yuzu-emu/mbedtls
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

CID update to RFC 9146

Browse source 
The DTLS 1.2 CID specification has been published as RFC 9146. This PR updates the implementation to match the RFC content.

Signed-off-by: Hannes Tschofenig <hannes.tschofenig@arm.com>
This commit is contained in:
Hannes Tschofenig 2021-10-12 09:22:33 +02:00 committed by Hannes Tschofenig
parent 52f83dc471
commit fd6cca4448
8 changed files with 308 additions and 69 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
include/mbedtls/check_config.h
View file

@ -839,6 +839,12 @@
#error "MBEDTLS_SSL_CID_OUT_LEN_MAX too large (max 255)"
#endif
#if !defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
defined(MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT)
#error "MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT defined, but not all prerequsites"
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && \
!defined(MBEDTLS_SSL_PROTO_TLS1_2)
#error "MBEDTLS_SSL_ENCRYPT_THEN_MAC defined, but not all prerequisites"

37
include/mbedtls/mbedtls_config.h
View file

@ -1320,9 +1320,7 @@
/**
* \def MBEDTLS_SSL_DTLS_CONNECTION_ID
*
* Enable support for the DTLS Connection ID extension
* (version draft-ietf-tls-dtls-connection-id-05,
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05)
* Enable support for the DTLS Connection ID extension,
* which allows to identify DTLS connections across changes
* in the underlying transport.
*
@ -1331,10 +1329,6 @@
* `mbedtls_ssl_conf_cid()`. See the corresponding documentation for
* more information.
*
* \warning The Connection ID extension is still in draft state.
* We make no stability promises for the availability
* or the shape of the API controlled by this option.
*
* The maximum lengths of outgoing and incoming CIDs can be configured
* through the options
* - MBEDTLS_SSL_CID_OUT_LEN_MAX
@ -1344,7 +1338,23 @@
*
* Uncomment to enable the Connection ID extension.
*/
//#define MBEDTLS_SSL_DTLS_CONNECTION_ID
#define MBEDTLS_SSL_DTLS_CONNECTION_ID
/**
* \def MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT
*
* Defines whether RFC 9146 (default) or the legacy version
* (version draft-ietf-tls-dtls-connection-id-05,
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05)
* is used.
*
* Set the value to 0 for the standard version, and
* 1 for the legacy draft version.
*
* Requires: MBEDTLS_SSL_DTLS_CONNECTION_ID
*/
#define MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT 0
/**
* \def MBEDTLS_SSL_ASYNC_PRIVATE
@ -3539,17 +3549,6 @@
//#define MBEDTLS_PSK_MAX_LEN 32 /**< Max size of TLS pre-shared keys, in bytes (default 256 bits) */
//#define MBEDTLS_SSL_COOKIE_TIMEOUT 60 /**< Default expiration delay of DTLS cookies, in seconds if HAVE_TIME, or in number of cookies issued */
/** \def MBEDTLS_TLS_EXT_CID
*
* At the time of writing, the CID extension has not been assigned its
* final value. Set this configuration option to make Mbed TLS use a
* different value.
*
* A future minor revision of Mbed TLS may change the default value of
* this option to match evolving standards and usage.
*/
//#define MBEDTLS_TLS_EXT_CID 254
/**
* Complete list of ciphersuites to use, in order of preference.
*

24
include/mbedtls/ssl.h
View file

@ -401,7 +401,13 @@
#define MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY 16
#endif
/** \} name SECTION: Module settings */
/*
* Default to standard CID mode
*/
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
!defined(MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT)
#define MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT 0
#endif
/*
* Length of the verify data for secure renegotiation
@ -571,15 +577,10 @@
#define MBEDTLS_TLS_EXT_SIG_ALG_CERT 50 /* RFC 8446 TLS 1.3 */
#define MBEDTLS_TLS_EXT_KEY_SHARE 51 /* RFC 8446 TLS 1.3 */
/* The value of the CID extension is still TBD as of
* draft-ietf-tls-dtls-connection-id-05
* (https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05).
*
* A future minor revision of Mbed TLS may change the default value of
* this option to match evolving standards and usage.
*/
#if !defined(MBEDTLS_TLS_EXT_CID)
#define MBEDTLS_TLS_EXT_CID 254 /* TBD */
#if MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 0
#define MBEDTLS_TLS_EXT_CID 54 /* RFC 9146 DTLS 1.2 CID */
#else
#define MBEDTLS_TLS_EXT_CID 254 /* Pre-RFC 9146 DTLS 1.2 CID */
#endif
#define MBEDTLS_TLS_EXT_ECJPAKE_KKPP 256 /* experimental */
@ -2003,8 +2004,9 @@ void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl,
* \brief Configure the use of the Connection ID (CID)
* extension in the next handshake.
*
* Reference: draft-ietf-tls-dtls-connection-id-05
* Reference: RFC 9146 (or draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
* for legacy version)
*
* The DTLS CID extension allows the reliable association of
* DTLS records to DTLS connections across changes in the

226
library/ssl_msg.c
View file

@ -388,8 +388,57 @@ static int ssl_parse_inner_plaintext( unsigned char const *content,
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID || MBEDTLS_SSL_PROTO_TLS1_3 */
/* `add_data` must have size 13 Bytes if the CID extension is disabled,
* and 13 + 1 + CID-length Bytes if the CID extension is enabled. */
/* The size of the `add_data` structure depends on various
* factors, namely
*
* 1) CID functionality disabled
*
* additional_data =
* 8: seq_num +
* 1: type +
* 2: version +
* 2: length of inner plaintext +
*
* size = 13 bytes
*
* 2) CID functionality based on RFC 9146 enabled
*
* size = 8 + 1 + 1 + 1 + 2 + 2 + 6 + 2 + CID-length
* = 23 + CID-length
*
* 3) CID functionality based on legacy CID version
according to draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* size = 13 + 1 + CID-length
*
* More information about the CID usage:
*
* Per Section 5.3 of draft-ietf-tls-dtls-connection-id-05 the
* size of the additional data structure is calculated as:
*
* additional_data =
* 8: seq_num +
* 1: tls12_cid +
* 2: DTLSCipherText.version +
* n: cid +
* 1: cid_length +
* 2: length_of_DTLSInnerPlaintext
*
* Per RFC 9146 the size of the add_data structure is calculated as:
*
* additional_data =
* 8: seq_num_placeholder +
* 1: tls12_cid +
* 1: cid_length +
* 1: tls12_cid +
* 2: DTLSCiphertext.version +
* 2: epoch +
* 6: sequence_number +
* n: cid +
* 2: length_of_DTLSInnerPlaintext
*
*/
static void ssl_extract_add_data_from_record( unsigned char* add_data,
size_t *add_data_len,
mbedtls_record *rec,
@ -397,21 +446,22 @@ static void ssl_extract_add_data_from_record( unsigned char* add_data,
tls_version,
size_t taglen )
{
/* Quoting RFC 5246 (TLS 1.2):
/* Several types of ciphers have been defined for use with TLS and DTLS,
* and the MAC calculations for those ciphers differ slightly. Further
* variants were added when the CID functionality was added with RFC 9146.
* This implementations also considers the use of a legacy version of the
* CID specification published in draft-ietf-tls-dtls-connection-id-05,
* which is used in deployments.
*
* We will distinguish between the non-CID and the CID cases below.
*
* --- Non-CID cases ---
*
* Quoting RFC 5246 (TLS 1.2):
*
* additional_data = seq_num + TLSCompressed.type +
* TLSCompressed.version + TLSCompressed.length;
*
* For the CID extension, this is extended as follows
* (quoting draft-ietf-tls-dtls-connection-id-05,
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05):
*
* additional_data = seq_num + DTLSPlaintext.type +
* DTLSPlaintext.version +
* cid +
* cid_length +
* length_of_DTLSInnerPlaintext;
*
* For TLS 1.3, the record sequence number is dropped from the AAD
* and encoded within the nonce of the AEAD operation instead.
* Moreover, the additional data involves the length of the TLS
@ -427,11 +477,72 @@ static void ssl_extract_add_data_from_record( unsigned char* add_data,
*
* TLSCiphertext.length = TLSInnerPlaintext.length + taglen.
*
* --- CID cases ---
*
* RFC 9146 uses a common pattern when constructing the data
* passed into a MAC / AEAD cipher.
*
* Data concatenation for MACs used with block ciphers with
* Encrypt-then-MAC Processing (with CID):
*
* data = seq_num_placeholder +
* tls12_cid +
* cid_length +
* tls12_cid +
* DTLSCiphertext.version +
* epoch +
* sequence_number +
* cid +
* DTLSCiphertext.length +
* IV +
* ENC(content + padding + padding_length)
*
* Data concatenation for MACs used with block ciphers (with CID):
*
* data = seq_num_placeholder +
* tls12_cid +
* cid_length +
* tls12_cid +
* DTLSCiphertext.version +
* epoch +
* sequence_number +
* cid +
* length_of_DTLSInnerPlaintext +
* DTLSInnerPlaintext.content +
* DTLSInnerPlaintext.real_type +
* DTLSInnerPlaintext.zeros
*
* AEAD ciphers use the following additional data calculation (with CIDs):
*
* additional_data = seq_num_placeholder +
* tls12_cid +
* cid_length +
* tls12_cid +
* DTLSCiphertext.version +
* epoch +
* sequence_number +
* cid +
* length_of_DTLSInnerPlaintext
*
* Section 5.3 of draft-ietf-tls-dtls-connection-id-05 (for legacy CID use)
* defines the additional data calculation as follows:
*
* additional_data = seq_num +
* tls12_cid +
* DTLSCipherText.version +
* cid +
* cid_length +
* length_of_DTLSInnerPlaintext
*/
unsigned char *cur = add_data;
size_t ad_len_field = rec->data_len;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 0
const unsigned char seq_num_placeholder[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
if( tls_version == MBEDTLS_SSL_VERSION_TLS1_3 )
{
@ -445,25 +556,78 @@ static void ssl_extract_add_data_from_record( unsigned char* add_data,
{
((void) tls_version);
((void) taglen);
memcpy( cur, rec->ctr, sizeof( rec->ctr ) );
cur += sizeof( rec->ctr );
}
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
#if MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 0
if( rec->cid_len != 0 )
{
// seq_num_placeholder
memcpy( cur, seq_num_placeholder, sizeof(seq_num_placeholder) );
cur += sizeof( seq_num_placeholder );
// tls12_cid type
*cur = rec->type;
cur++;
// cid_length
*cur = rec->cid_len;
cur++;
}
else
{
// epoch + sequence number
memcpy( cur, rec->ctr, sizeof( rec->ctr ) );
cur += sizeof( rec->ctr );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 0 */
#else
// epoch + sequence number
memcpy(cur, rec->ctr, sizeof(rec->ctr));
cur += sizeof(rec->ctr);
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
}
// type
*cur = rec->type;
cur++;
// version
memcpy( cur, rec->ver, sizeof( rec->ver ) );
cur += sizeof( rec->ver );
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 1
if (rec->cid_len != 0)
{
// CID
memcpy(cur, rec->cid, rec->cid_len);
cur += rec->cid_len;
// cid_length
*cur = rec->cid_len;
cur++;
// length of inner plaintext
MBEDTLS_PUT_UINT16_BE(ad_len_field, cur, 0);
cur += 2;
}
else
#elif defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT == 0
if( rec->cid_len != 0 )
{
// epoch + sequence number
memcpy(cur, rec->ctr, sizeof(rec->ctr));
cur += sizeof(rec->ctr);
// CID
memcpy( cur, rec->cid, rec->cid_len );
cur += rec->cid_len;
// length of inner plaintext
MBEDTLS_PUT_UINT16_BE( ad_len_field, cur, 0 );
cur += 2;
}
@ -538,7 +702,14 @@ int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_mode_t ssl_mode;
int auth_done = 0;
unsigned char * data;
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_OUT_LEN_MAX ];
/* For an explanation of the additional data length see
* the descrpition of ssl_extract_add_data_from_record().
*/
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
unsigned char add_data[23 + MBEDTLS_SSL_CID_OUT_LEN_MAX];
#else
unsigned char add_data[13];
#endif
size_t add_data_len;
size_t post_avail;
@ -1021,13 +1192,7 @@ int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
size_t sign_mac_length = 0;
#endif /* MBEDTLS_USE_PSA_CRYPTO */
/*
* MAC(MAC_write_key, seq_num +
* TLSCipherText.type +
* TLSCipherText.version +
* length_of( (IV +) ENC(...) ) +
* IV +
* ENC(content + padding + padding_length));
/* MAC(MAC_write_key, add_data, IV, ENC(content + padding + padding_length))
*/
if( post_avail < transform->maclen)
@ -1133,7 +1298,14 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
size_t padlen = 0, correct = 1;
#endif
unsigned char* data;
unsigned char add_data[13 + 1 + MBEDTLS_SSL_CID_IN_LEN_MAX ];
/* For an explanation of the additional data length see
* the descrpition of ssl_extract_add_data_from_record().
*/
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
unsigned char add_data[23 + MBEDTLS_SSL_CID_IN_LEN_MAX];
#else
unsigned char add_data[13];
#endif
size_t add_data_len;
#if !defined(MBEDTLS_DEBUG_C)
@ -3487,7 +3659,7 @@ static int ssl_parse_record_header( mbedtls_ssl_context const *ssl,
{
/* Shift pointers to account for record header including CID
* struct {
* ContentType special_type = tls12_cid;
* ContentType outer_type = tls12_cid;
* ProtocolVersion version;
* uint16 epoch;
* uint48 sequence_number;

3
library/ssl_tls12_client.c
View file

@ -235,9 +235,6 @@ static int ssl_write_cid_ext( mbedtls_ssl_context *ssl,
size_t ext_len;
/*
* Quoting draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* struct {
* opaque cid<0..2^8-1>;
* } ConnectionId;

6
library/ssl_tls12_server.c
View file

@ -358,9 +358,6 @@ static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
}
/*
* Quoting draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* struct {
* opaque cid<0..2^8-1>;
* } ConnectionId;
@ -1748,9 +1745,6 @@ static void ssl_write_cid_ext( mbedtls_ssl_context *ssl,
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding CID extension" ) );
/*
* Quoting draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* struct {
* opaque cid<0..2^8-1>;
* } ConnectionId;

19
tests/scripts/all.sh
View file

@ -2449,6 +2449,25 @@ component_test_variable_ssl_in_out_buffer_len_CID () {
tests/compat.sh
}
component_test_variable_ssl_in_out_buffer_len_CID_legacy () {
msg "build: MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID (legacy) enabled (ASan build)"
scripts/config.py set MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
scripts/config.py set MBEDTLS_SSL_DTLS_CONNECTION_ID
scripts/config.py set MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT 1
CC=gcc cmake -D CMAKE_BUILD_TYPE:String=Asan .
make
msg "test: MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID"
make test
msg "test: ssl-opt.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
tests/ssl-opt.sh
msg "test: compat.sh, MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH and MBEDTLS_SSL_DTLS_CONNECTION_ID enabled"
tests/compat.sh
}
component_test_ssl_alloc_buffer_and_mfl () {
msg "build: default config with memory buffer allocator and MFL extension"
scripts/config.py set MBEDTLS_MEMORY_BUFFER_ALLOC_C

50
tests/ssl-opt.sh
View file

@ -440,6 +440,14 @@ requires_max_content_len() {
requires_config_value_at_least "MBEDTLS_SSL_OUT_CONTENT_LEN" $1
}
CID_MODE=$( get_config_value_or_default "MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT" )
requires_cid_compat() {
if [ "$CID_MODE" = "0" ]; then
SKIP_NEXT="YES"
fi
}
# skip next test if GnuTLS isn't available
requires_gnutls() {
if [ -z "${GNUTLS_AVAILABLE:-}" ]; then
@ -2386,6 +2394,17 @@ run_test "Context serialization, client serializes, with CID" \
-S "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
requires_cid_compat
run_test "Context serialization, client serializes, with CID (legacy)" \
"$P_SRV dtls=1 serialize=0 exchanges=2 cid=1 cid_val=dead" \
"$P_CLI dtls=1 serialize=1 exchanges=2 cid=1 cid_val=beef" \
0 \
-c "Deserializing connection..." \
-S "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
run_test "Context serialization, server serializes, CCM" \
"$P_SRV dtls=1 serialize=1 exchanges=2" \
@ -2422,6 +2441,16 @@ run_test "Context serialization, server serializes, with CID" \
-C "Deserializing connection..." \
-s "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
requires_cid_compat
run_test "Context serialization, server serializes, with CID (legacy)" \
"$P_SRV dtls=1 serialize=1 exchanges=2 cid=1 cid_val=dead" \
"$P_CLI dtls=1 serialize=0 exchanges=2 cid=1 cid_val=beef" \
0 \
-C "Deserializing connection..." \
-s "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
run_test "Context serialization, both serialize, CCM" \
@ -2460,6 +2489,17 @@ run_test "Context serialization, both serialize, with CID" \
-s "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
requires_cid_compat
run_test "Context serialization, both serialize, with CID (legacy)" \
"$P_SRV dtls=1 serialize=1 exchanges=2 cid=1 cid_val=dead" \
"$P_CLI dtls=1 serialize=1 exchanges=2 cid=1 cid_val=beef" \
0 \
-c "Deserializing connection..." \
-s "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
run_test "Context serialization, re-init, client serializes, CCM" \
"$P_SRV dtls=1 serialize=0 exchanges=2" \
@ -2497,6 +2537,16 @@ run_test "Context serialization, re-init, client serializes, with CID" \
-S "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
requires_cid_compat
run_test "Context serialization, re-init, client serializes, with CID (legacy)" \
"$P_SRV dtls=1 serialize=0 exchanges=2 cid=1 cid_val=dead" \
"$P_CLI dtls=1 serialize=2 exchanges=2 cid=1 cid_val=beef" \
0 \
-c "Deserializing connection..." \
-S "Deserializing connection..."
requires_config_enabled MBEDTLS_SSL_CONTEXT_SERIALIZATION
run_test "Context serialization, re-init, server serializes, CCM" \
"$P_SRV dtls=1 serialize=2 exchanges=2" \