/* misc.c - miscellaneous functions * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, * 2005, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * 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 HAVE_W32_SYSTEM #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 #endif /*HAVE_W32_SYSTEM*/ #include "gpg.h" #ifdef HAVE_W32_SYSTEM # include "errors.h" # include "dynload.h" #endif /*HAVE_W32_SYSTEM*/ #include "util.h" #include "main.h" #include "photoid.h" #include "options.h" #include "i18n.h" static int string_count_chr (const char *string, int c) { int count; for (count=0; *string; string++ ) if ( *string == c ) count++; return count; } #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 registered 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 (gcry_mpi_t a) { u16 csum; byte *buffer; unsigned int nbytes; unsigned int nbits; if ( gcry_mpi_print (GCRYMPI_FMT_PGP, NULL, 0, &nbytes, a) ) BUG (); /* Fixme: For numbers not in secure memory we should use a stack * based buffer and only allocate a larger one if mpi_print returns * an error. */ buffer = (gcry_is_secure(a)? gcry_xmalloc_secure (nbytes) : gcry_xmalloc (nbytes)); if ( gcry_mpi_print (GCRYMPI_FMT_PGP, buffer, nbytes, NULL, a) ) BUG (); nbits = gcry_mpi_get_nbits (a); csum = checksum_u16 (nbits); csum += checksum (buffer, nbytes); xfree (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"), gcry_pk_algo_name (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"), gcry_cipher_algo_name (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"), gcry_md_algo_name (algo)); } } else if(algo==DIGEST_ALGO_MD5) log_info (_("WARNING: digest algorithm %s is deprecated\n"), gcry_md_algo_name (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; /* Although 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 takes place. * Of course, we could 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 additonal checks on * the OpenPGP contraints for the algo ID. */ int openpgp_cipher_test_algo( int algo ) { if ( algo < 0 || algo > 110 ) return gpg_error (GPG_ERR_CIPHER_ALGO); return gcry_cipher_test_algo (algo); } int openpgp_pk_test_algo( int algo ) { if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (algo < 0 || algo > 110) return gpg_error (GPG_ERR_PUBKEY_ALGO); return gcry_pk_test_algo (algo); } int openpgp_pk_test_algo2( int algo, unsigned int use ) { int use_buf = use; size_t sizeof_use_buf = sizeof (use_buf); if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (algo < 0 || algo > 110) return gpg_error (GPG_ERR_PUBKEY_ALGO); return gcry_pk_algo_info (algo, GCRYCTL_TEST_ALGO, &use_buf, &sizeof_use_buf); } 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_CERT | 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_CERT | PUBKEY_USAGE_SIG; break; case PUBKEY_ALGO_ELGAMAL_E: use = PUBKEY_USAGE_ENC; break; case PUBKEY_ALGO_DSA: use = PUBKEY_USAGE_CERT | PUBKEY_USAGE_SIG | PUBKEY_USAGE_AUTH; break; default: break; } return use; } int openpgp_md_test_algo( int algo ) { if (algo < 0 || algo > 110) return gpg_error (GPG_ERR_DIGEST_ALGO); return gcry_md_test_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 %s for more information\n"), "http://www.gnupg.org/faq/why-not-idea.html"); 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 xfreed. 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=xrealloc(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= xmalloc_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; if (str && !strcmp (str, "help")) { int i,maxlen=0; /* Figure out the longest option name so we can line these up neatly. */ for(i=0;opts[i].name;i++) if(opts[i].help && maxlen='A' && file[0]<='Z') || (file[0]>='a' && file[0]<='z')) && file[1]==':') #else || file[0]=='/' #endif ) return access(file,mode); else { /* At least as large as, but most often larger than we need. */ char *buffer=xmalloc(strlen(envpath)+1+strlen(file)+1); char *split,*item,*path=xstrdup(envpath); split=path; while((item=strsep(&split,PATHSEP_S))) { strcpy(buffer,item); strcat(buffer,"/"); strcat(buffer,file); ret=access(buffer,mode); if(ret==0) break; } xfree(path); xfree(buffer); } return ret; } /* Temporary helper. */ int pubkey_get_npkey( int algo ) { size_t n; if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NPKEY, NULL, &n)) n = 0; return n; } /* Temporary helper. */ int pubkey_get_nskey( int algo ) { size_t n; if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NSKEY, NULL, &n )) n = 0; return n; } /* Temporary helper. */ int pubkey_get_nsig( int algo ) { size_t n; if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NSIGN, NULL, &n)) n = 0; return n; } /* Temporary helper. */ int pubkey_get_nenc( int algo ) { size_t n; if (algo == GCRY_PK_ELG_E) algo = GCRY_PK_ELG; if (gcry_pk_algo_info( algo, GCRYCTL_GET_ALGO_NENCR, NULL, &n )) n = 0; return n; } /* Temporary helper. */ unsigned int pubkey_nbits( int algo, gcry_mpi_t *key ) { int rc, nbits; gcry_sexp_t sexp; if( algo == GCRY_PK_DSA ) { rc = gcry_sexp_build ( &sexp, NULL, "(public-key(dsa(p%m)(q%m)(g%m)(y%m)))", key[0], key[1], key[2], key[3] ); } else if( algo == GCRY_PK_ELG || algo == GCRY_PK_ELG_E ) { rc = gcry_sexp_build ( &sexp, NULL, "(public-key(elg(p%m)(g%m)(y%m)))", key[0], key[1], key[2] ); } else if( algo == GCRY_PK_RSA ) { rc = gcry_sexp_build ( &sexp, NULL, "(public-key(rsa(n%m)(e%m)))", key[0], key[1] ); } else return 0; if ( rc ) BUG (); nbits = gcry_pk_get_nbits( sexp ); gcry_sexp_release( sexp ); return nbits; } /* FIXME: Use gcry_mpi_print directly. */ int mpi_print( FILE *fp, gcry_mpi_t a, int mode ) { int n=0; if( !a ) return fprintf(fp, "[MPI_NULL]"); if( !mode ) { unsigned int n1; n1 = gcry_mpi_get_nbits(a); n += fprintf(fp, "[%u bits]", n1); } else { unsigned char *buffer; if (gcry_mpi_aprint (GCRYMPI_FMT_HEX, &buffer, NULL, a)) BUG (); fputs( buffer, fp ); n += strlen(buffer); gcry_free( buffer ); } return n; }