/* keygen.c - generate a key pair * Copyright (C) 1998 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 #include #include "util.h" #include "main.h" #include "packet.h" #include "cipher.h" #include "ttyio.h" #include "options.h" #include "keydb.h" #include "i18n.h" #if 0 #define TEST_ALGO 1 #define TEST_NBITS 256 #define TEST_UID "Karl Test" #endif #if defined(HAVE_RSA_CIPHER) && 0 #define ENABLE_RSA_KEYGEN 1 #endif static u16 checksum_u16( unsigned n ) { u16 a; a = (n >> 8) & 0xff; a |= n & 0xff; return a; } static u16 checksum( byte *p, unsigned n ) { u16 a; for(a=0; n; n-- ) a += *p++; return a; } static u16 checksum_mpi( MPI a ) { u16 csum; byte *buffer; unsigned nbytes; buffer = mpi_get_buffer( a, &nbytes, NULL ); csum = checksum_u16( nbytes*8 ); csum += checksum( buffer, nbytes ); m_free( buffer ); return csum; } static void write_uid( KBNODE root, const char *s ) { PACKET *pkt = m_alloc_clear(sizeof *pkt ); size_t n = strlen(s); pkt->pkttype = PKT_USER_ID; pkt->pkt.user_id = m_alloc( sizeof *pkt->pkt.user_id + n - 1 ); pkt->pkt.user_id->len = n; strcpy(pkt->pkt.user_id->name, s); add_kbnode( root, new_kbnode( pkt ) ); } static int write_selfsig( KBNODE root, KBNODE pub_root, PKT_secret_cert *skc ) { PACKET *pkt; PKT_signature *sig; PKT_user_id *uid; int rc=0; KBNODE node; PKT_public_cert *pkc; if( opt.verbose ) log_info(_("writing self signature\n")); /* get the uid packet from the list */ node = find_kbnode( root, PKT_USER_ID ); if( !node ) BUG(); /* no user id packet in tree */ uid = node->pkt->pkt.user_id; /* get the pkc packet from the pub_tree */ node = find_kbnode( pub_root, PKT_PUBLIC_CERT ); if( !node ) BUG(); pkc = node->pkt->pkt.public_cert; /* and make the signature */ rc = make_keysig_packet( &sig, pkc, uid, skc, 0x13, DIGEST_ALGO_RMD160 ); if( rc ) { log_error("make_keysig_packet failed: %s\n", g10_errstr(rc) ); return rc; } pkt = m_alloc_clear( sizeof *pkt ); pkt->pkttype = PKT_SIGNATURE; pkt->pkt.signature = sig; add_kbnode( root, new_kbnode( pkt ) ); return rc; } static int gen_elg(unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek, byte *salt, PKT_secret_cert **ret_skc ) { int rc; int i; PACKET *pkt; PKT_secret_cert *skc; PKT_public_cert *pkc; ELG_public_key pk; ELG_secret_key sk; MPI *factors; elg_generate( &pk, &sk, nbits, &factors ); skc = m_alloc_clear( sizeof *skc ); pkc = m_alloc_clear( sizeof *pkc ); skc->timestamp = pkc->timestamp = make_timestamp(); skc->valid_days = pkc->valid_days = 0; /* fixme: make it configurable*/ skc->pubkey_algo = pkc->pubkey_algo = PUBKEY_ALGO_ELGAMAL; pkc->d.elg.p = pk.p; pkc->d.elg.g = pk.g; pkc->d.elg.y = pk.y; skc->d.elg.p = sk.p; skc->d.elg.g = sk.g; skc->d.elg.y = sk.y; skc->d.elg.x = sk.x; skc->d.elg.is_protected = 0; skc->d.elg.protect.algo = 0; skc->d.elg.csum = checksum_mpi( skc->d.elg.x ); /* return an unprotected version of the skc */ *ret_skc = copy_secret_cert( NULL, skc ); if( dek ) { skc->d.elg.protect.algo = CIPHER_ALGO_BLOWFISH; skc->d.elg.protect.s2k = 1; skc->d.elg.protect.hash = DIGEST_ALGO_RMD160; memcpy(skc->d.elg.protect.salt, salt, 8); randomize_buffer(skc->d.elg.protect.iv, 8, 1); rc = protect_secret_key( skc, dek ); if( rc ) { log_error("protect_secret_key failed: %s\n", g10_errstr(rc) ); free_public_cert(pkc); free_secret_cert(skc); return rc; } } pkt = m_alloc_clear(sizeof *pkt); pkt->pkttype = PKT_PUBLIC_CERT; pkt->pkt.public_cert = pkc; add_kbnode(pub_root, new_kbnode( pkt )); /* don't know wether it make sense to have the factors, so for now * we store them in the secret keyring (but they are of secret) */ pkt = m_alloc_clear(sizeof *pkt); pkt->pkttype = PKT_SECRET_CERT; pkt->pkt.secret_cert = skc; add_kbnode(sec_root, new_kbnode( pkt )); for(i=0; factors[i]; i++ ) add_kbnode( sec_root, make_mpi_comment_node("#:ELG_factor:", factors[i] )); return 0; } #ifdef ENABLE_RSA_KEYGEN static int gen_rsa(unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek, byte *salt, PKT_secret_cert **ret_skc ) { int rc; PACKET *pkt; PKT_secret_cert *skc; PKT_public_cert *pkc; RSA_public_key pk; RSA_secret_key sk; rsa_generate( &pk, &sk, nbits ); skc = m_alloc_clear( sizeof *skc ); pkc = m_alloc_clear( sizeof *pkc ); skc->timestamp = pkc->timestamp = make_timestamp(); skc->valid_days = pkc->valid_days = 0; /* fixme: make it configurable*/ skc->pubkey_algo = pkc->pubkey_algo = PUBKEY_ALGO_RSA; memset(&pkc->mfx, 0, sizeof pkc->mfx); pkc->d.rsa.rsa_n = pk.n; pkc->d.rsa.rsa_e = pk.e; skc->d.rsa.rsa_n = sk.n; skc->d.rsa.rsa_e = sk.e; skc->d.rsa.rsa_d = sk.d; skc->d.rsa.rsa_p = sk.p; skc->d.rsa.rsa_q = sk.q; skc->d.rsa.rsa_u = sk.u; skc->d.rsa.csum = checksum_mpi( skc->d.rsa.rsa_d ); skc->d.rsa.csum += checksum_mpi( skc->d.rsa.rsa_p ); skc->d.rsa.csum += checksum_mpi( skc->d.rsa.rsa_q ); skc->d.rsa.csum += checksum_mpi( skc->d.rsa.rsa_u ); /* return an unprotected version of the skc */ *ret_skc = copy_secret_cert( NULL, skc ); if( dek ) { skc->d.rsa.is_protected = 1; skc->d.rsa.protect_algo = CIPHER_ALGO_BLOWFISH; randomize_buffer( skc->d.rsa.protect.blowfish.iv, 8, 1); skc->d.rsa.csum += checksum( skc->d.rsa.protect.blowfish.iv, 8 ); rc = protect_secret_key( skc, dek ); if( rc ) { log_error("protect_secret_key failed: %s\n", g10_errstr(rc) ); free_public_cert(pkc); free_secret_cert(skc); return rc; } } pkt = m_alloc_clear(sizeof *pkt); pkt->pkttype = PKT_PUBLIC_CERT; pkt->pkt.public_cert = pkc; add_kbnode(pub_root, new_kbnode( pkt )); pkt = m_alloc_clear(sizeof *pkt); pkt->pkttype = PKT_SECRET_CERT; pkt->pkt.secret_cert = skc; add_kbnode(sec_root, new_kbnode( pkt )); return rc; } #endif /*ENABLE_RSA_KEYGEN*/ static int gen_dsa(unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek, byte *salt, PKT_secret_cert **ret_skc ) { return G10ERR_GENERAL; } /**************** * Generate a keypair */ void generate_keypair() { char *answer; unsigned nbits; char *pub_fname = NULL; char *sec_fname = NULL; char *uid = NULL; KBNODE pub_root = NULL; KBNODE sec_root = NULL; PKT_secret_cert *skc = NULL; DEK *dek = NULL; byte *salt; int rc; int algo; const char *algo_name; char *aname, *acomment, *amail; #ifndef TEST_ALGO if( opt.batch || opt.answer_yes || opt.answer_no ) log_fatal(_("Key generation can only be used in interactive mode\n")); tty_printf(_("Please select the algorithm to use:\n" " (1) ElGamal is the suggested one.\n" " (2) DSA can only be used for signatures.\n")); #ifdef ENABLE_RSA_KEYGEN tty_printf(_(" (3) RSA cannot be used in the U.S.\n")); #endif #endif for(;;) { #ifdef TEST_ALGO algo = TEST_ALGO; #else #ifdef ENABLE_RSA_KEYGEN answer = tty_get(_("Your selection? (1,2,3) ")); #else answer = tty_get(_("Your selection? (1,2) ")); #endif tty_kill_prompt(); algo = *answer? atoi(answer): 1; m_free(answer); #endif if( algo == 1 ) { algo = PUBKEY_ALGO_ELGAMAL; algo_name = "ElGamal"; break; } else if( algo == 2 ) { algo = PUBKEY_ALGO_DSA; algo_name = "DSA"; tty_printf(_("Sorry; DSA is not yet supported.\n")); } #ifdef ENABLE_RSA_KEYGEN else if( algo == 3 ) { algo = PUBKEY_ALGO_RSA; algo_name = "RSA"; break; } #endif } tty_printf(_("About to generate a new %s keypair.\n" " minimum keysize is 768 bits\n" " default keysize is 1024 bits\n" " highest suggested keysize is 2048 bits\n"), algo_name ); for(;;) { #ifdef TEST_NBITS nbits = TEST_NBITS; #else answer = tty_get(_("What keysize do you want? (1024) ")); tty_kill_prompt(); nbits = *answer? atoi(answer): 1024; m_free(answer); #endif if( algo == PUBKEY_ALGO_DSA && (nbits < 512 || nbits > 1024) ) tty_printf(_("DSA does only allow keysizes from 512 to 1024\n")); else if( nbits < 768 ) tty_printf(_("keysize too small; 768 is smallest value allowed.\n")); else if( nbits > 2048 ) { tty_printf(_("Keysizes larger than 2048 are not suggested, because " "computations take REALLY long!\n")); answer = tty_get(_("Are you sure, that you want this keysize? ")); tty_kill_prompt(); if( answer_is_yes(answer) ) { m_free(answer); tty_printf(_("Okay, but keep in mind that your monitor " "and keyboard radiation is also very vulnerable " "to attacks!\n")); break; } m_free(answer); } else break; } tty_printf(_("Requested keysize is %u bits\n"), nbits ); if( algo == PUBKEY_ALGO_DSA && (nbits % 64) ) { nbits = ((nbits + 63) / 64) * 64; tty_printf(_("rounded up to %u bits\n"), nbits ); } else if( (nbits % 32) ) { nbits = ((nbits + 31) / 32) * 32; tty_printf(_("rounded up to %u bits\n"), nbits ); } #ifdef TEST_UID uid = m_alloc(strlen(TEST_UID)+1); strcpy(uid, TEST_UID); #else tty_printf( _("\n" "You need a User-ID to identify your key; the software constructs the user id\n" "from Real Name, Comment and Email Address in this form:\n" " \"Heinrich Heine (Der Dichter) \"\n\n") ); uid = NULL; aname=acomment=amail=NULL; for(;;) { char *p; if( !aname ) { for(;;) { m_free(aname); aname = tty_get(_("Real name: ")); trim_spaces(aname); tty_kill_prompt(); if( strpbrk( aname, "<([])>" ) ) tty_printf(_("Invalid character in name\n")); else if( isdigit(*aname) ) tty_printf(_("Name may not start with a digit\n")); else if( strlen(aname) < 5 ) tty_printf(_("Name must be at least 5 characters long\n")); else break; } } if( !amail ) { for(;;) { m_free(amail); amail = tty_get(_("Email address: ")); trim_spaces(amail); strlwr(amail); tty_kill_prompt(); if( !*amail ) break; /* no email address is okay */ else if( strcspn( amail, "abcdefghijklmnopqrstuvwxyz_-.@" ) || string_count_chr(amail,'@') != 1 || *amail == '@' || amail[strlen(amail)-1] == '@' || amail[strlen(amail)-1] == '.' || strstr(amail, "..") ) tty_printf(_("Not a valid email address\n")); else break; } } if( !acomment ) { for(;;) { m_free(acomment); acomment = tty_get(_("Comment: ")); trim_spaces(acomment); tty_kill_prompt(); if( !*acomment ) break; /* no comment is okay */ else if( strpbrk( acomment, "()" ) ) tty_printf(_("Invalid character in comment\n")); else break; } } m_free(uid); uid = p = m_alloc(strlen(aname)+strlen(amail)+strlen(acomment)+12+10); p = stpcpy(p, aname ); if( *acomment ) p = stpcpy(stpcpy(stpcpy(p," ("), acomment),")"); if( *amail ) p = stpcpy(stpcpy(stpcpy(p," <"), amail),">"); /* append a warning if we do not have dev/random * or it is switched into quick testmode */ if( quick_random_gen(-1) ) strcpy(p, " (INSECURE!)" ); tty_printf(_("You selected this USER-ID:\n \"%s\"\n\n"), uid); for(;;) { answer = tty_get(_("Edit (N)ame, (C)omment, (E)mail or (O)kay? ")); tty_kill_prompt(); if( strlen(answer) > 1 ) ; else if( *answer == 'N' || *answer == 'n' ) { m_free(aname); aname = NULL; break; } else if( *answer == 'C' || *answer == 'c' ) { m_free(acomment); acomment = NULL; break; } else if( *answer == 'E' || *answer == 'e' ) { m_free(amail); amail = NULL; break; } else if( *answer == 'O' || *answer == 'o' ) { m_free(aname); aname = NULL; m_free(acomment); acomment = NULL; m_free(amail); amail = NULL; break; } m_free(answer); } m_free(answer); if( !amail && !acomment && !amail ) break; m_free(uid); uid = NULL; } #endif tty_printf(_("You need a Passphrase to protect your secret key.\n\n") ); dek = m_alloc_secure( sizeof *dek + 8 ); salt = (byte*)dek + sizeof *dek; for(;;) { dek->algo = CIPHER_ALGO_BLOWFISH; randomize_buffer(salt, 8, 1); rc = make_dek_from_passphrase( dek , 2, salt ); if( rc == -1 ) { m_free(dek); dek = NULL; tty_printf(_( "You don't what a passphrase - this is probably a *bad* idea!\n" "I will do it anyway. You can change your passphrase at anytime,\n" "using this program with the option \"--change-passphrase\"\n\n")); break; } else if( rc == G10ERR_PASSPHRASE ) { tty_printf(_("passphrase not correctly repeated; try again.\n")); } else if( rc ) { m_free(dek); dek = NULL; m_free(uid); log_error("Error getting the passphrase: %s\n", g10_errstr(rc) ); return; } else break; /* okay */ } /* now check wether we a are allowed to write to the keyrings */ pub_fname = make_filename(opt.homedir, "pubring.gpg", NULL ); sec_fname = make_filename(opt.homedir, "secring.gpg", NULL ); if( opt.verbose ) { tty_printf(_("writing public certificate to '%s'\n"), pub_fname ); tty_printf(_("writing secret certificate to '%s'\n"), sec_fname ); } /* we create the packets as a tree of kbnodes. Because the structure * we create is known in advance we simply generate a linked list * The first packet is a dummy comment packet which we flag * as deleted. The very first packet must always be a CERT packet. */ pub_root = make_comment_node("#"); delete_kbnode(pub_root); sec_root = make_comment_node("#"); delete_kbnode(sec_root); tty_printf(_( "We need to generate a lot of random bytes. It is a good idea to perform\n" "some other action (work in another window, move the mouse, utilize the\n" "network and the disks) during the prime generation; this gives the random\n" "number generator a better chance to gain enough entropy.\n") ); if( algo == PUBKEY_ALGO_ELGAMAL ) rc = gen_elg(nbits, pub_root, sec_root, dek, salt, &skc ); #ifdef ENABLE_RSA_KEYGEN else if( algo == PUBKEY_ALGO_RSA ) rc = gen_rsa(nbits, pub_root, sec_root, dek, salt, &skc ); #endif else if( algo == PUBKEY_ALGO_DSA ) rc = gen_dsa(nbits, pub_root, sec_root, dek, salt, &skc ); else BUG(); if( !rc ) { add_kbnode( pub_root, make_comment_node("#created by GNUPG v" VERSION " (" PRINTABLE_OS_NAME ")")); add_kbnode( sec_root, make_comment_node("#created by GNUPG v" VERSION " (" PRINTABLE_OS_NAME ")")); } if( !rc ) write_uid(pub_root, uid ); if( !rc ) write_uid(sec_root, uid ); if( !rc ) rc = write_selfsig(pub_root, pub_root, skc); if( !rc ) rc = write_selfsig(sec_root, pub_root, skc); if( !rc ) { KBPOS pub_kbpos; KBPOS sec_kbpos; int rc1 = -1; int rc2 = -1; /* we can now write the certificates */ /* FIXME: should we check wether the user-id already exists? */ if( get_keyblock_handle( pub_fname, 0, &pub_kbpos ) ) { if( add_keyblock_resource( pub_fname, 1, 0 ) ) { log_error("can add keyblock file '%s'\n", pub_fname ); rc = G10ERR_CREATE_FILE; } else if( get_keyblock_handle( pub_fname, 0, &pub_kbpos ) ) { log_error("can get keyblock handle for '%s'\n", pub_fname ); rc = G10ERR_CREATE_FILE; } } if( rc ) ; else if( get_keyblock_handle( sec_fname, 1, &sec_kbpos ) ) { if( add_keyblock_resource( sec_fname, 1, 1 ) ) { log_error("can add keyblock file '%s'\n", sec_fname ); rc = G10ERR_CREATE_FILE; } else if( get_keyblock_handle( sec_fname, 1, &sec_kbpos ) ) { log_error("can get keyblock handle for '%s'\n", sec_fname ); rc = G10ERR_CREATE_FILE; } } if( rc ) ; else if( (rc=rc1=lock_keyblock( &pub_kbpos )) ) log_error("can't lock public keyring: %s\n", g10_errstr(rc) ); else if( (rc=rc2=lock_keyblock( &sec_kbpos )) ) log_error("can't lock secret keyring: %s\n", g10_errstr(rc) ); else if( (rc=insert_keyblock( &pub_kbpos, pub_root )) ) log_error("can't write public key: %s\n", g10_errstr(rc) ); else if( (rc=insert_keyblock( &sec_kbpos, sec_root )) ) log_error("can't write secret key: %s\n", g10_errstr(rc) ); else { tty_printf(_("public and secret key created and signed.\n") ); } if( !rc1 ) unlock_keyblock( &pub_kbpos ); if( !rc2 ) unlock_keyblock( &sec_kbpos ); } if( rc ) tty_printf(_("Key generation failed: %s\n"), g10_errstr(rc) ); release_kbnode( pub_root ); release_kbnode( sec_root ); if( skc ) /* the unprotected secret certificate */ free_secret_cert(skc); m_free(uid); m_free(dek); m_free(pub_fname); m_free(sec_fname); }