1500b3a50
Denys Vlasenko
2017-01-24
Subject
tls: if got CERTIFICATE_REQUEST, send an empty CERTIFICATE
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
networking/tls.c+45 -20
| @@ -484,21 +484,24 @@ static void prf_hmac(tls_state_t *tls, | |
| static void bad_record_die(tls_state_t *tls, const char *expected, int len) | |
| { | |
| - | bb_error_msg_and_die("got bad TLS record (len:%d) while expecting %s", len, expected); |
| + | bb_error_msg("got bad TLS record (len:%d) while expecting %s", len, expected); |
| if (len > 0) { | |
| uint8_t *p = tls->inbuf; | |
| - | while (len > 0) |
| + | while (len > 0) { |
| fprintf(stderr, " %02x", *p++); | |
| + | len--; |
| + | } |
| fputc('\n', stderr); | |
| } | |
| xfunc_die(); | |
| } | |
| - | static void tls_error_die(tls_state_t *tls) |
| + | static void tls_error_die(tls_state_t *tls, int line) |
| { | |
| dump_tls_record(tls->inbuf, tls->ofs_to_buffered + tls->buffered_size); | |
| - | bb_error_msg_and_die("TODO: useful diagnostic about %p", tls); |
| + | bb_error_msg_and_die("tls error at line %d cipher:%04x", line, tls->cipher_id); |
| } | |
| + | #define tls_error_die(tls) tls_error_die(tls, __LINE__) |
| #if 0 //UNUSED | |
| static void tls_free_inbuf(tls_state_t *tls) | |
| @@ -1343,6 +1346,26 @@ static void get_server_cert(tls_state_t *tls) | |
| find_key_in_der_cert(tls, certbuf + 10, len); | |
| } | |
| + | static void send_empty_client_cert(tls_state_t *tls) |
| + | { |
| + | struct client_empty_cert { |
| + | uint8_t type; |
| + | uint8_t len24_hi, len24_mid, len24_lo; |
| + | uint8_t cert_chain_len24_hi, cert_chain_len24_mid, cert_chain_len24_lo; |
| + | }; |
| + | struct client_empty_cert *record; |
| + | |
| + | record = tls_get_outbuf(tls, sizeof(*record)); |
| + | //FIXME: can just memcpy a ready-made one. |
| + | fill_handshake_record_hdr(record, HANDSHAKE_CERTIFICATE, sizeof(*record)); |
| + | record->cert_chain_len24_hi = 0; |
| + | record->cert_chain_len24_mid = 0; |
| + | record->cert_chain_len24_lo = 0; |
| + | |
| + | dbg(">> CERTIFICATE\n"); |
| + | xwrite_and_update_handshake_hash(tls, sizeof(*record)); |
| + | } |
| + | |
| static void send_client_key_exchange(tls_state_t *tls) | |
| { | |
| struct client_key_exchange { | |
| @@ -1584,23 +1607,25 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni) | |
| // 0c 00|01|c9 03|00|17|41|04|cd|9b|b4|29|1f|f6|b0|c2|84|82|7f|29|6a|47|4e|ec|87|0b|c1|9c|69|e1|f8|c6|d0|53|e9|27|90|a5|c8|02|15|75... | |
| dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len); | |
| //probably need to save it | |
| - | tls_xread_handshake_block(tls, 4); |
| + | len = tls_xread_handshake_block(tls, 4); |
| } | |
| - | // if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST) { |
| - | // dbg("<< CERTIFICATE_REQUEST\n"); |
| - | // RFC 5246: (in response to this,) "If no suitable certificate is available, |
| - | // the client MUST send a certificate message containing no |
| - | // certificates. That is, the certificate_list structure has a |
| - | // length of zero. ... |
| - | // Client certificates are sent using the Certificate structure |
| - | // defined in Section 7.4.2." |
| - | // (i.e. the same format as server certs) |
| - | // tls_xread_handshake_block(tls, 4); |
| - | // } |
| - | |
| - | if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) |
| - | tls_error_die(tls); |
| + | if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST) { |
| + | dbg("<< CERTIFICATE_REQUEST\n"); |
| + | // RFC 5246: "If no suitable certificate is available, |
| + | // the client MUST send a certificate message containing no |
| + | // certificates. That is, the certificate_list structure has a |
| + | // length of zero. ... |
| + | // Client certificates are sent using the Certificate structure |
| + | // defined in Section 7.4.2." |
| + | // (i.e. the same format as server certs) |
| + | send_empty_client_cert(tls); |
| + | len = tls_xread_handshake_block(tls, 4); |
| + | } |
| + | |
| + | if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) { |
| + | bad_record_die(tls, "'server hello done'", len); |
| + | } |
| // 0e 000000 (len:0) | |
| dbg("<< SERVER_HELLO_DONE\n"); | |
| @@ -1616,7 +1641,7 @@ void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni) | |
| /* Get CHANGE_CIPHER_SPEC */ | |
| len = tls_xread_record(tls); | |
| if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0) | |
| - | tls_error_die(tls); |
| + | bad_record_die(tls, "switch to encrypted traffic", len); |
| dbg("<< CHANGE_CIPHER_SPEC\n"); | |
| if (tls->cipher_id == TLS_RSA_WITH_NULL_SHA256) | |
| tls->min_encrypted_len_on_read = tls->MAC_size; | |