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tls: include signature_algorithms extension in client hello message

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function                                             old     new   delta
tls_xread_record                                     629     645     +16
.rodata                                           105167  105179     +12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 28/0)               Total: 28 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2022-09-08 16:31:44 +02:00
parent 526625bc83
commit 9bab580cd4
1 changed files with 73 additions and 18 deletions
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91
networking/tls.c
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@ -948,11 +948,46 @@ static int tls_has_buffered_record(tls_state_t *tls)
static const char *alert_text(int code) static const char *alert_text(int code)
{ {
//10 unexpected_message
//20 bad_record_mac
//21 decryption_failed
//22 record_overflow
//30 decompression_failure
//40 handshake_failure
//41 no_certificate
//42 bad_certificate
//43 unsupported_certificate
//44 certificate_revoked
//45 certificate_expired
//46 certificate_unknown
//47 illegal_parameter
//48 unknown_ca
//49 access_denied
//50 decode_error
//51 decrypt_error
//52 too_many_cids_requested
//60 export_restriction
//70 protocol_version
//71 insufficient_security
//80 internal_error
//86 inappropriate_fallback
//90 user_canceled
//100 no_renegotiation
//109 missing_extension
//110 unsupported_extension
//111 certificate_unobtainable
//112 unrecognized_name
//113 bad_certificate_status_response
//114 bad_certificate_hash_value
//115 unknown_psk_identity
//116 certificate_required
//120 no_application_protocol
switch (code) { switch (code) {
case 20: return "bad MAC"; case 20: return "bad MAC";
case 50: return "decode error"; case 50: return "decode error";
case 51: return "decrypt error";
case 40: return "handshake failure"; case 40: return "handshake failure";
case 51: return "decrypt error";
case 80: return "internal error";
case 112: return "unrecognized name"; case 112: return "unrecognized name";
} }
return itoa(code); return itoa(code);
@ -1531,26 +1566,47 @@ static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
#endif #endif
0x01,0x00, //not a cipher - comprtypes_len, comprtype 0x01,0x00, //not a cipher - comprtypes_len, comprtype
}; };
static const uint8_t supported_groups[] = { // https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml
static const uint8_t extensions[] = {
// is.gd responds with "handshake failure" to our hello if there's no supported_groups
0x00,0x0a, //extension_type: "supported_groups" 0x00,0x0a, //extension_type: "supported_groups"
0x00,2 * (1 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //ext len 0x00,2 * (1 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //ext len
0x00,2 * (0 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //list len 0x00,2 * (0 + ALLOW_CURVE_P256 + ALLOW_CURVE_X25519), //list len
#if ALLOW_CURVE_P256 #if ALLOW_CURVE_P256
0x00,0x17, //curve_secp256r1 (aka P256, aka prime256v1) 0x00,0x17, //curve_secp256r1 (aka P256, aka prime256v1)
#endif #endif
//0x00,0x18, //curve_secp384r1 //0x00,0x18, //curve_secp384r1
//0x00,0x19, //curve_secp521r1 //0x00,0x19, //curve_secp521r1
#if ALLOW_CURVE_X25519 #if ALLOW_CURVE_X25519
0x00,0x1d, //curve_x25519 (RFC 7748) 0x00,0x1d, //curve_x25519 (RFC 7748)
#endif #endif
//0x00,0x1e, //curve_x448 (RFC 7748) //0x00,0x1e, //curve_x448 (RFC 7748)
//0x00,0x0b,0x00,0x04,0x03,0x00,0x01,0x02, //extension_type: "ec_point_formats"
//0x00,0x16,0x00,0x00, //extension_type: "encrpypt-then-mac"
//0x00,0x17,0x00,0x00, //extension_type: "extended_master"
//0x00,0x23,0x00,0x00, //extension_type: "session_ticket"
// kojipkgs.fedoraproject.org responds with alert code 80 ("internal error")
// to our hello without signature_algorithms.
// It is satisfied with just 0x04,0x01.
0x00,0x0d, //extension_type: "signature_algorithms" (RFC5246 section 7.4.1.4.1):
#define SIGALGS (3 + 3 * ENABLE_FEATURE_TLS_SHA1)
0x00,2 * (1 + SIGALGS), //ext len
0x00,2 * (0 + SIGALGS), //list len
//Format: two bytes
// byte 1: 0:none,1:md5,2:sha1,3:sha224,4:sha256,5:sha384,6:sha512
// byte 2: 1:rsa,2:dsa,3:ecdsa
// (note that TLS 1.3 changes this, see RFC8446 section 4.2.3)
#if ENABLE_FEATURE_TLS_SHA1
0x02,0x01, //sha1 + rsa
0x02,0x02, //sha1 + dsa
0x02,0x03, //sha1 + ecdsa
#endif
0x04,0x01, //sha256 + rsa - kojipkgs.fedoraproject.org wants this
0x04,0x02, //sha256 + dsa
0x04,0x03, //sha256 + ecdsa
}; };
//static const uint8_t signature_algorithms[] = {
// 000d
// 0020
// 001e
// 0601 0602 0603 0501 0502 0503 0401 0402 0403 0301 0302 0303 0201 0202 0203
//};
struct client_hello { struct client_hello {
uint8_t type; uint8_t type;
@ -1591,8 +1647,7 @@ static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
int sni_len = sni ? strnlen(sni, 127 - 5) : 0; int sni_len = sni ? strnlen(sni, 127 - 5) : 0;
ext_len = 0; ext_len = 0;
/* is.gd responds with "handshake failure" to our hello if there's no supported_groups element */ ext_len += sizeof(extensions);
ext_len += sizeof(supported_groups);
if (sni_len) if (sni_len)
ext_len += 9 + sni_len; ext_len += 9 + sni_len;
@ -1626,7 +1681,7 @@ static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
ptr[8] = sni_len; //name len ptr[8] = sni_len; //name len
ptr = mempcpy(&ptr[9], sni, sni_len); ptr = mempcpy(&ptr[9], sni, sni_len);
} }
memcpy(ptr, supported_groups, sizeof(supported_groups)); memcpy(ptr, extensions, sizeof(extensions));
tls->hsd = xzalloc(sizeof(*tls->hsd)); tls->hsd = xzalloc(sizeof(*tls->hsd));
/* HANDSHAKE HASH: ^^^ + len if need to save saved_client_hello */ /* HANDSHAKE HASH: ^^^ + len if need to save saved_client_hello */