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tls: if got CERTIFICATE_REQUEST, send an empty CERTIFICATE

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wolfssl test server is not satisfied by an empty one,
but some real servers might be.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-01-24 17:06:10 +01:00
parent 49ecee098d
commit 1500b3a50d
1 changed files with 44 additions and 19 deletions
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63
networking/tls.c
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@ -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_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)
tls_error_die(tls);
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;