--- /dev/null
+/*
+ * scpssh.c - SSH implementation for PuTTY Secure Copy
+ * Joris van Rantwijk, Aug 1999.
+ * Based on PuTTY ssh.c by Simon Tatham.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <winsock.h>
+
+#include "putty.h"
+#include "ssh.h"
+#include "scp.h"
+
+#define SSH_MSG_DISCONNECT 1
+#define SSH_SMSG_PUBLIC_KEY 2
+#define SSH_CMSG_SESSION_KEY 3
+#define SSH_CMSG_USER 4
+#define SSH_CMSG_AUTH_PASSWORD 9
+#define SSH_CMSG_EXEC_CMD 13
+#define SSH_SMSG_SUCCESS 14
+#define SSH_SMSG_FAILURE 15
+#define SSH_CMSG_STDIN_DATA 16
+#define SSH_SMSG_STDOUT_DATA 17
+#define SSH_SMSG_STDERR_DATA 18
+#define SSH_CMSG_EOF 19
+#define SSH_SMSG_EXIT_STATUS 20
+#define SSH_CMSG_EXIT_CONFIRMATION 33
+#define SSH_MSG_DEBUG 36
+
+#define GET_32BIT(cp) \
+ (((unsigned long)(unsigned char)(cp)[0] << 24) | \
+ ((unsigned long)(unsigned char)(cp)[1] << 16) | \
+ ((unsigned long)(unsigned char)(cp)[2] << 8) | \
+ ((unsigned long)(unsigned char)(cp)[3]))
+
+#define PUT_32BIT(cp, value) { \
+ (cp)[0] = (value) >> 24; \
+ (cp)[1] = (value) >> 16; \
+ (cp)[2] = (value) >> 8; \
+ (cp)[3] = (value); }
+
+static SOCKET s = INVALID_SOCKET;
+
+static unsigned char session_key[32];
+static struct ssh_cipher *cipher = NULL;
+
+static char *savedhost;
+
+struct Packet {
+ long length;
+ int type;
+ unsigned long crc;
+ unsigned char *data;
+ unsigned char *body;
+ long maxlen;
+};
+
+static struct Packet pktin = { 0, 0, 0, NULL, 0 };
+static struct Packet pktout = { 0, 0, 0, NULL, 0 };
+
+
+static void s_write (char *buf, int len) {
+ while (len > 0) {
+ int i = send (s, buf, len, 0);
+ noise_ultralight(i);
+ if (i <= 0)
+ fatalbox("Lost connection while sending");
+ len -= i, buf += i;
+ }
+}
+
+static int s_read (char *buf, int len) {
+ int ret = 0;
+ while (len > 0) {
+ int i = recv (s, buf, len, 0);
+ noise_ultralight(i);
+ if (i > 0)
+ len -= i, buf += i, ret += i;
+ else
+ return i;
+ }
+ return ret;
+}
+
+/*
+ * Read and decrypt one incoming SSH packet.
+ */
+static void get_packet()
+{
+ unsigned char buf[4];
+ int ret;
+ int len, pad, biglen;
+
+next_packet:
+
+ pktin.type = 0;
+ pktin.length = 0;
+
+ ret = s_read(buf, 4);
+ if (ret != 4) {
+ closesocket(s);
+ s = INVALID_SOCKET;
+ return;
+ }
+
+ len = GET_32BIT(buf);
+
+#ifdef FWHACK
+ if (len == 0x52656d6f) {
+ len = 0x300;
+ }
+#endif
+
+ pad = 8 - (len % 8);
+ biglen = len + pad;
+ len -= 5; /* type and CRC */
+
+ pktin.length = len;
+ if (pktin.maxlen < biglen) {
+ pktin.maxlen = biglen;
+ pktin.data = (pktin.data == NULL) ?
+ smalloc(biglen) : srealloc(pktin.data, biglen);
+ }
+
+ ret = s_read(pktin.data, biglen);
+ if (ret != biglen) {
+ closesocket(s);
+ s = INVALID_SOCKET;
+ return;
+ }
+
+ if (cipher)
+ cipher->decrypt(pktin.data, biglen);
+
+ pktin.type = pktin.data[pad];
+ pktin.body = pktin.data + pad + 1;
+
+ if (pktin.type == SSH_MSG_DEBUG) {
+ if (verbose) {
+ int len = GET_32BIT(pktin.body);
+ fprintf(stderr, "Remote: ");
+ fwrite(pktin.body + 4, len, 1, stderr);
+ fprintf(stderr, "\n");
+ }
+ goto next_packet;
+ }
+}
+
+static void s_wrpkt_start(int type, int len) {
+ int pad, biglen;
+
+ len += 5; /* type and CRC */
+ pad = 8 - (len%8);
+ biglen = len + pad;
+
+ pktout.length = len-5;
+ if (pktout.maxlen < biglen) {
+ pktout.maxlen = biglen;
+ pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
+ realloc(pktout.data, biglen+4));
+ if (!pktout.data)
+ fatalbox("Out of memory");
+ }
+
+ pktout.type = type;
+ pktout.body = pktout.data+4+pad+1;
+}
+
+static void s_wrpkt(void) {
+ int pad, len, biglen, i;
+ unsigned long crc;
+
+ len = pktout.length + 5; /* type and CRC */
+ pad = 8 - (len%8);
+ biglen = len + pad;
+
+ pktout.body[-1] = pktout.type;
+ for (i=0; i<pad; i++)
+ pktout.data[i+4] = random_byte();
+ crc = crc32(pktout.data+4, biglen-4);
+ PUT_32BIT(pktout.data+biglen, crc);
+ PUT_32BIT(pktout.data, len);
+
+ if (cipher)
+ cipher->encrypt(pktout.data+4, biglen);
+
+ s_write(pktout.data, biglen+4);
+}
+
+static int do_ssh_init(void) {
+ char c;
+ char version[10];
+ char vstring[40];
+ int i;
+
+#ifdef FWHACK
+ i = 0;
+ while (s_read(&c, 1) == 1) {
+ if (c == 'S' && i < 2) i++;
+ else if (c == 'S' && i == 2) i = 2;
+ else if (c == 'H' && i == 2) break;
+ else i = 0;
+ }
+#else
+ if (s_read(&c,1) != 1 || c != 'S') return 0;
+ if (s_read(&c,1) != 1 || c != 'S') return 0;
+ if (s_read(&c,1) != 1 || c != 'H') return 0;
+#endif
+ if (s_read(&c,1) != 1 || c != '-') return 0;
+ i = 0;
+ while (1) {
+ if (s_read(&c,1) != 1)
+ return 0;
+ if (i >= 0) {
+ if (c == '-') {
+ version[i] = '\0';
+ i = -1;
+ } else if (i < sizeof(version)-1)
+ version[i++] = c;
+ }
+ else if (c == '\n')
+ break;
+ }
+
+ sprintf(vstring, "SSH-%s-7.7.7\n",
+ (strcmp(version, "1.5") <= 0 ? version : "1.5"));
+ s_write(vstring, strlen(vstring));
+ return 1;
+}
+
+
+/*
+ * Login on the server and request execution of the command.
+ */
+static void ssh_login(char *username, char *cmd)
+{
+ int i, j, len;
+ unsigned char session_id[16];
+ unsigned char *rsabuf, *keystr1, *keystr2;
+ unsigned char cookie[8];
+ struct RSAKey servkey, hostkey;
+ struct MD5Context md5c;
+ unsigned long supported_ciphers_mask;
+ int cipher_type;
+
+ extern struct ssh_cipher ssh_3des;
+ extern struct ssh_cipher ssh_blowfish;
+
+ get_packet();
+
+ if (pktin.type != SSH_SMSG_PUBLIC_KEY)
+ fatalbox("Public key packet not received");
+
+ memcpy(cookie, pktin.body, 8);
+
+ MD5Init(&md5c);
+
+ i = makekey(pktin.body+8, &servkey, &keystr1);
+ j = makekey(pktin.body+8+i, &hostkey, &keystr2);
+
+ supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
+
+ MD5Update(&md5c, keystr2, hostkey.bytes);
+ MD5Update(&md5c, keystr1, servkey.bytes);
+ MD5Update(&md5c, pktin.body, 8);
+
+ MD5Final(session_id, &md5c);
+
+ for (i=0; i<32; i++)
+ session_key[i] = random_byte();
+
+ len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
+
+ rsabuf = malloc(len);
+ if (!rsabuf)
+ fatalbox("Out of memory");
+
+ verify_ssh_host_key(savedhost, &hostkey);
+
+ for (i=0; i<32; i++) {
+ rsabuf[i] = session_key[i];
+ if (i < 16)
+ rsabuf[i] ^= session_id[i];
+ }
+
+ if (hostkey.bytes > servkey.bytes) {
+ rsaencrypt(rsabuf, 32, &servkey);
+ rsaencrypt(rsabuf, servkey.bytes, &hostkey);
+ } else {
+ rsaencrypt(rsabuf, 32, &hostkey);
+ rsaencrypt(rsabuf, hostkey.bytes, &servkey);
+ }
+
+ cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
+ SSH_CIPHER_3DES;
+ if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
+ fprintf(stderr, "Selected cipher not supported, falling back to 3DES\n");
+ cipher_type = SSH_CIPHER_3DES;
+ }
+
+ s_wrpkt_start(SSH_CMSG_SESSION_KEY, len+15);
+ pktout.body[0] = cipher_type;
+ memcpy(pktout.body+1, cookie, 8);
+ pktout.body[9] = (len*8) >> 8;
+ pktout.body[10] = (len*8) & 0xFF;
+ memcpy(pktout.body+11, rsabuf, len);
+ pktout.body[len+11] = pktout.body[len+12] = 0; /* protocol flags */
+ pktout.body[len+13] = pktout.body[len+14] = 0;
+ s_wrpkt();
+
+ free(rsabuf);
+
+ cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
+ &ssh_3des;
+ cipher->sesskey(session_key);
+
+ get_packet();
+
+ if (pktin.type != SSH_SMSG_SUCCESS)
+ fatalbox("Encryption not successfully enabled");
+
+ if (verbose)
+ fprintf(stderr, "Logging in as \"%s\".\n", username);
+ s_wrpkt_start(SSH_CMSG_USER, 4+strlen(username));
+ pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
+ pktout.body[3] = strlen(username);
+ memcpy(pktout.body+4, username, strlen(username));
+ s_wrpkt();
+
+ get_packet();
+
+ while (pktin.type == SSH_SMSG_FAILURE) {
+ char password[100];
+ char prompt[200];
+ sprintf(prompt, "%s@%s's password: ", username, savedhost);
+ ssh_get_password(prompt, password, 100);
+ s_wrpkt_start(SSH_CMSG_AUTH_PASSWORD, 4+strlen(password));
+ pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
+ pktout.body[3] = strlen(password);
+ memcpy(pktout.body+4, password, strlen(password));
+ s_wrpkt();
+ memset(password, 0, strlen(password));
+ get_packet();
+ if (pktin.type == SSH_SMSG_FAILURE) {
+ fprintf(stderr, "Access denied\n");
+ } else if (pktin.type != SSH_SMSG_SUCCESS) {
+ fatalbox("Strange packet received, type %d", pktin.type);
+ }
+ }
+
+ /* Execute command */
+ if (verbose)
+ fprintf(stderr, "Sending command: %s\n", cmd);
+ i = strlen(cmd);
+ s_wrpkt_start(SSH_CMSG_EXEC_CMD, 4+i);
+ PUT_32BIT(pktout.body, i);
+ memcpy(pktout.body+4, cmd, i);
+ s_wrpkt();
+}
+
+
+/*
+ * Receive a block of data over the SSH link. Block until
+ * all data is available. Return nr of bytes read (0 if lost connection).
+ */
+int ssh_recv(unsigned char *buf, int len)
+{
+ static int pending_input_len = 0;
+ static unsigned char *pending_input_ptr;
+ int to_read = len;
+
+ if (pending_input_len >= to_read) {
+ memcpy(buf, pending_input_ptr, to_read);
+ pending_input_ptr += to_read;
+ pending_input_len -= to_read;
+ return len;
+ }
+
+ if (pending_input_len > 0) {
+ memcpy(buf, pending_input_ptr, pending_input_len);
+ buf += pending_input_len;
+ to_read -= pending_input_len;
+ pending_input_len = 0;
+ }
+
+ if (s == INVALID_SOCKET)
+ return 0;
+ while (to_read > 0) {
+ get_packet();
+ if (s == INVALID_SOCKET)
+ return 0;
+ if (pktin.type == SSH_SMSG_STDOUT_DATA) {
+ int plen = GET_32BIT(pktin.body);
+ if (plen <= to_read) {
+ memcpy(buf, pktin.body + 4, plen);
+ buf += plen;
+ to_read -= plen;
+ } else {
+ memcpy(buf, pktin.body + 4, to_read);
+ pending_input_len = plen - to_read;
+ pending_input_ptr = pktin.body + 4 + to_read;
+ to_read = 0;
+ }
+ } else if (pktin.type == SSH_SMSG_STDERR_DATA) {
+ int plen = GET_32BIT(pktin.body);
+ fwrite(pktin.body + 4, plen, 1, stderr);
+ } else if (pktin.type == SSH_MSG_DISCONNECT) {
+ } else if (pktin.type == SSH_SMSG_SUCCESS ||
+ pktin.type == SSH_SMSG_FAILURE) {
+ } else if (pktin.type == SSH_SMSG_EXIT_STATUS) {
+ if (verbose)
+ fprintf(stderr, "Remote exit status %d\n",
+ GET_32BIT(pktin.body));
+ s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION, 0);
+ s_wrpkt();
+ if (verbose)
+ fprintf(stderr, "Closing connection\n");
+ closesocket(s);
+ s = INVALID_SOCKET;
+ }
+ }
+
+ return len;
+}
+
+
+/*
+ * Send a block of data over the SSH link.
+ * Block until all data is sent.
+ */
+void ssh_send(unsigned char *buf, int len)
+{
+ if (s == INVALID_SOCKET)
+ return;
+ s_wrpkt_start(SSH_CMSG_STDIN_DATA, 4 + len);
+ PUT_32BIT(pktout.body, len);
+ memcpy(pktout.body + 4, buf, len);
+ s_wrpkt();
+}
+
+
+/*
+ * Send an EOF notification to the server.
+ */
+void ssh_send_eof(void)
+{
+ if (s == INVALID_SOCKET)
+ return;
+ s_wrpkt_start(SSH_CMSG_EOF, 0);
+ s_wrpkt();
+}
+
+
+/*
+ * Set up the connection, login on the remote host and
+ * start execution of a command.
+ *
+ * Returns an error message, or NULL on success.
+ *
+ * Also places the canonical host name into `realhost'.
+ */
+char *ssh_init(char *host, int port, char *cmd, char **realhost) {
+ SOCKADDR_IN addr;
+ struct hostent *h;
+ unsigned long a;
+#ifdef FWHACK
+ char *FWhost;
+ int FWport;
+#endif
+
+ savedhost = malloc(1+strlen(host));
+ if (!savedhost)
+ fatalbox("Out of memory");
+ strcpy(savedhost, host);
+
+#ifdef FWHACK
+ FWhost = host;
+ FWport = port;
+ host = FWSTR;
+ port = 23;
+#endif
+
+ /*
+ * Try to find host.
+ */
+ if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
+ if ( (h = gethostbyname(host)) == NULL)
+ switch (WSAGetLastError()) {
+ case WSAENETDOWN: return "Network is down";
+ case WSAHOST_NOT_FOUND: case WSANO_DATA:
+ return "Host does not exist";
+ case WSATRY_AGAIN: return "Host not found";
+ default: return "gethostbyname: unknown error";
+ }
+ memcpy (&a, h->h_addr, sizeof(a));
+ *realhost = h->h_name;
+ } else
+ *realhost = host;
+#ifdef FWHACK
+ *realhost = FWhost;
+#endif
+ a = ntohl(a);
+
+ if (port < 0)
+ port = 22; /* default ssh port */
+
+ /*
+ * Open socket.
+ */
+ s = socket(AF_INET, SOCK_STREAM, 0);
+ if (s == INVALID_SOCKET)
+ switch (WSAGetLastError()) {
+ case WSAENETDOWN: return "Network is down";
+ case WSAEAFNOSUPPORT: return "TCP/IP support not present";
+ default: return "socket(): unknown error";
+ }
+
+ /*
+ * Bind to local address.
+ */
+ addr.sin_family = AF_INET;
+ addr.sin_addr.s_addr = htonl(INADDR_ANY);
+ addr.sin_port = htons(0);
+ if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
+ switch (WSAGetLastError()) {
+ case WSAENETDOWN: return "Network is down";
+ default: return "bind(): unknown error";
+ }
+
+ /*
+ * Connect to remote address.
+ */
+ addr.sin_addr.s_addr = htonl(a);
+ addr.sin_port = htons((short)port);
+ if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
+ switch (WSAGetLastError()) {
+ case WSAENETDOWN: return "Network is down";
+ case WSAECONNREFUSED: return "Connection refused";
+ case WSAENETUNREACH: return "Network is unreachable";
+ case WSAEHOSTUNREACH: return "No route to host";
+ default: return "connect(): unknown error";
+ }
+
+#ifdef FWHACK
+ send(s, "connect ", 8, 0);
+ send(s, FWhost, strlen(FWhost), 0);
+ {
+ char buf[20];
+ sprintf(buf, " %d\n", FWport);
+ send (s, buf, strlen(buf), 0);
+ }
+#endif
+
+ random_init();
+
+ if (!do_ssh_init())
+ return "Protocol initialisation error";
+
+ ssh_login(cfg.username, cmd);
+
+ return NULL;
+}
+
+/* end */
projects / u / mdw / putty / blobdiff