diff options
Diffstat (limited to 'src/ssl/rec_wri.cpp')
| -rw-r--r-- | src/ssl/rec_wri.cpp | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/src/ssl/rec_wri.cpp b/src/ssl/rec_wri.cpp new file mode 100644 index 000000000..258b4ec17 --- /dev/null +++ b/src/ssl/rec_wri.cpp @@ -0,0 +1,258 @@ +/** +* TLS Record Writing +* (C) 2004-2006 Jack Lloyd +* +* Released under the terms of the Botan license +*/ + +#include <botan/tls_record.h> +#include <botan/handshake_hash.h> +#include <botan/lookup.h> +#include <botan/loadstor.h> + +namespace Botan { + +/** +* Record_Writer Constructor +*/ +Record_Writer::Record_Writer(Socket& sock) : + socket(sock), buffer(DEFAULT_BUFFERSIZE) + { + reset(); + } + +/** +* Reset the state +*/ +void Record_Writer::reset() + { + compress.reset(); + cipher.reset(); + mac.reset(); + buffer.clear(); + do_compress = false; + major = minor = buf_type = 0; + pad_amount = mac_size = buf_pos = 0; + seq_no = 0; + } + +/** +* Set the version to use +*/ +void Record_Writer::set_version(Version_Code version) + { + if(version != SSL_V3 && version != TLS_V10) + throw Invalid_Argument("Record_Writer: Invalid protocol version"); + + major = (version >> 8) & 0xFF; + minor = (version & 0xFF); + } + +/** +* Set the compression algorithm +*/ +void Record_Writer::set_compressor(Filter* compressor) + { + throw TLS_Exception(INTERNAL_ERROR, "Compression not implemented (FIXME)"); + compress.append(compressor); + } + +/** +* Set the keys for writing +*/ +void Record_Writer::set_keys(const CipherSuite& suite, const SessionKeys& keys, + Connection_Side side) + { + cipher.reset(); + mac.reset(); + + SymmetricKey mac_key, cipher_key; + InitializationVector iv; + + if(side == CLIENT) + { + cipher_key = keys.client_cipher_key(); + iv = keys.client_iv(); + mac_key = keys.client_mac_key(); + } + else + { + cipher_key = keys.server_cipher_key(); + iv = keys.server_iv(); + mac_key = keys.server_mac_key(); + } + + const std::string cipher_algo = suite.cipher_algo(); + const std::string mac_algo = suite.mac_algo(); + + if(have_block_cipher(cipher_algo)) + { + cipher.append(get_cipher( + cipher_algo + "/CBC/NoPadding", + cipher_key, iv, ENCRYPTION) + ); + pad_amount = block_size_of(cipher_algo); + } + else if(have_stream_cipher(cipher_algo)) + { + cipher.append(get_cipher(cipher_algo, cipher_key, ENCRYPTION)); + pad_amount = 0; + } + else + throw Invalid_Argument("Record_Writer: Unknown cipher " + cipher_algo); + + if(have_hash(mac_algo)) + { + if(major == 3 && minor == 0) + mac.append(new MAC_Filter("SSL3-MAC(" + mac_algo + ")", mac_key)); + else + mac.append(new MAC_Filter("HMAC(" + mac_algo + ")", mac_key)); + + mac_size = output_length_of(mac_algo); + } + else + throw Invalid_Argument("Record_Writer: Unknown hash " + mac_algo); + } + +/** +* Send one or more records to the other side +*/ +void Record_Writer::send(byte type, byte input) + { + send(type, &input, 1); + } + +/** +* Send one or more records to the other side +*/ +void Record_Writer::send(byte type, const byte input[], u32bit length) + { + if(type != buf_type) + flush(); + + const u32bit BUFFER_SIZE = buffer.size(); + buf_type = type; + + // FIXME: compression right here + + buffer.copy(buf_pos, input, length); + if(buf_pos + length >= BUFFER_SIZE) + { + send_record(buf_type, buffer, length); + input += (BUFFER_SIZE - buf_pos); + length -= (BUFFER_SIZE - buf_pos); + while(length >= BUFFER_SIZE) + { + send_record(buf_type, input, BUFFER_SIZE); + input += BUFFER_SIZE; + length -= BUFFER_SIZE; + } + buffer.copy(input, length); + buf_pos = 0; + } + buf_pos += length; + } + +/** +* Split buffer into records, and send them all +*/ +void Record_Writer::flush() + { + const byte* buf_ptr = buffer.begin(); + u32bit offset = 0; + + while(offset != buf_pos) + { + u32bit record_size = buf_pos - offset; + if(record_size > MAX_PLAINTEXT_SIZE) + record_size = MAX_PLAINTEXT_SIZE; + + send_record(buf_type, buf_ptr + offset, record_size); + offset += record_size; + } + buf_type = 0; + buf_pos = 0; + } + +/** +* Encrypt and send the record +*/ +void Record_Writer::send_record(byte type, const byte buf[], u32bit length) + { + if(length >= MAX_COMPRESSED_SIZE) + throw TLS_Exception(INTERNAL_ERROR, + "Record_Writer: Compressed packet is too big"); + + if(mac_size == 0) + send_record(type, major, minor, buf, length); + else + { + mac.start_msg(); + for(u32bit j = 0; j != 8; j++) + mac.write(get_byte(j, seq_no)); + mac.write(type); + + if(major > 3 || (major == 3 && minor != 0)) + { + mac.write(major); + mac.write(minor); + } + + mac.write(get_byte(2, length)); + mac.write(get_byte(3, length)); + mac.write(buf, length); + mac.end_msg(); + + SecureVector<byte> buf_mac = mac.read_all(Pipe::LAST_MESSAGE); + + cipher.start_msg(); + cipher.write(buf, length); + cipher.write(buf_mac); + if(pad_amount) + { + u32bit pad_val = + (pad_amount - (1 + length + buf_mac.size())) % pad_amount; + + for(u32bit j = 0; j != pad_val + 1; j++) + cipher.write(pad_val); + } + cipher.end_msg(); + + SecureVector<byte> output = cipher.read_all(Pipe::LAST_MESSAGE); + + send_record(type, major, minor, output, output.size()); + + seq_no++; + } + } + +/** +* Send a final record packet +*/ +void Record_Writer::send_record(byte type, byte major, byte minor, + const byte out[], u32bit length) + { + if(length >= MAX_CIPHERTEXT_SIZE) + throw TLS_Exception(INTERNAL_ERROR, + "Record_Writer: Record is too big"); + + byte header[5] = { type, major, minor, 0 }; + for(u32bit j = 0; j != 2; j++) + header[j+3] = get_byte<u16bit>(j, length); + + // FIXME: tradoff of TCP/syscall overhead vs copy overhead + socket.write(header, 5); + socket.write(out, length); + } + +/** +* Send an alert +*/ +void Record_Writer::alert(Alert_Level level, Alert_Type type) + { + byte alert[2] = { level, type }; + send(ALERT, alert, sizeof(alert)); + flush(); + } + +} |