X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=gssapi.c;h=c2c7d94ff46aef0502a587bf47db9c868d18d47e;hb=53293ee30678d3db753e51820cc554c0b2b1bd97;hp=8189552ab37ab7b4c4cdae525eaa93dfa90d36a5;hpb=944e10700c98f8ac71c2385fd96671167463fcf0;p=~andy%2Ffetchmail diff --git a/gssapi.c b/gssapi.c index 8189552a..c2c7d94f 100644 --- a/gssapi.c +++ b/gssapi.c @@ -15,7 +15,7 @@ #include "socket.h" #include "i18n.h" -#include "md5.h" +#include "fm_md5.h" #include #include /* for htonl/ntohl */ @@ -33,81 +33,171 @@ # ifdef HAVE_GSSAPI_GSSAPI_GENERIC_H # include # endif -# ifndef HAVE_GSS_C_NT_HOSTBASED_SERVICE +# if HAVE_DECL_GSS_C_NT_HOSTBASED_SERVICE + 0 == 0 # define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name # endif # endif +static void decode_subr(const char *m, uint32_t code, int type, FILE *ostrm) +{ + uint32_t maj, min, context; + gss_buffer_desc msg = GSS_C_EMPTY_BUFFER; + + context = 0; + do { + maj = gss_display_status(&min, code, type, GSS_C_NO_OID, + &context, &msg); + + if (maj != GSS_S_COMPLETE) { + report(stderr, GT_("GSSAPI error in gss_display_status called from <%s>\n"), m); + break; + } + report(ostrm, GT_("GSSAPI error %s: %.*s\n"), m, + (int)msg.length, (char *)msg.value); + (void)gss_release_buffer(&min, &msg); + } while(context); +} + +static void decode_status(const char *m, uint32_t major, uint32_t minor, + FILE *ostrm) +{ + decode_subr(m, major, GSS_C_GSS_CODE, ostrm); + decode_subr(m, minor, GSS_C_MECH_CODE, ostrm); +} + #define GSSAUTH_P_NONE 1 #define GSSAUTH_P_INTEGRITY 2 #define GSSAUTH_P_PRIVACY 4 -int do_gssauth(int sock, char *command, char *service, char *hostname, char *username) +static int import_name(const char *service, const char *hostname, + gss_name_t *target_name, flag verbose) { - gss_buffer_desc request_buf, send_token; - gss_buffer_t sec_token; - gss_name_t target_name; - gss_ctx_id_t context; - gss_OID mech_name; - gss_qop_t quality; - int cflags; + char *buf1; + size_t buf1siz; OM_uint32 maj_stat, min_stat; - char buf1[8192], buf2[8192], server_conf_flags; - unsigned long buf_size; - int result; + gss_buffer_desc request_buf; /* first things first: get an imap ticket for host */ - snprintf(buf1, sizeof(buf1), "%s@%s", service, hostname); + buf1siz = strlen(service) + 1 + strlen(hostname) + 1; + buf1 = (char *)xmalloc(buf1siz); + snprintf(buf1, buf1siz, "%s@%s", service, hostname); request_buf.value = buf1; request_buf.length = strlen(buf1) + 1; - maj_stat = gss_import_name(&min_stat, &request_buf, GSS_C_NT_HOSTBASED_SERVICE, - &target_name); + maj_stat = gss_import_name(&min_stat, &request_buf, + GSS_C_NT_HOSTBASED_SERVICE, target_name); if (maj_stat != GSS_S_COMPLETE) { + decode_status("gss_import_name", maj_stat, min_stat, stderr); report(stderr, GT_("Couldn't get service name for [%s]\n"), buf1); return PS_AUTHFAIL; } - else if (outlevel >= O_DEBUG) { - gss_display_name(&min_stat, target_name, &request_buf, &mech_name); + else if (outlevel >= O_DEBUG && verbose) { + (void)gss_display_name(&min_stat, *target_name, &request_buf, NULL); report(stderr, GT_("Using service name [%s]\n"), (char *)request_buf.value); - gss_release_buffer(&min_stat, &request_buf); + } + (void)gss_release_buffer(&min_stat, &request_buf); + + return PS_SUCCESS; +} + +/* If we don't have suitable credentials, don't bother trying GSSAPI, but + * fail right away. This is to avoid that a server - such as Microsoft + * Exchange 2007 - gets wedged and refuses different authentication + * mechanisms afterwards. */ +int check_gss_creds(const char *service, const char *hostname) +{ + OM_uint32 maj_stat, min_stat; + gss_cred_usage_t cu; + gss_name_t target_name; + + (void)import_name(service, hostname, &target_name, FALSE); + (void)gss_release_name(&min_stat, &target_name); + + maj_stat = gss_inquire_cred(&min_stat, GSS_C_NO_CREDENTIAL, + NULL, NULL, &cu, NULL); + if (maj_stat != GSS_S_COMPLETE + || (cu != GSS_C_INITIATE && cu != GSS_C_BOTH)) { + if (outlevel >= O_DEBUG) { + decode_status("gss_inquire_cred", maj_stat, min_stat, stdout); + report(stdout, GT_("No suitable GSSAPI credentials found. Skipping GSSAPI authentication.\n")); + report(stdout, GT_("If you want to use GSSAPI, you need credentials first, possibly from kinit.\n")); + } + return PS_AUTHFAIL; } + return PS_SUCCESS; +} + +int do_gssauth(int sock, const char *command, const char *service, + const char *hostname, const char *username) +{ + gss_buffer_desc request_buf, send_token; + gss_buffer_t sec_token; + gss_name_t target_name; + gss_ctx_id_t context; + gss_qop_t quality; + int cflags; + OM_uint32 maj_stat, min_stat; + char buf1[8192], buf2[8192], server_conf_flags; + unsigned long buf_size; + int result; + + result = import_name(service, hostname, &target_name, TRUE); + if (result) + return result; + gen_send(sock, "%s GSSAPI", command); /* upon receipt of the GSSAPI authentication request, server returns - * null data ready response. */ + * a null data ready challenge to us. */ result = gen_recv(sock, buf1, sizeof buf1); if (result) return result; + if (buf1[0] != '+' || strspn(buf1 + 1, " \t") < strlen(buf1 + 1)) { + if (outlevel >= O_VERBOSE) { + report(stdout, GT_("Received malformed challenge to \"%s GSSAPI\"!\n"), command); + } + goto cancelfail; + } + + /* now start the security context initialisation loop... */ sec_token = GSS_C_NO_BUFFER; context = GSS_C_NO_CONTEXT; if (outlevel >= O_VERBOSE) report(stdout, GT_("Sending credentials\n")); do { - send_token.length = 0; + send_token.length = 0; send_token.value = NULL; - maj_stat = gss_init_sec_context(&min_stat, - GSS_C_NO_CREDENTIAL, - &context, - target_name, - GSS_C_NO_OID, - GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, - 0, - GSS_C_NO_CHANNEL_BINDINGS, - sec_token, - NULL, - &send_token, - NULL, + maj_stat = gss_init_sec_context(&min_stat, + GSS_C_NO_CREDENTIAL, + &context, + target_name, + GSS_C_NO_OID, + GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, + 0, + GSS_C_NO_CHANNEL_BINDINGS, + sec_token, + NULL, + &send_token, + NULL, NULL); + if (maj_stat!=GSS_S_COMPLETE && maj_stat!=GSS_S_CONTINUE_NEEDED) { - report(stderr, GT_("Error exchanging credentials\n")); - gss_release_name(&min_stat, &target_name); - /* wake up server and await NO response */ - SockWrite(sock, "\r\n", 2); + if (outlevel >= O_VERBOSE) + decode_status("gss_init_sec_context", maj_stat, min_stat, stdout); + (void)gss_release_name(&min_stat, &target_name); + +cancelfail: + /* wake up server and cancel authentication */ + suppress_tags = TRUE; + gen_send(sock, "*"); + suppress_tags = FALSE; + result = gen_recv(sock, buf1, sizeof buf1); + if (outlevel >= O_VERBOSE) + report(stderr, GT_("Error exchanging credentials\n")); if (result) return result; return PS_AUTHFAIL; @@ -116,7 +206,7 @@ int do_gssauth(int sock, char *command, char *service, char *hostname, char *use gss_release_buffer(&min_stat, &send_token); suppress_tags = TRUE; - gen_send(sock, buf1, strlen(buf1)); + gen_send(sock, "%s", buf1); suppress_tags = FALSE; if (maj_stat == GSS_S_CONTINUE_NEEDED) { @@ -145,9 +235,10 @@ int do_gssauth(int sock, char *command, char *service, char *hostname, char *use request_buf.length = 0; request_buf.value = buf2; - maj_stat = gss_unwrap(&min_stat, context, + maj_stat = gss_unwrap(&min_stat, context, &request_buf, &send_token, &cflags, &quality); if (maj_stat != GSS_S_COMPLETE) { + decode_status("gss_unwrap", maj_stat, min_stat, stderr); report(stderr, GT_("Couldn't unwrap security level data\n")); gss_release_buffer(&min_stat, &send_token); return PS_AUTHFAIL; @@ -189,7 +280,7 @@ int do_gssauth(int sock, char *command, char *service, char *hostname, char *use to64frombits(buf1, send_token.value, send_token.length); suppress_tags = TRUE; - result = gen_transact(sock, buf1, strlen(buf1)); + result = gen_transact(sock, "%s", buf1); suppress_tags = FALSE; /* flush security context */ @@ -197,6 +288,7 @@ int do_gssauth(int sock, char *command, char *service, char *hostname, char *use report(stdout, GT_("Releasing GSS credentials\n")); maj_stat = gss_delete_sec_context(&min_stat, &context, &send_token); if (maj_stat != GSS_S_COMPLETE) { + decode_status("gss_delete_sec_context", maj_stat, min_stat, stderr); report(stderr, GT_("Error releasing credentials\n")); return PS_AUTHFAIL; }