git.distorted.org.uk Git - u/mdw/putty/blob - ssh.h

   1 #include <stdio.h>
   2 #include <string.h>
   3
   4 #include "puttymem.h"
   5 #include "tree234.h"
   6 #include "network.h"
   7 #include "int64.h"
   8 #include "misc.h"
   9
  10 struct ssh_channel;
  11
  12 extern int sshfwd_write(struct ssh_channel *c, char *, int);
  13 extern void sshfwd_write_eof(struct ssh_channel *c);
  14 extern void sshfwd_unclean_close(struct ssh_channel *c);
  15 extern void sshfwd_unthrottle(struct ssh_channel *c, int bufsize);
  16
  17 /*
  18  * Useful thing.
  19  */
  20 #ifndef lenof
  21 #define lenof(x) ( (sizeof((x))) / (sizeof(*(x))))
  22 #endif
  23
  24 #define SSH_CIPHER_IDEA         1
  25 #define SSH_CIPHER_DES          2
  26 #define SSH_CIPHER_3DES         3
  27 #define SSH_CIPHER_BLOWFISH     6
  28
  29 #ifdef MSCRYPTOAPI
  30 #define APIEXTRA 8
  31 #else
  32 #define APIEXTRA 0
  33 #endif
  34
  35 #ifndef BIGNUM_INTERNAL
  36 typedef void *Bignum;
  37 #endif
  38
  39 struct RSAKey {
  40     int bits;
  41     int bytes;
  42 #ifdef MSCRYPTOAPI
  43     unsigned long exponent;
  44     unsigned char *modulus;
  45 #else
  46     Bignum modulus;
  47     Bignum exponent;
  48     Bignum private_exponent;
  49     Bignum p;
  50     Bignum q;
  51     Bignum iqmp;
  52 #endif
  53     char *comment;
  54 };
  55
  56 struct dss_key {
  57     Bignum p, q, g, y, x;
  58 };
  59
  60 int makekey(unsigned char *data, int len, struct RSAKey *result,
  61             unsigned char **keystr, int order);
  62 int makeprivate(unsigned char *data, int len, struct RSAKey *result);
  63 int rsaencrypt(unsigned char *data, int length, struct RSAKey *key);
  64 Bignum rsadecrypt(Bignum input, struct RSAKey *key);
  65 void rsasign(unsigned char *data, int length, struct RSAKey *key);
  66 void rsasanitise(struct RSAKey *key);
  67 int rsastr_len(struct RSAKey *key);
  68 void rsastr_fmt(char *str, struct RSAKey *key);
  69 void rsa_fingerprint(char *str, int len, struct RSAKey *key);
  70 int rsa_verify(struct RSAKey *key);
  71 unsigned char *rsa_public_blob(struct RSAKey *key, int *len);
  72 int rsa_public_blob_len(void *data, int maxlen);
  73 void freersakey(struct RSAKey *key);
  74
  75 #ifndef PUTTY_UINT32_DEFINED
  76 /* This makes assumptions about the int type. */
  77 typedef unsigned int uint32;
  78 #define PUTTY_UINT32_DEFINED
  79 #endif
  80 typedef uint32 word32;
  81
  82 unsigned long crc32_compute(const void *s, size_t len);
  83 unsigned long crc32_update(unsigned long crc_input, const void *s, size_t len);
  84
  85 /* SSH CRC compensation attack detector */
  86 void *crcda_make_context(void);
  87 void crcda_free_context(void *handle);
  88 int detect_attack(void *handle, unsigned char *buf, uint32 len,
  89                   unsigned char *IV);
  90
  91 /*
  92  * SSH2 RSA key exchange functions
  93  */
  94 struct ssh_hash;
  95 void *ssh_rsakex_newkey(char *data, int len);
  96 void ssh_rsakex_freekey(void *key);
  97 int ssh_rsakex_klen(void *key);
  98 void ssh_rsakex_encrypt(const struct ssh_hash *h, unsigned char *in, int inlen,
  99                         unsigned char *out, int outlen,
 100                         void *key);
 101
 102 typedef struct {
 103     uint32 h[4];
 104 } MD5_Core_State;
 105
 106 struct MD5Context {
 107 #ifdef MSCRYPTOAPI
 108     unsigned long hHash;
 109 #else
 110     MD5_Core_State core;
 111     unsigned char block[64];
 112     int blkused;
 113     uint32 lenhi, lenlo;
 114 #endif
 115 };
 116
 117 void MD5Init(struct MD5Context *context);
 118 void MD5Update(struct MD5Context *context, unsigned char const *buf,
 119                unsigned len);
 120 void MD5Final(unsigned char digest[16], struct MD5Context *context);
 121 void MD5Simple(void const *p, unsigned len, unsigned char output[16]);
 122
 123 void *hmacmd5_make_context(void);
 124 void hmacmd5_free_context(void *handle);
 125 void hmacmd5_key(void *handle, void const *key, int len);
 126 void hmacmd5_do_hmac(void *handle, unsigned char const *blk, int len,
 127                      unsigned char *hmac);
 128
 129 typedef struct {
 130     uint32 h[5];
 131     unsigned char block[64];
 132     int blkused;
 133     uint32 lenhi, lenlo;
 134 } SHA_State;
 135 void SHA_Init(SHA_State * s);
 136 void SHA_Bytes(SHA_State * s, void *p, int len);
 137 void SHA_Final(SHA_State * s, unsigned char *output);
 138 void SHA_Simple(void *p, int len, unsigned char *output);
 139
 140 void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
 141                       unsigned char *output);
 142 typedef struct {
 143     uint32 h[8];
 144     unsigned char block[64];
 145     int blkused;
 146     uint32 lenhi, lenlo;
 147 } SHA256_State;
 148 void SHA256_Init(SHA256_State * s);
 149 void SHA256_Bytes(SHA256_State * s, const void *p, int len);
 150 void SHA256_Final(SHA256_State * s, unsigned char *output);
 151 void SHA256_Simple(const void *p, int len, unsigned char *output);
 152
 153 typedef struct {
 154     uint64 h[8];
 155     unsigned char block[128];
 156     int blkused;
 157     uint32 len[4];
 158 } SHA512_State;
 159 void SHA512_Init(SHA512_State * s);
 160 void SHA512_Bytes(SHA512_State * s, const void *p, int len);
 161 void SHA512_Final(SHA512_State * s, unsigned char *output);
 162 void SHA512_Simple(const void *p, int len, unsigned char *output);
 163
 164 struct ssh_cipher {
 165     void *(*make_context)(void);
 166     void (*free_context)(void *);
 167     void (*sesskey) (void *, unsigned char *key);       /* for SSH-1 */
 168     void (*encrypt) (void *, unsigned char *blk, int len);
 169     void (*decrypt) (void *, unsigned char *blk, int len);
 170     int blksize;
 171     char *text_name;
 172 };
 173
 174 struct ssh2_cipher {
 175     void *(*make_context)(void);
 176     void (*free_context)(void *);
 177     void (*setiv) (void *, unsigned char *key); /* for SSH-2 */
 178     void (*setkey) (void *, unsigned char *key);/* for SSH-2 */
 179     void (*encrypt) (void *, unsigned char *blk, int len);
 180     void (*decrypt) (void *, unsigned char *blk, int len);
 181     char *name;
 182     int blksize;
 183     int keylen;
 184     unsigned int flags;
 185 #define SSH_CIPHER_IS_CBC       1
 186     char *text_name;
 187 };
 188
 189 struct ssh2_ciphers {
 190     int nciphers;
 191     const struct ssh2_cipher *const *list;
 192 };
 193
 194 struct ssh_mac {
 195     void *(*make_context)(void);
 196     void (*free_context)(void *);
 197     void (*setkey) (void *, unsigned char *key);
 198     /* whole-packet operations */
 199     void (*generate) (void *, unsigned char *blk, int len, unsigned long seq);
 200     int (*verify) (void *, unsigned char *blk, int len, unsigned long seq);
 201     /* partial-packet operations */
 202     void (*start) (void *);
 203     void (*bytes) (void *, unsigned char const *, int);
 204     void (*genresult) (void *, unsigned char *);
 205     int (*verresult) (void *, unsigned char const *);
 206     char *name;
 207     int len;
 208     char *text_name;
 209 };
 210
 211 struct ssh_hash {
 212     void *(*init)(void); /* also allocates context */
 213     void (*bytes)(void *, void *, int);
 214     void (*final)(void *, unsigned char *); /* also frees context */
 215     int hlen; /* output length in bytes */
 216     char *text_name;
 217 };
 218
 219 struct ssh_kex {
 220     char *name, *groupname;
 221     enum { KEXTYPE_DH, KEXTYPE_RSA } main_type;
 222     /* For DH */
 223     const unsigned char *pdata, *gdata; /* NULL means group exchange */
 224     int plen, glen;
 225     const struct ssh_hash *hash;
 226 };
 227
 228 struct ssh_kexes {
 229     int nkexes;
 230     const struct ssh_kex *const *list;
 231 };
 232
 233 struct ssh_signkey {
 234     void *(*newkey) (char *data, int len);
 235     void (*freekey) (void *key);
 236     char *(*fmtkey) (void *key);
 237     unsigned char *(*public_blob) (void *key, int *len);
 238     unsigned char *(*private_blob) (void *key, int *len);
 239     void *(*createkey) (unsigned char *pub_blob, int pub_len,
 240                         unsigned char *priv_blob, int priv_len);
 241     void *(*openssh_createkey) (unsigned char **blob, int *len);
 242     int (*openssh_fmtkey) (void *key, unsigned char *blob, int len);
 243     int (*pubkey_bits) (void *blob, int len);
 244     char *(*fingerprint) (void *key);
 245     int (*verifysig) (void *key, char *sig, int siglen,
 246                       char *data, int datalen);
 247     unsigned char *(*sign) (void *key, char *data, int datalen,
 248                             int *siglen);
 249     char *name;
 250     char *keytype;                     /* for host key cache */
 251 };
 252
 253 struct ssh_compress {
 254     char *name;
 255     /* For zlib@openssh.com: if non-NULL, this name will be considered once
 256      * userauth has completed successfully. */
 257     char *delayed_name;
 258     void *(*compress_init) (void);
 259     void (*compress_cleanup) (void *);
 260     int (*compress) (void *, unsigned char *block, int len,
 261                      unsigned char **outblock, int *outlen);
 262     void *(*decompress_init) (void);
 263     void (*decompress_cleanup) (void *);
 264     int (*decompress) (void *, unsigned char *block, int len,
 265                        unsigned char **outblock, int *outlen);
 266     int (*disable_compression) (void *);
 267     char *text_name;
 268 };
 269
 270 struct ssh2_userkey {
 271     const struct ssh_signkey *alg;     /* the key algorithm */
 272     void *data;                        /* the key data */
 273     char *comment;                     /* the key comment */
 274 };
 275
 276 /* The maximum length of any hash algorithm used in kex. (bytes) */
 277 #define SSH2_KEX_MAX_HASH_LEN (32) /* SHA-256 */
 278
 279 extern const struct ssh_cipher ssh_3des;
 280 extern const struct ssh_cipher ssh_des;
 281 extern const struct ssh_cipher ssh_blowfish_ssh1;
 282 extern const struct ssh2_ciphers ssh2_3des;
 283 extern const struct ssh2_ciphers ssh2_des;
 284 extern const struct ssh2_ciphers ssh2_aes;
 285 extern const struct ssh2_ciphers ssh2_blowfish;
 286 extern const struct ssh2_ciphers ssh2_arcfour;
 287 extern const struct ssh_hash ssh_sha1;
 288 extern const struct ssh_hash ssh_sha256;
 289 extern const struct ssh_kexes ssh_diffiehellman_group1;
 290 extern const struct ssh_kexes ssh_diffiehellman_group14;
 291 extern const struct ssh_kexes ssh_diffiehellman_gex;
 292 extern const struct ssh_kexes ssh_rsa_kex;
 293 extern const struct ssh_signkey ssh_dss;
 294 extern const struct ssh_signkey ssh_rsa;
 295 extern const struct ssh_mac ssh_hmac_md5;
 296 extern const struct ssh_mac ssh_hmac_sha1;
 297 extern const struct ssh_mac ssh_hmac_sha1_buggy;
 298 extern const struct ssh_mac ssh_hmac_sha1_96;
 299 extern const struct ssh_mac ssh_hmac_sha1_96_buggy;
 300
 301 void *aes_make_context(void);
 302 void aes_free_context(void *handle);
 303 void aes128_key(void *handle, unsigned char *key);
 304 void aes192_key(void *handle, unsigned char *key);
 305 void aes256_key(void *handle, unsigned char *key);
 306 void aes_iv(void *handle, unsigned char *iv);
 307 void aes_ssh2_encrypt_blk(void *handle, unsigned char *blk, int len);
 308 void aes_ssh2_decrypt_blk(void *handle, unsigned char *blk, int len);
 309
 310 /*
 311  * PuTTY version number formatted as an SSH version string.
 312  */
 313 extern char sshver[];
 314
 315 /*
 316  * Gross hack: pscp will try to start SFTP but fall back to scp1 if
 317  * that fails. This variable is the means by which scp.c can reach
 318  * into the SSH code and find out which one it got.
 319  */
 320 extern int ssh_fallback_cmd(void *handle);
 321
 322 #ifndef MSCRYPTOAPI
 323 void SHATransform(word32 * digest, word32 * data);
 324 #endif
 325
 326 int random_byte(void);
 327 void random_add_noise(void *noise, int length);
 328 void random_add_heavynoise(void *noise, int length);
 329
 330 void logevent(void *, const char *);
 331
 332 /* Allocate and register a new channel for port forwarding */
 333 void *new_sock_channel(void *handle, Socket s);
 334 void ssh_send_port_open(void *channel, char *hostname, int port, char *org);
 335
 336 /* Exports from portfwd.c */
 337 extern const char *pfd_newconnect(Socket * s, char *hostname, int port,
 338                                   void *c, Conf *conf, int addressfamily);
 339 /* desthost == NULL indicates dynamic (SOCKS) port forwarding */
 340 extern const char *pfd_addforward(char *desthost, int destport, char *srcaddr,
 341                                   int port, void *backhandle, Conf *conf,
 342                                   void **sockdata, int address_family);
 343 extern void pfd_close(Socket s);
 344 extern void pfd_terminate(void *sockdata);
 345 extern int pfd_send(Socket s, char *data, int len);
 346 extern void pfd_send_eof(Socket s);
 347 extern void pfd_confirm(Socket s);
 348 extern void pfd_unthrottle(Socket s);
 349 extern void pfd_override_throttle(Socket s, int enable);
 350
 351 /* Exports from x11fwd.c */
 352 enum {
 353     X11_TRANS_IPV4 = 0, X11_TRANS_IPV6 = 6, X11_TRANS_UNIX = 256
 354 };
 355 struct X11Display {
 356     /* Broken-down components of the display name itself */
 357     int unixdomain;
 358     char *hostname;
 359     int displaynum;
 360     int screennum;
 361     /* OSX sometimes replaces all the above with a full Unix-socket pathname */
 362     char *unixsocketpath;
 363
 364     /* PuTTY networking SockAddr to connect to the display, and associated
 365      * gubbins */
 366     SockAddr addr;
 367     int port;
 368     char *realhost;
 369
 370     /* Auth details we invented for the virtual display on the SSH server. */
 371     int remoteauthproto;
 372     unsigned char *remoteauthdata;
 373     int remoteauthdatalen;
 374     char *remoteauthprotoname;
 375     char *remoteauthdatastring;
 376
 377     /* Our local auth details for talking to the real X display. */
 378     int localauthproto;
 379     unsigned char *localauthdata;
 380     int localauthdatalen;
 381
 382     /*
 383      * Used inside x11fwd.c to remember recently seen
 384      * XDM-AUTHORIZATION-1 strings, to avoid replay attacks.
 385      */
 386     tree234 *xdmseen;
 387 };
 388 /*
 389  * x11_setup_display() parses the display variable and fills in an
 390  * X11Display structure. Some remote auth details are invented;
 391  * the supplied authtype parameter configures the preferred
 392  * authorisation protocol to use at the remote end. The local auth
 393  * details are looked up by calling platform_get_x11_auth.
 394  */
 395 extern struct X11Display *x11_setup_display(char *display, int authtype,
 396                                             Conf *);
 397 void x11_free_display(struct X11Display *disp);
 398 extern const char *x11_init(Socket *, struct X11Display *, void *,
 399                             const char *, int, Conf *);
 400 extern void x11_close(Socket);
 401 extern int x11_send(Socket, char *, int);
 402 extern void x11_send_eof(Socket s);
 403 extern void x11_unthrottle(Socket s);
 404 extern void x11_override_throttle(Socket s, int enable);
 405 char *x11_display(const char *display);
 406 /* Platform-dependent X11 functions */
 407 extern void platform_get_x11_auth(struct X11Display *display, Conf *);
 408     /* examine a mostly-filled-in X11Display and fill in localauth* */
 409 extern const int platform_uses_x11_unix_by_default;
 410     /* choose default X transport in the absence of a specified one */
 411 SockAddr platform_get_x11_unix_address(const char *path, int displaynum);
 412     /* make up a SockAddr naming the address for displaynum */
 413 char *platform_get_x_display(void);
 414     /* allocated local X display string, if any */
 415 /* Callbacks in x11.c usable _by_ platform X11 functions */
 416 /*
 417  * This function does the job of platform_get_x11_auth, provided
 418  * it is told where to find a normally formatted .Xauthority file:
 419  * it opens that file, parses it to find an auth record which
 420  * matches the display details in "display", and fills in the
 421  * localauth fields.
 422  *
 423  * It is expected that most implementations of
 424  * platform_get_x11_auth() will work by finding their system's
 425  * .Xauthority file, adjusting the display details if necessary
 426  * for local oddities like Unix-domain socket transport, and
 427  * calling this function to do the rest of the work.
 428  */
 429 void x11_get_auth_from_authfile(struct X11Display *display,
 430                                 const char *authfilename);
 431
 432 Bignum copybn(Bignum b);
 433 Bignum bn_power_2(int n);
 434 void bn_restore_invariant(Bignum b);
 435 Bignum bignum_from_long(unsigned long n);
 436 void freebn(Bignum b);
 437 Bignum modpow(Bignum base, Bignum exp, Bignum mod);
 438 Bignum modmul(Bignum a, Bignum b, Bignum mod);
 439 void decbn(Bignum n);
 440 extern Bignum Zero, One;
 441 Bignum bignum_from_bytes(const unsigned char *data, int nbytes);
 442 int ssh1_read_bignum(const unsigned char *data, int len, Bignum * result);
 443 int bignum_bitcount(Bignum bn);
 444 int ssh1_bignum_length(Bignum bn);
 445 int ssh2_bignum_length(Bignum bn);
 446 int bignum_byte(Bignum bn, int i);
 447 int bignum_bit(Bignum bn, int i);
 448 void bignum_set_bit(Bignum bn, int i, int value);
 449 int ssh1_write_bignum(void *data, Bignum bn);
 450 Bignum biggcd(Bignum a, Bignum b);
 451 unsigned short bignum_mod_short(Bignum number, unsigned short modulus);
 452 Bignum bignum_add_long(Bignum number, unsigned long addend);
 453 Bignum bigadd(Bignum a, Bignum b);
 454 Bignum bigsub(Bignum a, Bignum b);
 455 Bignum bigmul(Bignum a, Bignum b);
 456 Bignum bigmuladd(Bignum a, Bignum b, Bignum addend);
 457 Bignum bigdiv(Bignum a, Bignum b);
 458 Bignum bigmod(Bignum a, Bignum b);
 459 Bignum modinv(Bignum number, Bignum modulus);
 460 Bignum bignum_bitmask(Bignum number);
 461 Bignum bignum_rshift(Bignum number, int shift);
 462 int bignum_cmp(Bignum a, Bignum b);
 463 char *bignum_decimal(Bignum x);
 464
 465 #ifdef DEBUG
 466 void diagbn(char *prefix, Bignum md);
 467 #endif
 468
 469 void *dh_setup_group(const struct ssh_kex *kex);
 470 void *dh_setup_gex(Bignum pval, Bignum gval);
 471 void dh_cleanup(void *);
 472 Bignum dh_create_e(void *, int nbits);
 473 Bignum dh_find_K(void *, Bignum f);
 474
 475 int loadrsakey(const Filename *filename, struct RSAKey *key,
 476                char *passphrase, const char **errorstr);
 477 int rsakey_encrypted(const Filename *filename, char **comment);
 478 int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
 479                    char **commentptr, const char **errorstr);
 480
 481 int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase);
 482
 483 extern int base64_decode_atom(char *atom, unsigned char *out);
 484 extern int base64_lines(int datalen);
 485 extern void base64_encode_atom(unsigned char *data, int n, char *out);
 486 extern void base64_encode(FILE *fp, unsigned char *data, int datalen, int cpl);
 487
 488 /* ssh2_load_userkey can return this as an error */
 489 extern struct ssh2_userkey ssh2_wrong_passphrase;
 490 #define SSH2_WRONG_PASSPHRASE (&ssh2_wrong_passphrase)
 491
 492 int ssh2_userkey_encrypted(const Filename *filename, char **comment);
 493 struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
 494                                        char *passphrase, const char **errorstr);
 495 unsigned char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
 496                                     int *pub_blob_len, char **commentptr,
 497                                     const char **errorstr);
 498 int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
 499                       char *passphrase);
 500 const struct ssh_signkey *find_pubkey_alg(const char *name);
 501
 502 enum {
 503     SSH_KEYTYPE_UNOPENABLE,
 504     SSH_KEYTYPE_UNKNOWN,
 505     SSH_KEYTYPE_SSH1, SSH_KEYTYPE_SSH2,
 506     SSH_KEYTYPE_OPENSSH, SSH_KEYTYPE_SSHCOM
 507 };
 508 int key_type(const Filename *filename);
 509 char *key_type_to_str(int type);
 510
 511 int import_possible(int type);
 512 int import_target_type(int type);
 513 int import_encrypted(const Filename *filename, int type, char **comment);
 514 int import_ssh1(const Filename *filename, int type,
 515                 struct RSAKey *key, char *passphrase, const char **errmsg_p);
 516 struct ssh2_userkey *import_ssh2(const Filename *filename, int type,
 517                                  char *passphrase, const char **errmsg_p);
 518 int export_ssh1(const Filename *filename, int type,
 519                 struct RSAKey *key, char *passphrase);
 520 int export_ssh2(const Filename *filename, int type,
 521                 struct ssh2_userkey *key, char *passphrase);
 522
 523 void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
 524 void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
 525 void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
 526                               unsigned char *blk, int len);
 527 void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
 528                               unsigned char *blk, int len);
 529 void aes256_encrypt_pubkey(unsigned char *key, unsigned char *blk,
 530                            int len);
 531 void aes256_decrypt_pubkey(unsigned char *key, unsigned char *blk,
 532                            int len);
 533
 534 void des_encrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);
 535 void des_decrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);
 536
 537 /*
 538  * For progress updates in the key generation utility.
 539  */
 540 #define PROGFN_INITIALISE 1
 541 #define PROGFN_LIN_PHASE 2
 542 #define PROGFN_EXP_PHASE 3
 543 #define PROGFN_PHASE_EXTENT 4
 544 #define PROGFN_READY 5
 545 #define PROGFN_PROGRESS 6
 546 typedef void (*progfn_t) (void *param, int action, int phase, int progress);
 547
 548 int rsa_generate(struct RSAKey *key, int bits, progfn_t pfn,
 549                  void *pfnparam);
 550 int dsa_generate(struct dss_key *key, int bits, progfn_t pfn,
 551                  void *pfnparam);
 552 Bignum primegen(int bits, int modulus, int residue, Bignum factor,
 553                 int phase, progfn_t pfn, void *pfnparam);
 554
 555
 556 /*
 557  * zlib compression.
 558  */
 559 void *zlib_compress_init(void);
 560 void zlib_compress_cleanup(void *);
 561 void *zlib_decompress_init(void);
 562 void zlib_decompress_cleanup(void *);
 563 int zlib_compress_block(void *, unsigned char *block, int len,
 564                         unsigned char **outblock, int *outlen);
 565 int zlib_decompress_block(void *, unsigned char *block, int len,
 566                           unsigned char **outblock, int *outlen);
 567
 568 /*
 569  * SSH-1 agent messages.
 570  */
 571 #define SSH1_AGENTC_REQUEST_RSA_IDENTITIES    1
 572 #define SSH1_AGENT_RSA_IDENTITIES_ANSWER      2
 573 #define SSH1_AGENTC_RSA_CHALLENGE             3
 574 #define SSH1_AGENT_RSA_RESPONSE               4
 575 #define SSH1_AGENTC_ADD_RSA_IDENTITY          7
 576 #define SSH1_AGENTC_REMOVE_RSA_IDENTITY       8
 577 #define SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES 9 /* openssh private? */
 578
 579 /*
 580  * Messages common to SSH-1 and OpenSSH's SSH-2.
 581  */
 582 #define SSH_AGENT_FAILURE                    5
 583 #define SSH_AGENT_SUCCESS                    6
 584
 585 /*
 586  * OpenSSH's SSH-2 agent messages.
 587  */
 588 #define SSH2_AGENTC_REQUEST_IDENTITIES          11
 589 #define SSH2_AGENT_IDENTITIES_ANSWER            12
 590 #define SSH2_AGENTC_SIGN_REQUEST                13
 591 #define SSH2_AGENT_SIGN_RESPONSE                14
 592 #define SSH2_AGENTC_ADD_IDENTITY                17
 593 #define SSH2_AGENTC_REMOVE_IDENTITY             18
 594 #define SSH2_AGENTC_REMOVE_ALL_IDENTITIES       19
 595
 596 /*
 597  * Need this to warn about support for the original SSH-2 keyfile
 598  * format.
 599  */
 600 void old_keyfile_warning(void);