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Implement DTLS client move to new state machine
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Move all DTLS client side processing into the new state machine code. A
subsequent commit will clean up the old dead code.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
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@mattcaswell
mattcaswell committed Oct 30, 2015
1 parent 76af303 commit 473483d
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Showing 8 changed files with 214 additions and 54 deletions.
1 change: 1 addition & 0 deletions include/openssl/ssl.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1928,6 +1928,7 @@ void ERR_load_SSL_strings(void);
# define SSL_F_DTLS1_SEND_SERVER_HELLO 266
# define SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE 267
# define SSL_F_DTLS1_WRITE_APP_DATA_BYTES 268
# define SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC 371
# define SSL_F_DTLS_GET_REASSEMBLED_MESSAGE 370
# define SSL_F_READ_STATE_MACHINE 352
# define SSL_F_SSL3_ACCEPT 128
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76 changes: 53 additions & 23 deletions ssl/d1_both.c
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Original file line number Diff line number Diff line change
Expand Up @@ -582,6 +582,7 @@ int dtls_get_message(SSL *s, int *mt, unsigned long *len)
/*
* This isn't a real handshake message so skip the processing below.
*/
*len = (unsigned long)tmplen;
return 1;
}

Expand Down Expand Up @@ -1102,6 +1103,19 @@ static int dtls_get_reassembled_message(SSL *s, long *len)
return 0;
}


int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
{
if (s->state == a) {
if (dtls_construct_change_cipher_spec(s) == 0)
return -1;
}

/* SSL3_ST_CW_CHANGE_B */
return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
}


/*-
* for these 2 messages, we need to
* ssl->enc_read_ctx re-init
Expand All @@ -1111,39 +1125,55 @@ static int dtls_get_reassembled_message(SSL *s, long *len)
* ssl->session->read_compression assign
* ssl->session->read_hash assign
*/
int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
int dtls_construct_change_cipher_spec(SSL *s)
{
unsigned char *p;

if (s->state == a) {
p = (unsigned char *)s->init_buf->data;
*p++ = SSL3_MT_CCS;
s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
s->init_num = DTLS1_CCS_HEADER_LENGTH;

if (s->version == DTLS1_BAD_VER) {
s->d1->next_handshake_write_seq++;
s2n(s->d1->handshake_write_seq, p);
s->init_num += 2;
}
p = (unsigned char *)s->init_buf->data;
*p++ = SSL3_MT_CCS;
s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
s->init_num = DTLS1_CCS_HEADER_LENGTH;

s->init_off = 0;
if (s->version == DTLS1_BAD_VER) {
s->d1->next_handshake_write_seq++;
s2n(s->d1->handshake_write_seq, p);
s->init_num += 2;
}

dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
s->d1->handshake_write_seq, 0, 0);
s->init_off = 0;

/* buffer the message to handle re-xmits */
if (!dtls1_buffer_message(s, 1)) {
SSLerr(SSL_F_DTLS1_SEND_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
return -1;
}
dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
s->d1->handshake_write_seq, 0, 0);

s->state = b;
/* buffer the message to handle re-xmits */
if (!dtls1_buffer_message(s, 1)) {
SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
return 0;
}

/* SSL3_ST_CW_CHANGE_B */
return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
return 1;
}

#ifndef OPENSSL_NO_SCTP
enum WORK_STATE dtls_wait_for_dry(SSL *s)
{
int ret;

/* read app data until dry event */
ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
if (ret < 0)
return WORK_ERROR;

if (ret == 0) {
s->s3->in_read_app_data = 2;
s->rwstate = SSL_READING;
BIO_clear_retry_flags(SSL_get_rbio(s));
BIO_set_retry_read(SSL_get_rbio(s));
return WORK_MORE_A;
}
return WORK_FINISHED_CONTINUE;
}
#endif

int dtls1_read_failed(SSL *s, int code)
{
Expand Down
26 changes: 16 additions & 10 deletions ssl/d1_clnt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -126,7 +126,9 @@
#endif

static const SSL_METHOD *dtls1_get_client_method(int ver);
#if 0
static int dtls1_get_hello_verify(SSL *s);
#endif

static const SSL_METHOD *dtls1_get_client_method(int ver)
{
Expand Down Expand Up @@ -156,6 +158,7 @@ IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
dtls1_connect,
dtls1_get_client_method, DTLSv1_2_enc_data)

#if 0
int dtls1_connect(SSL *s)
{
BUF_MEM *buf = NULL;
Expand Down Expand Up @@ -785,13 +788,16 @@ int dtls1_connect(SSL *s)
cb(s, SSL_CB_CONNECT_EXIT, ret);
return (ret);
}
#endif

#if 0
static int dtls1_get_hello_verify(SSL *s)
{
int n, al, ok = 0;
unsigned char *data;
unsigned int cookie_len;

/* TODO: CHECK first_packet handling!!! */
s->first_packet = 1;
n = s->method->ssl_get_message(s,
DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A,
Expand All @@ -801,12 +807,14 @@ static int dtls1_get_hello_verify(SSL *s)

if (!ok)
return ((int)n);
}
#endif

if (s->s3->tmp.message_type != DTLS1_MT_HELLO_VERIFY_REQUEST) {
s->d1->send_cookie = 0;
s->s3->tmp.reuse_message = 1;
return (1);
}
enum MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, unsigned long n)
{
int al;
unsigned char *data;
unsigned int cookie_len;

data = (unsigned char *)s->init_msg;
data += 2;
Expand All @@ -820,11 +828,9 @@ static int dtls1_get_hello_verify(SSL *s)
memcpy(s->d1->cookie, data, cookie_len);
s->d1->cookie_len = cookie_len;

s->d1->send_cookie = 1;
return 1;

return MSG_PROCESS_FINISHED_READING;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
s->state = SSL_ST_ERR;
return -1;
statem_set_error(s);
return MSG_PROCESS_ERROR;
}
11 changes: 9 additions & 2 deletions ssl/s3_both.c
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Original file line number Diff line number Diff line change
Expand Up @@ -461,8 +461,15 @@ enum WORK_STATE tls_finish_handshake(SSL *s, enum WORK_STATE wst)

/* clean a few things up */
ssl3_cleanup_key_block(s);
BUF_MEM_free(s->init_buf);
s->init_buf = NULL;

if (!SSL_IS_DTLS(s)) {
/*
* We don't do this in DTLS because we may still need the init_buf
* in case there are any unexpected retransmits
*/
BUF_MEM_free(s->init_buf);
s->init_buf = NULL;
}

ssl_free_wbio_buffer(s);

Expand Down
34 changes: 33 additions & 1 deletion ssl/s3_clnt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -465,6 +465,7 @@ int tls_construct_client_hello(SSL *s)
return 0;
}

#if 0
int ssl3_get_server_hello(SSL *s)
{
int ok, al;
Expand Down Expand Up @@ -509,6 +510,7 @@ int ssl3_get_server_hello(SSL *s)
s->state = SSL_ST_ERR;
return (-1);
}
#endif

enum MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, unsigned long n)
{
Expand Down Expand Up @@ -1921,7 +1923,14 @@ enum MSG_PROCESS_RETURN tls_process_server_done(SSL *s, unsigned long n)
}
#endif

return MSG_PROCESS_FINISHED_READING;
#ifndef OPENSSL_NO_SCTP
/* Only applies to renegotiation */
if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))
&& s->renegotiate != 0)
return MSG_PROCESS_CONTINUE_PROCESSING;
else
#endif
return MSG_PROCESS_FINISHED_READING;
}

int ssl3_send_client_key_exchange(SSL *s)
Expand Down Expand Up @@ -2554,6 +2563,29 @@ int tls_client_key_exchange_post_work(SSL *s)
SSLerr(SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_INTERNAL_ERROR);
goto err;
}

#ifndef OPENSSL_NO_SCTP
if (SSL_IS_DTLS(s)) {
unsigned char sctpauthkey[64];
char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];

/*
* Add new shared key for SCTP-Auth, will be ignored if no SCTP
* used.
*/
snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
DTLS1_SCTP_AUTH_LABEL);

if (SSL_export_keying_material(s, sctpauthkey,
sizeof(sctpauthkey), labelbuffer,
sizeof(labelbuffer), NULL, 0, 0) <= 0)
goto err;

BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
sizeof(sctpauthkey), sctpauthkey);
}
#endif

return 1;
err:
OPENSSL_clear_free(pms, pmslen);
Expand Down
2 changes: 2 additions & 0 deletions ssl/ssl_err.c
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Original file line number Diff line number Diff line change
Expand Up @@ -112,6 +112,8 @@ static ERR_STRING_DATA SSL_str_functs[] = {
{ERR_FUNC(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE),
"dtls1_send_server_key_exchange"},
{ERR_FUNC(SSL_F_DTLS1_WRITE_APP_DATA_BYTES), "dtls1_write_app_data_bytes"},
{ERR_FUNC(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC),
"dtls_construct_change_cipher_spec"},
{ERR_FUNC(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE),
"DTLS_GET_REASSEMBLED_MESSAGE"},
{ERR_FUNC(SSL_F_READ_STATE_MACHINE), "READ_STATE_MACHINE"},
Expand Down
5 changes: 4 additions & 1 deletion ssl/ssl_locl.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1555,7 +1555,6 @@ typedef struct hm_fragment_st {
} hm_fragment;

typedef struct dtls1_state_st {
unsigned int send_cookie;
unsigned char cookie[DTLS1_COOKIE_LENGTH];
unsigned int cookie_len;

Expand Down Expand Up @@ -2062,6 +2061,7 @@ __owur enum MSG_PROCESS_RETURN tls_process_finished(SSL *s, unsigned long n);
__owur int ssl3_setup_key_block(SSL *s);
__owur int ssl3_send_change_cipher_spec(SSL *s, int state_a, int state_b);
__owur int tls_construct_change_cipher_spec(SSL *s);
__owur int dtls_construct_change_cipher_spec(SSL *s);
__owur int ssl3_change_cipher_state(SSL *s, int which);
void ssl3_cleanup_key_block(SSL *s);
__owur int ssl3_do_write(SSL *s, int type);
Expand All @@ -2075,6 +2075,7 @@ __owur int tls_get_message_body(SSL *s, unsigned long *len);
__owur int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen);
__owur int tls_construct_finished(SSL *s, const char *sender, int slen);
__owur enum WORK_STATE tls_finish_handshake(SSL *s, enum WORK_STATE wst);
__owur enum WORK_STATE dtls_wait_for_dry(SSL *s);
__owur int ssl3_num_ciphers(void);
__owur const SSL_CIPHER *ssl3_get_cipher(unsigned int u);
int ssl3_renegotiate(SSL *ssl);
Expand Down Expand Up @@ -2194,6 +2195,8 @@ __owur int ssl3_check_cert_and_algorithm(SSL *s);
__owur int ssl3_send_next_proto(SSL *s);
__owur int tls_construct_next_proto(SSL *s);
# endif
__owur enum MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s,
unsigned long n);

int dtls1_client_hello(SSL *s);

Expand Down

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