version 1.27, 2000/10/19 16:45:16 |
version 1.27.2.4, 2001/05/07 21:09:37 |
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RCSID("$OpenBSD$"); |
RCSID("$OpenBSD$"); |
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#include <openssl/bn.h> |
#include <openssl/bn.h> |
#include <openssl/rsa.h> |
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#include <openssl/dsa.h> |
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#include <openssl/md5.h> |
#include <openssl/md5.h> |
#include <openssl/dh.h> |
#include <openssl/dh.h> |
#include <openssl/hmac.h> |
#include <openssl/hmac.h> |
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#include "ssh.h" |
#include "ssh.h" |
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#include "ssh2.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
#include "rsa.h" |
#include "rsa.h" |
#include "buffer.h" |
#include "buffer.h" |
#include "packet.h" |
#include "packet.h" |
#include "uidswap.h" |
#include "uidswap.h" |
#include "compat.h" |
#include "compat.h" |
#include "readconf.h" |
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#include "bufaux.h" |
#include "bufaux.h" |
#include "ssh2.h" |
#include "cipher.h" |
#include "kex.h" |
#include "kex.h" |
#include "myproposal.h" |
#include "myproposal.h" |
#include "key.h" |
#include "key.h" |
#include "dsa.h" |
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#include "sshconnect.h" |
#include "sshconnect.h" |
#include "authfile.h" |
#include "authfile.h" |
#include "cli.h" |
#include "cli.h" |
#include "dispatch.h" |
#include "dh.h" |
#include "authfd.h" |
#include "authfd.h" |
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#include "log.h" |
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#include "readconf.h" |
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#include "readpass.h" |
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#include "match.h" |
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#include "dispatch.h" |
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#include "canohost.h" |
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void ssh_dh1_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); |
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void ssh_dhgex_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); |
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/* import */ |
/* import */ |
extern char *client_version_string; |
extern char *client_version_string; |
extern char *server_version_string; |
extern char *server_version_string; |
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* SSH2 key exchange |
* SSH2 key exchange |
*/ |
*/ |
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unsigned char *session_id2 = NULL; |
u_char *session_id2 = NULL; |
int session_id2_len = 0; |
int session_id2_len = 0; |
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char *xxx_host; |
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struct sockaddr *xxx_hostaddr; |
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Kex *xxx_kex = NULL; |
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int |
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check_host_key_callback(Key *hostkey) |
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{ |
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check_host_key(xxx_host, xxx_hostaddr, hostkey, |
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options.user_hostfile2, options.system_hostfile2); |
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return 0; |
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} |
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void |
void |
ssh_kex2(char *host, struct sockaddr *hostaddr) |
ssh_kex2(char *host, struct sockaddr *hostaddr) |
{ |
{ |
int i, plen; |
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Kex *kex; |
Kex *kex; |
Buffer *client_kexinit, *server_kexinit; |
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char *sprop[PROPOSAL_MAX]; |
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if (options.ciphers == NULL) { |
xxx_host = host; |
if (options.cipher == SSH_CIPHER_3DES) { |
xxx_hostaddr = hostaddr; |
options.ciphers = "3des-cbc"; |
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} else if (options.cipher == SSH_CIPHER_BLOWFISH) { |
if (options.ciphers == (char *)-1) { |
options.ciphers = "blowfish-cbc"; |
log("No valid ciphers for protocol version 2 given, using defaults."); |
} else if (options.cipher == SSH_CIPHER_DES) { |
options.ciphers = NULL; |
fatal("cipher DES not supported for protocol version 2"); |
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} |
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} |
} |
if (options.ciphers != NULL) { |
if (options.ciphers != NULL) { |
myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
} |
} |
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myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
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compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); |
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myproposal[PROPOSAL_ENC_ALGS_STOC] = |
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compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
if (options.compression) { |
if (options.compression) { |
myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib"; |
myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; |
myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; |
} else { |
} else { |
myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none"; |
myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
} |
} |
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if (options.macs != NULL) { |
/* buffers with raw kexinit messages */ |
myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
server_kexinit = xmalloc(sizeof(*server_kexinit)); |
myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
buffer_init(server_kexinit); |
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client_kexinit = kex_init(myproposal); |
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/* algorithm negotiation */ |
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kex_exchange_kexinit(client_kexinit, server_kexinit, sprop); |
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kex = kex_choose_conf(myproposal, sprop, 0); |
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for (i = 0; i < PROPOSAL_MAX; i++) |
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xfree(sprop[i]); |
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/* server authentication and session key agreement */ |
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switch(kex->kex_type) { |
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case DH_GRP1_SHA1: |
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ssh_dh1_client(kex, host, hostaddr, |
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client_kexinit, server_kexinit); |
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break; |
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case DH_GEX_SHA1: |
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ssh_dhgex_client(kex, host, hostaddr, client_kexinit, |
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server_kexinit); |
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break; |
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default: |
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fatal("Unsupported key exchange %d", kex->kex_type); |
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} |
} |
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if (options.hostkeyalgorithms != NULL) |
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myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
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options.hostkeyalgorithms; |
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buffer_free(client_kexinit); |
/* start key exchange */ |
buffer_free(server_kexinit); |
kex = kex_setup(myproposal); |
xfree(client_kexinit); |
kex->client_version_string=client_version_string; |
xfree(server_kexinit); |
kex->server_version_string=server_version_string; |
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kex->check_host_key=&check_host_key_callback; |
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debug("Wait SSH2_MSG_NEWKEYS."); |
xxx_kex = kex; |
packet_read_expect(&plen, SSH2_MSG_NEWKEYS); |
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packet_done(); |
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debug("GOT SSH2_MSG_NEWKEYS."); |
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debug("send SSH2_MSG_NEWKEYS."); |
dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
packet_start(SSH2_MSG_NEWKEYS); |
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packet_send(); |
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packet_write_wait(); |
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debug("done: send SSH2_MSG_NEWKEYS."); |
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session_id2 = kex->session_id; |
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session_id2_len = kex->session_id_len; |
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#ifdef DEBUG_KEXDH |
#ifdef DEBUG_KEXDH |
/* send 1st encrypted/maced/compressed message */ |
/* send 1st encrypted/maced/compressed message */ |
packet_start(SSH2_MSG_IGNORE); |
packet_start(SSH2_MSG_IGNORE); |
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packet_send(); |
packet_send(); |
packet_write_wait(); |
packet_write_wait(); |
#endif |
#endif |
debug("done: KEX2."); |
debug("done: ssh_kex2."); |
} |
} |
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/* diffie-hellman-group1-sha1 */ |
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void |
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ssh_dh1_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
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Buffer *client_kexinit, Buffer *server_kexinit) |
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{ |
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#ifdef DEBUG_KEXDH |
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int i; |
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#endif |
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int plen, dlen; |
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unsigned int klen, kout; |
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char *signature = NULL; |
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unsigned int slen; |
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char *server_host_key_blob = NULL; |
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Key *server_host_key; |
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unsigned int sbloblen; |
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DH *dh; |
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BIGNUM *dh_server_pub = 0; |
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BIGNUM *shared_secret = 0; |
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unsigned char *kbuf; |
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unsigned char *hash; |
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debug("Sending SSH2_MSG_KEXDH_INIT."); |
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/* generate and send 'e', client DH public key */ |
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dh = dh_new_group1(); |
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packet_start(SSH2_MSG_KEXDH_INIT); |
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packet_put_bignum2(dh->pub_key); |
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packet_send(); |
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packet_write_wait(); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "\np= "); |
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BN_print_fp(stderr, dh->p); |
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fprintf(stderr, "\ng= "); |
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BN_print_fp(stderr, dh->g); |
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fprintf(stderr, "\npub= "); |
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BN_print_fp(stderr, dh->pub_key); |
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fprintf(stderr, "\n"); |
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DHparams_print_fp(stderr, dh); |
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#endif |
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debug("Wait SSH2_MSG_KEXDH_REPLY."); |
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packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY); |
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debug("Got SSH2_MSG_KEXDH_REPLY."); |
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/* key, cert */ |
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server_host_key_blob = packet_get_string(&sbloblen); |
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server_host_key = dsa_key_from_blob(server_host_key_blob, sbloblen); |
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if (server_host_key == NULL) |
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fatal("cannot decode server_host_key_blob"); |
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check_host_key(host, hostaddr, server_host_key, |
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options.user_hostfile2, options.system_hostfile2); |
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/* DH paramter f, server public DH key */ |
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dh_server_pub = BN_new(); |
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if (dh_server_pub == NULL) |
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fatal("dh_server_pub == NULL"); |
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packet_get_bignum2(dh_server_pub, &dlen); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "\ndh_server_pub= "); |
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BN_print_fp(stderr, dh_server_pub); |
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fprintf(stderr, "\n"); |
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debug("bits %d", BN_num_bits(dh_server_pub)); |
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#endif |
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/* signed H */ |
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signature = packet_get_string(&slen); |
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packet_done(); |
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if (!dh_pub_is_valid(dh, dh_server_pub)) |
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packet_disconnect("bad server public DH value"); |
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klen = DH_size(dh); |
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kbuf = xmalloc(klen); |
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kout = DH_compute_key(kbuf, dh_server_pub, dh); |
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#ifdef DEBUG_KEXDH |
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debug("shared secret: len %d/%d", klen, kout); |
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fprintf(stderr, "shared secret == "); |
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for (i = 0; i< kout; i++) |
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fprintf(stderr, "%02x", (kbuf[i])&0xff); |
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fprintf(stderr, "\n"); |
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#endif |
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shared_secret = BN_new(); |
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BN_bin2bn(kbuf, kout, shared_secret); |
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memset(kbuf, 0, klen); |
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xfree(kbuf); |
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/* calc and verify H */ |
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hash = kex_hash( |
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client_version_string, |
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server_version_string, |
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buffer_ptr(client_kexinit), buffer_len(client_kexinit), |
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buffer_ptr(server_kexinit), buffer_len(server_kexinit), |
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server_host_key_blob, sbloblen, |
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dh->pub_key, |
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dh_server_pub, |
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shared_secret |
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); |
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xfree(server_host_key_blob); |
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DH_free(dh); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "hash == "); |
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for (i = 0; i< 20; i++) |
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fprintf(stderr, "%02x", (hash[i])&0xff); |
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fprintf(stderr, "\n"); |
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#endif |
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if (dsa_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1) |
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fatal("dsa_verify failed for server_host_key"); |
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key_free(server_host_key); |
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kex_derive_keys(kex, hash, shared_secret); |
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packet_set_kex(kex); |
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/* save session id */ |
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session_id2_len = 20; |
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session_id2 = xmalloc(session_id2_len); |
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memcpy(session_id2, hash, session_id2_len); |
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} |
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/* diffie-hellman-group-exchange-sha1 */ |
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/* |
/* |
* Estimates the group order for a Diffie-Hellman group that has an |
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* attack complexity approximately the same as O(2**bits). Estimate |
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* with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3))) |
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*/ |
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int |
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dh_estimate(int bits) |
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{ |
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if (bits < 64) |
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return (512); /* O(2**63) */ |
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if (bits < 128) |
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return (1024); /* O(2**86) */ |
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if (bits < 192) |
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return (2048); /* O(2**116) */ |
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return (4096); /* O(2**156) */ |
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} |
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void |
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ssh_dhgex_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
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Buffer *client_kexinit, Buffer *server_kexinit) |
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{ |
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#ifdef DEBUG_KEXDH |
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int i; |
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#endif |
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int plen, dlen; |
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unsigned int klen, kout; |
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char *signature = NULL; |
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unsigned int slen, nbits; |
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char *server_host_key_blob = NULL; |
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Key *server_host_key; |
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unsigned int sbloblen; |
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DH *dh; |
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BIGNUM *dh_server_pub = 0; |
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BIGNUM *shared_secret = 0; |
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BIGNUM *p = 0, *g = 0; |
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unsigned char *kbuf; |
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unsigned char *hash; |
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nbits = dh_estimate(kex->enc[MODE_OUT].cipher->key_len * 8); |
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debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST."); |
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packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST); |
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packet_put_int(nbits); |
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packet_send(); |
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packet_write_wait(); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "\nnbits = %d", nbits); |
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#endif |
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debug("Wait SSH2_MSG_KEX_DH_GEX_GROUP."); |
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packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_GROUP); |
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debug("Got SSH2_MSG_KEX_DH_GEX_GROUP."); |
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if ((p = BN_new()) == NULL) |
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fatal("BN_new"); |
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packet_get_bignum2(p, &dlen); |
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if ((g = BN_new()) == NULL) |
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fatal("BN_new"); |
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packet_get_bignum2(g, &dlen); |
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if ((dh = dh_new_group(g, p)) == NULL) |
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fatal("dh_new_group"); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "\np= "); |
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BN_print_fp(stderr, dh->p); |
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fprintf(stderr, "\ng= "); |
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BN_print_fp(stderr, dh->g); |
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fprintf(stderr, "\npub= "); |
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BN_print_fp(stderr, dh->pub_key); |
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fprintf(stderr, "\n"); |
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DHparams_print_fp(stderr, dh); |
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#endif |
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debug("Sending SSH2_MSG_KEX_DH_GEX_INIT."); |
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/* generate and send 'e', client DH public key */ |
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packet_start(SSH2_MSG_KEX_DH_GEX_INIT); |
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packet_put_bignum2(dh->pub_key); |
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packet_send(); |
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packet_write_wait(); |
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debug("Wait SSH2_MSG_KEX_DH_GEX_REPLY."); |
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packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_REPLY); |
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debug("Got SSH2_MSG_KEXDH_REPLY."); |
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/* key, cert */ |
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server_host_key_blob = packet_get_string(&sbloblen); |
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server_host_key = dsa_key_from_blob(server_host_key_blob, sbloblen); |
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if (server_host_key == NULL) |
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fatal("cannot decode server_host_key_blob"); |
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check_host_key(host, hostaddr, server_host_key, |
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options.user_hostfile2, options.system_hostfile2); |
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/* DH paramter f, server public DH key */ |
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dh_server_pub = BN_new(); |
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if (dh_server_pub == NULL) |
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fatal("dh_server_pub == NULL"); |
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packet_get_bignum2(dh_server_pub, &dlen); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "\ndh_server_pub= "); |
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BN_print_fp(stderr, dh_server_pub); |
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fprintf(stderr, "\n"); |
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debug("bits %d", BN_num_bits(dh_server_pub)); |
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#endif |
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/* signed H */ |
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signature = packet_get_string(&slen); |
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packet_done(); |
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if (!dh_pub_is_valid(dh, dh_server_pub)) |
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packet_disconnect("bad server public DH value"); |
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klen = DH_size(dh); |
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kbuf = xmalloc(klen); |
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kout = DH_compute_key(kbuf, dh_server_pub, dh); |
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#ifdef DEBUG_KEXDH |
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debug("shared secret: len %d/%d", klen, kout); |
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fprintf(stderr, "shared secret == "); |
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for (i = 0; i< kout; i++) |
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fprintf(stderr, "%02x", (kbuf[i])&0xff); |
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fprintf(stderr, "\n"); |
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#endif |
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shared_secret = BN_new(); |
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BN_bin2bn(kbuf, kout, shared_secret); |
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memset(kbuf, 0, klen); |
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xfree(kbuf); |
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/* calc and verify H */ |
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hash = kex_hash_gex( |
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client_version_string, |
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server_version_string, |
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buffer_ptr(client_kexinit), buffer_len(client_kexinit), |
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buffer_ptr(server_kexinit), buffer_len(server_kexinit), |
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server_host_key_blob, sbloblen, |
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nbits, dh->p, dh->g, |
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dh->pub_key, |
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dh_server_pub, |
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shared_secret |
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); |
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xfree(server_host_key_blob); |
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DH_free(dh); |
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#ifdef DEBUG_KEXDH |
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fprintf(stderr, "hash == "); |
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for (i = 0; i< 20; i++) |
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fprintf(stderr, "%02x", (hash[i])&0xff); |
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fprintf(stderr, "\n"); |
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#endif |
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if (dsa_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1) |
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fatal("dsa_verify failed for server_host_key"); |
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key_free(server_host_key); |
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kex_derive_keys(kex, hash, shared_secret); |
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packet_set_kex(kex); |
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/* save session id */ |
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session_id2_len = 20; |
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session_id2 = xmalloc(session_id2_len); |
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memcpy(session_id2, hash, session_id2_len); |
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} |
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/* |
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* Authenticate user |
* Authenticate user |
*/ |
*/ |
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typedef int sign_cb_fn( |
typedef int sign_cb_fn( |
Authctxt *authctxt, Key *key, |
Authctxt *authctxt, Key *key, |
unsigned char **sigp, int *lenp, unsigned char *data, int datalen); |
u_char **sigp, int *lenp, u_char *data, int datalen); |
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struct Authctxt { |
struct Authctxt { |
const char *server_user; |
const char *server_user; |
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const char *local_user; |
const char *host; |
const char *host; |
const char *service; |
const char *service; |
AuthenticationConnection *agent; |
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Authmethod *method; |
Authmethod *method; |
int success; |
int success; |
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char *authlist; |
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/* pubkey */ |
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Key *last_key; |
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sign_cb_fn *last_key_sign; |
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int last_key_hint; |
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AuthenticationConnection *agent; |
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/* hostbased */ |
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Key **keys; |
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int nkeys; |
}; |
}; |
struct Authmethod { |
struct Authmethod { |
char *name; /* string to compare against server's list */ |
char *name; /* string to compare against server's list */ |
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void input_userauth_success(int type, int plen, void *ctxt); |
void input_userauth_success(int type, int plen, void *ctxt); |
void input_userauth_failure(int type, int plen, void *ctxt); |
void input_userauth_failure(int type, int plen, void *ctxt); |
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void input_userauth_banner(int type, int plen, void *ctxt); |
void input_userauth_error(int type, int plen, void *ctxt); |
void input_userauth_error(int type, int plen, void *ctxt); |
void input_userauth_info_req(int type, int plen, void *ctxt); |
void input_userauth_info_req(int type, int plen, void *ctxt); |
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void input_userauth_pk_ok(int type, int plen, void *ctxt); |
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int userauth_none(Authctxt *authctxt); |
int userauth_none(Authctxt *authctxt); |
int userauth_pubkey(Authctxt *authctxt); |
int userauth_pubkey(Authctxt *authctxt); |
int userauth_passwd(Authctxt *authctxt); |
int userauth_passwd(Authctxt *authctxt); |
int userauth_kbdint(Authctxt *authctxt); |
int userauth_kbdint(Authctxt *authctxt); |
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int userauth_hostbased(Authctxt *authctxt); |
|
|
void authmethod_clear(); |
void userauth(Authctxt *authctxt, char *authlist); |
|
|
|
int |
|
sign_and_send_pubkey(Authctxt *authctxt, Key *k, |
|
sign_cb_fn *sign_callback); |
|
void clear_auth_state(Authctxt *authctxt); |
|
|
Authmethod *authmethod_get(char *authlist); |
Authmethod *authmethod_get(char *authlist); |
Authmethod *authmethod_lookup(const char *name); |
Authmethod *authmethod_lookup(const char *name); |
|
char *authmethods_get(void); |
|
|
Authmethod authmethods[] = { |
Authmethod authmethods[] = { |
{"publickey", |
{"publickey", |
userauth_pubkey, |
userauth_pubkey, |
&options.dsa_authentication, |
&options.pubkey_authentication, |
NULL}, |
NULL}, |
{"password", |
{"password", |
userauth_passwd, |
userauth_passwd, |
|
|
userauth_kbdint, |
userauth_kbdint, |
&options.kbd_interactive_authentication, |
&options.kbd_interactive_authentication, |
&options.batch_mode}, |
&options.batch_mode}, |
|
{"hostbased", |
|
userauth_hostbased, |
|
&options.hostbased_authentication, |
|
NULL}, |
{"none", |
{"none", |
userauth_none, |
userauth_none, |
NULL, |
NULL, |
|
|
}; |
}; |
|
|
void |
void |
ssh_userauth2(const char *server_user, char *host) |
ssh_userauth2(const char *local_user, const char *server_user, char *host, |
|
Key **keys, int nkeys) |
{ |
{ |
Authctxt authctxt; |
Authctxt authctxt; |
int type; |
int type; |
int plen; |
int plen; |
|
|
|
if (options.challenge_reponse_authentication) |
|
options.kbd_interactive_authentication = 1; |
|
|
debug("send SSH2_MSG_SERVICE_REQUEST"); |
debug("send SSH2_MSG_SERVICE_REQUEST"); |
packet_start(SSH2_MSG_SERVICE_REQUEST); |
packet_start(SSH2_MSG_SERVICE_REQUEST); |
packet_put_cstring("ssh-userauth"); |
packet_put_cstring("ssh-userauth"); |
|
|
char *reply = packet_get_string(&plen); |
char *reply = packet_get_string(&plen); |
debug("service_accept: %s", reply); |
debug("service_accept: %s", reply); |
xfree(reply); |
xfree(reply); |
packet_done(); |
|
} else { |
} else { |
debug("buggy server: service_accept w/o service"); |
debug("buggy server: service_accept w/o service"); |
} |
} |
packet_done(); |
packet_done(); |
debug("got SSH2_MSG_SERVICE_ACCEPT"); |
debug("got SSH2_MSG_SERVICE_ACCEPT"); |
|
|
|
if (options.preferred_authentications == NULL) |
|
options.preferred_authentications = authmethods_get(); |
|
|
/* setup authentication context */ |
/* setup authentication context */ |
authctxt.agent = ssh_get_authentication_connection(); |
authctxt.agent = ssh_get_authentication_connection(); |
authctxt.server_user = server_user; |
authctxt.server_user = server_user; |
|
authctxt.local_user = local_user; |
authctxt.host = host; |
authctxt.host = host; |
authctxt.service = "ssh-connection"; /* service name */ |
authctxt.service = "ssh-connection"; /* service name */ |
authctxt.success = 0; |
authctxt.success = 0; |
authctxt.method = authmethod_lookup("none"); |
authctxt.method = authmethod_lookup("none"); |
|
authctxt.authlist = NULL; |
|
authctxt.keys = keys; |
|
authctxt.nkeys = nkeys; |
if (authctxt.method == NULL) |
if (authctxt.method == NULL) |
fatal("ssh_userauth2: internal error: cannot send userauth none request"); |
fatal("ssh_userauth2: internal error: cannot send userauth none request"); |
authmethod_clear(); |
|
|
|
/* initial userauth request */ |
/* initial userauth request */ |
userauth_none(&authctxt); |
userauth_none(&authctxt); |
|
|
dispatch_init(&input_userauth_error); |
dispatch_init(&input_userauth_error); |
dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); |
dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); |
|
dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
|
|
if (authctxt.agent != NULL) |
if (authctxt.agent != NULL) |
ssh_close_authentication_connection(authctxt.agent); |
ssh_close_authentication_connection(authctxt.agent); |
|
|
debug("ssh-userauth2 successfull: method %s", authctxt.method->name); |
debug("ssh-userauth2 successful: method %s", authctxt.method->name); |
} |
} |
void |
void |
|
userauth(Authctxt *authctxt, char *authlist) |
|
{ |
|
if (authlist == NULL) { |
|
authlist = authctxt->authlist; |
|
} else { |
|
if (authctxt->authlist) |
|
xfree(authctxt->authlist); |
|
authctxt->authlist = authlist; |
|
} |
|
for (;;) { |
|
Authmethod *method = authmethod_get(authlist); |
|
if (method == NULL) |
|
fatal("Permission denied (%s).", authlist); |
|
authctxt->method = method; |
|
if (method->userauth(authctxt) != 0) { |
|
debug2("we sent a %s packet, wait for reply", method->name); |
|
break; |
|
} else { |
|
debug2("we did not send a packet, disable method"); |
|
method->enabled = NULL; |
|
} |
|
} |
|
} |
|
void |
input_userauth_error(int type, int plen, void *ctxt) |
input_userauth_error(int type, int plen, void *ctxt) |
{ |
{ |
fatal("input_userauth_error: bad message during authentication"); |
fatal("input_userauth_error: bad message during authentication: " |
|
"type %d", type); |
} |
} |
void |
void |
|
input_userauth_banner(int type, int plen, void *ctxt) |
|
{ |
|
char *msg, *lang; |
|
debug3("input_userauth_banner"); |
|
msg = packet_get_string(NULL); |
|
lang = packet_get_string(NULL); |
|
fprintf(stderr, "%s", msg); |
|
xfree(msg); |
|
xfree(lang); |
|
} |
|
void |
input_userauth_success(int type, int plen, void *ctxt) |
input_userauth_success(int type, int plen, void *ctxt) |
{ |
{ |
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
if (authctxt == NULL) |
if (authctxt == NULL) |
fatal("input_userauth_success: no authentication context"); |
fatal("input_userauth_success: no authentication context"); |
|
if (authctxt->authlist) |
|
xfree(authctxt->authlist); |
|
clear_auth_state(authctxt); |
authctxt->success = 1; /* break out */ |
authctxt->success = 1; /* break out */ |
} |
} |
void |
void |
input_userauth_failure(int type, int plen, void *ctxt) |
input_userauth_failure(int type, int plen, void *ctxt) |
{ |
{ |
Authmethod *method = NULL; |
|
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
char *authlist = NULL; |
char *authlist = NULL; |
int partial; |
int partial; |
|
|
packet_done(); |
packet_done(); |
|
|
if (partial != 0) |
if (partial != 0) |
debug("partial success"); |
log("Authenticated with partial success."); |
debug("authentications that can continue: %s", authlist); |
debug("authentications that can continue: %s", authlist); |
|
|
for (;;) { |
clear_auth_state(authctxt); |
method = authmethod_get(authlist); |
userauth(authctxt, authlist); |
if (method == NULL) |
} |
fatal("Unable to find an authentication method"); |
void |
authctxt->method = method; |
input_userauth_pk_ok(int type, int plen, void *ctxt) |
if (method->userauth(authctxt) != 0) { |
{ |
debug2("we sent a %s packet, wait for reply", method->name); |
Authctxt *authctxt = ctxt; |
|
Key *key = NULL; |
|
Buffer b; |
|
int alen, blen, sent = 0; |
|
char *pkalg, *pkblob, *fp; |
|
|
|
if (authctxt == NULL) |
|
fatal("input_userauth_pk_ok: no authentication context"); |
|
if (datafellows & SSH_BUG_PKOK) { |
|
/* this is similar to SSH_BUG_PKAUTH */ |
|
debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); |
|
pkblob = packet_get_string(&blen); |
|
buffer_init(&b); |
|
buffer_append(&b, pkblob, blen); |
|
pkalg = buffer_get_string(&b, &alen); |
|
buffer_free(&b); |
|
} else { |
|
pkalg = packet_get_string(&alen); |
|
pkblob = packet_get_string(&blen); |
|
} |
|
packet_done(); |
|
|
|
debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d", |
|
pkalg, blen, authctxt->last_key, authctxt->last_key_hint); |
|
|
|
do { |
|
if (authctxt->last_key == NULL || |
|
authctxt->last_key_sign == NULL) { |
|
debug("no last key or no sign cb"); |
break; |
break; |
} else { |
|
debug2("we did not send a packet, disable method"); |
|
method->enabled = NULL; |
|
} |
} |
} |
if (key_type_from_name(pkalg) == KEY_UNSPEC) { |
xfree(authlist); |
debug("unknown pkalg %s", pkalg); |
|
break; |
|
} |
|
if ((key = key_from_blob(pkblob, blen)) == NULL) { |
|
debug("no key from blob. pkalg %s", pkalg); |
|
break; |
|
} |
|
fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
|
debug2("input_userauth_pk_ok: fp %s", fp); |
|
xfree(fp); |
|
if (!key_equal(key, authctxt->last_key)) { |
|
debug("key != last_key"); |
|
break; |
|
} |
|
sent = sign_and_send_pubkey(authctxt, key, |
|
authctxt->last_key_sign); |
|
} while(0); |
|
|
|
if (key != NULL) |
|
key_free(key); |
|
xfree(pkalg); |
|
xfree(pkblob); |
|
|
|
/* unregister */ |
|
clear_auth_state(authctxt); |
|
dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); |
|
|
|
/* try another method if we did not send a packet*/ |
|
if (sent == 0) |
|
userauth(authctxt, NULL); |
|
|
} |
} |
|
|
int |
int |
|
|
packet_put_cstring(authctxt->service); |
packet_put_cstring(authctxt->service); |
packet_put_cstring(authctxt->method->name); |
packet_put_cstring(authctxt->method->name); |
packet_send(); |
packet_send(); |
packet_write_wait(); |
|
return 1; |
return 1; |
} |
} |
|
|
|
|
if(attempt != 1) |
if(attempt != 1) |
error("Permission denied, please try again."); |
error("Permission denied, please try again."); |
|
|
snprintf(prompt, sizeof(prompt), "%.30s@%.40s's password: ", |
snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
authctxt->server_user, authctxt->host); |
authctxt->server_user, authctxt->host); |
password = read_passphrase(prompt, 0); |
password = read_passphrase(prompt, 0); |
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
|
|
packet_put_cstring(password); |
packet_put_cstring(password); |
memset(password, 0, strlen(password)); |
memset(password, 0, strlen(password)); |
xfree(password); |
xfree(password); |
|
packet_inject_ignore(64); |
packet_send(); |
packet_send(); |
packet_write_wait(); |
|
return 1; |
return 1; |
} |
} |
|
|
|
void |
|
clear_auth_state(Authctxt *authctxt) |
|
{ |
|
/* XXX clear authentication state */ |
|
if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { |
|
debug3("clear_auth_state: key_free %p", authctxt->last_key); |
|
key_free(authctxt->last_key); |
|
} |
|
authctxt->last_key = NULL; |
|
authctxt->last_key_hint = -2; |
|
authctxt->last_key_sign = NULL; |
|
} |
|
|
int |
int |
sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
{ |
{ |
Buffer b; |
Buffer b; |
unsigned char *blob, *signature; |
u_char *blob, *signature; |
int bloblen, slen; |
int bloblen, slen; |
int skip = 0; |
int skip = 0; |
int ret = -1; |
int ret = -1; |
int have_sig = 1; |
int have_sig = 1; |
|
|
dsa_make_key_blob(k, &blob, &bloblen); |
debug3("sign_and_send_pubkey"); |
|
|
|
if (key_to_blob(k, &blob, &bloblen) == 0) { |
|
/* we cannot handle this key */ |
|
debug3("sign_and_send_pubkey: cannot handle key"); |
|
return 0; |
|
} |
/* data to be signed */ |
/* data to be signed */ |
buffer_init(&b); |
buffer_init(&b); |
if (datafellows & SSH_OLD_SESSIONID) { |
if (datafellows & SSH_OLD_SESSIONID) { |
buffer_append(&b, session_id2, session_id2_len); |
buffer_append(&b, session_id2, session_id2_len); |
skip = session_id2_len; |
skip = session_id2_len; |
} else { |
} else { |
buffer_put_string(&b, session_id2, session_id2_len); |
buffer_put_string(&b, session_id2, session_id2_len); |
skip = buffer_len(&b); |
skip = buffer_len(&b); |
|
|
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_cstring(&b, authctxt->server_user); |
buffer_put_cstring(&b, authctxt->server_user); |
buffer_put_cstring(&b, |
buffer_put_cstring(&b, |
datafellows & SSH_BUG_PUBKEYAUTH ? |
datafellows & SSH_BUG_PKSERVICE ? |
"ssh-userauth" : |
"ssh-userauth" : |
authctxt->service); |
authctxt->service); |
buffer_put_cstring(&b, authctxt->method->name); |
if (datafellows & SSH_BUG_PKAUTH) { |
buffer_put_char(&b, have_sig); |
buffer_put_char(&b, have_sig); |
buffer_put_cstring(&b, KEX_DSS); |
} else { |
|
buffer_put_cstring(&b, authctxt->method->name); |
|
buffer_put_char(&b, have_sig); |
|
buffer_put_cstring(&b, key_ssh_name(k)); |
|
} |
buffer_put_string(&b, blob, bloblen); |
buffer_put_string(&b, blob, bloblen); |
|
|
/* generate signature */ |
/* generate signature */ |
ret = (*sign_callback)(authctxt, k, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); |
ret = (*sign_callback)(authctxt, k, &signature, &slen, |
|
buffer_ptr(&b), buffer_len(&b)); |
if (ret == -1) { |
if (ret == -1) { |
xfree(blob); |
xfree(blob); |
buffer_free(&b); |
buffer_free(&b); |
return 0; |
return 0; |
} |
} |
#ifdef DEBUG_DSS |
#ifdef DEBUG_PK |
buffer_dump(&b); |
buffer_dump(&b); |
#endif |
#endif |
if (datafellows & SSH_BUG_PUBKEYAUTH) { |
if (datafellows & SSH_BUG_PKSERVICE) { |
buffer_clear(&b); |
buffer_clear(&b); |
buffer_append(&b, session_id2, session_id2_len); |
buffer_append(&b, session_id2, session_id2_len); |
|
skip = session_id2_len; |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
buffer_put_cstring(&b, authctxt->server_user); |
buffer_put_cstring(&b, authctxt->server_user); |
buffer_put_cstring(&b, authctxt->service); |
buffer_put_cstring(&b, authctxt->service); |
buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_char(&b, have_sig); |
buffer_put_char(&b, have_sig); |
buffer_put_cstring(&b, KEX_DSS); |
if (!(datafellows & SSH_BUG_PKAUTH)) |
|
buffer_put_cstring(&b, key_ssh_name(k)); |
buffer_put_string(&b, blob, bloblen); |
buffer_put_string(&b, blob, bloblen); |
} |
} |
xfree(blob); |
xfree(blob); |
|
|
/* append signature */ |
/* append signature */ |
buffer_put_string(&b, signature, slen); |
buffer_put_string(&b, signature, slen); |
xfree(signature); |
xfree(signature); |
|
|
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
packet_put_raw(buffer_ptr(&b), buffer_len(&b)); |
packet_put_raw(buffer_ptr(&b), buffer_len(&b)); |
buffer_free(&b); |
buffer_free(&b); |
|
|
/* send */ |
|
packet_send(); |
packet_send(); |
packet_write_wait(); |
|
|
|
return 1; |
return 1; |
} |
} |
|
|
/* sign callback */ |
int |
int dsa_sign_cb(Authctxt *authctxt, Key *key, unsigned char **sigp, int *lenp, |
send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, |
unsigned char *data, int datalen) |
int hint) |
{ |
{ |
return dsa_sign(key, sigp, lenp, data, datalen); |
u_char *blob; |
|
int bloblen, have_sig = 0; |
|
|
|
debug3("send_pubkey_test"); |
|
|
|
if (key_to_blob(k, &blob, &bloblen) == 0) { |
|
/* we cannot handle this key */ |
|
debug3("send_pubkey_test: cannot handle key"); |
|
return 0; |
|
} |
|
/* register callback for USERAUTH_PK_OK message */ |
|
authctxt->last_key_sign = sign_callback; |
|
authctxt->last_key_hint = hint; |
|
authctxt->last_key = k; |
|
dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
|
|
|
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
|
packet_put_cstring(authctxt->server_user); |
|
packet_put_cstring(authctxt->service); |
|
packet_put_cstring(authctxt->method->name); |
|
packet_put_char(have_sig); |
|
if (!(datafellows & SSH_BUG_PKAUTH)) |
|
packet_put_cstring(key_ssh_name(k)); |
|
packet_put_string(blob, bloblen); |
|
xfree(blob); |
|
packet_send(); |
|
return 1; |
} |
} |
|
|
int |
Key * |
userauth_pubkey_identity(Authctxt *authctxt, char *filename) |
load_identity_file(char *filename) |
{ |
{ |
Key *k; |
Key *private; |
int i, ret, try_next; |
char prompt[300], *passphrase; |
|
int quit, i; |
struct stat st; |
struct stat st; |
|
|
if (stat(filename, &st) != 0) { |
if (stat(filename, &st) < 0) { |
debug("key does not exist: %s", filename); |
debug3("no such identity: %s", filename); |
return 0; |
return NULL; |
} |
} |
debug("try pubkey: %s", filename); |
private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
|
if (private == NULL) { |
k = key_new(KEY_DSA); |
if (options.batch_mode) |
if (!load_private_key(filename, "", k, NULL)) { |
return NULL; |
int success = 0; |
|
char *passphrase; |
|
char prompt[300]; |
|
snprintf(prompt, sizeof prompt, |
snprintf(prompt, sizeof prompt, |
"Enter passphrase for %s key '%.100s': ", |
"Enter passphrase for key '%.100s': ", filename); |
key_type(k), filename); |
|
for (i = 0; i < options.number_of_password_prompts; i++) { |
for (i = 0; i < options.number_of_password_prompts; i++) { |
passphrase = read_passphrase(prompt, 0); |
passphrase = read_passphrase(prompt, 0); |
if (strcmp(passphrase, "") != 0) { |
if (strcmp(passphrase, "") != 0) { |
success = load_private_key(filename, passphrase, k, NULL); |
private = key_load_private_type(KEY_UNSPEC, filename, |
try_next = 0; |
passphrase, NULL); |
|
quit = 0; |
} else { |
} else { |
debug2("no passphrase given, try next key"); |
debug2("no passphrase given, try next key"); |
try_next = 1; |
quit = 1; |
} |
} |
memset(passphrase, 0, strlen(passphrase)); |
memset(passphrase, 0, strlen(passphrase)); |
xfree(passphrase); |
xfree(passphrase); |
if (success || try_next) |
if (private != NULL || quit) |
break; |
break; |
debug2("bad passphrase given, try again..."); |
debug2("bad passphrase given, try again..."); |
} |
} |
if (!success) { |
|
key_free(k); |
|
return 0; |
|
} |
|
} |
} |
ret = sign_and_send_pubkey(authctxt, k, dsa_sign_cb); |
return private; |
key_free(k); |
} |
|
|
|
int |
|
identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
|
u_char *data, int datalen) |
|
{ |
|
Key *private; |
|
int idx, ret; |
|
|
|
idx = authctxt->last_key_hint; |
|
if (idx < 0) |
|
return -1; |
|
private = load_identity_file(options.identity_files[idx]); |
|
if (private == NULL) |
|
return -1; |
|
ret = key_sign(private, sigp, lenp, data, datalen); |
|
key_free(private); |
return ret; |
return ret; |
} |
} |
|
|
/* sign callback */ |
int agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
int agent_sign_cb(Authctxt *authctxt, Key *key, unsigned char **sigp, int *lenp, |
u_char *data, int datalen) |
unsigned char *data, int datalen) |
|
{ |
{ |
return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
} |
} |
|
|
|
int key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
|
u_char *data, int datalen) |
|
{ |
|
return key_sign(key, sigp, lenp, data, datalen); |
|
} |
|
|
int |
int |
userauth_pubkey_agent(Authctxt *authctxt) |
userauth_pubkey_agent(Authctxt *authctxt) |
{ |
{ |
static int called = 0; |
static int called = 0; |
|
int ret = 0; |
char *comment; |
char *comment; |
Key *k; |
Key *k; |
int ret; |
|
|
|
if (called == 0) { |
if (called == 0) { |
k = ssh_get_first_identity(authctxt->agent, &comment, 2); |
if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
|
debug2("userauth_pubkey_agent: no keys at all"); |
called = 1; |
called = 1; |
} else { |
|
k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
|
} |
} |
|
k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
if (k == NULL) { |
if (k == NULL) { |
debug2("no more DSA keys from agent"); |
debug2("userauth_pubkey_agent: no more keys"); |
return 0; |
} else { |
|
debug("userauth_pubkey_agent: testing agent key %s", comment); |
|
xfree(comment); |
|
ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); |
|
if (ret == 0) |
|
key_free(k); |
} |
} |
debug("trying DSA agent key %s", comment); |
if (ret == 0) |
xfree(comment); |
debug2("userauth_pubkey_agent: no message sent"); |
ret = sign_and_send_pubkey(authctxt, k, agent_sign_cb); |
|
key_free(k); |
|
return ret; |
return ret; |
} |
} |
|
|
|
|
{ |
{ |
static int idx = 0; |
static int idx = 0; |
int sent = 0; |
int sent = 0; |
|
Key *key; |
|
char *filename; |
|
|
if (authctxt->agent != NULL) |
if (authctxt->agent != NULL) { |
sent = userauth_pubkey_agent(authctxt); |
do { |
while (sent == 0 && idx < options.num_identity_files2) |
sent = userauth_pubkey_agent(authctxt); |
sent = userauth_pubkey_identity(authctxt, options.identity_files2[idx++]); |
} while(!sent && authctxt->agent->howmany > 0); |
|
} |
|
while (!sent && idx < options.num_identity_files) { |
|
key = options.identity_keys[idx]; |
|
filename = options.identity_files[idx]; |
|
if (key == NULL) { |
|
debug("try privkey: %s", filename); |
|
key = load_identity_file(filename); |
|
if (key != NULL) { |
|
sent = sign_and_send_pubkey(authctxt, key, |
|
key_sign_cb); |
|
key_free(key); |
|
} |
|
} else if (key->type != KEY_RSA1) { |
|
debug("try pubkey: %s", filename); |
|
sent = send_pubkey_test(authctxt, key, |
|
identity_sign_cb, idx); |
|
} |
|
idx++; |
|
} |
return sent; |
return sent; |
} |
} |
|
|
|
|
packet_put_cstring(options.kbd_interactive_devices ? |
packet_put_cstring(options.kbd_interactive_devices ? |
options.kbd_interactive_devices : ""); |
options.kbd_interactive_devices : ""); |
packet_send(); |
packet_send(); |
packet_write_wait(); |
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); |
dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); |
return 1; |
return 1; |
} |
} |
|
|
/* |
/* |
* parse SSH2_MSG_USERAUTH_INFO_REQUEST, prompt user and send |
* parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
* SSH2_MSG_USERAUTH_INFO_RESPONSE |
|
*/ |
*/ |
void |
void |
input_userauth_info_req(int type, int plen, void *ctxt) |
input_userauth_info_req(int type, int plen, void *ctxt) |
{ |
{ |
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
char *name = NULL; |
char *name, *inst, *lang, *prompt, *response; |
char *inst = NULL; |
u_int num_prompts, i; |
char *lang = NULL; |
|
char *prompt = NULL; |
|
char *response = NULL; |
|
unsigned int num_prompts, i; |
|
int echo = 0; |
int echo = 0; |
|
|
debug2("input_userauth_info_req"); |
debug2("input_userauth_info_req"); |
|
|
name = packet_get_string(NULL); |
name = packet_get_string(NULL); |
inst = packet_get_string(NULL); |
inst = packet_get_string(NULL); |
lang = packet_get_string(NULL); |
lang = packet_get_string(NULL); |
|
|
if (strlen(name) > 0) |
if (strlen(name) > 0) |
cli_mesg(name); |
cli_mesg(name); |
xfree(name); |
|
|
|
if (strlen(inst) > 0) |
if (strlen(inst) > 0) |
cli_mesg(inst); |
cli_mesg(inst); |
|
xfree(name); |
xfree(inst); |
xfree(inst); |
xfree(lang); /* unused */ |
xfree(lang); |
|
|
num_prompts = packet_get_int(); |
num_prompts = packet_get_int(); |
/* |
/* |
|
|
} |
} |
packet_done(); /* done with parsing incoming message. */ |
packet_done(); /* done with parsing incoming message. */ |
|
|
|
packet_inject_ignore(64); |
packet_send(); |
packet_send(); |
packet_write_wait(); |
|
} |
} |
|
|
/* find auth method */ |
|
|
|
#define DELIM "," |
|
|
|
static char *def_authlist = "publickey,password"; |
|
static char *authlist_current = NULL; /* clean copy used for comparison */ |
|
static char *authname_current = NULL; /* last used auth method */ |
|
static char *authlist_working = NULL; /* copy that gets modified by strtok_r() */ |
|
static char *authlist_state = NULL; /* state variable for strtok_r() */ |
|
|
|
/* |
/* |
* Before starting to use a new authentication method list sent by the |
* this will be move to an external program (ssh-keysign) ASAP. ssh-keysign |
* server, reset internal variables. This should also be called when |
* will be setuid-root and the sbit can be removed from /usr/bin/ssh. |
* finished processing server list to free resources. |
|
*/ |
*/ |
void |
int |
authmethod_clear() |
userauth_hostbased(Authctxt *authctxt) |
{ |
{ |
if (authlist_current != NULL) { |
Key *private = NULL; |
xfree(authlist_current); |
Buffer b; |
authlist_current = NULL; |
u_char *signature, *blob; |
|
char *chost, *pkalg, *p; |
|
const char *service; |
|
u_int blen, slen; |
|
int ok, i, len, found = 0; |
|
|
|
p = get_local_name(packet_get_connection_in()); |
|
if (p == NULL) { |
|
error("userauth_hostbased: cannot get local ipaddr/name"); |
|
return 0; |
} |
} |
if (authlist_working != NULL) { |
len = strlen(p) + 2; |
xfree(authlist_working); |
chost = xmalloc(len); |
authlist_working = NULL; |
strlcpy(chost, p, len); |
|
strlcat(chost, ".", len); |
|
debug2("userauth_hostbased: chost %s", chost); |
|
/* check for a useful key */ |
|
for (i = 0; i < authctxt->nkeys; i++) { |
|
private = authctxt->keys[i]; |
|
if (private && private->type != KEY_RSA1) { |
|
found = 1; |
|
/* we take and free the key */ |
|
authctxt->keys[i] = NULL; |
|
break; |
|
} |
} |
} |
if (authname_current != NULL) { |
if (!found) { |
xfree(authname_current); |
xfree(chost); |
authlist_state = NULL; |
return 0; |
} |
} |
if (authlist_state != NULL) |
if (key_to_blob(private, &blob, &blen) == 0) { |
authlist_state = NULL; |
key_free(private); |
return; |
xfree(chost); |
|
return 0; |
|
} |
|
service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
|
authctxt->service; |
|
pkalg = xstrdup(key_ssh_name(private)); |
|
buffer_init(&b); |
|
/* construct data */ |
|
buffer_put_string(&b, session_id2, session_id2_len); |
|
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
|
buffer_put_cstring(&b, authctxt->server_user); |
|
buffer_put_cstring(&b, service); |
|
buffer_put_cstring(&b, authctxt->method->name); |
|
buffer_put_cstring(&b, pkalg); |
|
buffer_put_string(&b, blob, blen); |
|
buffer_put_cstring(&b, chost); |
|
buffer_put_cstring(&b, authctxt->local_user); |
|
#ifdef DEBUG_PK |
|
buffer_dump(&b); |
|
#endif |
|
debug2("xxx: chost %s", chost); |
|
ok = key_sign(private, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); |
|
key_free(private); |
|
buffer_free(&b); |
|
if (ok != 0) { |
|
error("key_sign failed"); |
|
xfree(chost); |
|
xfree(pkalg); |
|
return 0; |
|
} |
|
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
|
packet_put_cstring(authctxt->server_user); |
|
packet_put_cstring(authctxt->service); |
|
packet_put_cstring(authctxt->method->name); |
|
packet_put_cstring(pkalg); |
|
packet_put_string(blob, blen); |
|
packet_put_cstring(chost); |
|
packet_put_cstring(authctxt->local_user); |
|
packet_put_string(signature, slen); |
|
memset(signature, 's', slen); |
|
xfree(signature); |
|
xfree(chost); |
|
xfree(pkalg); |
|
|
|
packet_send(); |
|
return 1; |
} |
} |
|
|
|
/* find auth method */ |
|
|
/* |
/* |
* given auth method name, if configurable options permit this method fill |
* given auth method name, if configurable options permit this method fill |
* in auth_ident field and return true, otherwise return false. |
* in auth_ident field and return true, otherwise return false. |
|
|
return NULL; |
return NULL; |
} |
} |
|
|
|
/* XXX internal state */ |
|
static Authmethod *current = NULL; |
|
static char *supported = NULL; |
|
static char *preferred = NULL; |
/* |
/* |
* Given the authentication method list sent by the server, return the |
* Given the authentication method list sent by the server, return the |
* next method we should try. If the server initially sends a nil list, |
* next method we should try. If the server initially sends a nil list, |
* use a built-in default list. If the server sends a nil list after |
* use a built-in default list. |
* previously sending a valid list, continue using the list originally |
*/ |
* sent. |
|
*/ |
|
|
|
Authmethod * |
Authmethod * |
authmethod_get(char *authlist) |
authmethod_get(char *authlist) |
{ |
{ |
char *name = NULL, *authname_old; |
|
Authmethod *method = NULL; |
char *name = NULL; |
|
int next; |
|
|
/* Use a suitable default if we're passed a nil list. */ |
/* Use a suitable default if we're passed a nil list. */ |
if (authlist == NULL || strlen(authlist) == 0) |
if (authlist == NULL || strlen(authlist) == 0) |
authlist = def_authlist; |
authlist = options.preferred_authentications; |
|
|
if (authlist_current == NULL || strcmp(authlist, authlist_current) != 0) { |
if (supported == NULL || strcmp(authlist, supported) != 0) { |
/* start over if passed a different list */ |
debug3("start over, passed a different list %s", authlist); |
debug3("start over, passed a different list"); |
if (supported != NULL) |
authmethod_clear(); |
xfree(supported); |
authlist_current = xstrdup(authlist); |
supported = xstrdup(authlist); |
authlist_working = xstrdup(authlist); |
preferred = options.preferred_authentications; |
name = strtok_r(authlist_working, DELIM, &authlist_state); |
debug3("preferred %s", preferred); |
} else { |
current = NULL; |
/* |
} else if (current != NULL && authmethod_is_enabled(current)) |
* try to use previously used authentication method |
return current; |
* or continue to use previously passed list |
|
*/ |
|
name = (authname_current != NULL) ? |
|
authname_current : strtok_r(NULL, DELIM, &authlist_state); |
|
} |
|
|
|
while (name != NULL) { |
for (;;) { |
|
if ((name = match_list(preferred, supported, &next)) == NULL) { |
|
debug("no more auth methods to try"); |
|
current = NULL; |
|
return NULL; |
|
} |
|
preferred += next; |
debug3("authmethod_lookup %s", name); |
debug3("authmethod_lookup %s", name); |
method = authmethod_lookup(name); |
debug3("remaining preferred: %s", preferred); |
if (method != NULL && authmethod_is_enabled(method)) { |
if ((current = authmethod_lookup(name)) != NULL && |
|
authmethod_is_enabled(current)) { |
debug3("authmethod_is_enabled %s", name); |
debug3("authmethod_is_enabled %s", name); |
break; |
debug("next auth method to try is %s", name); |
|
return current; |
} |
} |
name = strtok_r(NULL, DELIM, &authlist_state); |
|
method = NULL; |
|
} |
} |
|
} |
|
|
authname_old = authname_current; |
|
if (method != NULL) { |
|
debug("next auth method to try is %s", name); |
|
authname_current = xstrdup(name); |
|
} else { |
|
debug("no more auth methods to try"); |
|
authname_current = NULL; |
|
} |
|
|
|
if (authname_old != NULL) |
#define DELIM "," |
xfree(authname_old); |
char * |
|
authmethods_get(void) |
|
{ |
|
Authmethod *method = NULL; |
|
char buf[1024]; |
|
|
return (method); |
buf[0] = '\0'; |
|
for (method = authmethods; method->name != NULL; method++) { |
|
if (authmethod_is_enabled(method)) { |
|
if (buf[0] != '\0') |
|
strlcat(buf, DELIM, sizeof buf); |
|
strlcat(buf, method->name, sizeof buf); |
|
} |
|
} |
|
return xstrdup(buf); |
} |
} |