/** * \file ssl_internal.h * * \brief Internal functions shared by the SSL modules */ /* * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved * SPDX-License-Identifier: GPL-2.0 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * 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_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(__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_MODE_CBC) /* 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 /* 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 */ /* * 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 */ #endif #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) unsigned char *psk; /*!< PSK from the callback */ size_t psk_len; /*!< Length of PSK from callback */ #endif #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 */ size_t ecrs_n; /*!< place for saving a length */ #endif #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 */ 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) mbedtls_sha256_context fin_sha256; #endif #if defined(MBEDTLS_SHA512_C) mbedtls_sha512_context fin_sha512; #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); int (*tls_prf)(const unsigned char *, size_t, const char *, const unsigned char *, size_t, unsigned char *, size_t); 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; /* * This structure contains a full set of runtime transform parameters * either in negotiation or active. */ struct mbedtls_ssl_transform { /* * Session specific crypto layer */ const mbedtls_ssl_ciphersuite_t *ciphersuite_info; /*!< Chosen cipersuite_info */ unsigned int keylen; /*!< symmetric key length (bytes) */ size_t minlen; /*!< min. ciphertext length */ size_t ivlen; /*!< IV length */ size_t fixed_ivlen; /*!< Fixed part of IV (AEAD) */ size_t maclen; /*!< MAC length */ unsigned char iv_enc[16]; /*!< IV (encryption) */ unsigned char iv_dec[16]; /*!< IV (decryption) */ #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) */ mbedtls_cipher_context_t cipher_ctx_enc; /*!< encryption context */ mbedtls_cipher_context_t cipher_ctx_dec; /*!< decryption context */ /* * Session specific compression layer */ #if defined(MBEDTLS_ZLIB_SUPPORT) z_stream ctx_deflate; /*!< compression context */ z_stream ctx_inflate; /*!< decompression context */ #endif }; #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 /* 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) 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 #endif /* ssl_internal.h */