

Definition at line 60 of file siv.cpp.

61  {
62  return m_cmac->key_spec().multiple(2);
63  }
size_t Botan::SIV_Encryption::minimum_final_size ( ) const
inlineoverridevirtual
Returns
required minimium size to finalize() - may be any length larger than this.

Implements Botan::Cipher_Mode.

Definition at line 92 of file siv.h.

92 { return 0; }
secure_vector<uint8_t>& Botan::SIV_Mode::msg_buf ( )
inlineprotectedinherited

Definition at line 61 of file siv.h.

Referenced by finish(), and Botan::SIV_Decryption::finish().

61 { return m_msg_buf; }
std::string Botan::SIV_Mode::name ( ) const
overridevirtualinherited

Implements Botan::Cipher_Mode.

Definition at line 39 of file siv.cpp.

40  {
41  return m_name;
42  }
size_t Botan::SIV_Encryption::output_length ( size_t  input_length) const
inlineoverridevirtual

Returns the size of the output if this transform is used to process a message with input_length bytes. Will throw if unable to give a precise answer.

Implements Botan::Cipher_Mode.

Definition at line 89 of file siv.h.

90  { return input_length + tag_size(); }
size_t tag_size() const override
Definition: siv.h:52
size_t Botan::SIV_Mode::process ( uint8_t  msg[],
size_t  msg_len 
)
overridevirtualinherited

Process message blocks

Input must be a multiple of update_granularity

Processes msg in place and returns bytes written. Normally this will be either msg_len (indicating the entire message was processed) or for certain AEAD modes zero (indicating that the mode requires the entire message be processed in one pass).

Parameters
msgthe message to be processed
msg_lenlength of the message in bytes

Implements Botan::Cipher_Mode.

Definition at line 94 of file siv.cpp.

95  {
96  // all output is saved for processing in finish
97  m_msg_buf.insert(m_msg_buf.end(), buf, buf + sz);
98  return 0;
99  }
virtual std::string Botan::Cipher_Mode::provider ( ) const
inlinevirtualinherited
Returns
provider information about this implementation. Default is "base", might also return "sse2", "avx2", "openssl", or some other arbitrary string.

Reimplemented in Botan::GCM_Mode.

Definition at line 202 of file cipher_mode.h.

202 { return "base"; }
void Botan::SIV_Mode::reset ( )
overridevirtualinherited

Resets just the message specific state and allows encrypting again under the existing key

Implements Botan::Cipher_Mode.

Definition at line 32 of file siv.cpp.

Referenced by Botan::SIV_Mode::clear().

33  {
34  m_nonce.clear();
35  m_msg_buf.clear();
36  m_ad_macs.clear();
37  }
secure_vector< uint8_t > Botan::SIV_Mode::S2V ( const uint8_t  text[],
size_t  text_len 
)
protectedinherited

Definition at line 101 of file siv.cpp.

References Botan::CMAC::poly_double(), and Botan::xor_buf().

Referenced by finish(), and Botan::SIV_Decryption::finish().

102  {
103  const uint8_t zero[16] = { 0 };
104 
105  secure_vector<uint8_t> V = m_cmac->process(zero, 16);
106 
107  for(size_t i = 0; i != m_ad_macs.size(); ++i)
108  {
109  V = CMAC::poly_double(V);
110  V ^= m_ad_macs[i];
111  }
112 
113  if(m_nonce.size())
114  {
115  V = CMAC::poly_double(V);
116  V ^= m_nonce;
117  }
118 
119  if(text_len < 16)
120  {
121  V = CMAC::poly_double(V);
122  xor_buf(V.data(), text, text_len);
123  V[text_len] ^= 0x80;
124  return m_cmac->process(V);
125  }
126 
127  m_cmac->update(text, text_len - 16);
128  xor_buf(V.data(), &text[text_len - 16], 16);
129  m_cmac->update(V);
130 
131  return m_cmac->final();
132  }
void xor_buf(T out[], const T in[], size_t length)
Definition: mem_ops.h:115
static secure_vector< uint8_t > poly_double(const secure_vector< uint8_t > &in)
Definition: cmac.cpp:15
template<typename Alloc >
void Botan::AEAD_Mode::set_ad ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 66 of file aead.h.

Referenced by Botan::TLS::write_record().

67  {
68  set_associated_data(ad.data(), ad.size());
69  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0
void Botan::SIV_Mode::set_associated_data ( const uint8_t  ad[],
size_t  ad_len 
)
inlineoverridevirtualinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

Unless reset by another call, the associated data is kept between messages. Thus, if the AD does not change, calling once (after set_key) is the optimum.

Parameters
adthe associated data
ad_lenlength of add in bytes

Implements Botan::AEAD_Mode.

Definition at line 35 of file siv.h.

36  {
37  set_associated_data_n(0, ad, ad_len);
38  }
void set_associated_data_n(size_t n, const uint8_t ad[], size_t ad_len)
Definition: siv.cpp:73
void Botan::SIV_Mode::set_associated_data_n ( size_t  n,
const uint8_t  ad[],
size_t  ad_len 
)
inherited

Sets the nth element of the vector of associated data

Parameters
nindex into the AD vector
adassociated data
ad_lenlength of associated data in bytes

Definition at line 73 of file siv.cpp.

74  {
75  if(n >= m_ad_macs.size())
76  m_ad_macs.resize(n+1);
77 
78  m_ad_macs[n] = m_cmac->process(ad, length);
79  }
template<typename Alloc >
void Botan::AEAD_Mode::set_associated_data_vec ( const std::vector< uint8_t, Alloc > &  ad)
inlineinherited

Set associated data that is not included in the ciphertext but that should be authenticated. Must be called after set_key and before start.

See set_associated_data().

Parameters
adthe associated data

Definition at line 51 of file aead.h.

52  {
53  set_associated_data(ad.data(), ad.size());
54  }
virtual void set_associated_data(const uint8_t ad[], size_t ad_len)=0
void Botan::SIV_Mode::set_ctr_iv ( secure_vector< uint8_t >  V)
protectedinherited

Definition at line 134 of file siv.cpp.

References Botan::SIV_Mode::ctr(), and Botan::StreamCipher::set_iv().

Referenced by finish(), and Botan::SIV_Decryption::finish().

135  {
136  V[8] &= 0x7F;
137  V[12] &= 0x7F;
138 
139  ctr().set_iv(V.data(), V.size());
140  }
StreamCipher & ctr()
Definition: siv.h:57
virtual void set_iv(const uint8_t iv[], size_t iv_len)=0
template<typename Alloc >
void Botan::Cipher_Mode::set_key ( const std::vector< uint8_t, Alloc > &  key)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 172 of file cipher_mode.h.

Referenced by botan_cipher_set_key().

173  {
174  set_key(key.data(), key.size());
175  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:172
void Botan::Cipher_Mode::set_key ( const SymmetricKey key)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material

Definition at line 181 of file cipher_mode.h.

References Botan::OctetString::begin(), and Botan::OctetString::length().

182  {
183  set_key(key.begin(), key.length());
184  }
void set_key(const std::vector< uint8_t, Alloc > &key)
Definition: cipher_mode.h:172
void Botan::Cipher_Mode::set_key ( const uint8_t  key[],
size_t  length 
)
inlineinherited

Set the symmetric key of this transform

Parameters
keycontains the key material
lengthin bytes of key param

Definition at line 191 of file cipher_mode.h.

192  {
193  if(!valid_keylength(length))
194  throw Invalid_Key_Length(name(), length);
195  key_schedule(key, length);
196  }
virtual std::string name() const =0
bool valid_keylength(size_t length) const
Definition: cipher_mode.h:162
template<typename Alloc >
void Botan::Cipher_Mode::start ( const std::vector< uint8_t, Alloc > &  nonce)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce

Definition at line 38 of file cipher_mode.h.

Referenced by botan_cipher_start(), and Botan::TLS::write_record().

39  {
40  start_msg(nonce.data(), nonce.size());
41  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0
void Botan::Cipher_Mode::start ( const uint8_t  nonce[],
size_t  nonce_len 
)
inlineinherited

Begin processing a message.

Parameters
noncethe per message nonce
nonce_lenlength of nonce

Definition at line 48 of file cipher_mode.h.

49  {
50  start_msg(nonce, nonce_len);
51  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0
void Botan::Cipher_Mode::start ( )
inlineinherited

Begin processing a message.

Definition at line 56 of file cipher_mode.h.

57  {
58  return start_msg(nullptr, 0);
59  }
virtual void start_msg(const uint8_t nonce[], size_t nonce_len)=0
size_t Botan::SIV_Mode::tag_size ( ) const
inlineoverridevirtualinherited
Returns
the size of the authentication tag used (in bytes)

Reimplemented from Botan::Cipher_Mode.

Definition at line 52 of file siv.h.

Referenced by Botan::SIV_Decryption::finish().

52 { return 16; }
void Botan::Cipher_Mode::update ( secure_vector< uint8_t > &  buffer,
size_t  offset = 0 
)
inlineinherited

Process some data. Input must be in size update_granularity() uint8_t blocks.

Parameters
bufferin/out parameter which will possibly be resized
offsetan offset into blocks to begin processing

Definition at line 81 of file cipher_mode.h.

References BOTAN_ASSERT.

Referenced by botan_cipher_update(), Botan::XTS_Encryption::finish(), Botan::ChaCha20Poly1305_Encryption::finish(), Botan::CBC_Encryption::finish(), Botan::CFB_Encryption::finish(), Botan::EAX_Encryption::finish(), Botan::XTS_Decryption::finish(), Botan::CFB_Decryption::finish(), Botan::CTS_Encryption::finish(), Botan::CBC_Decryption::finish(), Botan::TLS::TLS_CBC_HMAC_AEAD_Encryption::finish(), Botan::CTS_Decryption::finish(), and Botan::TLS::TLS_CBC_HMAC_AEAD_Decryption::finish().

82  {
83  BOTAN_ASSERT(buffer.size() >= offset, "Offset ok");
84  uint8_t* buf = buffer.data() + offset;
85  const size_t buf_size = buffer.size() - offset;
86 
87  const size_t written = process(buf, buf_size);
88  buffer.resize(offset + written);
89  }
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:27
virtual size_t process(uint8_t msg[], size_t msg_len)=0
size_t Botan::SIV_Mode::update_granularity ( ) const
overridevirtualinherited
Returns
size of required blocks to update

Implements Botan::Cipher_Mode.

Definition at line 49 of file siv.cpp.

50  {
51  /*
52  This value does not particularly matter as regardless SIV_Mode::update
53  buffers all input, so in theory this could be 1. However as for instance
54  Transform_Filter creates update_granularity() uint8_t buffers, use a
55  somewhat large size to avoid bouncing on a tiny buffer.
56  */
57  return 128;
58  }
bool Botan::Cipher_Mode::valid_keylength ( size_t  length) const
inlineinherited

Check whether a given key length is valid for this algorithm.

Parameters
lengththe key length to be checked.
Returns
true if the key length is valid.

Definition at line 162 of file cipher_mode.h.

163  {
164  return key_spec().valid_keylength(length);
165  }
bool valid_keylength(size_t length) const
Definition: key_spec.h:51
virtual Key_Length_Specification key_spec() const =0
bool Botan::SIV_Mode::valid_nonce_length ( size_t  nonce_len) const
overridevirtualinherited
Returns
true iff nonce_len is a valid length for the nonce

Implements Botan::Cipher_Mode.

Definition at line 44 of file siv.cpp.

45  {
46  return true;
47  }

The documentation for this class was generated from the following files: