# HG changeset patch # User Matt Johnston # Date 1383754732 -28800 # Node ID b298bb43862535ea342842646b81211742a38bd2 # Parent 774ad9b112ef109e6a1fdc592acd19ef4d504f9b refactor key generation, make it generate as required. Needs UI in server command line options diff -r 774ad9b112ef -r b298bb438625 Makefile.in --- a/Makefile.in Fri Nov 01 00:21:59 2013 +0800 +++ b/Makefile.in Thu Nov 07 00:18:52 2013 +0800 @@ -27,7 +27,8 @@ signkey.o rsa.o random.o \ queue.o \ atomicio.o compat.o fake-rfc2553.o \ - ltc_prng.o ecc.o ecdsa.o crypto_desc.o + ltc_prng.o ecc.o ecdsa.o crypto_desc.o \ + gensignkey.o gendss.o genrsa.o SVROBJS=svr-kex.o svr-auth.o sshpty.o \ svr-authpasswd.o svr-authpubkey.o svr-authpubkeyoptions.o svr-session.o svr-service.o \ @@ -44,7 +45,7 @@ tcp-accept.o listener.o process-packet.o \ common-runopts.o circbuffer.o -KEYOBJS=dropbearkey.o gendss.o genrsa.o +KEYOBJS=dropbearkey.o CONVERTOBJS=dropbearconvert.o keyimport.o diff -r 774ad9b112ef -r b298bb438625 debug.h --- a/debug.h Fri Nov 01 00:21:59 2013 +0800 +++ b/debug.h Thu Nov 07 00:18:52 2013 +0800 @@ -40,7 +40,6 @@ * since the printing may not sanitise strings etc. This will add a reasonable * amount to your executable size. */ /* #define DEBUG_TRACE */ -#define DEBUG_TRACE /* All functions writing to the cleartext payload buffer call * CHECKCLEARTOWRITE() before writing. This is only really useful if you're @@ -72,7 +71,7 @@ /* To debug with GDB it is easier to run with no forking of child processes. You will need to pass "-F" as well. */ -#define DEBUG_NOFORK +/* #define DEBUG_NOFORK */ /* For testing as non-root on shadowed systems, include the crypt of a password diff -r 774ad9b112ef -r b298bb438625 dropbearkey.c --- a/dropbearkey.c Fri Nov 01 00:21:59 2013 +0800 +++ b/dropbearkey.c Thu Nov 07 00:18:52 2013 +0800 @@ -57,12 +57,9 @@ static void printhelp(char * progname); -#define RSA_DEFAULT_SIZE 2048 -#define DSS_DEFAULT_SIZE 1024 -static void buf_writefile(buffer * buf, const char * filename); static void printpubkey(sign_key * key, int keytype); -static void justprintpub(const char* filename); +static int printpubfile(const char* filename); /* Print a help message */ static void printhelp(char * progname) { @@ -103,6 +100,30 @@ ,progname); } +/* fails fatally */ +static void check_signkey_bits(enum signkey_type type, int bits) +{ + switch (type) { +#ifdef DROPBEAR_RSA + case DROPBEAR_SIGNKEY_RSA: + if (bits < 512 || bits > 4096 || (bits % 8 != 0)) { + dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a" + " multiple of 8\n"); + } + break; +#endif +#ifdef DROPEAR_DSS + case DROPBEAR_SIGNKEY_DSS: + if (bits != 1024) { + dropbear_exit("DSS keys have a fixed size of 1024 bits\n"); + exit(EXIT_FAILURE); + } +#endif + default: + (void)0; /* quiet, compiler. ecdsa handles checks itself */ + } +} + #if defined(DBMULTI_dropbearkey) || !defined(DROPBEAR_MULTI) #if defined(DBMULTI_dropbearkey) && defined(DROPBEAR_MULTI) int dropbearkey_main(int argc, char ** argv) { @@ -118,7 +139,7 @@ enum signkey_type keytype = DROPBEAR_SIGNKEY_NONE; char * typetext = NULL; char * sizetext = NULL; - unsigned int bits; + unsigned int bits = 0; int printpub = 0; crypto_init(); @@ -174,8 +195,8 @@ } if (printpub) { - justprintpub(filename); - /* Not reached */ + int ret = printpubfile(filename); + exit(ret); } /* check/parse args */ @@ -216,106 +237,22 @@ exit(EXIT_FAILURE); } - // TODO: put RSA and DSS size checks into genrsa.c etc - switch (keytype) { -#ifdef DROPBEAR_RSA - case DROPBEAR_SIGNKEY_RSA: - if (bits < 512 || bits > 4096 || (bits % 8 != 0)) { - fprintf(stderr, "Bits must satisfy 512 <= bits <= 4096, and be a" - " multiple of 8\n"); - exit(EXIT_FAILURE); - } - break; -#endif -#ifdef DROPEAR_DSS - case DROPBEAR_SIGNKEY_DSS: - if (bits != 1024) { - fprintf(stderr, "DSS keys have a fixed size of 1024 bits\n"); - exit(EXIT_FAILURE); - } -#endif - default: - (void)0; /* quiet, compiler. ecdsa handles checks itself */ - } - - } else { - /* default key size */ - - switch (keytype) { -#ifdef DROPBEAR_RSA - case DROPBEAR_SIGNKEY_RSA: - bits = RSA_DEFAULT_SIZE; - break; -#endif -#ifdef DROPBEAR_DSS - case DROPBEAR_SIGNKEY_DSS: - bits = DSS_DEFAULT_SIZE; - break; -#endif -#ifdef DROPBEAR_ECDSA - case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: - bits = ECDSA_DEFAULT_SIZE; - break; -#endif - default: - exit(EXIT_FAILURE); /* not reached */ - } - } - + check_signkey_bits(keytype, bits);; + } - fprintf(stderr, "Will output %d bit %s secret key to '%s'\n", bits, - typetext, filename); - - /* don't want the file readable by others */ - umask(077); + fprintf(stderr, "Generating key, this may take a while...\n"); + if (signkey_generate(keytype, bits, filename) == DROPBEAR_FAILURE) + { + dropbear_exit("Failed to generate key.\n"); + } - /* now we can generate the key */ - key = new_sign_key(); - - fprintf(stderr, "Generating key, this may take a while...\n"); - switch(keytype) { -#ifdef DROPBEAR_RSA - case DROPBEAR_SIGNKEY_RSA: - key->rsakey = gen_rsa_priv_key(bits); - break; -#endif -#ifdef DROPBEAR_DSS - case DROPBEAR_SIGNKEY_DSS: - key->dsskey = gen_dss_priv_key(bits); - break; -#endif -#ifdef DROPBEAR_ECDSA - case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: - { - ecc_key *ecckey = gen_ecdsa_priv_key(bits); - keytype = ecdsa_signkey_type(ecckey); - *signkey_key_ptr(key, keytype) = ecckey; - } - break; -#endif - default: - fprintf(stderr, "Internal error, bad key type\n"); - exit(EXIT_FAILURE); - } - - buf = buf_new(MAX_PRIVKEY_SIZE); - - buf_put_priv_key(buf, key, keytype); - buf_setpos(buf, 0); - buf_writefile(buf, filename); - - buf_burn(buf); - buf_free(buf); - - printpubkey(key, keytype); - - sign_key_free(key); + printpubfile(filename); return EXIT_SUCCESS; } #endif -static void justprintpub(const char* filename) { +static int printpubfile(const char* filename) { buffer *buf = NULL; sign_key *key = NULL; @@ -353,7 +290,7 @@ sign_key_free(key); key = NULL; } - exit(err); + return err; } static void printpubkey(sign_key * key, int keytype) { @@ -402,35 +339,3 @@ m_free(fp); buf_free(buf); } - -/* Write a buffer to a file specified, failing if the file exists */ -static void buf_writefile(buffer * buf, const char * filename) { - - int fd; - int len; - - fd = open(filename, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); - if (fd < 0) { - fprintf(stderr, "Couldn't create new file %s\n", filename); - perror("Reason"); - buf_burn(buf); - exit(EXIT_FAILURE); - } - - /* write the file now */ - while (buf->pos != buf->len) { - len = write(fd, buf_getptr(buf, buf->len - buf->pos), - buf->len - buf->pos); - if (errno == EINTR) { - continue; - } - if (len <= 0) { - fprintf(stderr, "Failed writing file '%s'\n",filename); - perror("Reason"); - exit(EXIT_FAILURE); - } - buf_incrpos(buf, len); - } - - close(fd); -} diff -r 774ad9b112ef -r b298bb438625 ecdsa.c --- a/ecdsa.c Fri Nov 01 00:21:59 2013 +0800 +++ b/ecdsa.c Thu Nov 07 00:18:52 2013 +0800 @@ -8,6 +8,13 @@ #ifdef DROPBEAR_ECDSA +int signkey_is_ecdsa(enum signkey_type type) +{ + return type == DROPBEAR_SIGNKEY_ECDSA_NISTP256 + || type == DROPBEAR_SIGNKEY_ECDSA_NISTP384 + || type == DROPBEAR_SIGNKEY_ECDSA_NISTP521; +} + enum signkey_type ecdsa_signkey_type(ecc_key * key) { #ifdef DROPBEAR_ECC_256 if (key->dp == ecc_curve_nistp256.dp) { diff -r 774ad9b112ef -r b298bb438625 ecdsa.h --- a/ecdsa.h Fri Nov 01 00:21:59 2013 +0800 +++ b/ecdsa.h Thu Nov 07 00:18:52 2013 +0800 @@ -26,6 +26,8 @@ void buf_put_ecdsa_sign(buffer *buf, ecc_key *key, buffer *data_buf); int buf_ecdsa_verify(buffer *buf, ecc_key *key, buffer *data_buf); +/* Returns 1 on success */ +int signkey_is_ecdsa(enum signkey_type type); #endif diff -r 774ad9b112ef -r b298bb438625 gensignkey.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gensignkey.c Thu Nov 07 00:18:52 2013 +0800 @@ -0,0 +1,128 @@ +#include "includes.h" +#include "dbutil.h" +#include "buffer.h" +#include "ecdsa.h" +#include "genrsa.h" +#include "gendss.h" +#include "signkey.h" + +#define RSA_DEFAULT_SIZE 2048 +#define DSS_DEFAULT_SIZE 1024 + +// Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE +static int buf_writefile(buffer * buf, const char * filename) { + int ret = DROPBEAR_FAILURE; + int fd = -1; + + fd = open(filename, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); + if (fd < 0) { + dropbear_log(LOG_ERR, "Couldn't create new file %s: %s", + filename, strerror(errno)); + goto out; + } + + /* write the file now */ + while (buf->pos != buf->len) { + int len = write(fd, buf_getptr(buf, buf->len - buf->pos), + buf->len - buf->pos); + if (errno == EINTR) { + continue; + } + if (len <= 0) { + dropbear_log(LOG_ERR, "Failed writing file %s: %s", + filename, strerror(errno)); + goto out; + } + buf_incrpos(buf, len); + } + + ret = DROPBEAR_SUCCESS; + +out: + if (fd >= 0) { + m_close(fd); + } + return ret; +} + +/* returns 0 on failure */ +static int get_default_bits(enum signkey_type keytype) +{ + switch (keytype) { +#ifdef DROPBEAR_RSA + case DROPBEAR_SIGNKEY_RSA: + return RSA_DEFAULT_SIZE; +#endif +#ifdef DROPBEAR_DSS + case DROPBEAR_SIGNKEY_DSS: + return DSS_DEFAULT_SIZE; +#endif +#ifdef DROPBEAR_ECDSA + case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: + return ECDSA_DEFAULT_SIZE; + case DROPBEAR_SIGNKEY_ECDSA_NISTP521: + return 521; + case DROPBEAR_SIGNKEY_ECDSA_NISTP384: + return 384; + case DROPBEAR_SIGNKEY_ECDSA_NISTP256: + return 256; +#endif + default: + return 0; + } +} + + +int signkey_generate(enum signkey_type keytype, int bits, const char* filename) +{ + sign_key * key = NULL; + buffer *buf = NULL; + int ret = DROPBEAR_FAILURE; + if (bits == 0) + { + bits = get_default_bits(keytype); + } + + /* now we can generate the key */ + key = new_sign_key(); + + switch(keytype) { +#ifdef DROPBEAR_RSA + case DROPBEAR_SIGNKEY_RSA: + key->rsakey = gen_rsa_priv_key(bits); + break; +#endif +#ifdef DROPBEAR_DSS + case DROPBEAR_SIGNKEY_DSS: + key->dsskey = gen_dss_priv_key(bits); + break; +#endif +#ifdef DROPBEAR_ECDSA + case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: + case DROPBEAR_SIGNKEY_ECDSA_NISTP521: + case DROPBEAR_SIGNKEY_ECDSA_NISTP384: + case DROPBEAR_SIGNKEY_ECDSA_NISTP256: + { + ecc_key *ecckey = gen_ecdsa_priv_key(bits); + keytype = ecdsa_signkey_type(ecckey); + *signkey_key_ptr(key, keytype) = ecckey; + } + break; +#endif + default: + dropbear_exit("Internal error"); + } + + buf = buf_new(MAX_PRIVKEY_SIZE); + + buf_put_priv_key(buf, key, keytype); + sign_key_free(key); + key = NULL; + buf_setpos(buf, 0); + ret = buf_writefile(buf, filename); + + buf_burn(buf); + buf_free(buf); + buf = NULL; + return ret; +} diff -r 774ad9b112ef -r b298bb438625 gensignkey.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gensignkey.h Thu Nov 07 00:18:52 2013 +0800 @@ -0,0 +1,8 @@ +#ifndef _GENSIGNKEY_H +#define _GENSIGNKEY_H + +#include "signkey.h" + +int signkey_generate(enum signkey_type type, int bits, const char* filename); + +#endif diff -r 774ad9b112ef -r b298bb438625 keyimport.c --- a/keyimport.c Fri Nov 01 00:21:59 2013 +0800 +++ b/keyimport.c Thu Nov 07 00:18:52 2013 +0800 @@ -112,7 +112,7 @@ buffer * buf = NULL; sign_key *ret = NULL; - int type; + enum signkey_type type; buf = buf_new(MAX_PRIVKEY_SIZE); if (buf_readfile(buf, filename) == DROPBEAR_FAILURE) { @@ -501,7 +501,7 @@ return ret; } -static sign_key *openssh_read(const char *filename, char *passphrase) +static sign_key *openssh_read(const char *filename, char * UNUSED(passphrase)) { struct openssh_key *key; unsigned char *p; @@ -511,7 +511,7 @@ char *errmsg; char *modptr = NULL; int modlen = -9999; - int type; + enum signkey_type type; sign_key *retkey; buffer * blobbuf = NULL; @@ -1018,8 +1018,8 @@ } */ buffer *seq_buf = buf_new(400); - ecc_key **eck = signkey_ecc_key_ptr(key, key->type); - const unsigned long curve_size = (*eck)->dp->size; + ecc_key **eck = (ecc_key**)signkey_key_ptr(key, key->type); + const long curve_size = (*eck)->dp->size; int curve_oid_len = 0; const void* curve_oid = NULL; unsigned long pubkey_size = 2*curve_size+1; diff -r 774ad9b112ef -r b298bb438625 options.h --- a/options.h Fri Nov 01 00:21:59 2013 +0800 +++ b/options.h Thu Nov 07 00:18:52 2013 +0800 @@ -180,9 +180,9 @@ * PAM challenge/response. * You can't enable both PASSWORD and PAM. */ -#define ENABLE_SVR_PASSWORD_AUTH +//#define ENABLE_SVR_PASSWORD_AUTH /* PAM requires ./configure --enable-pam */ -//#define ENABLE_SVR_PAM_AUTH +#define ENABLE_SVR_PAM_AUTH #define ENABLE_SVR_PUBKEY_AUTH /* Whether to take public key options in diff -r 774ad9b112ef -r b298bb438625 signkey.c --- a/signkey.c Fri Nov 01 00:21:59 2013 +0800 +++ b/signkey.c Thu Nov 07 00:18:52 2013 +0800 @@ -181,7 +181,7 @@ } #endif #ifdef DROPBEAR_ECDSA - { + if (signkey_is_ecdsa(keytype)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, keytype); if (eck) { if (*eck) { @@ -249,7 +249,7 @@ } #endif #ifdef DROPBEAR_ECDSA - { + if (signkey_is_ecdsa(keytype)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, keytype); if (eck) { if (*eck) { @@ -289,10 +289,7 @@ } #endif #ifdef DROPBEAR_ECDSA - if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP256 - || type == DROPBEAR_SIGNKEY_ECDSA_NISTP384 - || type == DROPBEAR_SIGNKEY_ECDSA_NISTP521) - { + if (signkey_is_ecdsa(type)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, type); if (eck) { buf_put_ecdsa_pub_key(pubkeys, *eck); @@ -329,7 +326,7 @@ } #endif #ifdef DROPBEAR_ECDSA - { + if (signkey_is_ecdsa(type)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, type); if (eck) { buf_put_ecdsa_priv_key(buf, *eck); @@ -484,7 +481,7 @@ } #endif #ifdef DROPBEAR_ECDSA - { + if (signkey_is_ecdsa(type)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, type); if (eck) { buf_put_ecdsa_sign(sigblob, *eck, data_buf); @@ -535,7 +532,7 @@ } #endif #ifdef DROPBEAR_ECDSA - { + if (signkey_is_ecdsa(type)) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, type); if (eck) { return buf_ecdsa_verify(buf, *eck, data_buf); diff -r 774ad9b112ef -r b298bb438625 svr-kex.c --- a/svr-kex.c Fri Nov 01 00:21:59 2013 +0800 +++ b/svr-kex.c Thu Nov 07 00:18:52 2013 +0800 @@ -35,6 +35,7 @@ #include "random.h" #include "runopts.h" #include "ecc.h" +#include "gensignkey.h" static void send_msg_kexdh_reply(mp_int *dh_e, buffer *ecdh_qs); @@ -75,6 +76,82 @@ ses.requirenext[1] = 0; TRACE(("leave recv_msg_kexdh_init")) } + +static void svr_ensure_hostkey() { + + const char* fn = NULL; + char *fn_temp = NULL; + enum signkey_type type = ses.newkeys->algo_hostkey; + void **hostkey = signkey_key_ptr(svr_opts.hostkey, type); + int ret = DROPBEAR_FAILURE; + + if (hostkey && *hostkey) { + return; + } + + switch (type) + { +#ifdef DROPBEAR_RSA + case DROPBEAR_SIGNKEY_RSA: + fn = RSA_PRIV_FILENAME; + break; +#endif +#ifdef DROPBEAR_DSS + case DROPBEAR_SIGNKEY_DSS: + fn = DSS_PRIV_FILENAME; + break; +#endif +#ifdef DROPBEAR_ECDSA + case DROPBEAR_SIGNKEY_ECDSA_NISTP256: + case DROPBEAR_SIGNKEY_ECDSA_NISTP384: + case DROPBEAR_SIGNKEY_ECDSA_NISTP521: + fn = ECDSA_PRIV_FILENAME; + break; +#endif + default: + (void)0; + } + + if (readhostkey(fn, svr_opts.hostkey, &type) == DROPBEAR_SUCCESS) { + return; + } + + fn_temp = m_malloc(strlen(fn) + 20); + snprintf(fn_temp, strlen(fn)+20, "%s.tmp%d", fn, getpid()); + + if (signkey_generate(type, 0, fn_temp) == DROPBEAR_FAILURE) { + goto out; + } + + if (link(fn_temp, fn) < 0) { + if (errno != EEXIST) { + dropbear_log(LOG_ERR, "Failed moving key file to %s", fn); + /* XXX fallback to non-atomic copy for some filesystems? */ + goto out; + } + } + + ret = readhostkey(fn, svr_opts.hostkey, &type); + +out: + if (fn_temp) { + unlink(fn_temp); + m_free(fn_temp); + } + + if (ret == DROPBEAR_FAILURE) + { + dropbear_exit("Couldn't read or generate hostkey"); + } + + // directory for keys. + + // Create lockfile first, or wait if it exists. PID! + // Generate key + // write it, load to memory + // atomic rename, done. + +} /* Generate our side of the diffie-hellman key exchange value (dh_f), and * calculate the session key using the diffie-hellman algorithm. Following @@ -88,6 +165,9 @@ /* we can start creating the kexdh_reply packet */ CHECKCLEARTOWRITE(); + + svr_ensure_hostkey(); + buf_putbyte(ses.writepayload, SSH_MSG_KEXDH_REPLY); buf_put_pub_key(ses.writepayload, svr_opts.hostkey, ses.newkeys->algo_hostkey); diff -r 774ad9b112ef -r b298bb438625 svr-runopts.c --- a/svr-runopts.c Fri Nov 01 00:21:59 2013 +0800 +++ b/svr-runopts.c Thu Nov 07 00:18:52 2013 +0800 @@ -482,7 +482,7 @@ #endif #ifdef DROPBEAR_ECC_521 if (!svr_opts.hostkey->ecckey521) { - disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP521); + //disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP521); } #endif #endif