From 00783f762b4b14c198f8ae6800a9c85af42cf3dd Mon Sep 17 00:00:00 2001 From: Markus Friedl Date: Thu, 20 Sep 2012 00:18:06 +0200 Subject: [PATCH] auth2-gss.c: PACKET_SKIP_COMPAT --- ssh/auth2-gss.c | 87 ++++++++++++++++++++++++++++++------------------- 1 file changed, 53 insertions(+), 34 deletions(-) diff --git a/ssh/auth2-gss.c b/ssh/auth2-gss.c index ebb842f..7f5808c 100644 --- a/ssh/auth2-gss.c +++ b/ssh/auth2-gss.c @@ -38,6 +38,8 @@ #include "sshbuf.h" #include "err.h" #include "servconf.h" +#define PACKET_SKIP_COMPAT +#define PACKET_SKIP_COMPAT2 #include "packet.h" #include "ssh-gss.h" #include "monitor_wrap.h" @@ -59,17 +61,18 @@ userauth_gssapi(struct ssh *ssh) Authctxt *authctxt = ssh->authctxt; gss_OID_desc goid = {0, NULL}; Gssctxt *ctxt = NULL; - int mechs; + int r, mechs, present; gss_OID_set supported; - int present; OM_uint32 ms; - u_int len; + size_t len; u_char *doid = NULL; if (!authctxt->valid || authctxt->user == NULL) return (0); - mechs = ssh_packet_get_int(ssh); + if ((r = sshpkt_get_u32(ssh, &mechs)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); + if (mechs == 0) { debug("Mechanism negotiation is not supported"); return (0); @@ -83,7 +86,8 @@ userauth_gssapi(struct ssh *ssh) xfree(doid); present = 0; - doid = ssh_packet_get_string(ssh, &len); + if ((r = sshpkt_get_string(ssh, &doid, &len)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); if (len > 2 && doid[0] == SSH_GSS_OIDTYPE && doid[1] == len - 2) { @@ -114,12 +118,12 @@ userauth_gssapi(struct ssh *ssh) authctxt->methoddata = (void *)ctxt; - ssh_packet_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE); - /* Return the OID that we received */ - ssh_packet_put_string(ssh, doid, len); + if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE)) != 0 || + (r = sshpkt_put_string(ssh, doid, len)) != 0 || + (r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); - ssh_packet_send(ssh); xfree(doid); ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); @@ -137,36 +141,45 @@ input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh) gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; gss_buffer_desc recv_tok; OM_uint32 maj_status, min_status, flags; - u_int len; + u_char *p; + size_t len; + int r; if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) fatal("No authentication or GSSAPI context"); gssctxt = authctxt->methoddata; - recv_tok.value = ssh_packet_get_string(ssh, &len); - recv_tok.length = len; /* u_int vs. size_t */ - - ssh_packet_check_eom(ssh); + if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 || + (r = sshpkt_get_end(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); + recv_tok.value = p; + recv_tok.length = len; maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, &send_tok, &flags)); - xfree(recv_tok.value); + xfree(p); if (GSS_ERROR(maj_status)) { if (send_tok.length != 0) { - ssh_packet_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); - ssh_packet_put_string(ssh, send_tok.value, send_tok.length); - ssh_packet_send(ssh); + if ((r = sshpkt_start(ssh, + SSH2_MSG_USERAUTH_GSSAPI_ERRTOK)) != 0 || + (r = sshpkt_put_string(ssh, send_tok.value, + send_tok.length)) != 0 || + (r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); } authctxt->postponed = 0; ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); userauth_finish(ssh, 0, "gssapi-with-mic"); } else { if (send_tok.length != 0) { - ssh_packet_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN); - ssh_packet_put_string(ssh, send_tok.value, send_tok.length); - ssh_packet_send(ssh); + if ((r = sshpkt_start(ssh, + SSH2_MSG_USERAUTH_GSSAPI_TOKEN)) != 0 || + (r = sshpkt_put_string(ssh, send_tok.value, + send_tok.length)) != 0 || + (r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); } if (maj_status == GSS_S_COMPLETE) { ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); @@ -192,22 +205,25 @@ input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh) gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; gss_buffer_desc recv_tok; OM_uint32 maj_status; - u_int len; + size_t len; + u_char *p; + int r; if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) fatal("No authentication or GSSAPI context"); gssctxt = authctxt->methoddata; - recv_tok.value = ssh_packet_get_string(ssh, &len); - recv_tok.length = len; - - ssh_packet_check_eom(ssh); + if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 || + (r = sshpkt_get_end(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); /* Push the error token into GSSAPI to see what it says */ + recv_tok.value = p; + recv_tok.length = len; maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, &send_tok, NULL)); - xfree(recv_tok.value); + xfree(p); /* We can't return anything to the client, even if we wanted to */ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); @@ -230,7 +246,7 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh) { Authctxt *authctxt = ssh->authctxt; Gssctxt *gssctxt; - int authenticated; + int r, authenticated; if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) fatal("No authentication or GSSAPI context"); @@ -242,7 +258,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh) * the dispatcher once the exchange is complete */ - ssh_packet_check_eom(ssh); + if ((r = sshpkt_get_end(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); @@ -260,19 +277,21 @@ input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh) { Authctxt *authctxt = ssh->authctxt; Gssctxt *gssctxt; - int authenticated = 0; + int r, authenticated = 0; struct sshbuf *b; gss_buffer_desc mic, gssbuf; - u_int len; + u_char *p; + size_t len; if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) fatal("No authentication or GSSAPI context"); gssctxt = authctxt->methoddata; - mic.value = ssh_packet_get_string(ssh, &len); + if ((r = sshpkt_get_string(ssh, &p, &len)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); + mic.value = p; mic.length = len; - if ((b = sshbuf_new()) == NULL) fatal("%s: sshbuf_new failed", __func__); ssh_gssapi_buildmic(b, authctxt->user, authctxt->service, @@ -287,7 +306,7 @@ input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh) logit("GSSAPI MIC check failed"); sshbuf_free(b); - xfree(mic.value); + xfree(p); authctxt->postponed = 0; ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);