diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ssl_client.c')
| -rw-r--r-- | thirdparty/mbedtls/library/ssl_client.c | 1017 |
1 files changed, 1017 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/ssl_client.c b/thirdparty/mbedtls/library/ssl_client.c new file mode 100644 index 0000000000..345e608938 --- /dev/null +++ b/thirdparty/mbedtls/library/ssl_client.c @@ -0,0 +1,1017 @@ +/* + * TLS 1.2 and 1.3 client-side functions + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#include "common.h" + +#if defined(MBEDTLS_SSL_CLI_C) +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) || defined(MBEDTLS_SSL_PROTO_TLS1_2) + +#include <string.h> + +#include "debug_internal.h" +#include "mbedtls/error.h" +#include "mbedtls/platform.h" + +#include "ssl_client.h" +#include "ssl_misc.h" +#include "ssl_tls13_keys.h" +#include "ssl_debug_helpers.h" + +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_hostname_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + const unsigned char *end, + size_t *olen) +{ + unsigned char *p = buf; + size_t hostname_len; + + *olen = 0; + + if (ssl->hostname == NULL) { + return 0; + } + + MBEDTLS_SSL_DEBUG_MSG(3, + ("client hello, adding server name extension: %s", + ssl->hostname)); + + hostname_len = strlen(ssl->hostname); + + MBEDTLS_SSL_CHK_BUF_PTR(p, end, hostname_len + 9); + + /* + * Sect. 3, RFC 6066 (TLS Extensions Definitions) + * + * In order to provide any of the server names, clients MAY include an + * extension of type "server_name" in the (extended) client hello. The + * "extension_data" field of this extension SHALL contain + * "ServerNameList" where: + * + * struct { + * NameType name_type; + * select (name_type) { + * case host_name: HostName; + * } name; + * } ServerName; + * + * enum { + * host_name(0), (255) + * } NameType; + * + * opaque HostName<1..2^16-1>; + * + * struct { + * ServerName server_name_list<1..2^16-1> + * } ServerNameList; + * + */ + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SERVERNAME, p, 0); + p += 2; + + MBEDTLS_PUT_UINT16_BE(hostname_len + 5, p, 0); + p += 2; + + MBEDTLS_PUT_UINT16_BE(hostname_len + 3, p, 0); + p += 2; + + *p++ = MBEDTLS_BYTE_0(MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME); + + MBEDTLS_PUT_UINT16_BE(hostname_len, p, 0); + p += 2; + + memcpy(p, ssl->hostname, hostname_len); + + *olen = hostname_len + 9; + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_SERVERNAME); +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ + return 0; +} +#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ + +#if defined(MBEDTLS_SSL_ALPN) +/* + * ssl_write_alpn_ext() + * + * Structure of the application_layer_protocol_negotiation extension in + * ClientHello: + * + * opaque ProtocolName<1..2^8-1>; + * + * struct { + * ProtocolName protocol_name_list<2..2^16-1> + * } ProtocolNameList; + * + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_alpn_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + const unsigned char *end, + size_t *out_len) +{ + unsigned char *p = buf; + + *out_len = 0; + + if (ssl->conf->alpn_list == NULL) { + return 0; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding alpn extension")); + + + /* Check we have enough space for the extension type (2 bytes), the + * extension length (2 bytes) and the protocol_name_list length (2 bytes). + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_ALPN, p, 0); + /* Skip writing extension and list length for now */ + p += 6; + + /* + * opaque ProtocolName<1..2^8-1>; + * + * struct { + * ProtocolName protocol_name_list<2..2^16-1> + * } ProtocolNameList; + */ + for (const char **cur = ssl->conf->alpn_list; *cur != NULL; cur++) { + /* + * mbedtls_ssl_conf_set_alpn_protocols() checked that the length of + * protocol names is less than 255. + */ + size_t protocol_name_len = strlen(*cur); + + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 1 + protocol_name_len); + *p++ = (unsigned char) protocol_name_len; + memcpy(p, *cur, protocol_name_len); + p += protocol_name_len; + } + + *out_len = (size_t) (p - buf); + + /* List length = *out_len - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */ + MBEDTLS_PUT_UINT16_BE(*out_len - 6, buf, 4); + + /* Extension length = *out_len - 2 (ext_type) - 2 (ext_len) */ + MBEDTLS_PUT_UINT16_BE(*out_len - 4, buf, 2); + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_ALPN); +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ + return 0; +} +#endif /* MBEDTLS_SSL_ALPN */ + +#if defined(MBEDTLS_SSL_TLS1_2_SOME_ECC) || \ + defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) +/* + * Function for writing a supported groups (TLS 1.3) or supported elliptic + * curves (TLS 1.2) extension. + * + * The "extension_data" field of a supported groups extension contains a + * "NamedGroupList" value (TLS 1.3 RFC8446): + * enum { + * secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019), + * x25519(0x001D), x448(0x001E), + * ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102), + * ffdhe6144(0x0103), ffdhe8192(0x0104), + * ffdhe_private_use(0x01FC..0x01FF), + * ecdhe_private_use(0xFE00..0xFEFF), + * (0xFFFF) + * } NamedGroup; + * struct { + * NamedGroup named_group_list<2..2^16-1>; + * } NamedGroupList; + * + * The "extension_data" field of a supported elliptic curves extension contains + * a "NamedCurveList" value (TLS 1.2 RFC 8422): + * enum { + * deprecated(1..22), + * secp256r1 (23), secp384r1 (24), secp521r1 (25), + * x25519(29), x448(30), + * reserved (0xFE00..0xFEFF), + * deprecated(0xFF01..0xFF02), + * (0xFFFF) + * } NamedCurve; + * struct { + * NamedCurve named_curve_list<2..2^16-1> + * } NamedCurveList; + * + * The TLS 1.3 supported groups extension was defined to be a compatible + * generalization of the TLS 1.2 supported elliptic curves extension. They both + * share the same extension identifier. + * + */ +#define SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_2_FLAG 1 +#define SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_3_FLAG 2 + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_supported_groups_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + const unsigned char *end, + int flags, + size_t *out_len) +{ + unsigned char *p = buf; + unsigned char *named_group_list; /* Start of named_group_list */ + size_t named_group_list_len; /* Length of named_group_list */ + const uint16_t *group_list = mbedtls_ssl_get_groups(ssl); + + *out_len = 0; + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding supported_groups extension")); + + /* Check if we have space for header and length fields: + * - extension_type (2 bytes) + * - extension_data_length (2 bytes) + * - named_group_list_length (2 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); + p += 6; + + named_group_list = p; + + if (group_list == NULL) { + return MBEDTLS_ERR_SSL_BAD_CONFIG; + } + + for (; *group_list != 0; group_list++) { + int propose_group = 0; + + MBEDTLS_SSL_DEBUG_MSG(3, ("got supported group(%04x)", *group_list)); + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + if (flags & SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_3_FLAG) { +#if defined(PSA_WANT_ALG_ECDH) + if (mbedtls_ssl_tls13_named_group_is_ecdhe(*group_list) && + (mbedtls_ssl_get_ecp_group_id_from_tls_id(*group_list) != + MBEDTLS_ECP_DP_NONE)) { + propose_group = 1; + } +#endif +#if defined(PSA_WANT_ALG_FFDH) + if (mbedtls_ssl_tls13_named_group_is_ffdh(*group_list)) { + propose_group = 1; + } +#endif + } +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + +#if defined(MBEDTLS_SSL_TLS1_2_SOME_ECC) + if ((flags & SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_2_FLAG) && + mbedtls_ssl_tls12_named_group_is_ecdhe(*group_list) && + (mbedtls_ssl_get_ecp_group_id_from_tls_id(*group_list) != + MBEDTLS_ECP_DP_NONE)) { + propose_group = 1; + } +#endif /* MBEDTLS_SSL_TLS1_2_SOME_ECC */ + + if (propose_group) { + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + MBEDTLS_PUT_UINT16_BE(*group_list, p, 0); + p += 2; + MBEDTLS_SSL_DEBUG_MSG(3, ("NamedGroup: %s ( %x )", + mbedtls_ssl_named_group_to_str(*group_list), + *group_list)); + } + } + + /* Length of named_group_list */ + named_group_list_len = (size_t) (p - named_group_list); + if (named_group_list_len == 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("No group available.")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + /* Write extension_type */ + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SUPPORTED_GROUPS, buf, 0); + /* Write extension_data_length */ + MBEDTLS_PUT_UINT16_BE(named_group_list_len + 2, buf, 2); + /* Write length of named_group_list */ + MBEDTLS_PUT_UINT16_BE(named_group_list_len, buf, 4); + + MBEDTLS_SSL_DEBUG_BUF(3, "Supported groups extension", + buf + 4, named_group_list_len + 2); + + *out_len = (size_t) (p - buf); + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + mbedtls_ssl_tls13_set_hs_sent_ext_mask( + ssl, MBEDTLS_TLS_EXT_SUPPORTED_GROUPS); +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */ + + return 0; +} +#endif /* MBEDTLS_SSL_TLS1_2_SOME_ECC || + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_client_hello_cipher_suites( + mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + int *tls12_uses_ec, + size_t *out_len) +{ + unsigned char *p = buf; + const int *ciphersuite_list; + unsigned char *cipher_suites; /* Start of the cipher_suites list */ + size_t cipher_suites_len; + + *tls12_uses_ec = 0; + *out_len = 0; + + /* + * Ciphersuite list + * + * This is a list of the symmetric cipher options supported by + * the client, specifically the record protection algorithm + * ( including secret key length ) and a hash to be used with + * HKDF, in descending order of client preference. + */ + ciphersuite_list = ssl->conf->ciphersuite_list; + + /* Check there is space for the cipher suite list length (2 bytes). */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + p += 2; + + /* Write cipher_suites + * CipherSuite cipher_suites<2..2^16-2>; + */ + cipher_suites = p; + for (size_t i = 0; ciphersuite_list[i] != 0; i++) { + int cipher_suite = ciphersuite_list[i]; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + + ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(cipher_suite); + + if (mbedtls_ssl_validate_ciphersuite(ssl, ciphersuite_info, + ssl->handshake->min_tls_version, + ssl->tls_version) != 0) { + continue; + } + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \ + (defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)) + *tls12_uses_ec |= mbedtls_ssl_ciphersuite_uses_ec(ciphersuite_info); +#endif + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, add ciphersuite: %04x, %s", + (unsigned int) cipher_suite, + ciphersuite_info->name)); + + /* Check there is space for the cipher suite identifier (2 bytes). */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + MBEDTLS_PUT_UINT16_BE(cipher_suite, p, 0); + p += 2; + } + + /* + * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV + */ + int renegotiating = 0; +#if defined(MBEDTLS_SSL_RENEGOTIATION) + renegotiating = (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE); +#endif + if (!renegotiating) { + MBEDTLS_SSL_DEBUG_MSG(3, ("adding EMPTY_RENEGOTIATION_INFO_SCSV")); + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + MBEDTLS_PUT_UINT16_BE(MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO, p, 0); + p += 2; + } + + /* Write the cipher_suites length in number of bytes */ + cipher_suites_len = (size_t) (p - cipher_suites); + MBEDTLS_PUT_UINT16_BE(cipher_suites_len, buf, 0); + MBEDTLS_SSL_DEBUG_MSG(3, + ("client hello, got %" MBEDTLS_PRINTF_SIZET " cipher suites", + cipher_suites_len/2)); + + /* Output the total length of cipher_suites field. */ + *out_len = (size_t) (p - buf); + + return 0; +} + +/* + * Structure of the TLS 1.3 ClientHello message: + * + * struct { + * ProtocolVersion legacy_version = 0x0303; // TLS v1.2 + * Random random; + * opaque legacy_session_id<0..32>; + * CipherSuite cipher_suites<2..2^16-2>; + * opaque legacy_compression_methods<1..2^8-1>; + * Extension extensions<8..2^16-1>; + * } ClientHello; + * + * Structure of the (D)TLS 1.2 ClientHello message: + * + * struct { + * ProtocolVersion client_version; + * Random random; + * SessionID session_id; + * opaque cookie<0..2^8-1>; // DTLS 1.2 ONLY + * CipherSuite cipher_suites<2..2^16-2>; + * CompressionMethod compression_methods<1..2^8-1>; + * select (extensions_present) { + * case false: + * struct {}; + * case true: + * Extension extensions<0..2^16-1>; + * }; + * } ClientHello; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_client_hello_body(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len, + size_t *binders_len) +{ + int ret; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + unsigned char *p = buf; + unsigned char *p_extensions_len; /* Pointer to extensions length */ + size_t output_len; /* Length of buffer used by function */ + size_t extensions_len; /* Length of the list of extensions*/ + int tls12_uses_ec = 0; + + *out_len = 0; + *binders_len = 0; + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + unsigned char propose_tls12 = + (handshake->min_tls_version <= MBEDTLS_SSL_VERSION_TLS1_2) + && + (MBEDTLS_SSL_VERSION_TLS1_2 <= ssl->tls_version); +#endif +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + unsigned char propose_tls13 = + (handshake->min_tls_version <= MBEDTLS_SSL_VERSION_TLS1_3) + && + (MBEDTLS_SSL_VERSION_TLS1_3 <= ssl->tls_version); +#endif + + /* + * Write client_version (TLS 1.2) or legacy_version (TLS 1.3) + * + * In all cases this is the TLS 1.2 version. + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + mbedtls_ssl_write_version(p, ssl->conf->transport, + MBEDTLS_SSL_VERSION_TLS1_2); + p += 2; + + /* ... + * Random random; + * ... + * + * The random bytes have been prepared by ssl_prepare_client_hello() into + * the handshake->randbytes buffer and are copied here into the output + * buffer. + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, MBEDTLS_CLIENT_HELLO_RANDOM_LEN); + memcpy(p, handshake->randbytes, MBEDTLS_CLIENT_HELLO_RANDOM_LEN); + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, random bytes", + p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN); + p += MBEDTLS_CLIENT_HELLO_RANDOM_LEN; + + /* TLS 1.2: + * ... + * SessionID session_id; + * ... + * with + * opaque SessionID<0..32>; + * + * TLS 1.3: + * ... + * opaque legacy_session_id<0..32>; + * ... + * + * The (legacy) session identifier bytes have been prepared by + * ssl_prepare_client_hello() into the ssl->session_negotiate->id buffer + * and are copied here into the output buffer. + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, ssl->session_negotiate->id_len + 1); + *p++ = (unsigned char) ssl->session_negotiate->id_len; + memcpy(p, ssl->session_negotiate->id, ssl->session_negotiate->id_len); + p += ssl->session_negotiate->id_len; + + MBEDTLS_SSL_DEBUG_BUF(3, "session id", ssl->session_negotiate->id, + ssl->session_negotiate->id_len); + + /* DTLS 1.2 ONLY + * ... + * opaque cookie<0..2^8-1>; + * ... + */ +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { +#if !defined(MBEDTLS_SSL_PROTO_TLS1_3) + uint8_t cookie_len = 0; +#else + uint16_t cookie_len = 0; +#endif /* !MBEDTLS_SSL_PROTO_TLS1_3 */ + + if (handshake->cookie != NULL) { + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, cookie", + handshake->cookie, + handshake->cookie_len); + cookie_len = handshake->cookie_len; + } + + MBEDTLS_SSL_CHK_BUF_PTR(p, end, cookie_len + 1); + *p++ = (unsigned char) cookie_len; + if (cookie_len > 0) { + memcpy(p, handshake->cookie, cookie_len); + p += cookie_len; + } + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 && MBEDTLS_SSL_PROTO_DTLS */ + + /* Write cipher_suites */ + ret = ssl_write_client_hello_cipher_suites(ssl, p, end, + &tls12_uses_ec, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + + /* Write legacy_compression_methods (TLS 1.3) or + * compression_methods (TLS 1.2) + * + * For every TLS 1.3 ClientHello, this vector MUST contain exactly + * one byte set to zero, which corresponds to the 'null' compression + * method in prior versions of TLS. + * + * For TLS 1.2 ClientHello, for security reasons we do not support + * compression anymore, thus also just the 'null' compression method. + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + *p++ = 1; + *p++ = MBEDTLS_SSL_COMPRESS_NULL; + + /* Write extensions */ + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + /* Keeping track of the included extensions */ + handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE; +#endif + + /* First write extensions, then the total length */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + p_extensions_len = p; + p += 2; + +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + /* Write server name extension */ + ret = ssl_write_hostname_ext(ssl, p, end, &output_len); + if (ret != 0) { + return ret; + } + p += output_len; +#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ + +#if defined(MBEDTLS_SSL_ALPN) + ret = ssl_write_alpn_ext(ssl, p, end, &output_len); + if (ret != 0) { + return ret; + } + p += output_len; +#endif /* MBEDTLS_SSL_ALPN */ + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + if (propose_tls13) { + ret = mbedtls_ssl_tls13_write_client_hello_exts(ssl, p, end, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } +#endif + +#if defined(MBEDTLS_SSL_TLS1_2_SOME_ECC) || \ + defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + { + int ssl_write_supported_groups_ext_flags = 0; + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + if (propose_tls13 && mbedtls_ssl_conf_tls13_is_some_ephemeral_enabled(ssl)) { + ssl_write_supported_groups_ext_flags |= + SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_3_FLAG; + } +#endif +#if defined(MBEDTLS_SSL_TLS1_2_SOME_ECC) + if (propose_tls12 && tls12_uses_ec) { + ssl_write_supported_groups_ext_flags |= + SSL_WRITE_SUPPORTED_GROUPS_EXT_TLS1_2_FLAG; + } +#endif + if (ssl_write_supported_groups_ext_flags != 0) { + ret = ssl_write_supported_groups_ext(ssl, p, end, + ssl_write_supported_groups_ext_flags, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } + } +#endif /* MBEDTLS_SSL_TLS1_2_SOME_ECC || + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + +#if defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED) + int write_sig_alg_ext = 0; +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + write_sig_alg_ext = write_sig_alg_ext || + (propose_tls13 && mbedtls_ssl_conf_tls13_is_ephemeral_enabled(ssl)); +#endif +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + write_sig_alg_ext = write_sig_alg_ext || propose_tls12; +#endif + + if (write_sig_alg_ext) { + ret = mbedtls_ssl_write_sig_alg_ext(ssl, p, end, &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } +#endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */ + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + if (propose_tls12) { + ret = mbedtls_ssl_tls12_write_client_hello_exts(ssl, p, end, + tls12_uses_ec, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) + /* The "pre_shared_key" extension (RFC 8446 Section 4.2.11) + * MUST be the last extension in the ClientHello. + */ + if (propose_tls13 && mbedtls_ssl_conf_tls13_is_some_psk_enabled(ssl)) { + ret = mbedtls_ssl_tls13_write_identities_of_pre_shared_key_ext( + ssl, p, end, &output_len, binders_len); + if (ret != 0) { + return ret; + } + p += output_len; + } +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ + + /* Write the length of the list of extensions. */ + extensions_len = (size_t) (p - p_extensions_len) - 2; + + if (extensions_len == 0) { + p = p_extensions_len; + } else { + MBEDTLS_PUT_UINT16_BE(extensions_len, p_extensions_len, 0); + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, total extension length: %" \ + MBEDTLS_PRINTF_SIZET, extensions_len)); + MBEDTLS_SSL_DEBUG_BUF(3, "client hello extensions", + p_extensions_len, extensions_len); + } + + *out_len = (size_t) (p - buf); + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_generate_random(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *randbytes = ssl->handshake->randbytes; + size_t gmt_unix_time_len = 0; + + /* + * Generate the random bytes + * + * TLS 1.2 case: + * struct { + * uint32 gmt_unix_time; + * opaque random_bytes[28]; + * } Random; + * + * TLS 1.3 case: + * opaque Random[32]; + */ + if (ssl->tls_version == MBEDTLS_SSL_VERSION_TLS1_2) { +#if defined(MBEDTLS_HAVE_TIME) + mbedtls_time_t gmt_unix_time = mbedtls_time(NULL); + MBEDTLS_PUT_UINT32_BE(gmt_unix_time, randbytes, 0); + gmt_unix_time_len = 4; + + MBEDTLS_SSL_DEBUG_MSG(3, + ("client hello, current time: %" MBEDTLS_PRINTF_LONGLONG, + (long long) gmt_unix_time)); +#endif /* MBEDTLS_HAVE_TIME */ + } + + ret = ssl->conf->f_rng(ssl->conf->p_rng, + randbytes + gmt_unix_time_len, + MBEDTLS_CLIENT_HELLO_RANDOM_LEN - gmt_unix_time_len); + return ret; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_prepare_client_hello(mbedtls_ssl_context *ssl) +{ + int ret; + size_t session_id_len; + mbedtls_ssl_session *session_negotiate = ssl->session_negotiate; + + if (session_negotiate == NULL) { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \ + defined(MBEDTLS_SSL_SESSION_TICKETS) && \ + defined(MBEDTLS_HAVE_TIME) + + /* Check if a tls13 ticket has been configured. */ + if (ssl->handshake->resume != 0 && + session_negotiate->tls_version == MBEDTLS_SSL_VERSION_TLS1_3 && + session_negotiate->ticket != NULL) { + mbedtls_ms_time_t now = mbedtls_ms_time(); + mbedtls_ms_time_t age = now - session_negotiate->ticket_reception_time; + if (age < 0 || + age > (mbedtls_ms_time_t) session_negotiate->ticket_lifetime * 1000) { + /* Without valid ticket, disable session resumption.*/ + MBEDTLS_SSL_DEBUG_MSG( + 3, ("Ticket expired, disable session resumption")); + ssl->handshake->resume = 0; + } + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && + MBEDTLS_SSL_SESSION_TICKETS && + MBEDTLS_HAVE_TIME */ + + /* Bet on the highest configured version if we are not in a TLS 1.2 + * renegotiation or session resumption. + */ +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + ssl->handshake->min_tls_version = ssl->tls_version; + } else +#endif + { + if (ssl->handshake->resume) { + ssl->tls_version = session_negotiate->tls_version; + ssl->handshake->min_tls_version = ssl->tls_version; + } else { + ssl->handshake->min_tls_version = ssl->conf->min_tls_version; + } + } + + /* + * Generate the random bytes, except when responding to a verify request + * where we MUST reuse the previously generated random bytes + * (RFC 6347 4.2.1). + */ +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if ((ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM) || + (ssl->handshake->cookie == NULL)) +#endif + { +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + if (!ssl->handshake->hello_retry_request_flag) +#endif + { + ret = ssl_generate_random(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "Random bytes generation failed", ret); + return ret; + } + } + } + + /* + * Prepare session identifier. At that point, the length of the session + * identifier in the SSL context `ssl->session_negotiate->id_len` is equal + * to zero, except in the case of a TLS 1.2 session renegotiation or + * session resumption. + */ + session_id_len = session_negotiate->id_len; + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) + if (ssl->tls_version == MBEDTLS_SSL_VERSION_TLS1_2) { + if (session_id_len < 16 || session_id_len > 32 || +#if defined(MBEDTLS_SSL_RENEGOTIATION) + ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE || +#endif + ssl->handshake->resume == 0) { + session_id_len = 0; + } + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + /* + * RFC 5077 section 3.4: "When presenting a ticket, the client MAY + * generate and include a Session ID in the TLS ClientHello." + */ + int renegotiating = 0; +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + renegotiating = 1; + } +#endif + if (!renegotiating) { + if ((session_negotiate->ticket != NULL) && + (session_negotiate->ticket_len != 0)) { + session_id_len = 32; + } + } +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */ + +#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) + if (ssl->tls_version == MBEDTLS_SSL_VERSION_TLS1_3) { + /* + * Create a legacy session identifier for the purpose of middlebox + * compatibility only if one has not been created already, which is + * the case if we are here for the TLS 1.3 second ClientHello. + * + * Versions of TLS before TLS 1.3 supported a "session resumption" + * feature which has been merged with pre-shared keys in TLS 1.3 + * version. A client which has a cached session ID set by a pre-TLS 1.3 + * server SHOULD set this field to that value. In compatibility mode, + * this field MUST be non-empty, so a client not offering a pre-TLS 1.3 + * session MUST generate a new 32-byte value. This value need not be + * random but SHOULD be unpredictable to avoid implementations fixating + * on a specific value (also known as ossification). Otherwise, it MUST + * be set as a zero-length vector ( i.e., a zero-valued single byte + * length field ). + */ + session_id_len = 32; + } +#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ + + if (session_id_len != session_negotiate->id_len) { + session_negotiate->id_len = session_id_len; + if (session_id_len > 0) { + ret = ssl->conf->f_rng(ssl->conf->p_rng, + session_negotiate->id, + session_id_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "creating session id failed", ret); + return ret; + } + } + } + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \ + defined(MBEDTLS_SSL_SESSION_TICKETS) && \ + defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + if (ssl->tls_version == MBEDTLS_SSL_VERSION_TLS1_3 && + ssl->handshake->resume) { + int hostname_mismatch = ssl->hostname != NULL || + session_negotiate->hostname != NULL; + if (ssl->hostname != NULL && session_negotiate->hostname != NULL) { + hostname_mismatch = strcmp( + ssl->hostname, session_negotiate->hostname) != 0; + } + + if (hostname_mismatch) { + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Hostname mismatch the session ticket, " + "disable session resumption.")); + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + } else { + return mbedtls_ssl_session_set_hostname(session_negotiate, + ssl->hostname); + } +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && + MBEDTLS_SSL_SESSION_TICKETS && + MBEDTLS_SSL_SERVER_NAME_INDICATION */ + + return 0; +} +/* + * Write ClientHello handshake message. + * Handler for MBEDTLS_SSL_CLIENT_HELLO + */ +int mbedtls_ssl_write_client_hello(mbedtls_ssl_context *ssl) +{ + int ret = 0; + unsigned char *buf; + size_t buf_len, msg_len, binders_len; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write client hello")); + + MBEDTLS_SSL_PROC_CHK(ssl_prepare_client_hello(ssl)); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg( + ssl, MBEDTLS_SSL_HS_CLIENT_HELLO, + &buf, &buf_len)); + + MBEDTLS_SSL_PROC_CHK(ssl_write_client_hello_body(ssl, buf, + buf + buf_len, + &msg_len, + &binders_len)); + +#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + ssl->out_msglen = msg_len + 4; + mbedtls_ssl_send_flight_completed(ssl); + + /* + * The two functions below may try to send data on the network and + * can return with the MBEDTLS_ERR_SSL_WANT_READ error code when they + * fail to do so and the transmission has to be retried later. In that + * case as in fatal error cases, we return immediately. But we must have + * set the handshake state to the next state at that point to ensure + * that we will not write and send again a ClientHello when we + * eventually succeed in sending the pending data. + */ + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_HELLO); + + if ((ret = mbedtls_ssl_write_handshake_msg(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_handshake_msg", ret); + return ret; + } + + if ((ret = mbedtls_ssl_flight_transmit(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_flight_transmit", ret); + return ret; + } + } else +#endif /* MBEDTLS_SSL_PROTO_TLS1_2 && MBEDTLS_SSL_PROTO_DTLS */ + { + + ret = mbedtls_ssl_add_hs_hdr_to_checksum(ssl, + MBEDTLS_SSL_HS_CLIENT_HELLO, + msg_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_add_hs_hdr_to_checksum", ret); + return ret; + } + ret = ssl->handshake->update_checksum(ssl, buf, msg_len - binders_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "update_checksum", ret); + return ret; + } +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) + if (binders_len > 0) { + MBEDTLS_SSL_PROC_CHK( + mbedtls_ssl_tls13_write_binders_of_pre_shared_key_ext( + ssl, buf + msg_len - binders_len, buf + msg_len)); + ret = ssl->handshake->update_checksum(ssl, buf + msg_len - binders_len, + binders_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "update_checksum", ret); + return ret; + } + } +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg(ssl, + buf_len, + msg_len)); + + /* + * Set next state. Note that if TLS 1.3 is proposed, this may be + * overwritten by mbedtls_ssl_tls13_finalize_client_hello(). + */ + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_HELLO); + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + if (ssl->handshake->min_tls_version <= MBEDTLS_SSL_VERSION_TLS1_3 && + MBEDTLS_SSL_VERSION_TLS1_3 <= ssl->tls_version) { + ret = mbedtls_ssl_tls13_finalize_client_hello(ssl); + } +#endif + } + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + MBEDTLS_SSL_PRINT_EXTS( + 3, MBEDTLS_SSL_HS_CLIENT_HELLO, ssl->handshake->sent_extensions); +#endif + +cleanup: + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write client hello")); + return ret; +} + +#endif /* MBEDTLS_SSL_PROTO_TLS1_3 || MBEDTLS_SSL_PROTO_TLS1_2 */ +#endif /* MBEDTLS_SSL_CLI_C */ |