From 96c0d81f51e80fdb7ddab1fbf870d71843e7425f Mon Sep 17 00:00:00 2001 From: Jan Cholasta Date: Wed, 14 Mar 2012 07:54:16 -0400 Subject: SSH: Canonicalize host name and do reverse DNS lookup SSH: Allow clients to explicitly specify host alias This change removes the need to canonicalize host names on the responder side - the relevant code was removed. SSH: Canonicalize host name and do reverse DNS lookup in sss_ssh_knownhostsproxy https://fedorahosted.org/sssd/ticket/1245 --- src/responder/ssh/sshsrv.c | 7 --- src/responder/ssh/sshsrv_cmd.c | 97 +++++++++++++++----------------------- src/responder/ssh/sshsrv_private.h | 1 - 3 files changed, 38 insertions(+), 67 deletions(-) (limited to 'src/responder') diff --git a/src/responder/ssh/sshsrv.c b/src/responder/ssh/sshsrv.c index 242704530..28a5e9c01 100644 --- a/src/responder/ssh/sshsrv.c +++ b/src/responder/ssh/sshsrv.c @@ -26,7 +26,6 @@ #include "responder/common/responder.h" #include "responder/ssh/sshsrv_private.h" #include "providers/data_provider.h" -#include "resolv/async_resolv.h" struct sbus_method monitor_ssh_methods[] = { { MON_CLI_METHOD_PING, monitor_common_pong }, @@ -129,12 +128,6 @@ int ssh_process_init(TALLOC_CTX *mem_ctx, ssh_dp_reconnect_init, iter); } - ret = resolv_init(ssh_ctx, ev, RESOLV_DEFAULT_TIMEOUT, &ssh_ctx->resolv); - if (ret != EOK) { - DEBUG(SSSDBG_FATAL_FAILURE, ("Could not set up resolver context\n")); - return ret; - } - DEBUG(SSSDBG_TRACE_FUNC, ("SSH Initialization complete\n")); return EOK; diff --git a/src/responder/ssh/sshsrv_cmd.c b/src/responder/ssh/sshsrv_cmd.c index be79f0c9c..9d553f73e 100644 --- a/src/responder/ssh/sshsrv_cmd.c +++ b/src/responder/ssh/sshsrv_cmd.c @@ -33,7 +33,6 @@ #include "responder/common/responder.h" #include "responder/common/responder_packet.h" #include "responder/ssh/sshsrv_private.h" -#include "resolv/async_resolv.h" static errno_t ssh_cmd_parse_request(struct ssh_cmd_ctx *cmd_ctx); @@ -85,16 +84,14 @@ done: return ssh_cmd_done(cmd_ctx, ret); } -static void -ssh_host_pubkeys_resolv_done(struct tevent_req *req); +static errno_t +ssh_host_pubkeys_search(struct ssh_cmd_ctx *cmd_ctx); static int sss_ssh_cmd_get_host_pubkeys(struct cli_ctx *cctx) { - struct ssh_ctx *ssh_ctx = cctx->rctx->pvt_ctx; - struct ssh_cmd_ctx *cmd_ctx; errno_t ret; - struct tevent_req *req; + struct ssh_cmd_ctx *cmd_ctx; cmd_ctx = talloc_zero(cctx, struct ssh_cmd_ctx); if (!cmd_ctx) { @@ -109,8 +106,9 @@ sss_ssh_cmd_get_host_pubkeys(struct cli_ctx *cctx) } DEBUG(SSSDBG_TRACE_FUNC, - ("Requesting SSH host public keys for [%s] from [%s]\n", - cmd_ctx->name, cmd_ctx->domname ? cmd_ctx->domname : "")); + ("Requesting SSH host public keys for [%s][%s] from [%s]\n", + cmd_ctx->name, cmd_ctx->alias ? cmd_ctx->alias : "", + cmd_ctx->domname ? cmd_ctx->domname : "")); if (cmd_ctx->domname) { cmd_ctx->domain = responder_get_domain(cctx->rctx->domains, @@ -124,54 +122,12 @@ sss_ssh_cmd_get_host_pubkeys(struct cli_ctx *cctx) cmd_ctx->check_next = true; } - /* canonicalize host name */ - req = resolv_gethostbyname_send(cmd_ctx, cctx->rctx->ev, ssh_ctx->resolv, - cmd_ctx->name, IPV4_FIRST, - default_host_dbs); - if (!req) { - ret = ENOMEM; - DEBUG(SSSDBG_OP_FAILURE, - ("Out of memory sending resolver request\n")); - goto done; - } - - tevent_req_set_callback(req, ssh_host_pubkeys_resolv_done, cmd_ctx); - ret = EAGAIN; + ret = ssh_host_pubkeys_search(cmd_ctx); done: return ssh_cmd_done(cmd_ctx, ret); } -static errno_t -ssh_host_pubkeys_search(struct ssh_cmd_ctx *cmd_ctx); - -static void -ssh_host_pubkeys_resolv_done(struct tevent_req *req) -{ - struct ssh_cmd_ctx *cmd_ctx = tevent_req_callback_data(req, - struct ssh_cmd_ctx); - errno_t ret; - int resolv_status; - struct resolv_hostent *hostent; - - ret = resolv_gethostbyname_recv(req, cmd_ctx, - &resolv_status, NULL, &hostent); - talloc_zfree(req); - if (ret == EOK) { - if (strcmp(cmd_ctx->name, hostent->name) != 0) { - cmd_ctx->alias = cmd_ctx->name; - cmd_ctx->name = hostent->name; - } - } else { - DEBUG(SSSDBG_OP_FAILURE, - ("Failed to resolve [%s]: %s\n", cmd_ctx->name, - resolv_strerror(resolv_status))); - } - - ret = ssh_host_pubkeys_search(cmd_ctx); - ssh_cmd_done(cmd_ctx, ret); -} - static void ssh_dp_send_req_done(struct tevent_req *req) { @@ -600,28 +556,30 @@ ssh_cmd_parse_request(struct ssh_cmd_ctx *cmd_ctx) uint8_t *body; size_t body_len; size_t c = 0; - uint32_t reserved; + uint32_t flags; uint32_t name_len; char *name; + uint32_t alias_len; + char *alias; sss_packet_get_body(cctx->creq->in, &body, &body_len); - SAFEALIGN_COPY_UINT32_CHECK(&reserved, body+c, body_len, &c); - if (reserved != 0) { + SAFEALIGN_COPY_UINT32_CHECK(&flags, body+c, body_len, &c); + if (flags > 1) { + DEBUG(SSSDBG_CRIT_FAILURE, ("Invalid flags received [0x%x]\n", flags)); return EINVAL; } SAFEALIGN_COPY_UINT32_CHECK(&name_len, body+c, body_len, &c); if (name_len == 0) { + DEBUG(SSSDBG_CRIT_FAILURE, ("Zero-length name is not valid\n")); return EINVAL; } name = (char *)(body+c); - if (!sss_utf8_check((const uint8_t *)name, name_len-1)) { - DEBUG(SSSDBG_CRIT_FAILURE, ("Supplied data is not valid UTF-8 string\n")); - return EINVAL; - } - if (strnlen(name, name_len) != name_len-1) { + if (!sss_utf8_check((const uint8_t *)name, name_len-1) || + name[name_len-1] != 0) { + DEBUG(SSSDBG_CRIT_FAILURE, ("Name is not valid UTF-8 string\n")); return EINVAL; } c += name_len; @@ -633,6 +591,27 @@ ssh_cmd_parse_request(struct ssh_cmd_ctx *cmd_ctx) return ENOENT; } + if (flags & 1) { + SAFEALIGN_COPY_UINT32_CHECK(&alias_len, body+c, body_len, &c); + if (alias_len == 0) { + DEBUG(SSSDBG_CRIT_FAILURE, ("Zero-length alias is not valid\n")); + return EINVAL; + } + + alias = (char *)(body+c); + if (!sss_utf8_check((const uint8_t *)alias, alias_len-1) || + alias[alias_len-1] != 0) { + DEBUG(SSSDBG_CRIT_FAILURE, ("Alias is not valid UTF-8 string\n")); + return EINVAL; + } + c += alias_len; + + if (strcmp(cmd_ctx->name, alias) != 0) { + cmd_ctx->alias = talloc_strdup(cmd_ctx, alias); + if (!cmd_ctx->alias) return ENOMEM; + } + } + return EOK; } diff --git a/src/responder/ssh/sshsrv_private.h b/src/responder/ssh/sshsrv_private.h index 315e4f294..ab9edf7c3 100644 --- a/src/responder/ssh/sshsrv_private.h +++ b/src/responder/ssh/sshsrv_private.h @@ -31,7 +31,6 @@ struct ssh_ctx { struct resp_ctx *rctx; - struct resolv_ctx *resolv; }; struct ssh_cmd_ctx { -- cgit