diff options
author | Jaap Keuter <jaap.keuter@xs4all.nl> | 2006-05-18 17:08:41 +0000 |
---|---|---|
committer | Jaap Keuter <jaap.keuter@xs4all.nl> | 2006-05-18 17:08:41 +0000 |
commit | f08e4931e1d0cf5cd1e3815059f03c4d616e3d06 (patch) | |
tree | c16289e3c5f15a2cbaad34eb3399bb03737b693b | |
parent | 635ae7e19aad099a3d4c58f2b9e7fe3a8951d526 (diff) |
From Ted Percival:
I have updated the TELNET dissector to dissect encryption negotiation
commands as specified by RFC 2946.
svn path=/trunk/; revision=18187
-rw-r--r-- | epan/dissectors/packet-telnet.c | 133 |
1 files changed, 129 insertions, 4 deletions
diff --git a/epan/dissectors/packet-telnet.c b/epan/dissectors/packet-telnet.c index 2c39500557..38a7ef7915 100644 --- a/epan/dissectors/packet-telnet.c +++ b/epan/dissectors/packet-telnet.c @@ -50,6 +50,9 @@ static int hf_telnet_auth_mod_cred_fwd = -1; static int hf_telnet_auth_mod_enc = -1; static int hf_telnet_auth_krb5_type = -1; +static int hf_telnet_enc_cmd = -1; +static int hf_telnet_enc_type = -1; + static gint ett_telnet = -1; static gint ett_telnet_subopt = -1; static gint ett_status_subopt = -1; @@ -593,6 +596,50 @@ dissect_rfc_subopt(packet_info *pinfo _U_, const char *optname _U_, tvbuff_t *tv val_to_str(cmd, rfc_opt_vals, "Unknown (%u)")); } +#define TN_ENC_IS 0 +#define TN_ENC_SUPPORT 1 +#define TN_ENC_REPLY 2 +#define TN_ENC_START 3 +#define TN_ENC_END 4 +#define TN_ENC_REQUEST_START 5 +#define TN_ENC_REQUEST_END 6 +#define TN_ENC_ENC_KEYID 7 +#define TN_ENC_DEC_KEYID 8 +static const value_string enc_cmd_vals[] = { + { TN_ENC_IS, "IS" }, + { TN_ENC_SUPPORT, "SUPPORT" }, + { TN_ENC_REPLY, "REPLY" }, + { TN_ENC_START, "START" }, + { TN_ENC_END, "END" }, + { TN_ENC_REQUEST_START, "REQUEST-START" }, + { TN_ENC_REQUEST_END, "REQUEST-END" }, + { TN_ENC_ENC_KEYID, "ENC_KEYID" }, + { TN_ENC_DEC_KEYID, "DEC_KEYID" }, + { 0, NULL } +}; + +#define TN_ENCTYPE_NULL 0 +#define TN_ENCTYPE_DES_CFB64 1 +#define TN_ENCTYPE_DES_OFB64 2 +#define TN_ENCTYPE_DES3_CFB64 3 +#define TN_ENCTYPE_DES3_OFB64 4 +#define TN_ENCTYPE_CAST5_40_CFB64 8 +#define TN_ENCTYPE_CAST5_40_OFB64 9 +#define TN_ENCTYPE_CAST128_CFB64 10 +#define TN_ENCTYPE_CAST128_OFB64 11 +static const value_string enc_type_vals[] = { + { TN_ENCTYPE_NULL, "NULL" }, + { TN_ENCTYPE_DES_CFB64, "DES_CFB64" }, + { TN_ENCTYPE_DES_OFB64, "DES_OFB64" }, + { TN_ENCTYPE_DES3_CFB64, "DES3_CFB64" }, + { TN_ENCTYPE_DES3_OFB64, "DES3_OFB64" }, + { TN_ENCTYPE_CAST5_40_CFB64, "CAST5_40_CFB64" }, + { TN_ENCTYPE_CAST5_40_OFB64, "CAST5_40_OFB64" }, + { TN_ENCTYPE_CAST128_CFB64, "CAST128_CFB64" }, + { TN_ENCTYPE_CAST128_OFB64, "CAST128_OFB64" }, + { 0, NULL } +}; + #define TN_AC_IS 0 #define TN_AC_SEND 1 @@ -836,6 +883,79 @@ dissect_authentication_subopt(packet_info *pinfo, const char *optname _U_, tvbuf } } +/* This function only uses the octet in the buffer at 'offset' */ +static void dissect_encryption_type(tvbuff_t *tvb, int offset, proto_tree *tree) { + guint8 etype; + etype = tvb_get_guint8(tvb, offset); + proto_tree_add_uint(tree, hf_telnet_enc_type, tvb, offset, 1, etype); +} + +static void +dissect_encryption_subopt(packet_info *pinfo, const char *optname _U_, tvbuff_t *tvb, int offset, int len, proto_tree *tree) +{ + guint8 ecmd, key_first_octet; + + ecmd = tvb_get_guint8(tvb, offset); + proto_tree_add_uint(tree, hf_telnet_enc_cmd, tvb, offset, 1, ecmd); + + offset++; + len--; + + switch(ecmd) { + case TN_ENC_IS: + case TN_ENC_REPLY: + /* encryption type, type-specific data ... */ + if (len > 0) { + dissect_encryption_type(tvb, offset, tree); + offset++; + len--; + proto_tree_add_text(tree, tvb, offset, len, "Type-specific data"); + } + break; + + case TN_ENC_SUPPORT: + /* list of encryption types ... */ + while (len > 0) { + dissect_encryption_type(tvb, offset, tree); + offset++; + len--; + } + break; + + case TN_ENC_START: + /* keyid ... */ + if (len > 0) { + key_first_octet = tvb_get_guint8(tvb, offset); + proto_tree_add_text(tree, tvb, offset, len, (key_first_octet == 0) ? "Default key" : "Key ID"); + } + break; + + case TN_ENC_END: + /* no data */ + break; + + case TN_ENC_REQUEST_START: + /* (optional) keyid */ + if (len > 0) + proto_tree_add_text(tree, tvb, offset, len, "Key ID (advisory)"); + break; + + case TN_ENC_REQUEST_END: + /* no data */ + break; + + case TN_ENC_ENC_KEYID: + case TN_ENC_DEC_KEYID: + /* (optional) keyid - if not supplied, there are no more known keys */ + if (len > 0) + proto_tree_add_text(tree, tvb, offset, len, "Key ID"); + break; + + default: + proto_tree_add_text(tree, tvb, offset, len, "Unknown command"); + } +} + static tn_opt options[] = { { "Binary Transmission", /* RFC 856 */ @@ -1108,7 +1228,7 @@ static tn_opt options[] = { &ett_enc_subopt, VARIABLE_LENGTH, 1, - NULL /* XXX - fill me in */ + dissect_encryption_subopt }, { "New Environment Option", /* RFC 1572 */ @@ -1151,7 +1271,7 @@ static tn_opt options[] = { VARIABLE_LENGTH, 1, dissect_comport_subopt - }, + } }; @@ -1556,7 +1676,12 @@ proto_register_telnet(void) { &hf_telnet_auth_krb5_type, { "Command", "telnet.auth.krb5.cmd", FT_UINT8, BASE_DEC, VALS(auth_krb5_types), 0, "Krb5 Authentication sub-command", HFILL }}, - + { &hf_telnet_enc_cmd, + { "Enc Cmd", "telnet.enc.cmd", FT_UINT8, BASE_DEC, + VALS(enc_cmd_vals), 0, "Encryption command", HFILL }}, + { &hf_telnet_enc_type, + { "Enc Type", "telnet.enc.type", FT_UINT8, BASE_DEC, + VALS(enc_type_vals), 0, "Encryption type", HFILL }}, }; static gint *ett[] = { &ett_telnet, @@ -1596,7 +1721,7 @@ proto_register_telnet(void) &ett_xauth_subopt, &ett_charset_subopt, &ett_rsp_subopt, - &ett_comport_subopt, + &ett_comport_subopt }; proto_telnet = proto_register_protocol("Telnet", "TELNET", "telnet"); |