Annexe A. Structures de données du protocole et valeurs constantes (Protocol Data Structures and Constant Values)

Cette annexe fournit une liste complète de toutes les structures de données et valeurs constantes utilisées dans le protocole TLS 1.2.

A.1. Couche d'enregistrement (Record Layer)

struct {
    uint8 major;
    uint8 minor;
} ProtocolVersion;

ProtocolVersion version = { 3, 3 };  /* TLS v1.2 */

enum {
    change_cipher_spec(20), alert(21), handshake(22),
    application_data(23), (255)
} ContentType;

struct {
    ContentType type;
    ProtocolVersion version;
    uint16 length;
    opaque fragment[TLSPlaintext.length];
} TLSPlaintext;

struct {
    ContentType type;
    ProtocolVersion version;
    uint16 length;
    opaque fragment[TLSCompressed.length];
} TLSCompressed;

struct {
    ContentType type;
    ProtocolVersion version;
    uint16 length;
    select (SecurityParameters.cipher_type) {
        case stream: GenericStreamCipher;
        case block:  GenericBlockCipher;
        case aead:   GenericAEADCipher;
    } fragment;
} TLSCiphertext;

A.2. Message de changement de spécifications de chiffrement (Change Cipher Specs Message)

struct {
    enum { change_cipher_spec(1), (255) } type;
} ChangeCipherSpec;

A.3. Messages d'alerte (Alert Messages)

enum { warning(1), fatal(2), (255) } AlertLevel;

enum {
    close_notify(0),
    unexpected_message(10),
    bad_record_mac(20),
    decryption_failed_RESERVED(21),
    record_overflow(22),
    decompression_failure(30),
    handshake_failure(40),
    no_certificate_RESERVED(41),
    bad_certificate(42),
    unsupported_certificate(43),
    certificate_revoked(44),
    certificate_expired(45),
    certificate_unknown(46),
    illegal_parameter(47),
    unknown_ca(48),
    access_denied(49),
    decode_error(50),
    decrypt_error(51),
    export_restriction_RESERVED(60),
    protocol_version(70),
    insufficient_security(71),
    internal_error(80),
    user_canceled(90),
    no_renegotiation(100),
    unsupported_extension(110),
    (255)
} AlertDescription;

struct {
    AlertLevel level;
    AlertDescription description;
} Alert;

A.4. Protocole de poignée de main (Handshake Protocol)

enum {
    hello_request(0), client_hello(1), server_hello(2),
    certificate(11), server_key_exchange (12),
    certificate_request(13), server_hello_done(14),
    certificate_verify(15), client_key_exchange(16),
    finished(20),
    (255)
} HandshakeType;

struct {
    HandshakeType msg_type;
    uint24 length;
    select (HandshakeType) {
        case hello_request:       HelloRequest;
        case client_hello:        ClientHello;
        case server_hello:        ServerHello;
        case certificate:         Certificate;
        case server_key_exchange: ServerKeyExchange;
        case certificate_request: CertificateRequest;
        case server_hello_done:   ServerHelloDone;
        case certificate_verify:  CertificateVerify;
        case client_key_exchange: ClientKeyExchange;
        case finished:            Finished;
    } body;
} Handshake;

A.5. La suite de chiffrement (The Cipher Suite)

Voici les identifiants de suite de chiffrement définis pour TLS 1.2:

TLS_NULL_WITH_NULL_NULL               = { 0x00,0x00 };
TLS_RSA_WITH_NULL_MD5                 = { 0x00,0x01 };
TLS_RSA_WITH_NULL_SHA                 = { 0x00,0x02 };
TLS_RSA_WITH_NULL_SHA256              = { 0x00,0x3B };
TLS_RSA_WITH_RC4_128_MD5              = { 0x00,0x04 };
TLS_RSA_WITH_RC4_128_SHA              = { 0x00,0x05 };
TLS_RSA_WITH_3DES_EDE_CBC_SHA         = { 0x00,0x0A };
TLS_RSA_WITH_AES_128_CBC_SHA          = { 0x00,0x2F };
TLS_RSA_WITH_AES_256_CBC_SHA          = { 0x00,0x35 };
TLS_RSA_WITH_AES_128_CBC_SHA256       = { 0x00,0x3C };
TLS_RSA_WITH_AES_256_CBC_SHA256       = { 0x00,0x3D };
TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA      = { 0x00,0x0D };
TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA      = { 0x00,0x10 };
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x13 };
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x16 };
TLS_DH_DSS_WITH_AES_128_CBC_SHA       = { 0x00,0x30 };
TLS_DH_RSA_WITH_AES_128_CBC_SHA       = { 0x00,0x31 };
TLS_DHE_DSS_WITH_AES_128_CBC_SHA      = { 0x00,0x32 };
TLS_DHE_RSA_WITH_AES_128_CBC_SHA      = { 0x00,0x33 };
TLS_DH_DSS_WITH_AES_256_CBC_SHA       = { 0x00,0x36 };
TLS_DH_RSA_WITH_AES_256_CBC_SHA       = { 0x00,0x37 };
TLS_DHE_DSS_WITH_AES_256_CBC_SHA      = { 0x00,0x38 };
TLS_DHE_RSA_WITH_AES_256_CBC_SHA      = { 0x00,0x39 };
TLS_DH_DSS_WITH_AES_128_CBC_SHA256    = { 0x00,0x3E };
TLS_DH_RSA_WITH_AES_128_CBC_SHA256    = { 0x00,0x3F };
TLS_DHE_DSS_WITH_AES_128_CBC_SHA256   = { 0x00,0x40 };
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256   = { 0x00,0x67 };
TLS_DH_DSS_WITH_AES_256_CBC_SHA256    = { 0x00,0x68 };
TLS_DH_RSA_WITH_AES_256_CBC_SHA256    = { 0x00,0x69 };
TLS_DHE_DSS_WITH_AES_256_CBC_SHA256   = { 0x00,0x6A };
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256   = { 0x00,0x6B };
TLS_DH_anon_WITH_RC4_128_MD5          = { 0x00,0x18 };
TLS_DH_anon_WITH_3DES_EDE_CBC_SHA     = { 0x00,0x1B };
TLS_DH_anon_WITH_AES_128_CBC_SHA      = { 0x00,0x34 };
TLS_DH_anon_WITH_AES_256_CBC_SHA      = { 0x00,0x3A };
TLS_DH_anon_WITH_AES_128_CBC_SHA256   = { 0x00,0x6C };
TLS_DH_anon_WITH_AES_256_CBC_SHA256   = { 0x00,0x6D };

Note: TLS_RSA_WITH_AES_128_CBC_SHA est la suite de chiffrement obligatoire à implémenter.

A.6. Les paramètres de sécurité (The Security Parameters)

enum { server, client } ConnectionEnd;

enum { tls_prf_sha256 } PRFAlgorithm;

enum { null, rc4, 3des, aes } BulkCipherAlgorithm;

enum { stream, block, aead } CipherType;

enum { null, hmac_md5, hmac_sha1, hmac_sha256,
     hmac_sha384, hmac_sha512} MACAlgorithm;

enum { null(0), (255) } CompressionMethod;

struct {
    ConnectionEnd          entity;
    PRFAlgorithm           prf_algorithm;
    BulkCipherAlgorithm    bulk_cipher_algorithm;
    CipherType             cipher_type;
    uint8                  enc_key_length;
    uint8                  block_length;
    uint8                  fixed_iv_length;
    uint8                  record_iv_length;
    MACAlgorithm           mac_algorithm;
    uint8                  mac_length;
    uint8                  mac_key_length;
    CompressionMethod      compression_algorithm;
    opaque                 master_secret[48];
    opaque                 client_random[32];
    opaque                 server_random[32];
} SecurityParameters;

Note: Pour des définitions complètes de structures de données et des descriptions détaillées, veuillez vous référer au texte complet de l'annexe A de la RFC 5246.