Ethereal-dev: [Ethereal-dev] patch for SSH Version 1 support
Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.
From: Huagang Xie <xie@xxxxxxxx>
Date: Mon, 27 Jan 2003 22:08:34 -0800
Hello, Here is the patch to support SSH version 1 dissection support, it include, - added ssh version 1 support - fixed desegmentation length checking bug - seperated the disection for ssh v2 and v1 Enjoy it, Huagang -- LIDS secure linux kernel http://www.lids.org/ 1024D/B6EFB028 4731 2BF7 7735 4DBD 3771 4E24 B53B B60A B6EF B028
Index: packet-ssh.c =================================================================== RCS file: /cvsroot/ethereal/packet-ssh.c,v retrieving revision 1.2 diff -u -r1.2 packet-ssh.c --- packet-ssh.c 27 Jan 2003 19:40:55 -0000 1.2 +++ packet-ssh.c 28 Jan 2003 06:01:16 -0000 @@ -26,7 +26,7 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * - * Note: only support SSHv2 now. + * Note: support SSH v1 and v2 now. * */ @@ -69,6 +69,15 @@ #define SSH2_MSG_KEX_DH_GEX_REPLY 33 #define SSH2_MSG_KEX_DH_GEX_REQUEST 34 +/* SSH Version 1 definition , from openssh ssh1.h */ + +#define SSH_MSG_NONE 0 /* no message */ +#define SSH_MSG_DISCONNECT 1 /* cause (string) */ +#define SSH_SMSG_PUBLIC_KEY 2 /* ck,msk,srvk,hostk */ +#define SSH_CMSG_SESSION_KEY 3 /* key (BIGNUM) */ +#define SSH_CMSG_USER 4 /* user (string) */ + + #define SSH_VERSION_UNKNOWN 0 #define SSH_VERSION_1 1 #define SSH_VERSION_2 2 @@ -122,12 +131,13 @@ static gint ett_ssh = -1; static gint ett_key_exchange= -1; static gint ett_key_init= -1; +static gint ett_ssh1= -1; static gboolean ssh_desegment = TRUE; #define TCP_PORT_SSH 22 -static const value_string ssh_msg_vals[] = { +static const value_string ssh2_msg_vals[] = { {SSH2_MSG_DISCONNECT, "Disconnect"}, {SSH2_MSG_IGNORE, "Ignore"}, {SSH2_MSG_UNIMPLEMENTED, "Unimplemented"}, @@ -144,6 +154,14 @@ { 0, NULL } }; +static const value_string ssh1_msg_vals[] = { + {SSH_MSG_NONE,"No Message"}, + {SSH_MSG_DISCONNECT, "Disconnect"}, + {SSH_SMSG_PUBLIC_KEY,"Public Key"}, + {SSH_CMSG_SESSION_KEY,"Session Key"}, + {SSH_CMSG_USER,"User"}, +}; + static const value_string ssh_opcode_vals[] = { { 0, NULL } @@ -151,6 +169,12 @@ static int ssh_dissect_key_init(tvbuff_t *tvb, int offset, proto_tree *tree); +static int ssh_dissect_ssh1(tvbuff_t *tvb, packet_info *pinfo, + int offset, proto_tree *tree,int is_response, + int number, gboolean *need_desegmentation); +static int ssh_dissect_ssh2(tvbuff_t *tvb, packet_info *pinfo, + int offset, proto_tree *tree,int is_response, + int number, gboolean *need_desegmentation ); static int ssh_dissect_key_exchange(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree,int is_response, int number, gboolean *need_desegmentation ); @@ -262,18 +286,17 @@ } } - /* we will not decode SSH1 now */ - if(this_data->counter != 0 && version != SSH_VERSION_2) { + if(this_data->counter != 0 && version == SSH_VERSION_UNKNOWN) { offset = ssh_dissect_encrypted_packet(tvb, pinfo, offset,ssh_tree,is_response); return; } while((remain_length = tvb_reported_length_remaining(tvb,offset))> 0 ) { - need_desegmentation = FALSE; last_offset = offset; this_number = this_data->counter+number; + if(number > 1 && is_newdata) { /* update the this_data and flow_data */ if(is_response) { @@ -284,29 +307,131 @@ } number++; - if(this_number == 0) { - offset = ssh_dissect_protocol(tvb, pinfo,offset,ssh_tree, - is_response,&version, &need_desegmentation); + offset = ssh_dissect_protocol(tvb, pinfo, + offset,ssh_tree, is_response, + &version, &need_desegmentation); if(!is_response) { global_data->version= version; } } else { - /* response, 1, 2 is key_exchange */ - /* request, 1,2,3,4 is key_exchange */ - if((is_response && this_number > 3) || (!is_response && this_number>4)) { - offset = ssh_dissect_encrypted_packet(tvb, pinfo, - offset,ssh_tree,is_response); - } else { - offset = ssh_dissect_key_exchange(tvb,pinfo, + if(version == SSH_VERSION_1) { + offset = ssh_dissect_ssh1(tvb, pinfo, + offset,ssh_tree,is_response,this_number, + &need_desegmentation); + } else if(version == SSH_VERSION_2) { + offset = ssh_dissect_ssh2(tvb, pinfo, offset,ssh_tree,is_response,this_number, &need_desegmentation); } } + if(need_desegmentation) return; } } +static int +ssh_dissect_ssh2(tvbuff_t *tvb, packet_info *pinfo, + int offset, proto_tree *tree,int is_response, int this_number, + gboolean *need_desegmentation) +{ + + if((is_response && this_number > 3) || (!is_response && this_number>4)) { + offset = ssh_dissect_encrypted_packet(tvb, pinfo, + offset,tree,is_response); + } else { + offset = ssh_dissect_key_exchange(tvb,pinfo, + offset,tree,is_response,this_number, + need_desegmentation); + } + + return offset; +} +static int +ssh_dissect_ssh1(tvbuff_t *tvb, packet_info *pinfo, + int offset, proto_tree *tree,int is_response, + int number, gboolean *need_desegmentation) +{ + guint plen, padding_length,len; + guint8 msg_code; + guint remain_length=0; + + proto_item *tf; + proto_item *ssh1_tree =NULL; + + if (ssh_desegment && pinfo->can_desegment) { + remain_length = tvb_reported_length_remaining(tvb,offset); + if(remain_length < 4) { + pinfo->desegment_offset = offset; + pinfo->desegment_len = 4-remain_length; + *need_desegmentation = TRUE; + return offset; + } + } + plen = tvb_get_ntohl(tvb, offset) ; + + padding_length = 8 - plen%8; + if (ssh_desegment && pinfo->can_desegment) { + if(plen+4+padding_length > remain_length ) { + pinfo->desegment_offset = offset; + pinfo->desegment_len = plen+padding_length - remain_length; + *need_desegmentation = TRUE; + return offset; + } + } + + if (check_col(pinfo->cinfo, COL_INFO)) { + col_add_fstr(pinfo->cinfo, COL_INFO, "%s: ", + is_response?"Server":"Client"); + } + + if (tree) { + proto_tree_add_uint(tree, hf_ssh_packet_length, tvb, + offset, 4, plen); + } + offset+=4; +/* padding length */ + + if (tree) { + proto_tree_add_uint(tree, hf_ssh_padding_length, tvb, + offset, padding_length, padding_length); + } + offset += padding_length; + + if(tree) { + tf=proto_tree_add_text(tree,tvb,offset,-1,"SSH Version 1"); + ssh1_tree = proto_item_add_subtree(tf ,ett_ssh1); + } + /* msg_code */ + if(number == 1 ) { + msg_code = tvb_get_guint8(tvb, offset); + if (tree) { + proto_tree_add_uint_format(ssh1_tree, hf_ssh_msg_code, tvb, + offset, 1, msg_code,"Msg code: %s (%u)", + val_to_str(msg_code, ssh1_msg_vals, "Unknown (%u)"), + msg_code); + } + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, "%s", + val_to_str(msg_code, ssh1_msg_vals, "Unknown (%u)")); + } + offset += 1; + len = plen -1; + } else { + len = plen; + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, "Encrypted packet len %d", len); + } + } + /* payload */ + if (tree) { + proto_tree_add_item(ssh1_tree, hf_ssh_payload, + tvb, offset, len, FALSE); + } + offset+=len; + + return offset; +} static int ssh_dissect_key_exchange(tvbuff_t *tvb, packet_info *pinfo, @@ -334,7 +459,7 @@ plen = tvb_get_ntohl(tvb, offset) ; if (ssh_desegment && pinfo->can_desegment) { - if(plen < remain_length - 4 ) { + if(plen +4 > remain_length ) { pinfo->desegment_offset = offset; pinfo->desegment_len = plen+4 - remain_length; *need_desegmentation = TRUE; @@ -369,13 +494,13 @@ if (tree) { proto_tree_add_uint_format(key_ex_tree, hf_ssh_msg_code, tvb, offset, 1, msg_code,"Msg code: %s (%u)", - val_to_str(msg_code, ssh_msg_vals, "Unknown (%u)"), + val_to_str(msg_code, ssh2_msg_vals, "Unknown (%u)"), msg_code); } if (check_col(pinfo->cinfo, COL_INFO)) { col_append_fstr(pinfo->cinfo, COL_INFO, "%s", - val_to_str(msg_code, ssh_msg_vals, "Unknown (%u)")); + val_to_str(msg_code, ssh2_msg_vals, "Unknown (%u)")); } offset += 1; @@ -450,9 +575,11 @@ } if(!is_response) { - if(tvb_strncaseeql(tvb,offset,"SSH-2.",6) == 0 ) { + if(tvb_strncaseeql(tvb,offset,"SSH-2.",6) == 0 ) { + *(version) = SSH_VERSION_2; + }else if(tvb_strncaseeql(tvb,offset,"SSH-1.99-",9) == 0 ) { *(version) = SSH_VERSION_2; - }else if(tvb_strncaseeql(tvb,offset,"SSH-1.",6) == 0 ) { + }else if(tvb_strncaseeql(tvb,offset,"SSH-1.",6) == 0 ) { *(version) = SSH_VERSION_1; } } @@ -788,6 +915,7 @@ static gint *ett[] = { &ett_ssh, &ett_key_exchange, + &ett_ssh1, &ett_key_init }; module_t *ssh_module;
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