diff options
| -rw-r--r-- | ssl/ssl.h | 2 | ||||
| -rw-r--r-- | ssl/ssl_locl.h | 17 | ||||
| -rw-r--r-- | ssl/t1_ext.c | 82 | ||||
| -rw-r--r-- | ssl/t1_lib.c | 3 |
4 files changed, 96 insertions, 8 deletions
@@ -1266,7 +1266,7 @@ const char *SSL_get_psk_identity(const SSL *s); * * Returns nonzero on success. You cannot register twice for the same * extension number, and registering for an extension number already - * handled by OpenSSL will succeed, but the callbacks will not be invoked. + * handled by OpenSSL will fail. * * NULL can be registered for any callback function. For the client * functions, a NULL custom_cli_ext_first_cb_fn sends an empty ClientHello diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h index f9a67b3832..af08597474 100644 --- a/ssl/ssl_locl.h +++ b/ssl/ssl_locl.h @@ -528,11 +528,26 @@ typedef struct cert_pkey_st typedef struct { unsigned short ext_type; + /* Per-connection flags relating to this extension type: not used + * if part of an SSL_CTX structure. + */ + unsigned short ext_flags; custom_ext_add_cb add_cb; custom_ext_parse_cb parse_cb; void *arg; } custom_ext_method; +/* ext_flags values */ + +/* Indicates an extension has been received. + * Used to check for unsolicited or duplicate extensions. + */ +#define SSL_EXT_FLAG_RECEIVED 0x1 +/* Indicates an extension has been sent: used to + * enable sending of corresponding ServerHello extension. + */ +#define SSL_EXT_FLAG_SENT 0x2 + typedef struct { custom_ext_method *meths; size_t meths_count; @@ -1380,6 +1395,8 @@ int srp_verify_server_param(SSL *s, int *al); /* t1_ext.c */ +void custom_ext_init(custom_ext_methods *meths); + int custom_ext_parse(SSL *s, int server, unsigned short ext_type, const unsigned char *ext_data, diff --git a/ssl/t1_ext.c b/ssl/t1_ext.c index ba6d3ded74..bd14806e6a 100644 --- a/ssl/t1_ext.c +++ b/ssl/t1_ext.c @@ -73,6 +73,16 @@ static custom_ext_method *custom_ext_find(custom_ext_methods *exts, } return NULL; } +/* Initialise custom extensions flags to indicate neither sent nor + * received. + */ +void custom_ext_init(custom_ext_methods *exts) + { + size_t i; + custom_ext_method *meth = exts->meths; + for (i = 0; i < exts->meths_count; i++, meth++) + meth->ext_flags = 0; + } /* pass received custom extension data to the application for parsing */ @@ -86,7 +96,28 @@ int custom_ext_parse(SSL *s, int server, custom_ext_method *meth; meth = custom_ext_find(exts, ext_type); /* If not found or no parse function set, return success */ - if (!meth || !meth->parse_cb) + /* If not found return success */ + if (!meth) + return 1; + if (!server) + { + /* If it's ServerHello we can't have any extensions not + * sent in ClientHello. + */ + if (!(meth->ext_flags & SSL_EXT_FLAG_SENT)) + { + *al = TLS1_AD_UNSUPPORTED_EXTENSION; + return 0; + } + } + /* If already present it's a duplicate */ + if (meth->ext_flags & SSL_EXT_FLAG_RECEIVED) + { + *al = TLS1_AD_DECODE_ERROR; + return 0; + } + meth->ext_flags |= SSL_EXT_FLAG_RECEIVED; + if (!meth->parse_cb) return 1; return meth->parse_cb(s, ext_type, ext_data, ext_size, al, meth->arg); @@ -112,11 +143,17 @@ int custom_ext_add(SSL *s, int server, unsigned short outlen = 0; meth = exts->meths + i; - /* For servers no callback omits extension, - * For clients it sends empty extension. - */ - if (server && !meth->add_cb) - continue; + if (server) + { + /* For ServerHello only send extensions present + * in ClientHello. + */ + if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED)) + continue; + /* If callback absent for server skip it */ + if (!meth->add_cb) + continue; + } if (meth->add_cb) { int cb_retval = 0; @@ -137,6 +174,14 @@ int custom_ext_add(SSL *s, int server, memcpy(ret, out, outlen); ret += outlen; } + /* We can't send duplicates: code logic should prevent this */ + OPENSSL_assert(!(meth->ext_flags & SSL_EXT_FLAG_SENT)); + /* Indicate extension has been sent: this is both a sanity + * check to ensure we don't send duplicate extensions + * and indicates to servers that an extension can be + * sent in ServerHello. + */ + meth->ext_flags |= SSL_EXT_FLAG_SENT; } *pret = ret; return 1; @@ -170,6 +215,30 @@ static int custom_ext_set(custom_ext_methods *exts, void *arg) { custom_ext_method *meth; + /* See if it is a supported internally */ + switch(ext_type) + { + case TLSEXT_TYPE_application_layer_protocol_negotiation: + case TLSEXT_TYPE_ec_point_formats: + case TLSEXT_TYPE_elliptic_curves: + case TLSEXT_TYPE_heartbeat: + case TLSEXT_TYPE_next_proto_neg: + case TLSEXT_TYPE_padding: + case TLSEXT_TYPE_renegotiate: + case TLSEXT_TYPE_server_name: + case TLSEXT_TYPE_session_ticket: + case TLSEXT_TYPE_signature_algorithms: + case TLSEXT_TYPE_srp: + case TLSEXT_TYPE_status_request: + case TLSEXT_TYPE_use_srtp: +#ifdef TLSEXT_TYPE_opaque_prf_input + case TLSEXT_TYPE_opaque_prf_input: +#endif +#ifdef TLSEXT_TYPE_encrypt_then_mac + case TLSEXT_TYPE_encrypt_then_mac: +#endif + return 0; + } /* Search for duplicate */ if (custom_ext_find(exts, ext_type)) return 0; @@ -183,6 +252,7 @@ static int custom_ext_set(custom_ext_methods *exts, } meth = exts->meths + exts->meths_count; + memset(meth, 0, sizeof(custom_ext_method)); meth->parse_cb = parse_cb; meth->add_cb = add_cb; meth->ext_type = ext_type; diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c index 3b3e0e334f..f13b3762c9 100644 --- a/ssl/t1_lib.c +++ b/ssl/t1_lib.c @@ -1444,7 +1444,7 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned c } ret += el; } - + custom_ext_init(&s->cert->cli_ext); /* Add custom TLS Extensions to ClientHello */ if (!custom_ext_add(s, 0, &ret, limit, al)) return NULL; @@ -2422,6 +2422,7 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n) { int al = -1; + custom_ext_init(&s->cert->srv_ext); if (ssl_scan_clienthello_tlsext(s, p, d, n, &al) <= 0) { ssl3_send_alert(s,SSL3_AL_FATAL,al); 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