extern const struct ssh_mac ssh_sha1;
extern const struct ssh_mac ssh_sha1_buggy;

/*
 * PuTTY version number formatted as an SSH version string. 
 */
extern char sshver[];

/*
 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
 * that fails. This variable is the means by which scp.c can reach
 * into the SSH code and find out which one it got.
 */
extern int ssh_fallback_cmd(void *handle);

#ifndef MSCRYPTOAPI
void SHATransform(word32 * digest, word32 * data);
#endif

int random_byte(void);
void random_add_noise(void *noise, int length);
void random_add_heavynoise(void *noise, int length);

void logevent(void *, const char *);

/* Allocate and register a new channel for port forwarding */
void *new_sock_channel(void *handle, Socket s);
void ssh_send_port_open(void *channel, char *hostname, int port, char *org);

/* Exports from portfwd.c */
extern const char *pfd_newconnect(Socket * s, char *hostname, int port,
				  void *c, const Config *cfg);
/* desthost == NULL indicates dynamic (SOCKS) port forwarding */
extern const char *pfd_addforward(char *desthost, int destport, char *srcaddr,
				  int port, void *backhandle,
				  const Config *cfg);
extern void pfd_close(Socket s);
extern int pfd_send(Socket s, char *data, int len);
extern void pfd_confirm(Socket s);
extern void pfd_unthrottle(Socket s);
extern void pfd_override_throttle(Socket s, int enable);

/* Exports from x11fwd.c */
extern const char *x11_init(Socket *, char *, void *, void *, const char *,
			    int, const Config *);
extern void x11_close(Socket);
extern int x11_send(Socket, char *, int);
extern void *x11_invent_auth(char *, int, char *, int, int);
extern void x11_free_auth(void *);
extern void x11_unthrottle(Socket s);
extern void x11_override_throttle(Socket s, int enable);
extern int x11_get_screen_number(char *display);
void x11_get_real_auth(void *authv, char *display);
char *x11_display(const char *display);

/* Platform-dependent X11 functions */
extern void platform_get_x11_auth(char *display, int *proto,
                                  unsigned char *data, int *datalen);
extern const char platform_x11_best_transport[];
/* best X11 hostname for this platform if none specified */
SockAddr platform_get_x11_unix_address(int displaynum, char **canonicalname);
/* make up a SockAddr naming the address for displaynum */

Bignum copybn(Bignum b);
Bignum bn_power_2(int n);
void bn_restore_invariant(Bignum b);
Bignum bignum_from_long(unsigned long n);
void freebn(Bignum b);
Bignum modpow(Bignum base, Bignum exp, Bignum mod);
Bignum modmul(Bignum a, Bignum b, Bignum mod);
void decbn(Bignum n);
extern Bignum Zero, One;
Bignum bignum_from_bytes(const unsigned char *data, int nbytes);
int ssh1_read_bignum(const unsigned char *data, int len, Bignum * result);
int bignum_bitcount(Bignum bn);
int ssh1_bignum_length(Bignum bn);
int ssh2_bignum_length(Bignum bn);
int bignum_byte(Bignum bn, int i);
int bignum_bit(Bignum bn, int i);
void bignum_set_bit(Bignum bn, int i, int value);
int ssh1_write_bignum(void *data, Bignum bn);
Bignum biggcd(Bignum a, Bignum b);
unsigned short bignum_mod_short(Bignum number, unsigned short modulus);
Bignum bignum_add_long(Bignum number, unsigned long addend);
Bignum bigmul(Bignum a, Bignum b);
Bignum bigmuladd(Bignum a, Bignum b, Bignum addend);
Bignum bigdiv(Bignum a, Bignum b);
Bignum bigmod(Bignum a, Bignum b);
Bignum modinv(Bignum number, Bignum modulus);
Bignum bignum_bitmask(Bignum number);
Bignum bignum_rshift(Bignum number, int shift);
int bignum_cmp(Bignum a, Bignum b);
char *bignum_decimal(Bignum x);

#ifdef DEBUG
void diagbn(char *prefix, Bignum md);
#endif

void *dh_setup_group1(void);
void *dh_setup_group(Bignum pval, Bignum gval);
void dh_cleanup(void *);
Bignum dh_create_e(void *, int nbits);
Bignum dh_find_K(void *, Bignum f);

int loadrsakey(const Filename *filename, struct RSAKey *key,
	       char *passphrase, const char **errorstr);
int rsakey_encrypted(const Filename *filename, char **comment);
int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
		   const char **errorstr);

int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase);

extern int base64_decode_atom(char *atom, unsigned char *out);
extern int base64_lines(int datalen);
extern void base64_encode_atom(unsigned char *data, int n, char *out);
extern void base64_encode(FILE *fp, unsigned char *data, int datalen, int cpl);

/* ssh2_load_userkey can return this as an error */
extern struct ssh2_userkey ssh2_wrong_passphrase;
#define SSH2_WRONG_PASSPHRASE (&ssh2_wrong_passphrase)

int ssh2_userkey_encrypted(const Filename *filename, char **comment);
struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
				       char *passphrase, const char **errorstr);
char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
			   int *pub_blob_len, const char **errorstr);
int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
		      char *passphrase);
const struct ssh_signkey *find_pubkey_alg(const char *name);

enum {
    SSH_KEYTYPE_UNOPENABLE,
    SSH_KEYTYPE_UNKNOWN,
    SSH_KEYTYPE_SSH1, SSH_KEYTYPE_SSH2,
    SSH_KEYTYPE_OPENSSH, SSH_KEYTYPE_SSHCOM
};
int key_type(const Filename *filename);
char *key_type_to_str(int type);

int import_possible(int type);
int import_target_type(int type);
int import_encrypted(const Filename *filename, int type, char **comment);
int import_ssh1(const Filename *filename, int type,
		struct RSAKey *key, char *passphrase);
struct ssh2_userkey *import_ssh2(const Filename *filename, int type,
				 char *passphrase);
int export_ssh1(const Filename *filename, int type,
		struct RSAKey *key, char *passphrase);
int export_ssh2(const Filename *filename, int type,
                struct ssh2_userkey *key, char *passphrase);

void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
			      unsigned char *blk, int len);
void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
			      unsigned char *blk, int len);
void aes256_encrypt_pubkey(unsigned char *key, unsigned char *blk,
			   int len);
void aes256_decrypt_pubkey(unsigned char *key, unsigned char *blk,
			   int len);

void des_encrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);
void des_decrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);

/*
 * For progress updates in the key generation utility.
 */
#define PROGFN_INITIALISE 1
#define PROGFN_LIN_PHASE 2
#define PROGFN_EXP_PHASE 3
#define PROGFN_PHASE_EXTENT 4
#define PROGFN_READY 5
#define PROGFN_PROGRESS 6
typedef void (*progfn_t) (void *param, int action, int phase, int progress);

int rsa_generate(struct RSAKey *key, int bits, progfn_t pfn,
		 void *pfnparam);
int dsa_generate(struct dss_key *key, int bits, progfn_t pfn,
		 void *pfnparam);
Bignum primegen(int bits, int modulus, int residue, Bignum factor,
		int phase, progfn_t pfn, void *pfnparam);


/*
 * zlib compression.
 */
void *zlib_compress_init(void);
void zlib_compress_cleanup(void *);
void *zlib_decompress_init(void);
void zlib_decompress_cleanup(void *);
int zlib_compress_block(void *, unsigned char *block, int len,
			unsigned char **outblock, int *outlen);
int zlib_decompress_block(void *, unsigned char *block, int len,
			  unsigned char **outblock, int *outlen);

/*
 * SSH1 agent messages.
 */
#define SSH1_AGENTC_REQUEST_RSA_IDENTITIES    1
#define SSH1_AGENT_RSA_IDENTITIES_ANSWER      2
#define SSH1_AGENTC_RSA_CHALLENGE             3
#define SSH1_AGENT_RSA_RESPONSE               4
#define SSH1_AGENTC_ADD_RSA_IDENTITY          7
#define SSH1_AGENTC_REMOVE_RSA_IDENTITY       8
#define SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES 9	/* openssh private? */

/*
 * Messages common to SSH1 and OpenSSH's SSH2.
 */
#define SSH_AGENT_FAILURE                    5
#define SSH_AGENT_SUCCESS                    6

/*
 * OpenSSH's SSH2 agent messages.
 */
#define SSH2_AGENTC_REQUEST_IDENTITIES          11
#define SSH2_AGENT_IDENTITIES_ANSWER            12
#define SSH2_AGENTC_SIGN_REQUEST                13
#define SSH2_AGENT_SIGN_RESPONSE                14
#define SSH2_AGENTC_ADD_IDENTITY                17
#define SSH2_AGENTC_REMOVE_IDENTITY             18
#define SSH2_AGENTC_REMOVE_ALL_IDENTITIES       19

/*
 * Need this to warn about support for the original SSH2 keyfile
 * format.
 */
void old_keyfile_warning(void);