X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/510132b69d4fdceca750f6de39b2be84c49006c8..2fff96d8cea95213d66e7ba65e36cae6adcf403a:/openssh/gss-serv.c diff --git a/openssh/gss-serv.c b/openssh/gss-serv.c index fc2a9ac..2c26762 100644 --- a/openssh/gss-serv.c +++ b/openssh/gss-serv.c @@ -1,5 +1,7 @@ +/* $OpenBSD: gss-serv.c,v 1.5 2003/11/17 11:06:07 markus Exp $ */ + /* - * Copyright (c) 2001 Simon Wilkinson. All rights reserved. + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -26,25 +28,19 @@ #ifdef GSSAPI -#include "ssh.h" -#include "ssh1.h" -#include "ssh2.h" -#include "xmalloc.h" #include "buffer.h" #include "bufaux.h" -#include "packet.h" #include "compat.h" #include -#include "cipher.h" #include "kex.h" #include "auth.h" #include "log.h" #include "channels.h" #include "session.h" -#include "dispatch.h" #include "servconf.h" -#include "compat.h" -#include "misc.h" +#include "monitor_wrap.h" +#include "xmalloc.h" +#include "getput.h" #include "ssh-gss.h" @@ -52,690 +48,418 @@ extern ServerOptions options; extern u_char *session_id2; extern int session_id2_len; -void userauth_reply(Authctxt *authctxt, int authenticated); -static void gssapi_unsetenv(const char *var); - -typedef struct ssh_gssapi_cred_cache { - char *filename; - char *envvar; - char *envval; - void *data; -} ssh_gssapi_cred_cache; - -static struct ssh_gssapi_cred_cache gssapi_cred_store = {NULL,NULL,NULL}; -unsigned char ssh1_key_digest[16]; /* used for ssh1 gssapi */ +static ssh_gssapi_client gssapi_client = + { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, + GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}}; -/* - * Environment variables pointing to delegated credentials - */ -static char *delegation_env[] = { - "X509_USER_PROXY", /* GSSAPI/SSLeay */ - "KRB5CCNAME", /* Krb5 and possibly SSLeay */ - NULL -}; +ssh_gssapi_mech gssapi_null_mech = + { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; #ifdef KRB5 - -#ifdef HEIMDAL -#include -#else -#include -#define krb5_get_err_text(context,code) error_message(code) +extern ssh_gssapi_mech gssapi_kerberos_mech; +extern ssh_gssapi_mech gssapi_kerberos_mech_old; +#endif +#ifdef GSI +extern ssh_gssapi_mech gssapi_gsi_mech; +extern ssh_gssapi_mech gssapi_gsi_mech_old; #endif -static krb5_context krb_context = NULL; +ssh_gssapi_mech* supported_mechs[]= { +#ifdef KRB5 + &gssapi_kerberos_mech, + &gssapi_kerberos_mech_old, /* Support for legacy clients */ +#endif +#ifdef GSI + &gssapi_gsi_mech, + &gssapi_gsi_mech_old, /* Support for legacy clients */ +#endif + &gssapi_null_mech, +}; -/* Initialise the krb5 library, so we can use it for those bits that - * GSSAPI won't do */ +#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG +static int limited = 0; +#endif -int ssh_gssapi_krb5_init() { - krb5_error_code problem; - - if (krb_context !=NULL) - return 1; - - problem = krb5_init_context(&krb_context); - if (problem) { - log("Cannot initialize krb5 context"); - return 0; +/* Unpriviledged */ +void +ssh_gssapi_supported_oids(gss_OID_set *oidset) +{ + int i = 0; + OM_uint32 min_status; + int present; + gss_OID_set supported; + + gss_create_empty_oid_set(&min_status, oidset); + /* Ask priviledged process what mechanisms it supports. */ + PRIVSEP(gss_indicate_mechs(&min_status, &supported)); + + while (supported_mechs[i]->name != NULL) { + if (GSS_ERROR(gss_test_oid_set_member(&min_status, + &supported_mechs[i]->oid, supported, &present))) + present = 0; + if (present) + gss_add_oid_set_member(&min_status, + &supported_mechs[i]->oid, oidset); + i++; } - krb5_init_ets(krb_context); +} - return 1; -} -/* Check if this user is OK to login. This only works with krb5 - other - * GSSAPI mechanisms will need their own. - * Returns true if the user is OK to log in, otherwise returns 0 +/* Wrapper around accept_sec_context + * Requires that the context contains: + * oid + * credentials (from ssh_gssapi_acquire_cred) */ +/* Priviledged */ +OM_uint32 +ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok, + gss_buffer_desc *send_tok, OM_uint32 *flags) +{ + OM_uint32 status; + gss_OID mech; -int -ssh_gssapi_krb5_userok(char *name) { - krb5_principal princ; - int retval; + ctx->major = gss_accept_sec_context(&ctx->minor, + &ctx->context, ctx->creds, recv_tok, + GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech, + send_tok, flags, NULL, &ctx->client_creds); - if (ssh_gssapi_krb5_init() == 0) - return 0; - - if ((retval=krb5_parse_name(krb_context, gssapi_client_name.value, - &princ))) { - log("krb5_parse_name(): %.100s", - krb5_get_err_text(krb_context,retval)); - return 0; - } - if (krb5_kuserok(krb_context, princ, name)) { - retval = 1; - log("Authorized to %s, krb5 principal %s (krb5_kuserok)",name, - (char *)gssapi_client_name.value); - } + if (GSS_ERROR(ctx->major)) + ssh_gssapi_error(ctx); + + if (ctx->client_creds) + debug("Received some client credentials"); else - retval = 0; - - krb5_free_principal(krb_context, princ); - return retval; -} - -/* Make sure that this is called _after_ we've setuid to the user */ + debug("Got no client credentials"); -/* This writes out any forwarded credentials. Its specific to the Kerberos - * GSSAPI mechanism - * - * We assume that our caller has made sure that the user has selected - * delegated credentials, and that the client_creds structure is correctly - * populated. - */ + status = ctx->major; -void -ssh_gssapi_krb5_storecreds() { - krb5_ccache ccache; - krb5_error_code problem; - krb5_principal princ; - char ccname[35]; - static char name[40]; - int tmpfd; - OM_uint32 maj_status,min_status; - - - if (gssapi_client_creds==NULL) { - debug("No credentials stored"); - return; - } - - if (ssh_gssapi_krb5_init() == 0) - return; - - if (options.gss_use_session_ccache) { - snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d_XXXXXX",geteuid()); - - if ((tmpfd = mkstemp(ccname))==-1) { - log("mkstemp(): %.100s", strerror(errno)); - return; - } - if (fchmod(tmpfd, S_IRUSR | S_IWUSR) == -1) { - log("fchmod(): %.100s", strerror(errno)); - close(tmpfd); - return; - } - } else { - snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d",geteuid()); - tmpfd = open(ccname, O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR); - if (tmpfd == -1) { - log("open(): %.100s", strerror(errno)); - return; - } - } - - close(tmpfd); - snprintf(name, sizeof(name), "FILE:%s",ccname); - - if ((problem = krb5_cc_resolve(krb_context, name, &ccache))) { - log("krb5_cc_default(): %.100s", - krb5_get_err_text(krb_context,problem)); - return; - } - - if ((problem = krb5_parse_name(krb_context, gssapi_client_name.value, - &princ))) { - log("krb5_parse_name(): %.100s", - krb5_get_err_text(krb_context,problem)); - krb5_cc_destroy(krb_context,ccache); - return; - } - - if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) { - log("krb5_cc_initialize(): %.100s", - krb5_get_err_text(krb_context,problem)); - krb5_free_principal(krb_context,princ); - krb5_cc_destroy(krb_context,ccache); - return; - } - - krb5_free_principal(krb_context,princ); - - #ifdef HEIMDAL - if ((problem = krb5_cc_copy_cache(krb_context, - gssapi_client_creds->ccache, - ccache))) { - log("krb5_cc_copy_cache(): %.100s", - krb5_get_err_text(krb_context,problem)); - krb5_cc_destroy(krb_context,ccache); - return; - } - #else - if ((maj_status = gss_krb5_copy_ccache(&min_status, - gssapi_client_creds, - ccache))) { - log("gss_krb5_copy_ccache() failed"); - ssh_gssapi_error(maj_status,min_status); - krb5_cc_destroy(krb_context,ccache); - return; + /* Now, if we're complete and we have the right flags, then + * we flag the user as also having been authenticated + */ + + if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) && + (*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) { + if (ssh_gssapi_getclient(ctx, &gssapi_client)) + fatal("Couldn't convert client name"); +#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG + if (flags && (*flags & GSS_C_GLOBUS_LIMITED_PROXY_FLAG)) + limited=1; +#endif } - #endif - - krb5_cc_close(krb_context,ccache); + return (status); +} -#ifdef USE_PAM - do_pam_putenv("KRB5CCNAME",name); +/* + * This parses an exported name, extracting the mechanism specific portion + * to use for ACL checking. It verifies that the name belongs the mechanism + * originally selected. + */ +static OM_uint32 +ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name) +{ + char *tok; + OM_uint32 offset; + OM_uint32 oidl; + + tok=ename->value; + +#ifdef GSI /* GSI gss_export_name() is broken. */ + if ((ctx->oid->length == gssapi_gsi_mech.oid.length) && + (memcmp(ctx->oid->elements, gssapi_gsi_mech.oid.elements, + gssapi_gsi_mech.oid.length) == 0)) { + name->length = ename->length; + name->value = xmalloc(ename->length+1); + memcpy(name->value, ename->value, ename->length); + return GSS_S_COMPLETE; + } #endif - gssapi_cred_store.filename=strdup(ccname); - gssapi_cred_store.envvar="KRB5CCNAME"; - gssapi_cred_store.envval=strdup(name); + /* + * Check that ename is long enough for all of the fixed length + * header, and that the initial ID bytes are correct + */ - return; -} + if (ename->length<6 || memcmp(tok,"\x04\x01", 2)!=0) + return GSS_S_FAILURE; -#endif /* KRB5 */ + /* + * Extract the OID, and check it. Here GSSAPI breaks with tradition + * and does use the OID type and length bytes. To confuse things + * there are two lengths - the first including these, and the + * second without. + */ -#ifdef GSI -#include + oidl = GET_16BIT(tok+2); /* length including next two bytes */ + oidl = oidl-2; /* turn it into the _real_ length of the variable OID */ -/* - * Check if this user is OK to login under GSI. User has been authenticated - * as identity in global 'client_name.value' and is trying to log in as passed - * username in 'name'. - * - * Returns non-zero if user is authorized, 0 otherwise. - */ -int -ssh_gssapi_gsi_userok(char *name) -{ - int authorized = 0; - - /* This returns 0 on success */ - authorized = (globus_gss_assist_userok(gssapi_client_name.value, - name) == 0); - - debug("GSI user %s is%s authorized as target user %s", - (char *) gssapi_client_name.value, - (authorized ? "" : " not"), - name); - - return authorized; + /* + * Check the BER encoding for correct type and length, that the + * string is long enough and that the OID matches that in our context + */ + if (tok[4] != 0x06 || tok[5] != oidl || + ename->length < oidl+6 || + !ssh_gssapi_check_oid(ctx,tok+6,oidl)) + return GSS_S_FAILURE; + + offset = oidl+6; + + if (ename->length < offset+4) + return GSS_S_FAILURE; + + name->length = GET_32BIT(tok+offset); + offset += 4; + + if (ename->length < offset+name->length) + return GSS_S_FAILURE; + + name->value = xmalloc(name->length+1); + memcpy(name->value,tok+offset,name->length); + ((char *)name->value)[name->length] = 0; + + return GSS_S_COMPLETE; } -/* - * Handle setting up child environment for GSI. - * - * Make sure that this is called _after_ we've setuid to the user. - */ -void -ssh_gssapi_gsi_storecreds() +/* Extract the client details from a given context. This can only reliably + * be called once for a context */ + +/* Priviledged (called from accept_secure_ctx) */ +OM_uint32 +ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) { - OM_uint32 major_status; - OM_uint32 minor_status; - - - if (gssapi_client_creds != NULL) - { - char *creds_env = NULL; - - /* - * This is the current hack with the GSI gssapi library to - * export credentials to disk. - */ - - debug("Exporting delegated credentials"); - - minor_status = 0xdee0; /* Magic value */ - major_status = - gss_inquire_cred(&minor_status, - gssapi_client_creds, - (gss_name_t *) &creds_env, - NULL, - NULL, - NULL); - - if ((major_status == GSS_S_COMPLETE) && - (minor_status == 0xdee1) && - (creds_env != NULL)) - { - char *value; - - /* - * String is of the form: - * X509_USER_DELEG_PROXY=filename - * so we parse out the filename - * and then set X509_USER_PROXY - * to point at it. - */ - value = strchr(creds_env, '='); - - if (value != NULL) - { - *value = '\0'; - value++; -#ifdef USE_PAM - do_pam_putenv("X509_USER_PROXY",value); -#endif - gssapi_cred_store.filename=NULL; - gssapi_cred_store.envvar="X509_USER_PROXY"; - gssapi_cred_store.envval=strdup(value); - - return; - } - else - { - log("Failed to parse delegated credentials string '%s'", - creds_env); - } - } - else - { - log("Failed to export delegated credentials (error %ld)", - major_status); - } - } -} + int i = 0; + + gss_buffer_desc ename; + + client->mech = NULL; + + while (supported_mechs[i]->name != NULL) { + if (supported_mechs[i]->oid.length == ctx->oid->length && + (memcmp(supported_mechs[i]->oid.elements, + ctx->oid->elements, ctx->oid->length) == 0)) + client->mech = supported_mechs[i]; + i++; + } + + if (client->mech == NULL) + return GSS_S_FAILURE; + + if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, + &client->displayname, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } -#endif /* GSI */ + if ((ctx->major = gss_export_name(&ctx->minor, ctx->client, + &ename))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename, + &client->exportedname))) { + return (ctx->major); + } + + /* We can't copy this structure, so we just move the pointer to it */ + client->creds = ctx->client_creds; + ctx->client_creds = GSS_C_NO_CREDENTIAL; + return (ctx->major); +} + +/* As user - called on fatal/exit */ void -ssh_gssapi_cleanup_creds(void *ignored) +ssh_gssapi_cleanup_creds(void) { - if (gssapi_cred_store.filename!=NULL) { + if (gssapi_client.store.filename != NULL) { /* Unlink probably isn't sufficient */ - debug("removing gssapi cred file\"%s\"",gssapi_cred_store.filename); - unlink(gssapi_cred_store.filename); + debug("removing gssapi cred file\"%s\"", gssapi_client.store.filename); + unlink(gssapi_client.store.filename); } } -void -ssh_gssapi_storecreds() +/* As user */ +void +ssh_gssapi_storecreds(void) { - switch (gssapi_client_type) { -#ifdef KRB5 - case GSS_KERBEROS: - ssh_gssapi_krb5_storecreds(); - break; -#endif -#ifdef GSI - case GSS_GSI: - ssh_gssapi_gsi_storecreds(); - break; -#endif /* GSI */ - case GSS_LAST_ENTRY: - /* GSSAPI not used in this authentication */ - debug("No GSSAPI credentials stored"); - break; - default: - log("ssh_gssapi_do_child: Unknown mechanism"); - - } - - if (options.gss_cleanup_creds) { - fatal_add_cleanup(ssh_gssapi_cleanup_creds, NULL); - } - + if (gssapi_client.mech && gssapi_client.mech->storecreds) { + (*gssapi_client.mech->storecreds)(&gssapi_client); + } else + debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism"); } /* This allows GSSAPI methods to do things to the childs environment based * on the passed authentication process and credentials. - * - * Question: If we didn't use userauth_external for some reason, should we - * still delegate credentials? */ -void -ssh_gssapi_do_child(char ***envp, u_int *envsizep) +/* As user */ +void +ssh_gssapi_do_child(char ***envp, u_int *envsizep) { - if (gssapi_cred_store.envvar!=NULL && - gssapi_cred_store.envval!=NULL) { - - debug("Setting %s to %s", gssapi_cred_store.envvar, - gssapi_cred_store.envval); - child_set_env(envp, envsizep, gssapi_cred_store.envvar, - gssapi_cred_store.envval); - } + if (gssapi_client.store.envvar != NULL && + gssapi_client.store.envval != NULL) { - switch(gssapi_client_type) { -#ifdef KRB5 - case GSS_KERBEROS: break; -#endif -#ifdef GSI - case GSS_GSI: break; -#endif - case GSS_LAST_ENTRY: - debug("No GSSAPI credentials stored"); - break; - default: - log("ssh_gssapi_do_child: Unknown mechanism"); + debug("Setting %s to %s", gssapi_client.store.envvar, + gssapi_client.store.envval); + child_set_env(envp, envsizep, gssapi_client.store.envvar, + gssapi_client.store.envval); } } +/* Priviledged */ int ssh_gssapi_userok(char *user) { - if (gssapi_client_name.length==0 || - gssapi_client_name.value==NULL) { + if (gssapi_client.exportedname.length == 0 || + gssapi_client.exportedname.value == NULL) { debug("No suitable client data"); return 0; } - switch (gssapi_client_type) { -#ifdef KRB5 - case GSS_KERBEROS: - return(ssh_gssapi_krb5_userok(user)); - break; /* Not reached */ -#endif -#ifdef GSI - case GSS_GSI: - return(ssh_gssapi_gsi_userok(user)); - break; /* Not reached */ -#endif /* GSI */ - case GSS_LAST_ENTRY: - debug("Client not GSSAPI"); - break; - default: - debug("Unknown client authentication type"); +#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG + if (limited) { + debug("limited proxy not acceptable for remote login"); + return 0; } - return(0); -} - -int -userauth_external(Authctxt *authctxt) -{ - packet_check_eom(); - - return(ssh_gssapi_userok(authctxt->user)); +#endif + if (gssapi_client.mech && gssapi_client.mech->userok) + return ((*gssapi_client.mech->userok)(&gssapi_client, user)); + else + debug("ssh_gssapi_userok: Unknown GSSAPI mechanism"); + return (0); } -void input_gssapi_token(int type, u_int32_t plen, void *ctxt); -void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt); - -/* We only support those mechanisms that we know about (ie ones that we know - * how to check local user kuserok and the like +/* Return a list of the gss-group1-sha1-x mechanisms supported by this + * program. + * + * We only support the mechanisms that we've indicated in the list above, + * but we check that they're supported by the GSSAPI mechanism on the + * machine. We also check, before including them in the list, that + * we have the necesary information in order to carry out the key exchange + * (that is, that the user has credentials, the server's creds are accessible, + * etc) + * + * The way that this is done is fairly nasty, as we do a lot of work that + * is then thrown away. This should possibly be implemented with a cache + * that stores the results (in an expanded Gssctxt structure), which are + * then used by the first calls if that key exchange mechanism is chosen. */ -int -userauth_gssapi(Authctxt *authctxt) -{ - gss_OID_desc oid= {0,NULL}; - Gssctxt *ctxt; - int mechs; - gss_OID_set supported; + +/* Unpriviledged */ +char * +ssh_gssapi_server_mechanisms() { + gss_OID_set supported; + Gssctxt *ctx = NULL; + OM_uint32 maj_status, min_status; + Buffer buf; + int i = 0; + int first = 0; int present; - OM_uint32 ms; - u_int len; - - if (!authctxt->valid || authctxt->user == NULL) - return 0; - - if (datafellows & SSH_OLD_GSSAPI) { - debug("Early drafts of GSSAPI userauth not supported"); - return 0; - } - - mechs=packet_get_int(); - if (mechs==0) { - debug("Mechanism negotiation is not supported"); - return 0; - } + char * mechs; + if (datafellows & SSH_OLD_GSSAPI) return NULL; + ssh_gssapi_supported_oids(&supported); - do { - if (oid.elements) - xfree(oid.elements); - oid.elements = packet_get_string(&len); - oid.length = len; - gss_test_oid_set_member(&ms, &oid, supported, &present); - mechs--; - } while (mechs>0 && !present); - if (!present) { - xfree(oid.elements); - return(0); + buffer_init(&buf); + + while(supported_mechs[i]->name != NULL) { + if ((maj_status=gss_test_oid_set_member(&min_status, + &supported_mechs[i]->oid, + supported, + &present))) { + present=0; + } + + if (present) { + if (!GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, + &supported_mechs[i]->oid)))) { + /* Append gss_group1_sha1_x to our list */ + if (first++!=0) + buffer_put_char(&buf,','); + buffer_append(&buf, KEX_GSS_SHA1, + sizeof(KEX_GSS_SHA1)-1); + buffer_append(&buf, + supported_mechs[i]->enc_name, + strlen(supported_mechs[i]->enc_name)); + debug("GSSAPI mechanism %s (%s%s) supported", + supported_mechs[i]->name, KEX_GSS_SHA1, + supported_mechs[i]->enc_name); + } else { + debug("no credentials for GSSAPI mechanism %s", + supported_mechs[i]->name); + } + } else { + debug("GSSAPI mechanism %s not supported", + supported_mechs[i]->name); + } + ssh_gssapi_delete_ctx(&ctx); + i++; } - ctxt=xmalloc(sizeof(Gssctxt)); - authctxt->methoddata=(void *)ctxt; + buffer_put_char(&buf,'\0'); - ssh_gssapi_build_ctx(ctxt); - ssh_gssapi_set_oid(ctxt,&oid); - - if (ssh_gssapi_acquire_cred(ctxt)) - return 0; - - /* Send SSH_MSG_USERAUTH_GSSAPI_RESPONSE */ - - if (!compat20) - packet_start(SSH_SMSG_AUTH_GSSAPI_RESPONSE); + mechs=xmalloc(buffer_len(&buf)); + buffer_get(&buf,mechs,buffer_len(&buf)); + buffer_free(&buf); + if (strlen(mechs)==0) + return(NULL); else - packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE); - packet_put_string(oid.elements,oid.length); - packet_send(); - packet_write_wait(); - xfree(oid.elements); - - if (!compat20) - dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN, - &input_gssapi_token); - else - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, - &input_gssapi_token); - authctxt->postponed = 1; - - return 0; -} - -void -input_gssapi_token(int type, u_int32_t plen, void *ctxt) -{ - Authctxt *authctxt = ctxt; - Gssctxt *gssctxt; - gss_buffer_desc send_tok,recv_tok; - OM_uint32 maj_status, min_status; - - if (authctxt == NULL || authctxt->methoddata == NULL) - fatal("No authentication or GSSAPI context"); - - gssctxt=authctxt->methoddata; - - recv_tok.value=packet_get_string(&recv_tok.length); - - maj_status=ssh_gssapi_accept_ctx(gssctxt, &recv_tok, &send_tok, NULL); - packet_check_eom(); - - if (GSS_ERROR(maj_status)) { - /* Failure */ - authctxt->postponed = 0; - dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN, NULL); - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); - userauth_finish(authctxt, 0, "gssapi"); - } - - if (send_tok.length != 0) { - /* Send a packet back to the client */ - if (!compat20) - packet_start(SSH_MSG_AUTH_GSSAPI_TOKEN); - else - packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); - packet_put_string(send_tok.value,send_tok.length); - packet_send(); - packet_write_wait(); - gss_release_buffer(&min_status, &send_tok); - } - - if (maj_status == GSS_S_COMPLETE) { - dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN, NULL); - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,NULL); - /* ssh1 does not have an extra message here */ - if (!compat20) - input_gssapi_exchange_complete(0, 0, ctxt); - else - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, - &input_gssapi_exchange_complete); - } + return(mechs); } -/* This is called when the client thinks we've completed authentication. - * It should only be enabled in the dispatch handler by the function above, - * which only enables it once the GSSAPI exchange is complete. - */ +/* Return the OID that corresponds to the given context name */ -void -input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt) -{ - Authctxt *authctxt = ctxt; - Gssctxt *gssctxt; - int authenticated; - - if(strcmp(authctxt->user,"") == 0) { - char *user; - char *gridmapped_name = NULL; - struct passwd *pw = NULL; - if(globus_gss_assist_gridmap(gssapi_client_name.value, - &gridmapped_name) == 0) { - user = gridmapped_name; - debug("I gridmapped and got %s", user); - pw = getpwnam(user); - if (pw && allowed_user(pw)) { - authctxt->user = user; - authctxt->pw = pwcopy(pw); - authctxt->valid = 1; - } - } - } +/* Unpriviledged */ +gss_OID +ssh_gssapi_server_id_kex(char *name) { + int i=0; + + if (strncmp(name, KEX_GSS_SHA1, sizeof(KEX_GSS_SHA1)-1) !=0) { + return(NULL); + } + + name+=sizeof(KEX_GSS_SHA1)-1; /* Move to the start of the MIME string */ + + while (supported_mechs[i]->name!=NULL && + strcmp(name,supported_mechs[i]->enc_name)!=0) { + i++; + } - - if (authctxt == NULL || authctxt->methoddata == NULL) - fatal("No authentication or GSSAPI context"); - - gssctxt=authctxt->methoddata; - - /* This should never happen, but better safe than sorry. */ - if (gssctxt->status != GSS_S_COMPLETE) { - packet_disconnect("Context negotiation is not complete"); - } + if (supported_mechs[i]->name==NULL) + return (NULL); - if (ssh_gssapi_getclient(gssctxt,&gssapi_client_type, - &gssapi_client_name, - &gssapi_client_creds)) { - fatal("Couldn't convert client name"); - } - - authenticated = ssh_gssapi_userok(authctxt->user); - - /* ssh1 needs to exchange the hash of the keys */ - if (!compat20) { - if (authenticated) { - - OM_uint32 maj_status, min_status; - gss_buffer_desc gssbuf,msg_tok; - - /* ssh1 uses wrap */ - gssbuf.value=ssh1_key_digest; - gssbuf.length=sizeof(ssh1_key_digest); - if ((maj_status=gss_wrap(&min_status, - gssctxt->context, - 0, - GSS_C_QOP_DEFAULT, - &gssbuf, - NULL, - &msg_tok))) { - ssh_gssapi_error(maj_status,min_status); - fatal("Couldn't wrap keys"); - } - packet_start(SSH_SMSG_AUTH_GSSAPI_HASH); - packet_put_string((char *)msg_tok.value,msg_tok.length); - packet_send(); - packet_write_wait(); - gss_release_buffer(&min_status,&msg_tok); - } else { - packet_start(SSH_MSG_AUTH_GSSAPI_ABORT); - packet_send(); - packet_write_wait(); - } - } + debug("using GSSAPI mechanism %s (%s%s)", supported_mechs[i]->name, + KEX_GSS_SHA1, supported_mechs[i]->enc_name); - authctxt->postponed = 0; - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); - userauth_finish(authctxt, authenticated, "gssapi"); + return &supported_mechs[i]->oid; } -/* - * Clean our environment on startup. This means removing any environment - * strings that might inadvertantly been in root's environment and - * could cause serious security problems if we think we set them. - */ -void -ssh_gssapi_clean_env(void) +/* Priviledged */ +int +ssh_gssapi_localname(char **user) { - char *envstr; - int envstr_index; - - - for (envstr_index = 0; - (envstr = delegation_env[envstr_index]) != NULL; - envstr_index++) { - - if (getenv(envstr)) { - debug("Clearing environment variable %s", envstr); - gssapi_unsetenv(envstr); - } - } + *user = NULL; + if (gssapi_client.displayname.length==0 || + gssapi_client.displayname.value==NULL) { + debug("No suitable client data"); + return(0);; + } + if (gssapi_client.mech && gssapi_client.mech->localname) { + return((*gssapi_client.mech->localname)(&gssapi_client,user)); + } else { + debug("Unknown client authentication type"); + } + return(0); } -/* - * Wrapper around unsetenv. - */ -static void -gssapi_unsetenv(const char *var) +/* Priviledged */ +OM_uint32 +ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) { -#ifdef HAVE_UNSETENV - unsetenv(var); - -#else /* !HAVE_UNSETENV */ - extern char **environ; - char **p1 = environ; /* New array list */ - char **p2 = environ; /* Current array list */ - int len = strlen(var); - - /* - * Walk through current environ array (p2) copying each pointer - * to new environ array (p1) unless the pointer is to the item - * we want to delete. Copy happens in place. - */ - while (*p2) { - if ((strncmp(*p2, var, len) == 0) && - ((*p2)[len] == '=')) { - /* - * *p2 points at item to be deleted, just skip over it - */ - p2++; - } else { - /* - * *p2 points at item we want to save, so copy it - */ - *p1 = *p2; - p1++; - p2++; - } - } + ctx->major = gss_verify_mic(&ctx->minor, ctx->context, + gssbuf, gssmic, NULL); - /* And make sure new array is NULL terminated */ - *p1 = NULL; -#endif /* HAVE_UNSETENV */ + return (ctx->major); } -#endif /* GSSAPI */ +#endif