Botan
1.11.15
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#include <gcm.h>
Public Types | |
typedef SCAN_Name | Spec |
Public Member Functions | |
bool | authenticated () const override |
void | clear () override |
size_t | default_nonce_length () const override |
void | finish (secure_vector< byte > &final_block, size_t offset=0) override |
GCM_Decryption (BlockCipher *cipher, size_t tag_size=16) | |
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 |
virtual std::string | provider () const |
template<typename Alloc > | |
void | set_ad (const std::vector< byte, Alloc > &ad) |
void | set_associated_data (const byte ad[], size_t ad_len) override |
template<typename Alloc > | |
void | set_associated_data_vec (const std::vector< byte, Alloc > &ad) |
template<typename Alloc > | |
void | set_key (const std::vector< byte, Alloc > &key) |
void | set_key (const SymmetricKey &key) |
void | set_key (const byte key[], size_t length) |
template<typename Alloc > | |
secure_vector< byte > | start (const std::vector< byte, Alloc > &nonce) |
secure_vector< byte > | start (const byte nonce[], size_t nonce_len) |
secure_vector< byte > | start () |
template<typename Alloc > | |
secure_vector< byte > | start_vec (const std::vector< byte, Alloc > &nonce) |
size_t | tag_size () const override |
void | update (secure_vector< byte > &blocks, size_t offset=0) override |
size_t | update_granularity () const |
bool | valid_keylength (size_t length) const |
bool | valid_nonce_length (size_t) const override |
Protected Attributes | |
const size_t | BS = 16 |
const std::string | m_cipher_name |
std::unique_ptr< StreamCipher > | m_ctr |
std::unique_ptr< GHASH > | m_ghash |
const size_t | m_tag_size |
typedef SCAN_Name Botan::Transform::Spec [inherited] |
Definition at line 27 of file transform.h.
Botan::GCM_Decryption::GCM_Decryption | ( | BlockCipher * | cipher, |
size_t | tag_size = 16 |
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) | [inline] |
bool Botan::AEAD_Mode::authenticated | ( | ) | const [inline, override, virtual, inherited] |
Returns true iff this mode provides authentication as well as confidentiality.
Reimplemented from Botan::Cipher_Mode.
Definition at line 25 of file aead.h.
{ return true; }
void Botan::GCM_Mode::clear | ( | ) | [override, virtual, inherited] |
Implements Botan::Transform.
Definition at line 172 of file gcm.cpp.
References Botan::GCM_Mode::m_ctr, and Botan::GCM_Mode::m_ghash.
size_t Botan::AEAD_Mode::default_nonce_length | ( | ) | const [inline, override, virtual, inherited] |
Default AEAD nonce size (a commonly supported value among AEAD modes, and large enough that random collisions are unlikely).
Implements Botan::Transform.
Reimplemented in Botan::CCM_Mode.
Definition at line 57 of file aead.h.
{ return 12; }
void Botan::GCM_Decryption::finish | ( | secure_vector< byte > & | final_block, |
size_t | offset = 0 |
||
) | [override, virtual] |
Complete processing of a message.
final_block | in/out parameter which must be at least minimum_final_size() bytes, and will be set to any final output |
offset | an offset into final_block to begin processing |
Implements Botan::Transform.
Definition at line 264 of file gcm.cpp.
References BOTAN_ASSERT, Botan::GCM_Mode::m_ctr, Botan::GCM_Mode::m_ghash, mac, Botan::same_mem(), and Botan::GCM_Mode::tag_size().
{ BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane"); const size_t sz = buffer.size() - offset; byte* buf = &buffer[offset]; BOTAN_ASSERT(sz >= tag_size(), "Have the tag as part of final input"); const size_t remaining = sz - tag_size(); // handle any final input before the tag if(remaining) { m_ghash->update(buf, remaining); m_ctr->cipher(buf, buf, remaining); } auto mac = m_ghash->final(); const byte* included_tag = &buffer[remaining]; if(!same_mem(&mac[0], included_tag, tag_size())) throw Integrity_Failure("GCM tag check failed"); buffer.resize(offset + remaining); }
Key_Length_Specification Botan::GCM_Mode::key_spec | ( | ) | const [override, virtual, inherited] |
Implements Botan::Keyed_Transform.
Definition at line 188 of file gcm.cpp.
References Botan::GCM_Mode::m_ctr.
{ return m_ctr->key_spec(); }
size_t Botan::GCM_Decryption::minimum_final_size | ( | ) | const [inline, override, virtual] |
Implements Botan::Transform.
Definition at line 97 of file gcm.h.
{ return tag_size(); }
std::string Botan::GCM_Mode::name | ( | ) | const [override, virtual, inherited] |
Implements Botan::Transform.
Definition at line 178 of file gcm.cpp.
References Botan::GCM_Mode::m_cipher_name.
Referenced by Botan::GCM_Mode::GCM_Mode().
{ return (m_cipher_name + "/GCM"); }
size_t Botan::GCM_Decryption::output_length | ( | size_t | input_length | ) | const [inline, override, virtual] |
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::Transform.
Definition at line 91 of file gcm.h.
References BOTAN_ASSERT.
{ BOTAN_ASSERT(input_length > tag_size(), "Sufficient input"); return input_length - tag_size(); }
virtual std::string Botan::Transform::provider | ( | ) | const [inline, virtual, inherited] |
Return some short name describing the provider of this tranformation. Useful in cases where multiple implementations are available (eg, different implementations of AES). Default "core" is used for the 'standard' implementation included in the library.
Definition at line 120 of file transform.h.
{ return "core"; }
void Botan::AEAD_Mode::set_ad | ( | const std::vector< byte, Alloc > & | ad | ) | [inline, inherited] |
Definition at line 48 of file aead.h.
{ set_associated_data(&ad[0], ad.size()); }
void Botan::GCM_Mode::set_associated_data | ( | const byte | ad[], |
size_t | ad_len | ||
) | [override, virtual, inherited] |
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.
ad | the associated data |
ad_len | length of add in bytes |
Implements Botan::AEAD_Mode.
Definition at line 205 of file gcm.cpp.
References Botan::GCM_Mode::m_ghash.
{ m_ghash->set_associated_data(ad, ad_len); }
void Botan::AEAD_Mode::set_associated_data_vec | ( | const std::vector< byte, Alloc > & | ad | ) | [inline, inherited] |
Definition at line 42 of file aead.h.
{ set_associated_data(&ad[0], ad.size()); }
void Botan::Keyed_Transform::set_key | ( | const std::vector< byte, Alloc > & | key | ) | [inline, inherited] |
Definition at line 148 of file transform.h.
Referenced by botan_cipher_set_key().
{ set_key(&key[0], key.size()); }
void Botan::Keyed_Transform::set_key | ( | const SymmetricKey & | key | ) | [inline, inherited] |
Definition at line 153 of file transform.h.
References Botan::OctetString::begin(), and Botan::OctetString::length().
{ set_key(key.begin(), key.length()); }
void Botan::Keyed_Transform::set_key | ( | const byte | key[], |
size_t | length | ||
) | [inline, inherited] |
Set the symmetric key of this transform
key | contains the key material |
length | in bytes of key param |
Definition at line 163 of file transform.h.
{ if(!valid_keylength(length)) throw Invalid_Key_Length(name(), length); key_schedule(key, length); }
secure_vector<byte> Botan::Transform::start | ( | const std::vector< byte, Alloc > & | nonce | ) | [inline, inherited] |
Begin processing a message.
nonce | the per message nonce |
Definition at line 34 of file transform.h.
Referenced by botan_cipher_start().
{ return start(&nonce[0], nonce.size()); }
secure_vector<byte> Botan::Transform::start | ( | const byte | nonce[], |
size_t | nonce_len | ||
) | [inline, inherited] |
Begin processing a message.
nonce | the per message nonce |
nonce_len | length of nonce |
Definition at line 55 of file transform.h.
{ return start_raw(nonce, nonce_len); }
secure_vector<byte> Botan::Transform::start | ( | ) | [inline, inherited] |
Begin processing a message.
Definition at line 63 of file transform.h.
{ return start_raw(nullptr, 0); }
secure_vector<byte> Botan::Transform::start_vec | ( | const std::vector< byte, Alloc > & | nonce | ) | [inline, inherited] |
Begin processing a message.
nonce | the per message nonce |
Definition at line 45 of file transform.h.
{ return start(&nonce[0], nonce.size()); }
size_t Botan::GCM_Mode::tag_size | ( | ) | const [inline, override, virtual, inherited] |
Return the size of the authentication tag used (in bytes)
Reimplemented from Botan::Cipher_Mode.
Definition at line 36 of file gcm.h.
Referenced by Botan::GCM_Encryption::finish(), and finish().
{ return m_tag_size; }
void Botan::GCM_Decryption::update | ( | secure_vector< byte > & | blocks, |
size_t | offset = 0 |
||
) | [override, virtual] |
Process some data. Input must be in size update_granularity() byte blocks.
blocks | in/out paramter which will possibly be resized |
offset | an offset into blocks to begin processing |
Implements Botan::Transform.
Definition at line 254 of file gcm.cpp.
References BOTAN_ASSERT, Botan::GCM_Mode::m_ctr, and Botan::GCM_Mode::m_ghash.
{ BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane"); const size_t sz = buffer.size() - offset; byte* buf = &buffer[offset]; m_ghash->update(buf, sz); m_ctr->cipher(buf, buf, sz); }
size_t Botan::GCM_Mode::update_granularity | ( | ) | const [virtual, inherited] |
Implements Botan::Transform.
Definition at line 183 of file gcm.cpp.
{ return 4096; // CTR-BE's internal block size }
bool Botan::Keyed_Transform::valid_keylength | ( | size_t | length | ) | const [inline, inherited] |
Check whether a given key length is valid for this algorithm.
length | the key length to be checked. |
Definition at line 142 of file transform.h.
References Botan::Key_Length_Specification::valid_keylength().
{ return key_spec().valid_keylength(length); }
bool Botan::GCM_Mode::valid_nonce_length | ( | size_t | nonce_len | ) | const [inline, override, virtual, inherited] |
Return true iff nonce_len is a valid length for the nonce
Implements Botan::Transform.
Definition at line 34 of file gcm.h.
{ return true; }
const size_t Botan::GCM_Mode::BS = 16 [protected, inherited] |
Definition at line 42 of file gcm.h.
Referenced by Botan::GCM_Mode::GCM_Mode().
const std::string Botan::GCM_Mode::m_cipher_name [protected, inherited] |
Definition at line 45 of file gcm.h.
Referenced by Botan::GCM_Mode::name().
std::unique_ptr<StreamCipher> Botan::GCM_Mode::m_ctr [protected, inherited] |
Definition at line 47 of file gcm.h.
Referenced by Botan::GCM_Mode::clear(), finish(), Botan::GCM_Mode::GCM_Mode(), Botan::GCM_Mode::key_spec(), Botan::GCM_Encryption::update(), and update().
std::unique_ptr<GHASH> Botan::GCM_Mode::m_ghash [protected, inherited] |
Definition at line 48 of file gcm.h.
Referenced by Botan::GCM_Mode::clear(), Botan::GCM_Encryption::finish(), finish(), Botan::GCM_Mode::GCM_Mode(), Botan::GCM_Mode::set_associated_data(), Botan::GCM_Encryption::update(), and update().
const size_t Botan::GCM_Mode::m_tag_size [protected, inherited] |
Definition at line 44 of file gcm.h.
Referenced by Botan::GCM_Mode::GCM_Mode().