Botan 3.9.0
Crypto and TLS for C&
Botan::TLS::Datagram_Sequence_Numbers Class Referencefinal

#include <tls_seq_numbers.h>

Inheritance diagram for Botan::TLS::Datagram_Sequence_Numbers:
Botan::TLS::Connection_Sequence_Numbers

Public Member Functions

bool already_seen (uint64_t sequence) const override
uint16_t current_read_epoch () const override
uint16_t current_write_epoch () const override
 Datagram_Sequence_Numbers ()
void new_read_cipher_state () override
void new_write_cipher_state () override
uint64_t next_read_sequence () override
uint64_t next_write_sequence (uint16_t epoch) override
void read_accept (uint64_t sequence) override
void reset () override

Detailed Description

Definition at line 76 of file tls_seq_numbers.h.

Constructor & Destructor Documentation

◆ Datagram_Sequence_Numbers()

Botan::TLS::Datagram_Sequence_Numbers::Datagram_Sequence_Numbers ( )
inline

Definition at line 78 of file tls_seq_numbers.h.

References reset().

Member Function Documentation

◆ already_seen()

bool Botan::TLS::Datagram_Sequence_Numbers::already_seen ( uint64_t sequence) const
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 108 of file tls_seq_numbers.h.

108 {
109 const size_t window_size = sizeof(m_window_bits) * 8;
110
111 if(sequence > m_window_highest) {
112 return false;
113 }
114
115 const uint64_t offset = m_window_highest - sequence;
116
117 if(offset >= window_size) {
118 return true; // really old?
119 }
120
121 return (((m_window_bits >> offset) & 1) == 1);
122 }

◆ current_read_epoch()

uint16_t Botan::TLS::Datagram_Sequence_Numbers::current_read_epoch ( ) const
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 96 of file tls_seq_numbers.h.

96{ return m_read_epoch; }

◆ current_write_epoch()

uint16_t Botan::TLS::Datagram_Sequence_Numbers::current_write_epoch ( ) const
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 98 of file tls_seq_numbers.h.

98{ return m_write_epoch; }

◆ new_read_cipher_state()

void Botan::TLS::Datagram_Sequence_Numbers::new_read_cipher_state ( )
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 89 of file tls_seq_numbers.h.

89{ m_read_epoch++; }

◆ new_write_cipher_state()

void Botan::TLS::Datagram_Sequence_Numbers::new_write_cipher_state ( )
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 91 of file tls_seq_numbers.h.

91 {
92 m_write_epoch++;
93 m_write_seqs[m_write_epoch] = 0;
94 }

◆ next_read_sequence()

uint64_t Botan::TLS::Datagram_Sequence_Numbers::next_read_sequence ( )
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 106 of file tls_seq_numbers.h.

106{ throw Invalid_State("DTLS uses explicit sequence numbers"); }

◆ next_write_sequence()

uint64_t Botan::TLS::Datagram_Sequence_Numbers::next_write_sequence ( uint16_t epoch)
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 100 of file tls_seq_numbers.h.

100 {
101 auto i = m_write_seqs.find(epoch);
102 BOTAN_ASSERT(i != m_write_seqs.end(), "Found epoch");
103 return (static_cast<uint64_t>(epoch) << 48) | i->second++;
104 }
#define BOTAN_ASSERT(expr, assertion_made)
Definition assert.h:62

References BOTAN_ASSERT.

◆ read_accept()

void Botan::TLS::Datagram_Sequence_Numbers::read_accept ( uint64_t sequence)
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 124 of file tls_seq_numbers.h.

124 {
125 const size_t window_size = sizeof(m_window_bits) * 8;
126
127 if(sequence > m_window_highest) {
128 // We've received a later sequence which advances our window
129 const uint64_t offset = sequence - m_window_highest;
130 m_window_highest += offset;
131
132 if(offset >= window_size) {
133 m_window_bits = 0;
134 } else {
135 m_window_bits <<= offset;
136 }
137
138 m_window_bits |= 0x01;
139 } else {
140 const uint64_t offset = m_window_highest - sequence;
141
142 if(offset < window_size) {
143 // We've received an old sequence but still within our window
144 m_window_bits |= (static_cast<uint64_t>(1) << offset);
145 } else {
146 // This occurs only if we have reset state (DTLS reconnection case)
147 m_window_highest = sequence;
148 m_window_bits = 0;
149 }
150 }
151 }

◆ reset()

void Botan::TLS::Datagram_Sequence_Numbers::reset ( )
inlineoverridevirtual

Implements Botan::TLS::Connection_Sequence_Numbers.

Definition at line 80 of file tls_seq_numbers.h.

80 {
81 m_write_seqs.clear();
82 m_write_seqs[0] = 0;
83 m_write_epoch = 0;
84 m_read_epoch = 0;
85 m_window_highest = 0;
86 m_window_bits = 0;
87 }

Referenced by Datagram_Sequence_Numbers().


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