/* misc.c - miscellaneous functions * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, * 2004, 2005 Free Software Foundation, Inc. * * This file is part of GnuPG. * * GnuPG is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * GnuPG is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ #include #include #include #include #include #include #if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2 #include #include #endif #ifdef HAVE_SETRLIMIT #include #include #include #endif #ifdef ENABLE_SELINUX_HACKS #include #endif #ifdef _WIN32 #include #include #include #include #ifndef CSIDL_APPDATA #define CSIDL_APPDATA 0x001a #endif #ifndef CSIDL_LOCAL_APPDATA #define CSIDL_LOCAL_APPDATA 0x001c #endif #ifndef CSIDL_FLAG_CREATE #define CSIDL_FLAG_CREATE 0x8000 #endif #include "errors.h" #include "dynload.h" #endif /*_WIN32*/ #include "util.h" #include "main.h" #include "photoid.h" #include "options.h" #include "i18n.h" #include "cardglue.h" #ifdef ENABLE_SELINUX_HACKS /* A object and a global variable to keep track of files marked as secured. */ struct secured_file_item { struct secured_file_item *next; ino_t ino; dev_t dev; }; static struct secured_file_item *secured_files; #endif /*ENABLE_SELINUX_HACKS*/ #if defined(__linux__) && defined(__alpha__) && __GLIBC__ < 2 static int setsysinfo(unsigned long op, void *buffer, unsigned long size, int *start, void *arg, unsigned long flag) { return syscall(__NR_osf_setsysinfo, op, buffer, size, start, arg, flag); } void trap_unaligned(void) { unsigned int buf[2]; buf[0] = SSIN_UACPROC; buf[1] = UAC_SIGBUS | UAC_NOPRINT; setsysinfo(SSI_NVPAIRS, buf, 1, 0, 0, 0); } #else void trap_unaligned(void) { /* dummy */ } #endif int disable_core_dumps() { #ifdef HAVE_DOSISH_SYSTEM return 0; #else #ifdef HAVE_SETRLIMIT struct rlimit limit; limit.rlim_cur = 0; limit.rlim_max = 0; if( !setrlimit( RLIMIT_CORE, &limit ) ) return 0; if( errno != EINVAL && errno != ENOSYS ) log_fatal(_("can't disable core dumps: %s\n"), strerror(errno) ); #endif return 1; #endif } /* For the sake of SELinux we want to restrict access through gpg to certain files we keep under our own control. This function registers such a file and is_secured_file may then be used to check whether a file has ben registered as secured. */ void register_secured_file (const char *fname) { #ifdef ENABLE_SELINUX_HACKS struct stat buf; struct secured_file_item *sf; /* Note that we stop immediatley if something goes wrong here. */ if (stat (fname, &buf)) log_fatal (_("fstat of `%s' failed in %s: %s\n"), fname, "register_secured_file", strerror (errno)); /* log_debug ("registering `%s' i=%lu.%lu\n", fname, */ /* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */ for (sf=secured_files; sf; sf = sf->next) { if (sf->ino == buf.st_ino && sf->dev == buf.st_dev) return; /* Already registered. */ } sf = xmalloc (sizeof *sf); sf->ino = buf.st_ino; sf->dev = buf.st_dev; sf->next = secured_files; secured_files = sf; #endif /*ENABLE_SELINUX_HACKS*/ } /* Remove a file registerd as secure. */ void unregister_secured_file (const char *fname) { #ifdef ENABLE_SELINUX_HACKS struct stat buf; struct secured_file_item *sf, *sfprev; if (stat (fname, &buf)) { log_error (_("fstat of `%s' failed in %s: %s\n"), fname, "unregister_secured_file", strerror (errno)); return; } /* log_debug ("unregistering `%s' i=%lu.%lu\n", fname, */ /* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */ for (sfprev=NULL,sf=secured_files; sf; sfprev=sf, sf = sf->next) { if (sf->ino == buf.st_ino && sf->dev == buf.st_dev) { if (sfprev) sfprev->next = sf->next; else secured_files = sf->next; xfree (sf); return; } } #endif /*ENABLE_SELINUX_HACKS*/ } /* Return true if FD is corresponds to a secured file. Using -1 for FS is allowed and will return false. */ int is_secured_file (int fd) { #ifdef ENABLE_SELINUX_HACKS struct stat buf; struct secured_file_item *sf; if (fd == -1) return 0; /* No file descriptor so it can't be secured either. */ /* Note that we print out a error here and claim that a file is secure if something went wrong. */ if (fstat (fd, &buf)) { log_error (_("fstat(%d) failed in %s: %s\n"), fd, "is_secured_file", strerror (errno)); return 1; } /* log_debug ("is_secured_file (%d) i=%lu.%lu\n", fd, */ /* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */ for (sf=secured_files; sf; sf = sf->next) { if (sf->ino == buf.st_ino && sf->dev == buf.st_dev) return 1; /* Yes. */ } #endif /*ENABLE_SELINUX_HACKS*/ return 0; /* No. */ } /* Return true if FNAME is corresponds to a secured file. Using NULL, "" or "-" for FS is allowed and will return false. This function is used before creating a file, thus it won't fail if the file does not exist. */ int is_secured_filename (const char *fname) { #ifdef ENABLE_SELINUX_HACKS struct stat buf; struct secured_file_item *sf; if (iobuf_is_pipe_filename (fname) || !*fname) return 0; /* Note that we print out a error here and claim that a file is secure if something went wrong. */ if (stat (fname, &buf)) { if (errno == ENOENT || errno == EPERM || errno == EACCES) return 0; log_error (_("fstat of `%s' failed in %s: %s\n"), fname, "is_secured_filename", strerror (errno)); return 1; } /* log_debug ("is_secured_filename (%s) i=%lu.%lu\n", fname, */ /* (unsigned long)buf.st_dev, (unsigned long)buf.st_ino); */ for (sf=secured_files; sf; sf = sf->next) { if (sf->ino == buf.st_ino && sf->dev == buf.st_dev) return 1; /* Yes. */ } #endif /*ENABLE_SELINUX_HACKS*/ return 0; /* No. */ } u16 checksum_u16( unsigned n ) { u16 a; a = (n >> 8) & 0xff; a += n & 0xff; return a; } u16 checksum( byte *p, unsigned n ) { u16 a; for(a=0; n; n-- ) a += *p++; return a; } u16 checksum_mpi( MPI a ) { u16 csum; byte *buffer; unsigned nbytes; unsigned nbits; buffer = mpi_get_buffer( a, &nbytes, NULL ); nbits = mpi_get_nbits(a); csum = checksum_u16( nbits ); csum += checksum( buffer, nbytes ); m_free( buffer ); return csum; } u32 buffer_to_u32( const byte *buffer ) { unsigned long a; a = *buffer << 24; a |= buffer[1] << 16; a |= buffer[2] << 8; a |= buffer[3]; return a; } void print_pubkey_algo_note( int algo ) { if(algo >= 100 && algo <= 110) { static int warn=0; if(!warn) { warn=1; log_info(_("WARNING: using experimental public key algorithm %s\n"), pubkey_algo_to_string(algo)); } } } void print_cipher_algo_note( int algo ) { if(algo >= 100 && algo <= 110) { static int warn=0; if(!warn) { warn=1; log_info(_("WARNING: using experimental cipher algorithm %s\n"), cipher_algo_to_string(algo)); } } } void print_digest_algo_note( int algo ) { if(algo >= 100 && algo <= 110) { static int warn=0; if(!warn) { warn=1; log_info(_("WARNING: using experimental digest algorithm %s\n"), digest_algo_to_string(algo)); } } else if(algo==DIGEST_ALGO_MD5) log_info(_("WARNING: digest algorithm %s is deprecated\n"), digest_algo_to_string(algo)); } /* Return a string which is used as a kind of process ID */ const byte * get_session_marker( size_t *rlen ) { static byte marker[SIZEOF_UNSIGNED_LONG*2]; static int initialized; if ( !initialized ) { volatile ulong aa, bb; /* we really want the uninitialized value */ ulong a, b; initialized = 1; /* also this marker is guessable it is not easy to use this * for a faked control packet because an attacker does not * have enough control about the time the verification does * take place. Of course, we can add just more random but * than we need the random generator even for verification * tasks - which does not make sense. */ a = aa ^ (ulong)getpid(); b = bb ^ (ulong)time(NULL); memcpy( marker, &a, SIZEOF_UNSIGNED_LONG ); memcpy( marker+SIZEOF_UNSIGNED_LONG, &b, SIZEOF_UNSIGNED_LONG ); } *rlen = sizeof(marker); return marker; } /**************** * Wrapper around the libgcrypt function with addional checks on * openPGP contraints for the algo ID. */ int openpgp_cipher_test_algo( int algo ) { if( algo < 0 || algo > 110 ) return G10ERR_CIPHER_ALGO; return check_cipher_algo(algo); } int openpgp_pk_test_algo( int algo, unsigned int usage_flags ) { if( algo < 0 || algo > 110 ) return G10ERR_PUBKEY_ALGO; return check_pubkey_algo2( algo, usage_flags ); } int openpgp_pk_algo_usage ( int algo ) { int use = 0; /* they are hardwired in gpg 1.0 */ switch ( algo ) { case PUBKEY_ALGO_RSA: use = PUBKEY_USAGE_SIG | PUBKEY_USAGE_ENC | PUBKEY_USAGE_AUTH; break; case PUBKEY_ALGO_RSA_E: use = PUBKEY_USAGE_ENC; break; case PUBKEY_ALGO_RSA_S: use = PUBKEY_USAGE_SIG; break; case PUBKEY_ALGO_ELGAMAL_E: use = PUBKEY_USAGE_ENC; break; case PUBKEY_ALGO_DSA: use = PUBKEY_USAGE_SIG | PUBKEY_USAGE_AUTH; break; default: break; } return use; } int openpgp_md_test_algo( int algo ) { if( algo < 0 || algo > 110 ) return G10ERR_DIGEST_ALGO; return check_digest_algo(algo); } #ifdef USE_IDEA /* Special warning for the IDEA cipher */ void idea_cipher_warn(int show) { static int warned=0; if(!warned || show) { log_info(_("the IDEA cipher plugin is not present\n")); log_info(_("please see http://www.gnupg.org/why-not-idea.html " "for more information\n")); warned=1; } } #endif static unsigned long get_signature_count(PKT_secret_key *sk) { #ifdef ENABLE_CARD_SUPPORT if(sk && sk->is_protected && sk->protect.s2k.mode==1002) { struct agent_card_info_s info; if(agent_scd_getattr("SIG-COUNTER",&info)==0) return info.sig_counter; } #endif /* How to do this without a card? */ return 0; } /* Expand %-strings. Returns a string which must be m_freed. Returns NULL if the string cannot be expanded (too large). */ char * pct_expando(const char *string,struct expando_args *args) { const char *ch=string; int idx=0,maxlen=0,done=0; u32 pk_keyid[2]={0,0},sk_keyid[2]={0,0}; char *ret=NULL; if(args->pk) keyid_from_pk(args->pk,pk_keyid); if(args->sk) keyid_from_sk(args->sk,sk_keyid); /* This is used so that %k works in photoid command strings in --list-secret-keys (which of course has a sk, but no pk). */ if(!args->pk && args->sk) keyid_from_sk(args->sk,pk_keyid); while(*ch!='\0') { char *str=NULL; if(!done) { /* 8192 is way bigger than we'll need here */ if(maxlen>=8192) goto fail; maxlen+=1024; ret=m_realloc(ret,maxlen); } done=0; if(*ch=='%') { switch(*(ch+1)) { case 's': /* short key id */ if(idx+8sk)); idx+=strlen(&ret[idx]); done=1; } break; case 'p': /* primary pk fingerprint of a sk */ case 'f': /* pk fingerprint */ case 'g': /* sk fingerprint */ { byte array[MAX_FINGERPRINT_LEN]; size_t len; int i; if((*(ch+1))=='p' && args->sk) { if(args->sk->is_primary) fingerprint_from_sk(args->sk,array,&len); else if(args->sk->main_keyid[0] || args->sk->main_keyid[1]) { PKT_public_key *pk= m_alloc_clear(sizeof(PKT_public_key)); if(get_pubkey_fast(pk,args->sk->main_keyid)==0) fingerprint_from_pk(pk,array,&len); else memset(array,0,(len=MAX_FINGERPRINT_LEN)); free_public_key(pk); } else memset(array,0,(len=MAX_FINGERPRINT_LEN)); } else if((*(ch+1))=='f' && args->pk) fingerprint_from_pk(args->pk,array,&len); else if((*(ch+1))=='g' && args->sk) fingerprint_from_sk(args->sk,array,&len); else memset(array,0,(len=MAX_FINGERPRINT_LEN)); if(idx+(len*2)imagetype,0); /* fall through */ case 'T': /* e.g. "image/jpeg" */ if(str==NULL) str=image_type_to_string(args->imagetype,2); if(idx+strlen(str)=0 && algo<=3) return 0; #else if(algo>=0 && algo<=2) return 0; #endif return G10ERR_COMPR_ALGO; } int default_cipher_algo(void) { if(opt.def_cipher_algo) return opt.def_cipher_algo; else if(opt.personal_cipher_prefs) return opt.personal_cipher_prefs[0].value; else return opt.s2k_cipher_algo; } /* There is no default_digest_algo function, but see sign.c:hash_for() */ int default_compress_algo(void) { if(opt.compress_algo!=-1) return opt.compress_algo; else if(opt.personal_compress_prefs) return opt.personal_compress_prefs[0].value; else return DEFAULT_COMPRESS_ALGO; } const char * compliance_option_string(void) { switch(opt.compliance) { case CO_RFC2440: return "--openpgp"; case CO_PGP2: return "--pgp2"; case CO_PGP6: return "--pgp6"; case CO_PGP7: return "--pgp7"; case CO_PGP8: return "--pgp8"; default: return "???"; } } static const char * compliance_string(void) { switch(opt.compliance) { case CO_RFC2440: return "OpenPGP"; case CO_PGP2: return "PGP 2.x"; case CO_PGP6: return "PGP 6.x"; case CO_PGP7: return "PGP 7.x"; case CO_PGP8: return "PGP 8.x"; default: return "???"; } } void compliance_failure(void) { log_info(_("this message may not be usable by %s\n"),compliance_string()); opt.compliance=CO_GNUPG; } /* Break a string into successive option pieces. Accepts single word options and key=value argument options. */ char * optsep(char **stringp) { char *tok,*end; tok=*stringp; if(tok) { end=strpbrk(tok," ,="); if(end) { int sawequals=0; char *ptr=end; /* what we need to do now is scan along starting with *end, If the next character we see (ignoring spaces) is an = sign, then there is an argument. */ while(*ptr) { if(*ptr=='=') sawequals=1; else if(*ptr!=' ') break; ptr++; } /* There is an argument, so grab that too. At this point, ptr points to the first character of the argument. */ if(sawequals) { /* Is it a quoted argument? */ if(*ptr=='"') { ptr++; end=strchr(ptr,'"'); if(end) end++; } else end=strpbrk(ptr," ,"); } if(end && *end) { *end='\0'; *stringp=end+1; } else *stringp=NULL; } else *stringp=NULL; } return tok; } /* Breaks an option value into key and value. Returns NULL if there is no value. Note that "string" is modified to remove the =value part. */ char * argsplit(char *string) { char *equals,*arg=NULL; equals=strchr(string,'='); if(equals) { char *quote,*space; *equals='\0'; arg=equals+1; /* Quoted arg? */ quote=strchr(arg,'"'); if(quote) { arg=quote+1; quote=strchr(arg,'"'); if(quote) *quote='\0'; } else { size_t spaces; /* Trim leading spaces off of the arg */ spaces=strspn(arg," "); arg+=spaces; } /* Trim tailing spaces off of the tag */ space=strchr(string,' '); if(space) *space='\0'; } return arg; } /* Return the length of the initial token, leaving off any argument. */ static size_t optlen(const char *s) { char *end=strpbrk(s," ="); if(end) return end-s; else return strlen(s); } int parse_options(char *str,unsigned int *options, struct parse_options *opts,int noisy) { char *tok; while((tok=optsep(&str))) { int i,rev=0; char *otok=tok; if(tok[0]=='\0') continue; if(ascii_strncasecmp("no-",tok,3)==0) { rev=1; tok+=3; } for(i=0;opts[i].name;i++) { size_t toklen=optlen(tok); if(ascii_strncasecmp(opts[i].name,tok,toklen)==0) { /* We have a match, but it might be incomplete */ if(toklen!=strlen(opts[i].name)) { int j; for(j=i+1;opts[j].name;j++) { if(ascii_strncasecmp(opts[j].name,tok,toklen)==0) { if(noisy) log_info(_("ambiguous option `%s'\n"),otok); return 0; } } } if(rev) { *options&=~opts[i].bit; if(opts[i].value) *opts[i].value=NULL; } else { *options|=opts[i].bit; if(opts[i].value) *opts[i].value=argsplit(tok); } break; } } if(!opts[i].name) { if(noisy) log_info(_("unknown option `%s'\n"),otok); return 0; } } return 1; } /* This is a helper function to load a Windows function from either of one DLLs. */ #ifdef HAVE_W32_SYSTEM static HRESULT w32_shgetfolderpath (HWND a, int b, HANDLE c, DWORD d, LPSTR e) { static int initialized; static HRESULT (* WINAPI func)(HWND,int,HANDLE,DWORD,LPSTR); if (!initialized) { static char *dllnames[] = { "shell32.dll", "shfolder.dll", NULL }; void *handle; int i; initialized = 1; for (i=0, handle = NULL; !handle && dllnames[i]; i++) { handle = dlopen (dllnames[i], RTLD_LAZY); if (handle) { func = dlsym (handle, "SHGetFolderPathA"); if (!func) { dlclose (handle); handle = NULL; } } } } if (func) return func (a,b,c,d,e); else return -1; } #endif /*HAVE_W32_SYSTEM*/ /* Set up the default home directory. The usual --homedir option should be parsed later. */ char * default_homedir (void) { char *dir; dir = getenv("GNUPGHOME"); #ifdef HAVE_W32_SYSTEM if (!dir || !*dir) dir = read_w32_registry_string (NULL, "Software\\GNU\\GnuPG", "HomeDir"); if (!dir || !*dir) { char path[MAX_PATH]; /* It might be better to use LOCAL_APPDATA because this is defined as "non roaming" and thus more likely to be kept locally. For private keys this is desired. However, given that many users copy private keys anyway forth and back, using a system roaming serives might be better than to let them do it manually. A security conscious user will anyway use the registry entry to have better control. */ if (w32_shgetfolderpath (NULL, CSIDL_APPDATA|CSIDL_FLAG_CREATE, NULL, 0, path) >= 0) { char *tmp = xmalloc (strlen (path) + 6 +1); strcpy (stpcpy (tmp, path), "\\gnupg"); dir = tmp; /* Try to create the directory if it does not yet exists. */ if (access (dir, F_OK)) CreateDirectory (dir, NULL); } } #endif /*HAVE_W32_SYSTEM*/ if (!dir || !*dir) dir = GNUPG_HOMEDIR; return dir; }