Add support for DSA authentication in SSH2, following clever ideas

[u/mdw/putty] / ssh.h

#include <string.h>

#include "puttymem.h"
#include "network.h"
#include "int64.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, struct RSAKey *result,
	    unsigned char **keystr, int order);
int makeprivate(unsigned char *data, struct RSAKey *result);
void 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);
void freersakey(struct RSAKey *key);

typedef unsigned int word32;
typedef unsigned int uint32;

unsigned long crc32(const void *s, size_t len);

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 (*sesskey) (unsigned char *key);	/* for ssh 1 */
    void (*encrypt) (unsigned char *blk, int len);
    void (*decrypt) (unsigned char *blk, int len);
    int blksize;
};

struct ssh2_cipher {
    void (*setcsiv) (unsigned char *key);	/* for ssh 2 */
    void (*setcskey) (unsigned char *key);	/* for ssh 2 */
    void (*setsciv) (unsigned char *key);	/* for ssh 2 */
    void (*setsckey) (unsigned char *key);	/* for ssh 2 */
    void (*encrypt) (unsigned char *blk, int len);
    void (*decrypt) (unsigned char *blk, int len);
    char *name;
    int blksize;
    int keylen;
};

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

struct ssh_mac {
    void (*setcskey) (unsigned char *key);
    void (*setsckey) (unsigned char *key);
    void (*generate) (unsigned char *blk, int len, unsigned long seq);
    int (*verify) (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);
    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);
    int (*compress) (unsigned char *block, int len,
		     unsigned char **outblock, int *outlen);
    void (*decompress_init) (void);
    int (*decompress) (unsigned char *block, int len,
		       unsigned char **outblock, int *outlen);
    int (*disable_compression) (void);
};

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_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;
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;

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

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(unsigned char *data, int nbytes);
int ssh1_read_bignum(unsigned char *data, 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);

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

int loadrsakey(char *filename, struct RSAKey *key, char *passphrase);
int rsakey_encrypted(char *filename, char **comment);

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

void base64_encode_atom(unsigned char *data, int n, char *out);

/* 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(char *filename, char **comment);
struct ssh2_userkey *ssh2_load_userkey(char *filename, char *passphrase);
char *ssh2_userkey_loadpub(char *filename, char **algorithm,
			   int *pub_blob_len);
int ssh2_save_userkey(char *filename, struct ssh2_userkey *key,
		      char *passphrase);

int keyfile_version(char *filename);

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 aes256_encrypt_pubkey(unsigned char *key, unsigned char *blk,
			   int len);
void aes256_decrypt_pubkey(unsigned char *key, unsigned char *blk,
			   int len);

/*
 * For progress updates in the key generation utility.
 */
#define PROGFN_LIN_PHASE 1
#define PROGFN_EXP_PHASE 2
#define PROGFN_PHASE_EXTENT 3
#define PROGFN_READY 4
#define PROGFN_PROGRESS 5
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_decompress_init(void);
int zlib_compress_block(unsigned char *block, int len,
			unsigned char **outblock, int *outlen);
int zlib_decompress_block(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