diff options
Diffstat (limited to 'crypto/openssh/auth-krb5.c')
| -rw-r--r-- | crypto/openssh/auth-krb5.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/crypto/openssh/auth-krb5.c b/crypto/openssh/auth-krb5.c new file mode 100644 index 000000000000..0f645676d9de --- /dev/null +++ b/crypto/openssh/auth-krb5.c @@ -0,0 +1,273 @@ +/* + * Kerberos v5 authentication and ticket-passing routines. + * + * $FreeBSD$ + */ + +#include "includes.h" +RCSID("$OpenBSD: auth-krb5.c,v 1.6 2002/03/04 17:27:39 stevesk Exp $"); + +#include "ssh.h" +#include "ssh1.h" +#include "packet.h" +#include "xmalloc.h" +#include "log.h" +#include "servconf.h" +#include "uidswap.h" +#include "auth.h" + +#ifdef KRB5 +#include <krb5.h> + +extern ServerOptions options; + +static int +krb5_init(void *context) +{ + Authctxt *authctxt = (Authctxt *)context; + krb5_error_code problem; + static int cleanup_registered = 0; + + if (authctxt->krb5_ctx == NULL) { + problem = krb5_init_context(&authctxt->krb5_ctx); + if (problem) + return (problem); + krb5_init_ets(authctxt->krb5_ctx); + } + if (!cleanup_registered) { + fatal_add_cleanup(krb5_cleanup_proc, authctxt); + cleanup_registered = 1; + } + return (0); +} + +/* + * Try krb5 authentication. server_user is passed for logging purposes + * only, in auth is received ticket, in client is returned principal + * from the ticket + */ +int +auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client) +{ + krb5_error_code problem; + krb5_principal server; + krb5_data reply; + krb5_ticket *ticket; + int fd, ret; + + ret = 0; + server = NULL; + ticket = NULL; + reply.length = 0; + + problem = krb5_init(authctxt); + if (problem) + goto err; + + problem = krb5_auth_con_init(authctxt->krb5_ctx, + &authctxt->krb5_auth_ctx); + if (problem) + goto err; + + fd = packet_get_connection_in(); + problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx, + authctxt->krb5_auth_ctx, &fd); + if (problem) + goto err; + + problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL , + KRB5_NT_SRV_HST, &server); + if (problem) + goto err; + + problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx, + auth, server, NULL, NULL, &ticket); + if (problem) + goto err; + + problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client, + &authctxt->krb5_user); + if (problem) + goto err; + + /* if client wants mutual auth */ + problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, + &reply); + if (problem) + goto err; + + /* Check .k5login authorization now. */ + if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, + authctxt->pw->pw_name)) + goto err; + + if (client) + krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, + client); + + packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE); + packet_put_string((char *) reply.data, reply.length); + packet_send(); + packet_write_wait(); + + ret = 1; + err: + if (server) + krb5_free_principal(authctxt->krb5_ctx, server); + if (ticket) + krb5_free_ticket(authctxt->krb5_ctx, ticket); + if (reply.length) + xfree(reply.data); + + if (problem) { + if (authctxt->krb5_ctx != NULL) + debug("Kerberos v5 authentication failed: %s", + krb5_get_err_text(authctxt->krb5_ctx, problem)); + else + debug("Kerberos v5 authentication failed: %d", + problem); + } + + return (ret); +} + +int +auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt) +{ + krb5_error_code problem; + krb5_ccache ccache = NULL; + char *pname; + + if (authctxt->pw == NULL || authctxt->krb5_user == NULL) + return (0); + + temporarily_use_uid(authctxt->pw); + + problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache); + if (problem) + goto fail; + + problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, + authctxt->krb5_user); + if (problem) + goto fail; + + problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, + ccache, tgt); + if (problem) + goto fail; + + authctxt->krb5_fwd_ccache = ccache; + ccache = NULL; + + authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); + + problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, + &pname); + if (problem) + goto fail; + + debug("Kerberos v5 TGT accepted (%s)", pname); + + restore_uid(); + + return (1); + + fail: + if (problem) + debug("Kerberos v5 TGT passing failed: %s", + krb5_get_err_text(authctxt->krb5_ctx, problem)); + if (ccache) + krb5_cc_destroy(authctxt->krb5_ctx, ccache); + + restore_uid(); + + return (0); +} + +int +auth_krb5_password(Authctxt *authctxt, const char *password) +{ + krb5_error_code problem; + + if (authctxt->pw == NULL) + return (0); + + temporarily_use_uid(authctxt->pw); + + problem = krb5_init(authctxt); + if (problem) + goto out; + + problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, + &authctxt->krb5_user); + if (problem) + goto out; + + problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, + &authctxt->krb5_fwd_ccache); + if (problem) + goto out; + + problem = krb5_cc_initialize(authctxt->krb5_ctx, + authctxt->krb5_fwd_ccache, authctxt->krb5_user); + if (problem) + goto out; + + restore_uid(); + problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, + authctxt->krb5_fwd_ccache, password, 1, NULL); + temporarily_use_uid(authctxt->pw); + + if (problem) + goto out; + + authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); + + out: + restore_uid(); + + if (problem) { + if (authctxt->krb5_ctx != NULL) + debug("Kerberos password authentication failed: %s", + krb5_get_err_text(authctxt->krb5_ctx, problem)); + else + debug("Kerberos password authentication failed: %d", + problem); + + krb5_cleanup_proc(authctxt); + + if (options.kerberos_or_local_passwd) + return (-1); + else + return (0); + } + return (1); +} + +void +krb5_cleanup_proc(void *context) +{ + Authctxt *authctxt = (Authctxt *)context; + + debug("krb5_cleanup_proc called"); + if (authctxt->krb5_fwd_ccache) { + krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); + authctxt->krb5_fwd_ccache = NULL; + } + if (authctxt->krb5_user) { + krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); + authctxt->krb5_user = NULL; + } + if (authctxt->krb5_auth_ctx) { + krb5_auth_con_free(authctxt->krb5_ctx, + authctxt->krb5_auth_ctx); + authctxt->krb5_auth_ctx = NULL; + } + if (authctxt->krb5_ctx) { + krb5_free_context(authctxt->krb5_ctx); + authctxt->krb5_ctx = NULL; + } +} + +#endif /* KRB5 */ |