#include <stdio.h>
#include <string.h>

#include "puttymem.h"
#include "network.h"
#include "int64.h"
#include "misc.h"

struct ssh_channel;

extern void sshfwd_close(struct ssh_channel *c);
extern int sshfwd_write(struct ssh_channel *c, char *, int);
extern void sshfwd_unthrottle(struct ssh_channel *c, int bufsize);

/*
 * Useful thing.
 */
#ifndef lenof
#define lenof(x) ( (sizeof((x))) / (sizeof(*(x))))
#endif

#define SSH_CIPHER_IDEA		1
#define SSH_CIPHER_DES		2
#define SSH_CIPHER_3DES		3
#define SSH_CIPHER_BLOWFISH	6

#ifdef MSCRYPTOAPI
#define APIEXTRA 8
#else
#define APIEXTRA 0
#endif

#ifndef BIGNUM_INTERNAL
typedef void *Bignum;
#endif

struct RSAKey {
    int bits;
    int bytes;
#ifdef MSCRYPTOAPI
    unsigned long exponent;
    unsigned char *modulus;
#else
    Bignum modulus;
    Bignum exponent;
    Bignum private_exponent;
    Bignum p;
    Bignum q;
    Bignum iqmp;
#endif
    char *comment;
};

struct dss_key {
    Bignum p, q, g, y, x;
};

int makekey(unsigned char *data, int len, struct RSAKey *result,
	    unsigned char **keystr, int order);
int makeprivate(unsigned char *data, int len, struct RSAKey *result);
int rsaencrypt(unsigned char *data, int length, struct RSAKey *key);
Bignum rsadecrypt(Bignum input, struct RSAKey *key);
void rsasign(unsigned char *data, int length, struct RSAKey *key);
void rsasanitise(struct RSAKey *key);
int rsastr_len(struct RSAKey *key);
void rsastr_fmt(char *str, struct RSAKey *key);
void rsa_fingerprint(char *str, int len, struct RSAKey *key);
int rsa_verify(struct RSAKey *key);
unsigned char *rsa_public_blob(struct RSAKey *key, int *len);
int rsa_public_blob_len(void *data, int maxlen);
void freersakey(struct RSAKey *key);

typedef unsigned int word32;
typedef unsigned int uint32;

unsigned long crc32_compute(const void *s, size_t len);
unsigned long crc32_update(unsigned long crc_input, const void *s, size_t len);

/* SSH CRC compensation attack detector */
void *crcda_make_context(void);
void crcda_free_context(void *handle);
int detect_attack(void *handle, unsigned char *buf, uint32 len,
		  unsigned char *IV);

typedef struct {
    uint32 h[4];
} MD5_Core_State;

struct MD5Context {
#ifdef MSCRYPTOAPI
    unsigned long hHash;
#else
    MD5_Core_State core;
    unsigned char block[64];
    int blkused;
    uint32 lenhi, lenlo;
#endif
};

void MD5Init(struct MD5Context *context);
void MD5Update(struct MD5Context *context, unsigned char const *buf,
	       unsigned len);
void MD5Final(unsigned char digest[16], struct MD5Context *context);

typedef struct {
    uint32 h[5];
    unsigned char block[64];
    int blkused;
    uint32 lenhi, lenlo;
} SHA_State;
void SHA_Init(SHA_State * s);
void SHA_Bytes(SHA_State * s, void *p, int len);
void SHA_Final(SHA_State * s, unsigned char *output);
void SHA_Simple(void *p, int len, unsigned char *output);

void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
		      unsigned char *output);

typedef struct {
    uint64 h[8];
    unsigned char block[128];
    int blkused;
    uint32 len[4];
} SHA512_State;
void SHA512_Init(SHA512_State * s);
void SHA512_Bytes(SHA512_State * s, const void *p, int len);
void SHA512_Final(SHA512_State * s, unsigned char *output);
void SHA512_Simple(const void *p, int len, unsigned char *output);

struct ssh_cipher {
    void *(*make_context)(void);
    void (*free_context)(void *);
    void (*sesskey) (void *, unsigned char *key);	/* for ssh 1 */
    void (*encrypt) (void *, unsigned char *blk, int len);
    void (*decrypt) (void *, unsigned char *blk, int len);
    int blksize;
    char *text_name;
};

struct ssh2_cipher {
    void *(*make_context)(void);
    void (*free_context)(void *);
    void (*setiv) (void *, unsigned char *key);	/* for ssh 2 */
    void (*setkey) (void *, unsigned char *key);/* for ssh 2 */
    void (*encrypt) (void *, unsigned char *blk, int len);
    void (*decrypt) (void *, unsigned char *blk, int len);
    char *name;
    int blksize;
    int keylen;
    char *text_name;
};

struct ssh2_ciphers {
    int nciphers;
    const struct ssh2_cipher *const *list;
};

struct ssh_mac {
    void *(*make_context)(void);
    void (*free_context)(void *);
    void (*setkey) (void *, unsigned char *key);
    void (*generate) (void *, unsigned char *blk, int len, unsigned long seq);
    int (*verify) (void *, unsigned char *blk, int len, unsigned long seq);
    char *name;
    int len;
};

struct ssh_kex {
    /*
     * Plugging in another KEX algorithm requires structural chaos,
     * so it's hard to abstract them into nice little structures
     * like this. Hence, for the moment, this is just a
     * placeholder. I claim justification in the fact that OpenSSH
     * does this too :-)
     */
    char *name;
};

struct ssh_signkey {
    void *(*newkey) (char *data, int len);
    void (*freekey) (void *key);
    char *(*fmtkey) (void *key);
    unsigned char *(*public_blob) (void *key, int *len);
    unsigned char *(*private_blob) (void *key, int *len);
    void *(*createkey) (unsigned char *pub_blob, int pub_len,
			unsigned char *priv_blob, int priv_len);
    void *(*openssh_createkey) (unsigned char **blob, int *len);
    int (*openssh_fmtkey) (void *key, unsigned char *blob, int len);
    int (*pubkey_bits) (void *blob, int len);
    char *(*fingerprint) (void *key);
    int (*verifysig) (void *key, char *sig, int siglen,
		      char *data, int datalen);
    unsigned char *(*sign) (void *key, char *data, int datalen,
			    int *siglen);
    char *name;
    char *keytype;		       /* for host key cache */
};

struct ssh_compress {
    char *name;
    void *(*compress_init) (void);
    void (*compress_cleanup) (void *);
    int (*compress) (void *, unsigned char *block, int len,
		     unsigned char **outblock, int *outlen);
    void *(*decompress_init) (void);
    void (*decompress_cleanup) (void *);
    int (*decompress) (void *, unsigned char *block, int len,
		       unsigned char **outblock, int *outlen);
    int (*disable_compression) (void *);
    char *text_name;
};

struct ssh2_userkey {
    const struct ssh_signkey *alg;     /* the key algorithm */
    void *data;			       /* the key data */
    char *comment;		       /* the key comment */
};

extern const struct ssh_cipher ssh_3des;
extern const struct ssh_cipher ssh_des;
extern const struct ssh_cipher ssh_blowfish_ssh1;
extern const struct ssh2_ciphers ssh2_3des;
extern const struct ssh2_ciphers ssh2_des;
extern const struct ssh2_ciphers ssh2_aes;
extern const struct ssh2_ciphers ssh2_blowfish;
extern const struct ssh_kex ssh_diffiehellman;
extern const struct ssh_kex ssh_diffiehellman_gex;
extern const struct ssh_signkey ssh_dss;
extern const struct ssh_signkey ssh_rsa;
extern const struct ssh_mac ssh_md5;