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pigweed / third_party / github / ARMmbed / mbedtls / 2f28c1031f8d74c5c760534952c022fb463216dc / . / include / mbedtls / ssl_internal.h
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/**
* \file ssl_internal.h
*
* \brief Internal functions shared by the SSL modules
*/
/*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#ifndef MBEDTLS_SSL_INTERNAL_H
#define MBEDTLS_SSL_INTERNAL_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "ssl.h"
#include "cipher.h"
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#endif
#if defined(MBEDTLS_MD5_C)
#include "md5.h"
#endif
#if defined(MBEDTLS_SHA1_C)
#include "sha1.h"
#endif
#if defined(MBEDTLS_SHA256_C)
#include "sha256.h"
#endif
#if defined(MBEDTLS_SHA512_C)
#include "sha512.h"
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
#include "ecjpake.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#include "psa_util.h"
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
!defined(inline) && !defined(__cplusplus)
#define inline __inline
#endif
/* Determine minimum supported version */
#define MBEDTLS_SSL_MIN_MAJOR_VERSION MBEDTLS_SSL_MAJOR_VERSION_3
#if defined(MBEDTLS_SSL_PROTO_SSL3)
#define MBEDTLS_SSL_MIN_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_0
#else
#if defined(MBEDTLS_SSL_PROTO_TLS1)
#define MBEDTLS_SSL_MIN_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_1
#else
#if defined(MBEDTLS_SSL_PROTO_TLS1_1)
#define MBEDTLS_SSL_MIN_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_2
#else
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#define MBEDTLS_SSL_MIN_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_3
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 */
#endif /* MBEDTLS_SSL_PROTO_TLS1 */
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#define MBEDTLS_SSL_MIN_VALID_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_1
#define MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION MBEDTLS_SSL_MAJOR_VERSION_3
/* Determine maximum supported version */
#define MBEDTLS_SSL_MAX_MAJOR_VERSION MBEDTLS_SSL_MAJOR_VERSION_3
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#define MBEDTLS_SSL_MAX_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_3
#else
#if defined(MBEDTLS_SSL_PROTO_TLS1_1)
#define MBEDTLS_SSL_MAX_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_2
#else
#if defined(MBEDTLS_SSL_PROTO_TLS1)
#define MBEDTLS_SSL_MAX_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_1
#else
#if defined(MBEDTLS_SSL_PROTO_SSL3)
#define MBEDTLS_SSL_MAX_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_0
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
#endif /* MBEDTLS_SSL_PROTO_TLS1 */
#endif /* MBEDTLS_SSL_PROTO_TLS1_1 */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
/* Shorthand for restartable ECC */
#if defined(MBEDTLS_ECP_RESTARTABLE) && \
defined(MBEDTLS_SSL_CLI_C) && \
defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
#define MBEDTLS_SSL__ECP_RESTARTABLE
#endif
#define MBEDTLS_SSL_INITIAL_HANDSHAKE 0
#define MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS 1 /* In progress */
#define MBEDTLS_SSL_RENEGOTIATION_DONE 2 /* Done or aborted */
#define MBEDTLS_SSL_RENEGOTIATION_PENDING 3 /* Requested (server only) */
/*
* DTLS retransmission states, see RFC 6347 4.2.4
*
* The SENDING state is merged in PREPARING for initial sends,
* but is distinct for resends.
*
* Note: initial state is wrong for server, but is not used anyway.
*/
#define MBEDTLS_SSL_RETRANS_PREPARING 0
#define MBEDTLS_SSL_RETRANS_SENDING 1
#define MBEDTLS_SSL_RETRANS_WAITING 2
#define MBEDTLS_SSL_RETRANS_FINISHED 3
/*
* Allow extra bytes for record, authentication and encryption overhead:
* counter (8) + header (5) + IV(16) + MAC (16-48) + padding (0-256)
* and allow for a maximum of 1024 of compression expansion if
* enabled.
*/
#if defined(MBEDTLS_ZLIB_SUPPORT)
#define MBEDTLS_SSL_COMPRESSION_ADD 1024
#else
#define MBEDTLS_SSL_COMPRESSION_ADD 0
#endif
#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
( defined(MBEDTLS_CIPHER_MODE_CBC) && \
( defined(MBEDTLS_AES_C) || \
defined(MBEDTLS_CAMELLIA_C) || \
defined(MBEDTLS_ARIA_C) || \
defined(MBEDTLS_DES_C) ) )
#define MBEDTLS_SSL_SOME_MODES_USE_MAC
#endif
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
/* Ciphersuites using HMAC */
#if defined(MBEDTLS_SHA512_C)
#define MBEDTLS_SSL_MAC_ADD 48 /* SHA-384 used for HMAC */
#elif defined(MBEDTLS_SHA256_C)
#define MBEDTLS_SSL_MAC_ADD 32 /* SHA-256 used for HMAC */
#else
#define MBEDTLS_SSL_MAC_ADD 20 /* SHA-1 used for HMAC */
#endif
#else /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
/* AEAD ciphersuites: GCM and CCM use a 128 bits tag */
#define MBEDTLS_SSL_MAC_ADD 16
#endif
#if defined(MBEDTLS_CIPHER_MODE_CBC)
#define MBEDTLS_SSL_PADDING_ADD 256
#else
#define MBEDTLS_SSL_PADDING_ADD 0
#endif
#define MBEDTLS_SSL_PAYLOAD_OVERHEAD ( MBEDTLS_SSL_COMPRESSION_ADD + \
MBEDTLS_MAX_IV_LENGTH + \
MBEDTLS_SSL_MAC_ADD + \
MBEDTLS_SSL_PADDING_ADD \
)
#define MBEDTLS_SSL_IN_PAYLOAD_LEN ( MBEDTLS_SSL_PAYLOAD_OVERHEAD + \
( MBEDTLS_SSL_IN_CONTENT_LEN ) )
#define MBEDTLS_SSL_OUT_PAYLOAD_LEN ( MBEDTLS_SSL_PAYLOAD_OVERHEAD + \
( MBEDTLS_SSL_OUT_CONTENT_LEN ) )
/* The maximum number of buffered handshake messages. */
#define MBEDTLS_SSL_MAX_BUFFERED_HS 4
/* Maximum length we can advertise as our max content length for
RFC 6066 max_fragment_length extension negotiation purposes
(the lesser of both sizes, if they are unequal.)
*/
#define MBEDTLS_TLS_EXT_ADV_CONTENT_LEN ( \
(MBEDTLS_SSL_IN_CONTENT_LEN > MBEDTLS_SSL_OUT_CONTENT_LEN) \
? ( MBEDTLS_SSL_OUT_CONTENT_LEN ) \
: ( MBEDTLS_SSL_IN_CONTENT_LEN ) \
)
/*
* Check that we obey the standard's message size bounds
*/
#if MBEDTLS_SSL_MAX_CONTENT_LEN > 16384
#error "Bad configuration - record content too large."
#endif
#if MBEDTLS_SSL_IN_CONTENT_LEN > MBEDTLS_SSL_MAX_CONTENT_LEN
#error "Bad configuration - incoming record content should not be larger than MBEDTLS_SSL_MAX_CONTENT_LEN."
#endif
#if MBEDTLS_SSL_OUT_CONTENT_LEN > MBEDTLS_SSL_MAX_CONTENT_LEN
#error "Bad configuration - outgoing record content should not be larger than MBEDTLS_SSL_MAX_CONTENT_LEN."
#endif
#if MBEDTLS_SSL_IN_PAYLOAD_LEN > MBEDTLS_SSL_MAX_CONTENT_LEN + 2048
#error "Bad configuration - incoming protected record payload too large."
#endif
#if MBEDTLS_SSL_OUT_PAYLOAD_LEN > MBEDTLS_SSL_MAX_CONTENT_LEN + 2048
#error "Bad configuration - outgoing protected record payload too large."
#endif
/* Calculate buffer sizes */
/* Note: Even though the TLS record header is only 5 bytes
long, we're internally using 8 bytes to store the
implicit sequence number. */
#define MBEDTLS_SSL_HEADER_LEN 13
#define MBEDTLS_SSL_IN_BUFFER_LEN \
( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_IN_PAYLOAD_LEN ) )
#define MBEDTLS_SSL_OUT_BUFFER_LEN \
( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_OUT_PAYLOAD_LEN ) )
#ifdef MBEDTLS_ZLIB_SUPPORT
/* Compression buffer holds both IN and OUT buffers, so should be size of the larger */
#define MBEDTLS_SSL_COMPRESS_BUFFER_LEN ( \
( MBEDTLS_SSL_IN_BUFFER_LEN > MBEDTLS_SSL_OUT_BUFFER_LEN ) \
? MBEDTLS_SSL_IN_BUFFER_LEN \
: MBEDTLS_SSL_OUT_BUFFER_LEN \
)
#endif
/*
* TLS extension flags (for extensions with outgoing ServerHello content
* that need it (e.g. for RENEGOTIATION_INFO the server already knows because
* of state of the renegotiation flag, so no indicator is required)
*/
#define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT (1 << 0)
#define MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK (1 << 1)
#ifdef __cplusplus
extern "C" {
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/*
* Abstraction for a grid of allowed signature-hash-algorithm pairs.
*/
struct mbedtls_ssl_sig_hash_set_t
{
/* At the moment, we only need to remember a single suitable
* hash algorithm per signature algorithm. As long as that's
* the case - and we don't need a general lookup function -
* we can implement the sig-hash-set as a map from signatures
* to hash algorithms. */
mbedtls_md_type_t rsa;
mbedtls_md_type_t ecdsa;
};
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
typedef int mbedtls_ssl_tls_prf_cb( const unsigned char *secret, size_t slen,
const char *label,
const unsigned char *random, size_t rlen,
unsigned char *dstbuf, size_t dlen );
/*
* This structure contains the parameters only needed during handshake.
*/
struct mbedtls_ssl_handshake_params
{
/*
* Handshake specific crypto variables
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
mbedtls_ssl_sig_hash_set_t hash_algs; /*!< Set of suitable sig-hash pairs */
#endif
#if defined(MBEDTLS_DHM_C)
mbedtls_dhm_context dhm_ctx; /*!< DHM key exchange */
#endif
#if defined(MBEDTLS_ECDH_C)
mbedtls_ecdh_context ecdh_ctx; /*!< ECDH key exchange */
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_ecc_curve_t ecdh_psa_curve;
psa_key_handle_t ecdh_psa_privkey;
unsigned char ecdh_psa_peerkey[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
size_t ecdh_psa_peerkey_len;
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#endif /* MBEDTLS_ECDH_C */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
mbedtls_ecjpake_context ecjpake_ctx; /*!< EC J-PAKE key exchange */
#if defined(MBEDTLS_SSL_CLI_C)
unsigned char *ecjpake_cache; /*!< Cache for ClientHello ext */
size_t ecjpake_cache_len; /*!< Length of cached data */
#endif
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
const mbedtls_ecp_curve_info **curves; /*!< Supported elliptic curves */
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_key_handle_t psk_opaque; /*!< Opaque PSK from the callback */
#endif /* MBEDTLS_USE_PSA_CRYPTO */
unsigned char *psk; /*!< PSK from the callback */
size_t psk_len; /*!< Length of PSK from callback */
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_ssl_key_cert *key_cert; /*!< chosen key/cert pair (server) */
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
int sni_authmode; /*!< authmode from SNI callback */
mbedtls_ssl_key_cert *sni_key_cert; /*!< key/cert list from SNI */
mbedtls_x509_crt *sni_ca_chain; /*!< trusted CAs from SNI callback */
mbedtls_x509_crl *sni_ca_crl; /*!< trusted CAs CRLs from SNI */
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
int ecrs_enabled; /*!< Handshake supports EC restart? */
mbedtls_x509_crt_restart_ctx ecrs_ctx; /*!< restart context */
enum { /* this complements ssl->state with info on intra-state operations */
ssl_ecrs_none = 0, /*!< nothing going on (yet) */
ssl_ecrs_crt_verify, /*!< Certificate: crt_verify() */
ssl_ecrs_ske_start_processing, /*!< ServerKeyExchange: pk_verify() */
ssl_ecrs_cke_ecdh_calc_secret, /*!< ClientKeyExchange: ECDH step 2 */
ssl_ecrs_crt_vrfy_sign, /*!< CertificateVerify: pk_sign() */
} ecrs_state; /*!< current (or last) operation */
mbedtls_x509_crt *ecrs_peer_cert; /*!< The peer's CRT chain. */
size_t ecrs_n; /*!< place for saving a length */
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
!defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
mbedtls_pk_context peer_pubkey; /*!< The public key from the peer. */
#endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
unsigned int out_msg_seq; /*!< Outgoing handshake sequence number */
unsigned int in_msg_seq; /*!< Incoming handshake sequence number */
unsigned char *verify_cookie; /*!< Cli: HelloVerifyRequest cookie
Srv: unused */
unsigned char verify_cookie_len; /*!< Cli: cookie length
Srv: flag for sending a cookie */
uint32_t retransmit_timeout; /*!< Current value of timeout */
unsigned char retransmit_state; /*!< Retransmission state */
mbedtls_ssl_flight_item *flight; /*!< Current outgoing flight */
mbedtls_ssl_flight_item *cur_msg; /*!< Current message in flight */
unsigned char *cur_msg_p; /*!< Position in current message */
unsigned int in_flight_start_seq; /*!< Minimum message sequence in the
flight being received */
mbedtls_ssl_transform *alt_transform_out; /*!< Alternative transform for
resending messages */
unsigned char alt_out_ctr[8]; /*!< Alternative record epoch/counter
for resending messages */
#if defined(MBEDTLS_SSL_CID)
/* The state of CID configuration in this handshake. */
uint8_t cid_in_use; /*!< This indicates whether the use of the CID extension
* has been negotited. Possible values are
* #MBEDTLS_SSL_CID_ENABLED and
* #MBEDTLS_SSL_CID_DISABLED. */
unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ]; /*! The peer's CID */
uint8_t peer_cid_len; /*!< The length of
* \c peer_cid. */
#endif /* MBEDTLS_SSL_CID */
struct
{
size_t total_bytes_buffered; /*!< Cumulative size of heap allocated
* buffers used for message buffering. */
uint8_t seen_ccs; /*!< Indicates if a CCS message has
* been seen in the current flight. */
struct mbedtls_ssl_hs_buffer
{
unsigned is_valid : 1;
unsigned is_fragmented : 1;
unsigned is_complete : 1;
unsigned char *data;
size_t data_len;
} hs[MBEDTLS_SSL_MAX_BUFFERED_HS];
struct
{
unsigned char *data;
size_t len;
unsigned epoch;
} future_record;
} buffering;
uint16_t mtu; /*!< Handshake mtu, used to fragment outgoing messages */
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/*
* Checksum contexts
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
mbedtls_md5_context fin_md5;
mbedtls_sha1_context fin_sha1;
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_SHA256_C)
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_hash_operation_t fin_sha256_psa;
#else
mbedtls_sha256_context fin_sha256;
#endif
#endif
#if defined(MBEDTLS_SHA512_C)
#if defined(MBEDTLS_USE_PSA_CRYPTO)
psa_hash_operation_t fin_sha384_psa;
#else
mbedtls_sha512_context fin_sha512;
#endif
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
void (*update_checksum)(mbedtls_ssl_context *, const unsigned char *, size_t);
void (*calc_verify)(mbedtls_ssl_context *, unsigned char *);
void (*calc_finished)(mbedtls_ssl_context *, unsigned char *, int);
mbedtls_ssl_tls_prf_cb *tls_prf;
mbedtls_ssl_ciphersuite_t const *ciphersuite_info;
size_t pmslen; /*!< premaster length */
unsigned char randbytes[64]; /*!< random bytes */
unsigned char premaster[MBEDTLS_PREMASTER_SIZE];
/*!< premaster secret */
int resume; /*!< session resume indicator*/
int max_major_ver; /*!< max. major version client*/
int max_minor_ver; /*!< max. minor version client*/
int cli_exts; /*!< client extension presence*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
int new_session_ticket; /*!< use NewSessionTicket? */
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
int extended_ms; /*!< use Extended Master Secret? */
#endif
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
unsigned int async_in_progress : 1; /*!< an asynchronous operation is in progress */
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
/** Asynchronous operation context. This field is meant for use by the
* asynchronous operation callbacks (mbedtls_ssl_config::f_async_sign_start,
* mbedtls_ssl_config::f_async_decrypt_start,
* mbedtls_ssl_config::f_async_resume, mbedtls_ssl_config::f_async_cancel).
* The library does not use it internally. */
void *user_async_ctx;
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
};
typedef struct mbedtls_ssl_hs_buffer mbedtls_ssl_hs_buffer;
/*
* Representation of decryption/encryption transformations on records
*
* There are the following general types of record transformations:
* - Stream transformations (TLS versions <= 1.2 only)
* Transformation adding a MAC and applying a stream-cipher
* to the authenticated message.
* - CBC block cipher transformations ([D]TLS versions <= 1.2 only)
* In addition to the distinction of the order of encryption and
* authentication, there's a fundamental difference between the
* handling in SSL3 & TLS 1.0 and TLS 1.1 and TLS 1.2: For SSL3
* and TLS 1.0, the final IV after processing a record is used
* as the IV for the next record. No explicit IV is contained
* in an encrypted record. The IV for the first record is extracted
* at key extraction time. In contrast, for TLS 1.1 and 1.2, no
* IV is generated at key extraction time, but every encrypted
* record is explicitly prefixed by the IV with which it was encrypted.
* - AEAD transformations ([D]TLS versions >= 1.2 only)
* These come in two fundamentally different versions, the first one
* used in TLS 1.2, excluding ChaChaPoly ciphersuites, and the second
* one used for ChaChaPoly ciphersuites in TLS 1.2 as well as for TLS 1.3.
* In the first transformation, the IV to be used for a record is obtained
* as the concatenation of an explicit, static 4-byte IV and the 8-byte
* record sequence number, and explicitly prepending this sequence number
* to the encrypted record. In contrast, in the second transformation
* the IV is obtained by XOR'ing a static IV obtained at key extraction
* time with the 8-byte record sequence number, without prepending the
* latter to the encrypted record.
*
* In addition to type and version, the following parameters are relevant:
* - The symmetric cipher algorithm to be used.
* - The (static) encryption/decryption keys for the cipher.
* - For stream/CBC, the type of message digest to be used.
* - For stream/CBC, (static) encryption/decryption keys for the digest.
* - For AEAD transformations, the size (potentially 0) of an explicit,
* random initialization vector placed in encrypted records.
* - For some transformations (currently AEAD and CBC in SSL3 and TLS 1.0)
* an implicit IV. It may be static (e.g. AEAD) or dynamic (e.g. CBC)
* and (if present) is combined with the explicit IV in a transformation-
* dependent way (e.g. appending in TLS 1.2 and XOR'ing in TLS 1.3).
* - For stream/CBC, a flag determining the order of encryption and MAC.
* - The details of the transformation depend on the SSL/TLS version.
* - The length of the authentication tag.
*
* Note: Except for CBC in SSL3 and TLS 1.0, these parameters are
* constant across multiple encryption/decryption operations.
* For CBC, the implicit IV needs to be updated after each
* operation.
*
* The struct below refines this abstract view as follows:
* - The cipher underlying the transformation is managed in
* cipher contexts cipher_ctx_{enc/dec}, which must have the
* same cipher type. The mode of these cipher contexts determines
* the type of the transformation in the sense above: e.g., if
* the type is MBEDTLS_CIPHER_AES_256_CBC resp. MBEDTLS_CIPHER_AES_192_GCM
* then the transformation has type CBC resp. AEAD.
* - The cipher keys are never stored explicitly but
* are maintained within cipher_ctx_{enc/dec}.
* - For stream/CBC transformations, the message digest contexts
* used for the MAC's are stored in md_ctx_{enc/dec}. These contexts
* are unused for AEAD transformations.
* - For stream/CBC transformations and versions > SSL3, the
* MAC keys are not stored explicitly but maintained within
* md_ctx_{enc/dec}.
* - For stream/CBC transformations and version SSL3, the MAC
* keys are stored explicitly in mac_enc, mac_dec and have
* a fixed size of 20 bytes. These fields are unused for
* AEAD transformations or transformations >= TLS 1.0.
* - For transformations using an implicit IV maintained within
* the transformation context, its contents are stored within
* iv_{enc/dec}.
* - The value of ivlen indicates the length of the IV.
* This is redundant in case of stream/CBC transformations
* which always use 0 resp. the cipher's block length as the
* IV length, but is needed for AEAD ciphers and may be
* different from the underlying cipher's block length
* in this case.
* - The field fixed_ivlen is nonzero for AEAD transformations only
* and indicates the length of the static part of the IV which is
* constant throughout the communication, and which is stored in
* the first fixed_ivlen bytes of the iv_{enc/dec} arrays.
* Note: For CBC in SSL3 and TLS 1.0, the fields iv_{enc/dec}
* still store IV's for continued use across multiple transformations,
* so it is not true that fixed_ivlen == 0 means that iv_{enc/dec} are
* not being used!
* - minor_ver denotes the SSL/TLS version
* - For stream/CBC transformations, maclen denotes the length of the
* authentication tag, while taglen is unused and 0.
* - For AEAD transformations, taglen denotes the length of the
* authentication tag, while maclen is unused and 0.
* - For CBC transformations, encrypt_then_mac determines the
* order of encryption and authentication. This field is unused
* in other transformations.
*
*/
struct mbedtls_ssl_transform
{
/*
* Session specific crypto layer
*/
size_t minlen; /*!< min. ciphertext length */
size_t ivlen; /*!< IV length */
size_t fixed_ivlen; /*!< Fixed part of IV (AEAD) */
size_t maclen; /*!< MAC(CBC) len */
size_t taglen; /*!< TAG(AEAD) len */
unsigned char iv_enc[16]; /*!< IV (encryption) */
unsigned char iv_dec[16]; /*!< IV (decryption) */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/* Needed only for SSL v3.0 secret */
unsigned char mac_enc[20]; /*!< SSL v3.0 secret (enc) */
unsigned char mac_dec[20]; /*!< SSL v3.0 secret (dec) */
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
mbedtls_md_context_t md_ctx_enc; /*!< MAC (encryption) */
mbedtls_md_context_t md_ctx_dec; /*!< MAC (decryption) */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
int encrypt_then_mac; /*!< flag for EtM activation */
#endif
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */
mbedtls_cipher_context_t cipher_ctx_enc; /*!< encryption context */
mbedtls_cipher_context_t cipher_ctx_dec; /*!< decryption context */
int minor_ver;
/*
* Session specific compression layer
*/
#if defined(MBEDTLS_ZLIB_SUPPORT)
z_stream ctx_deflate; /*!< compression context */
z_stream ctx_inflate; /*!< decompression context */
#endif
};
/*
* Internal representation of record frames
*
* Instances come in two flavors:
* (1) Encrypted
* These always have data_offset = 0
* (2) Unencrypted
* These have data_offset set to the amount of
* pre-expansion during record protection. Concretely,
* this is the length of the fixed part of the explicit IV
* used for encryption, or 0 if no explicit IV is used
* (e.g. for CBC in TLS 1.0, or stream ciphers).
*
* The reason for the data_offset in the unencrypted case
* is to allow for in-place conversion of an unencrypted to
* an encrypted record. If the offset wasn't included, the
* encrypted content would need to be shifted afterwards to
* make space for the fixed IV.
*
*/
typedef struct
{
uint8_t ctr[8]; /*!< Record sequence number */
uint8_t type; /*!< Record type */
uint8_t ver[2]; /*!< SSL/TLS version */
unsigned char *buf; /*!< Memory buffer enclosing the record content */
size_t buf_len; /*!< Buffer length */
size_t data_offset; /*!< Offset of record content */
size_t data_len; /*!< Length of record content */
} mbedtls_record;
#if defined(MBEDTLS_X509_CRT_PARSE_C)
/*
* List of certificate + private key pairs
*/
struct mbedtls_ssl_key_cert
{
mbedtls_x509_crt *cert; /*!< cert */
mbedtls_pk_context *key; /*!< private key */
mbedtls_ssl_key_cert *next; /*!< next key/cert pair */
};
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
/*
* List of handshake messages kept around for resending
*/
struct mbedtls_ssl_flight_item
{
unsigned char *p; /*!< message, including handshake headers */
size_t len; /*!< length of p */
unsigned char type; /*!< type of the message: handshake or CCS */
mbedtls_ssl_flight_item *next; /*!< next handshake message(s) */
};
#endif /* MBEDTLS_SSL_PROTO_DTLS */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/* Find an entry in a signature-hash set matching a given hash algorithm. */
mbedtls_md_type_t mbedtls_ssl_sig_hash_set_find( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg );
/* Add a signature-hash-pair to a signature-hash set */
void mbedtls_ssl_sig_hash_set_add( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg,
mbedtls_md_type_t md_alg );
/* Allow exactly one hash algorithm for each signature. */
void mbedtls_ssl_sig_hash_set_const_hash( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_md_type_t md_alg );
/* Setup an empty signature-hash set */
static inline void mbedtls_ssl_sig_hash_set_init( mbedtls_ssl_sig_hash_set_t *set )
{
mbedtls_ssl_sig_hash_set_const_hash( set, MBEDTLS_MD_NONE );
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2) &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
/**
* \brief Free referenced items in an SSL transform context and clear
* memory
*
* \param transform SSL transform context
*/
void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform );
/**
* \brief Free referenced items in an SSL handshake context and clear
* memory
*
* \param ssl SSL context
*/
void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl );
int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl );
int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl );
void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl );
int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl );
void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl );
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl );
int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl );
int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl );
void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl );
/**
* \brief Update record layer
*
* This function roughly separates the implementation
* of the logic of (D)TLS from the implementation
* of the secure transport.
*
* \param ssl The SSL context to use.
* \param update_hs_digest This indicates if the handshake digest
* should be automatically updated in case
* a handshake message is found.
*
* \return 0 or non-zero error code.
*
* \note A clarification on what is called 'record layer' here
* is in order, as many sensible definitions are possible:
*
* The record layer takes as input an untrusted underlying
* transport (stream or datagram) and transforms it into
* a serially multiplexed, secure transport, which
* conceptually provides the following:
*
* (1) Three datagram based, content-agnostic transports
* for handshake, alert and CCS messages.
* (2) One stream- or datagram-based transport
* for application data.
* (3) Functionality for changing the underlying transform
* securing the contents.
*
* The interface to this functionality is given as follows:
*
* a Updating
* [Currently implemented by mbedtls_ssl_read_record]
*
* Check if and on which of the four 'ports' data is pending:
* Nothing, a controlling datagram of type (1), or application
* data (2). In any case data is present, internal buffers
* provide access to the data for the user to process it.
* Consumption of type (1) datagrams is done automatically
* on the next update, invalidating that the internal buffers
* for previous datagrams, while consumption of application
* data (2) is user-controlled.
*
* b Reading of application data
* [Currently manual adaption of ssl->in_offt pointer]
*
* As mentioned in the last paragraph, consumption of data
* is different from the automatic consumption of control
* datagrams (1) because application data is treated as a stream.
*
* c Tracking availability of application data
* [Currently manually through decreasing ssl->in_msglen]
*
* For efficiency and to retain datagram semantics for
* application data in case of DTLS, the record layer
* provides functionality for checking how much application
* data is still available in the internal buffer.
*
* d Changing the transformation securing the communication.
*
* Given an opaque implementation of the record layer in the
* above sense, it should be possible to implement the logic
* of (D)TLS on top of it without the need to know anything
* about the record layer's internals. This is done e.g.
* in all the handshake handling functions, and in the
* application data reading function mbedtls_ssl_read.
*
* \note The above tries to give a conceptual picture of the
* record layer, but the current implementation deviates
* from it in some places. For example, our implementation of
* the update functionality through mbedtls_ssl_read_record
* discards datagrams depending on the current state, which
* wouldn't fall under the record layer's responsibility
* following the above definition.
*
*/
int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl,
unsigned update_hs_digest );
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want );
int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush );
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );
int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl );
int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl );
int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl );
void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
const mbedtls_ssl_ciphersuite_t *ciphersuite_info );
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex );
#endif
#if defined(MBEDTLS_PK_C)
unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk );
unsigned char mbedtls_ssl_sig_from_pk_alg( mbedtls_pk_type_t type );
mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig );
#endif
mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash );
unsigned char mbedtls_ssl_hash_from_md_alg( int md );
int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md );
#if defined(MBEDTLS_ECP_C)
int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id );
#endif
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl,
mbedtls_md_type_t md );
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
static inline mbedtls_pk_context *mbedtls_ssl_own_key( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_key_cert *key_cert;
if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
key_cert = ssl->handshake->key_cert;
else
key_cert = ssl->conf->key_cert;
return( key_cert == NULL ? NULL : key_cert->key );
}
static inline mbedtls_x509_crt *mbedtls_ssl_own_cert( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_key_cert *key_cert;
if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
key_cert = ssl->handshake->key_cert;
else
key_cert = ssl->conf->key_cert;
return( key_cert == NULL ? NULL : key_cert->cert );
}
/*
* Check usage of a certificate wrt extensions:
* keyUsage, extendedKeyUsage (later), and nSCertType (later).
*
* Warning: cert_endpoint is the endpoint of the cert (ie, of our peer when we
* check a cert we received from them)!
*
* Return 0 if everything is OK, -1 if not.
*/
int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
const mbedtls_ssl_ciphersuite_t *ciphersuite,
int cert_endpoint,
uint32_t *flags );
#endif /* MBEDTLS_X509_CRT_PARSE_C */
void mbedtls_ssl_write_version( int major, int minor, int transport,
unsigned char ver[2] );
void mbedtls_ssl_read_version( int *major, int *minor, int transport,
const unsigned char ver[2] );
static inline size_t mbedtls_ssl_hdr_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( 13 );
#else
((void) ssl);
#endif
return( 5 );
}
static inline size_t mbedtls_ssl_hs_hdr_len( const mbedtls_ssl_context *ssl )
{
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
return( 12 );
#else
((void) ssl);
#endif
return( 4 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl );
void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl );
int mbedtls_ssl_resend( mbedtls_ssl_context *ssl );
int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl );
#endif
/* Visible for testing purposes only */
#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context *ssl );
void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl );
#endif
int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
const mbedtls_ssl_session *src );
/* constant-time buffer comparison */
static inline int mbedtls_ssl_safer_memcmp( const void *a, const void *b, size_t n )
{
size_t i;
volatile const unsigned char *A = (volatile const unsigned char *) a;
volatile const unsigned char *B = (volatile const unsigned char *) b;
volatile unsigned char diff = 0;
for( i = 0; i < n; i++ )
{
/* Read volatile data in order before computing diff.
* This avoids IAR compiler warning:
* 'the order of volatile accesses is undefined ..' */
unsigned char x = A[i], y = B[i];
diff |= x ^ y;
}
return( diff );
}
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl,
unsigned char *output,
unsigned char *data, size_t data_len );
#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
/* The hash buffer must have at least MBEDTLS_MD_MAX_SIZE bytes of length. */
int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
unsigned char *hash, size_t *hashlen,
unsigned char *data, size_t data_len,
mbedtls_md_type_t md_alg );
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
#ifdef __cplusplus
}
#endif
void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform );
int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context *ssl,
mbedtls_ssl_transform *transform,
mbedtls_record *rec );
#endif /* ssl_internal.h */