diff options
Diffstat (limited to 'sshconnect.c')
| -rw-r--r-- | sshconnect.c | 246 |
1 files changed, 135 insertions, 111 deletions
diff --git a/sshconnect.c b/sshconnect.c index e6175f11..d96f8e02 100644 --- a/sshconnect.c +++ b/sshconnect.c @@ -8,7 +8,7 @@ */ #include "includes.h" -RCSID("$Id: sshconnect.c,v 1.17 1999/12/07 04:38:32 damien Exp $"); +RCSID("$Id: sshconnect.c,v 1.18 1999/12/13 23:47:16 damien Exp $"); #ifdef HAVE_OPENSSL #include <openssl/bn.h> @@ -156,8 +156,10 @@ ssh_create_socket(uid_t original_real_uid, int privileged) fatal("rresvport: %.100s", strerror(errno)); debug("Allocated local port %d.", p); } else { - /* Just create an ordinary socket on arbitrary port. We - use the user's uid to create the socket. */ + /* + * Just create an ordinary socket on arbitrary port. We use + * the user's uid to create the socket. + */ temporarily_use_uid(original_real_uid); sock = socket(AF_INET, SOCK_STREAM, 0); if (sock < 0) @@ -209,9 +211,11 @@ ssh_connect(const char *host, struct sockaddr_in * hostaddr, /* No host lookup made yet. */ hp = NULL; - /* Try to connect several times. On some machines, the first time - will sometimes fail. In general socket code appears to behave - quite magically on many machines. */ + /* + * Try to connect several times. On some machines, the first time + * will sometimes fail. In general socket code appears to behave + * quite magically on many machines. + */ for (attempt = 0; attempt < connection_attempts; attempt++) { if (attempt > 0) debug("Trying again..."); @@ -1087,39 +1091,21 @@ read_yes_or_no(const char *prompt, int defval) } /* - * Starts a dialog with the server, and authenticates the current user on the - * server. This does not need any extra privileges. The basic connection - * to the server must already have been established before this is called. - * User is the remote user; if it is NULL, the current local user name will - * be used. Anonymous indicates that no rhosts authentication will be used. - * If login fails, this function prints an error and never returns. - * This function does not require super-user privileges. + * check whether the supplied host key is valid, return only if ok. */ + void -ssh_login(int host_key_valid, - RSA *own_host_key, - const char *orighost, - struct sockaddr_in *hostaddr, - uid_t original_real_uid) +check_host_key(char *host, + struct sockaddr_in *hostaddr, + RSA *host_key) { - int i, type; - struct passwd *pw; - BIGNUM *key; - RSA *host_key, *file_key; - RSA *public_key; - int bits, rbits; - unsigned char session_key[SSH_SESSION_KEY_LENGTH]; - const char *server_user, *local_user; - char *cp, *host, *ip = NULL; + RSA *file_key; + char *ip = NULL; char hostline[1000], *hostp; - unsigned char check_bytes[8]; - unsigned int supported_ciphers, supported_authentications, protocol_flags; HostStatus host_status; HostStatus ip_status; int host_ip_differ = 0; int local = (ntohl(hostaddr->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; - int payload_len, clen, sum_len = 0; - u_int32_t rand = 0; /* * Turn off check_host_ip for proxy connects, since @@ -1131,88 +1117,14 @@ ssh_login(int host_key_valid, if (options.check_host_ip) ip = xstrdup(inet_ntoa(hostaddr->sin_addr)); - /* Convert the user-supplied hostname into all lowercase. */ - host = xstrdup(orighost); - for (cp = host; *cp; cp++) - if (isupper(*cp)) - *cp = tolower(*cp); - - /* Exchange protocol version identification strings with the server. */ - ssh_exchange_identification(); - - /* Put the connection into non-blocking mode. */ - packet_set_nonblocking(); - - /* Get local user name. Use it as server user if no user name was given. */ - pw = getpwuid(original_real_uid); - if (!pw) - fatal("User id %d not found from user database.", original_real_uid); - local_user = xstrdup(pw->pw_name); - server_user = options.user ? options.user : local_user; - - debug("Waiting for server public key."); - - /* Wait for a public key packet from the server. */ - packet_read_expect(&payload_len, SSH_SMSG_PUBLIC_KEY); - - /* Get check bytes from the packet. */ - for (i = 0; i < 8; i++) - check_bytes[i] = packet_get_char(); - - /* Get the public key. */ - public_key = RSA_new(); - bits = packet_get_int();/* bits */ - public_key->e = BN_new(); - packet_get_bignum(public_key->e, &clen); - sum_len += clen; - public_key->n = BN_new(); - packet_get_bignum(public_key->n, &clen); - sum_len += clen; - - rbits = BN_num_bits(public_key->n); - if (bits != rbits) { - log("Warning: Server lies about size of server public key: " - "actual size is %d bits vs. announced %d.", rbits, bits); - log("Warning: This may be due to an old implementation of ssh."); - } - /* Get the host key. */ - host_key = RSA_new(); - bits = packet_get_int();/* bits */ - host_key->e = BN_new(); - packet_get_bignum(host_key->e, &clen); - sum_len += clen; - host_key->n = BN_new(); - packet_get_bignum(host_key->n, &clen); - sum_len += clen; - - rbits = BN_num_bits(host_key->n); - if (bits != rbits) { - log("Warning: Server lies about size of server host key: " - "actual size is %d bits vs. announced %d.", rbits, bits); - log("Warning: This may be due to an old implementation of ssh."); - } - /* Store the host key from the known host file in here so that we - can compare it with the key for the IP address. */ + /* + * Store the host key from the known host file in here so that we can + * compare it with the key for the IP address. + */ file_key = RSA_new(); file_key->n = BN_new(); file_key->e = BN_new(); - /* Get protocol flags. */ - protocol_flags = packet_get_int(); - packet_set_protocol_flags(protocol_flags); - - supported_ciphers = packet_get_int(); - supported_authentications = packet_get_int(); - - debug("Received server public key (%d bits) and host key (%d bits).", - BN_num_bits(public_key->n), BN_num_bits(host_key->n)); - - packet_integrity_check(payload_len, - 8 + 4 + sum_len + 0 + 4 + 0 + 0 + 4 + 4 + 4, - SSH_SMSG_PUBLIC_KEY); - - compute_session_id(session_id, check_bytes, host_key->n, public_key->n); - /* * Check if the host key is present in the user\'s list of known * hosts or in the systemwide list. @@ -1372,9 +1284,121 @@ ssh_login(int host_key_valid, */ break; } - if (options.check_host_ip) xfree(ip); +} + +/* + * Starts a dialog with the server, and authenticates the current user on the + * server. This does not need any extra privileges. The basic connection + * to the server must already have been established before this is called. + * User is the remote user; if it is NULL, the current local user name will + * be used. Anonymous indicates that no rhosts authentication will be used. + * If login fails, this function prints an error and never returns. + * This function does not require super-user privileges. + */ +void +ssh_login(int host_key_valid, + RSA *own_host_key, + const char *orighost, + struct sockaddr_in *hostaddr, + uid_t original_real_uid) +{ + int i, type; + struct passwd *pw; + BIGNUM *key; + RSA *host_key; + RSA *public_key; + int bits, rbits; + unsigned char session_key[SSH_SESSION_KEY_LENGTH]; + const char *server_user, *local_user; + char *host, *cp; + unsigned char check_bytes[8]; + unsigned int supported_ciphers, supported_authentications; + unsigned int server_flags, client_flags; + int payload_len, clen, sum_len = 0; + u_int32_t rand = 0; + + /* Convert the user-supplied hostname into all lowercase. */ + host = xstrdup(orighost); + for (cp = host; *cp; cp++) + if (isupper(*cp)) + *cp = tolower(*cp); + + /* Exchange protocol version identification strings with the server. */ + ssh_exchange_identification(); + + /* Put the connection into non-blocking mode. */ + packet_set_nonblocking(); + + /* Get local user name. Use it as server user if no user name was given. */ + pw = getpwuid(original_real_uid); + if (!pw) + fatal("User id %d not found from user database.", original_real_uid); + local_user = xstrdup(pw->pw_name); + server_user = options.user ? options.user : local_user; + + debug("Waiting for server public key."); + + /* Wait for a public key packet from the server. */ + packet_read_expect(&payload_len, SSH_SMSG_PUBLIC_KEY); + + /* Get check bytes from the packet. */ + for (i = 0; i < 8; i++) + check_bytes[i] = packet_get_char(); + + /* Get the public key. */ + public_key = RSA_new(); + bits = packet_get_int();/* bits */ + public_key->e = BN_new(); + packet_get_bignum(public_key->e, &clen); + sum_len += clen; + public_key->n = BN_new(); + packet_get_bignum(public_key->n, &clen); + sum_len += clen; + + rbits = BN_num_bits(public_key->n); + if (bits != rbits) { + log("Warning: Server lies about size of server public key: " + "actual size is %d bits vs. announced %d.", rbits, bits); + log("Warning: This may be due to an old implementation of ssh."); + } + /* Get the host key. */ + host_key = RSA_new(); + bits = packet_get_int();/* bits */ + host_key->e = BN_new(); + packet_get_bignum(host_key->e, &clen); + sum_len += clen; + host_key->n = BN_new(); + packet_get_bignum(host_key->n, &clen); + sum_len += clen; + + rbits = BN_num_bits(host_key->n); + if (bits != rbits) { + log("Warning: Server lies about size of server host key: " + "actual size is %d bits vs. announced %d.", rbits, bits); + log("Warning: This may be due to an old implementation of ssh."); + } + + /* Get protocol flags. */ + server_flags = packet_get_int(); + packet_set_protocol_flags(server_flags); + + supported_ciphers = packet_get_int(); + supported_authentications = packet_get_int(); + + debug("Received server public key (%d bits) and host key (%d bits).", + BN_num_bits(public_key->n), BN_num_bits(host_key->n)); + + packet_integrity_check(payload_len, + 8 + 4 + sum_len + 0 + 4 + 0 + 0 + 4 + 4 + 4, + SSH_SMSG_PUBLIC_KEY); + + check_host_key(host, hostaddr, host_key); + + client_flags = SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN; + + compute_session_id(session_id, check_bytes, host_key->n, public_key->n); /* Generate a session key. */ arc4random_stir(); @@ -1465,7 +1489,7 @@ ssh_login(int host_key_valid, packet_put_bignum(key); /* Send protocol flags. */ - packet_put_int(SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN); + packet_put_int(client_flags); /* Send the packet now. */ packet_send(); |