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ssh.h
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#include <stdio.h>
#include <string.h>
#include "puttymem.h"
#include "tree234.h"
#include "network.h"
#include "misc.h"
struct ssh_channel;
/*
* Buffer management constants. There are several of these for
* various different purposes:
*
* - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
* on a local data stream before we throttle the whole SSH
* connection (in SSH-1 only). Throttling the whole connection is
* pretty drastic so we set this high in the hope it won't
* happen very often.
*
* - SSH_MAX_BACKLOG is the amount of backlog that must build up
* on the SSH connection itself before we defensively throttle
* _all_ local data streams. This is pretty drastic too (though
* thankfully unlikely in SSH-2 since the window mechanism should
* ensure that the server never has any need to throttle its end
* of the connection), so we set this high as well.
*
* - OUR_V2_WINSIZE is the default window size we present on SSH-2
* channels.
*
* - OUR_V2_BIGWIN is the window size we advertise for the only
* channel in a simple connection. It must be <= INT_MAX.
*
* - OUR_V2_MAXPKT is the official "maximum packet size" we send
* to the remote side. This actually has nothing to do with the
* size of the _packet_, but is instead a limit on the amount
* of data we're willing to receive in a single SSH2 channel
* data message.
*
* - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
* _packet_ we're prepared to cope with. It must be a multiple
* of the cipher block size, and must be at least 35000.
*/
#define SSH1_BUFFER_LIMIT 32768
#define SSH_MAX_BACKLOG 32768
#define OUR_V2_WINSIZE 16384
#define OUR_V2_BIGWIN 0x7fffffff
#define OUR_V2_MAXPKT 0x4000UL
#define OUR_V2_PACKETLIMIT 0x9000UL
typedef struct PacketQueueNode PacketQueueNode;
struct PacketQueueNode {
PacketQueueNode *next, *prev;
size_t formal_size; /* contribution to PacketQueueBase's total_size */
bool on_free_queue; /* is this packet scheduled for freeing? */
};
typedef struct PktIn {
int type;
unsigned long sequence; /* SSH-2 incoming sequence number */
PacketQueueNode qnode; /* for linking this packet on to a queue */
BinarySource_IMPLEMENTATION;
} PktIn;
typedef struct PktOut {
size_t prefix; /* bytes up to and including type field */
size_t length; /* total bytes, including prefix */
int type;
size_t minlen; /* SSH-2: ensure wire length is at least this */
unsigned char *data; /* allocated storage */
size_t maxlen; /* amount of storage allocated for `data' */
/* Extra metadata used in SSH packet logging mode, allowing us to
* log in the packet header line that the packet came from a
* connection-sharing downstream and what if anything unusual was
* done to it. The additional_log_text field is expected to be a
* static string - it will not be freed. */
unsigned downstream_id;
const char *additional_log_text;
PacketQueueNode qnode; /* for linking this packet on to a queue */
BinarySink_IMPLEMENTATION;
} PktOut;
typedef struct PacketQueueBase {
PacketQueueNode end;
size_t total_size; /* sum of all formal_size fields on the queue */
struct IdempotentCallback *ic;
} PacketQueueBase;
typedef struct PktInQueue {
PacketQueueBase pqb;
PktIn *(*after)(PacketQueueBase *, PacketQueueNode *prev, bool pop);
} PktInQueue;
typedef struct PktOutQueue {
PacketQueueBase pqb;
PktOut *(*after)(PacketQueueBase *, PacketQueueNode *prev, bool pop);
} PktOutQueue;
void pq_base_push(PacketQueueBase *pqb, PacketQueueNode *node);
void pq_base_push_front(PacketQueueBase *pqb, PacketQueueNode *node);
void pq_base_concatenate(PacketQueueBase *dest,
PacketQueueBase *q1, PacketQueueBase *q2);
void pq_in_init(PktInQueue *pq);
void pq_out_init(PktOutQueue *pq);
void pq_in_clear(PktInQueue *pq);
void pq_out_clear(PktOutQueue *pq);
#define pq_push(pq, pkt) \
TYPECHECK((pq)->after(&(pq)->pqb, NULL, false) == pkt, \
pq_base_push(&(pq)->pqb, &(pkt)->qnode))
#define pq_push_front(pq, pkt) \
TYPECHECK((pq)->after(&(pq)->pqb, NULL, false) == pkt, \
pq_base_push_front(&(pq)->pqb, &(pkt)->qnode))
#define pq_peek(pq) ((pq)->after(&(pq)->pqb, &(pq)->pqb.end, false))
#define pq_pop(pq) ((pq)->after(&(pq)->pqb, &(pq)->pqb.end, true))
#define pq_concatenate(dst, q1, q2) \
TYPECHECK((q1)->after(&(q1)->pqb, NULL, false) == \
(dst)->after(&(dst)->pqb, NULL, false) && \
(q2)->after(&(q2)->pqb, NULL, false) == \
(dst)->after(&(dst)->pqb, NULL, false), \
pq_base_concatenate(&(dst)->pqb, &(q1)->pqb, &(q2)->pqb))
#define pq_first(pq) pq_peek(pq)
#define pq_next(pq, pkt) ((pq)->after(&(pq)->pqb, &(pkt)->qnode, false))
/*
* Packet type contexts, so that ssh2_pkt_type can correctly decode
* the ambiguous type numbers back into the correct type strings.
*/
typedef enum {
SSH2_PKTCTX_NOKEX,
SSH2_PKTCTX_DHGROUP,
SSH2_PKTCTX_DHGEX,
SSH2_PKTCTX_ECDHKEX,
SSH2_PKTCTX_HYBRIDKEX,
SSH2_PKTCTX_GSSKEX,
SSH2_PKTCTX_RSAKEX
} Pkt_KCtx;
typedef enum {
SSH2_PKTCTX_NOAUTH,
SSH2_PKTCTX_PUBLICKEY,
SSH2_PKTCTX_PASSWORD,
SSH2_PKTCTX_GSSAPI,
SSH2_PKTCTX_KBDINTER
} Pkt_ACtx;
typedef struct PacketLogSettings {
bool omit_passwords, omit_data;
Pkt_KCtx kctx;
Pkt_ACtx actx;
} PacketLogSettings;
#define MAX_BLANKS 4 /* no packet needs more censored sections than this */
int ssh1_censor_packet(
const PacketLogSettings *pls, int type, bool sender_is_client,
ptrlen pkt, logblank_t *blanks);
int ssh2_censor_packet(
const PacketLogSettings *pls, int type, bool sender_is_client,
ptrlen pkt, logblank_t *blanks);
PktOut *ssh_new_packet(void);
void ssh_free_pktout(PktOut *pkt);
Socket *ssh_connection_sharing_init(
const char *host, int port, Conf *conf, LogContext *logctx,
Plug *sshplug, ssh_sharing_state **state);
void ssh_connshare_provide_connlayer(ssh_sharing_state *sharestate,
ConnectionLayer *cl);
bool ssh_share_test_for_upstream(const char *host, int port, Conf *conf);
void share_got_pkt_from_server(ssh_sharing_connstate *ctx, int type,
const void *pkt, int pktlen);
void share_activate(ssh_sharing_state *sharestate,
const char *server_verstring);
void sharestate_free(ssh_sharing_state *state);
int share_ndownstreams(ssh_sharing_state *state);
void ssh_connshare_log(Ssh *ssh, int event, const char *logtext,
const char *ds_err, const char *us_err);
void share_setup_x11_channel(ssh_sharing_connstate *cs, share_channel *chan,
unsigned upstream_id, unsigned server_id,
unsigned server_currwin, unsigned server_maxpkt,
unsigned client_adjusted_window,
const char *peer_addr, int peer_port, int endian,
int protomajor, int protominor,
const void *initial_data, int initial_len);
/* Per-application overrides for what roles we can take in connection
* sharing, regardless of user configuration (e.g. pscp will never be
* an upstream) */
extern const bool share_can_be_downstream;
extern const bool share_can_be_upstream;
struct X11Display;
struct X11FakeAuth;
/* Structure definition centralised here because the SSH-1 and SSH-2
* connection layers both use it. But the client module (portfwd.c)
* should not try to look inside here. */
struct ssh_rportfwd {
unsigned sport, dport;
char *shost, *dhost;
int addressfamily;
char *log_description; /* name of remote listening port, for logging */
ssh_sharing_connstate *share_ctx;
PortFwdRecord *pfr;
};
void free_rportfwd(struct ssh_rportfwd *rpf);
typedef struct ConnectionLayerVtable ConnectionLayerVtable;
struct ConnectionLayerVtable {
/* Allocate and free remote-to-local port forwardings, called by
* PortFwdManager or by connection sharing */
struct ssh_rportfwd *(*rportfwd_alloc)(
ConnectionLayer *cl,
const char *shost, int sport, const char *dhost, int dport,
int addressfamily, const char *log_description, PortFwdRecord *pfr,
ssh_sharing_connstate *share_ctx);
void (*rportfwd_remove)(ConnectionLayer *cl, struct ssh_rportfwd *rpf);
/* Open a local-to-remote port forwarding channel, called by
* PortFwdManager */
SshChannel *(*lportfwd_open)(
ConnectionLayer *cl, const char *hostname, int port,
const char *description, const SocketEndpointInfo *peerinfo,
Channel *chan);
/* Initiate opening of a 'session'-type channel */
SshChannel *(*session_open)(ConnectionLayer *cl, Channel *chan);
/* Open outgoing channels for X and agent forwarding. (Used in the
* SSH server.) */
SshChannel *(*serverside_x11_open)(ConnectionLayer *cl, Channel *chan,
const SocketEndpointInfo *pi);
SshChannel *(*serverside_agent_open)(ConnectionLayer *cl, Channel *chan);
/* Add an X11 display for ordinary X forwarding */
struct X11FakeAuth *(*add_x11_display)(
ConnectionLayer *cl, int authtype, struct X11Display *x11disp);
/* Add and remove X11 displays for connection sharing downstreams */
struct X11FakeAuth *(*add_sharing_x11_display)(
ConnectionLayer *cl, int authtype, ssh_sharing_connstate *share_cs,
share_channel *share_chan);
void (*remove_sharing_x11_display)(
ConnectionLayer *cl, struct X11FakeAuth *auth);
/* Pass through an outgoing SSH packet from a downstream */
void (*send_packet_from_downstream)(
ConnectionLayer *cl, unsigned id, int type,
const void *pkt, int pktlen, const char *additional_log_text);
/* Allocate/free an upstream channel number associated with a
* sharing downstream */
unsigned (*alloc_sharing_channel)(ConnectionLayer *cl,
ssh_sharing_connstate *connstate);
void (*delete_sharing_channel)(ConnectionLayer *cl, unsigned localid);
/* Indicate that a downstream has sent a global request with the
* want-reply flag, so that when a reply arrives it will be passed
* back to that downstrean */
void (*sharing_queue_global_request)(
ConnectionLayer *cl, ssh_sharing_connstate *connstate);
/* Indicate that the last downstream has disconnected */
void (*sharing_no_more_downstreams)(ConnectionLayer *cl);
/* Query whether the connection layer is doing agent forwarding */
bool (*agent_forwarding_permitted)(ConnectionLayer *cl);
/* Set the size of the main terminal window (if any) */
void (*terminal_size)(ConnectionLayer *cl, int width, int height);
/* Indicate that the backlog on standard output has cleared */
void (*stdout_unthrottle)(ConnectionLayer *cl, size_t bufsize);
/* Query the size of the backlog on standard _input_ */
size_t (*stdin_backlog)(ConnectionLayer *cl);
/* Tell the connection layer that the SSH connection itself has
* backed up, so it should tell all currently open channels to
* cease reading from their local input sources if they can. (Or
* tell it that that state of affairs has gone away again.) */
void (*throttle_all_channels)(ConnectionLayer *cl, bool throttled);
/* Ask the connection layer about its current preference for
* line-discipline options. */
bool (*ldisc_option)(ConnectionLayer *cl, int option);
/* Communicate _to_ the connection layer (from the main session
* channel) what its preference for line-discipline options is. */
void (*set_ldisc_option)(ConnectionLayer *cl, int option, bool value);
/* Communicate to the connection layer whether X forwarding was
* successfully enabled (for purposes of knowing whether to accept
* subsequent channel-opens). */
void (*enable_x_fwd)(ConnectionLayer *cl);
/* Communicate / query whether the main session channel currently
* wants user input. The set function is called by mainchan; the
* query function is called by the top-level ssh.c. */
void (*set_wants_user_input)(ConnectionLayer *cl, bool wanted);
bool (*get_wants_user_input)(ConnectionLayer *cl);
/* Notify the connection layer that more data has been added to
* the user input queue. */
void (*got_user_input)(ConnectionLayer *cl);
};
struct ConnectionLayer {
LogContext *logctx;
const struct ConnectionLayerVtable *vt;
};
static inline struct ssh_rportfwd *ssh_rportfwd_alloc(
ConnectionLayer *cl, const char *sh, int sp, const char *dh, int dp,
int af, const char *log, PortFwdRecord *pfr, ssh_sharing_connstate *cs)
{ return cl->vt->rportfwd_alloc(cl, sh, sp, dh, dp, af, log, pfr, cs); }
static inline void ssh_rportfwd_remove(
ConnectionLayer *cl, struct ssh_rportfwd *rpf)
{ cl->vt->rportfwd_remove(cl, rpf); }
static inline SshChannel *ssh_lportfwd_open(
ConnectionLayer *cl, const char *host, int port,
const char *desc, const SocketEndpointInfo *pi, Channel *chan)
{ return cl->vt->lportfwd_open(cl, host, port, desc, pi, chan); }
static inline SshChannel *ssh_session_open(ConnectionLayer *cl, Channel *chan)
{ return cl->vt->session_open(cl, chan); }
static inline SshChannel *ssh_serverside_x11_open(
ConnectionLayer *cl, Channel *chan, const SocketEndpointInfo *pi)
{ return cl->vt->serverside_x11_open(cl, chan, pi); }
static inline SshChannel *ssh_serverside_agent_open(
ConnectionLayer *cl, Channel *chan)
{ return cl->vt->serverside_agent_open(cl, chan); }
static inline struct X11FakeAuth *ssh_add_x11_display(
ConnectionLayer *cl, int authtype, struct X11Display *x11disp)
{ return cl->vt->add_x11_display(cl, authtype, x11disp); }
static inline struct X11FakeAuth *ssh_add_sharing_x11_display(
ConnectionLayer *cl, int authtype, ssh_sharing_connstate *share_cs,
share_channel *share_chan)
{ return cl->vt->add_sharing_x11_display(cl, authtype, share_cs, share_chan); }
static inline void ssh_remove_sharing_x11_display(
ConnectionLayer *cl, struct X11FakeAuth *auth)
{ cl->vt->remove_sharing_x11_display(cl, auth); }
static inline void ssh_send_packet_from_downstream(
ConnectionLayer *cl, unsigned id, int type,
const void *pkt, int len, const char *log)
{ cl->vt->send_packet_from_downstream(cl, id, type, pkt, len, log); }
static inline unsigned ssh_alloc_sharing_channel(
ConnectionLayer *cl, ssh_sharing_connstate *connstate)
{ return cl->vt->alloc_sharing_channel(cl, connstate); }
static inline void ssh_delete_sharing_channel(
ConnectionLayer *cl, unsigned localid)
{ cl->vt->delete_sharing_channel(cl, localid); }
static inline void ssh_sharing_queue_global_request(
ConnectionLayer *cl, ssh_sharing_connstate *connstate)
{ cl->vt->sharing_queue_global_request(cl, connstate); }
static inline void ssh_sharing_no_more_downstreams(ConnectionLayer *cl)
{ cl->vt->sharing_no_more_downstreams(cl); }
static inline bool ssh_agent_forwarding_permitted(ConnectionLayer *cl)
{ return cl->vt->agent_forwarding_permitted(cl); }
static inline void ssh_terminal_size(ConnectionLayer *cl, int w, int h)
{ cl->vt->terminal_size(cl, w, h); }
static inline void ssh_stdout_unthrottle(ConnectionLayer *cl, size_t bufsize)
{ cl->vt->stdout_unthrottle(cl, bufsize); }
static inline size_t ssh_stdin_backlog(ConnectionLayer *cl)
{ return cl->vt->stdin_backlog(cl); }
static inline void ssh_throttle_all_channels(ConnectionLayer *cl, bool thr)
{ cl->vt->throttle_all_channels(cl, thr); }
static inline bool ssh_ldisc_option(ConnectionLayer *cl, int option)
{ return cl->vt->ldisc_option(cl, option); }
static inline void ssh_set_ldisc_option(ConnectionLayer *cl, int opt, bool val)
{ cl->vt->set_ldisc_option(cl, opt, val); }
static inline void ssh_enable_x_fwd(ConnectionLayer *cl)
{ cl->vt->enable_x_fwd(cl); }
static inline void ssh_set_wants_user_input(ConnectionLayer *cl, bool wanted)
{ cl->vt->set_wants_user_input(cl, wanted); }
static inline bool ssh_get_wants_user_input(ConnectionLayer *cl)
{ return cl->vt->get_wants_user_input(cl); }
static inline void ssh_got_user_input(ConnectionLayer *cl)
{ cl->vt->got_user_input(cl); }
/* Exports from portfwd.c */
PortFwdManager *portfwdmgr_new(ConnectionLayer *cl);
void portfwdmgr_free(PortFwdManager *mgr);
void portfwdmgr_config(PortFwdManager *mgr, Conf *conf);
void portfwdmgr_close(PortFwdManager *mgr, PortFwdRecord *pfr);
void portfwdmgr_close_all(PortFwdManager *mgr);
char *portfwdmgr_connect(PortFwdManager *mgr, Channel **chan_ret,
char *hostname, int port, SshChannel *c,
int addressfamily);
bool portfwdmgr_listen(PortFwdManager *mgr, const char *host, int port,
const char *keyhost, int keyport, Conf *conf);
bool portfwdmgr_unlisten(PortFwdManager *mgr, const char *host, int port);
Channel *portfwd_raw_new(ConnectionLayer *cl, Plug **plug, bool start_ready);
void portfwd_raw_free(Channel *pfchan);
void portfwd_raw_setup(Channel *pfchan, Socket *s, SshChannel *sc);
Socket *platform_make_agent_socket(Plug *plug, const char *dirprefix,
char **error, char **name);
LogContext *ssh_get_logctx(Ssh *ssh);
/* Communications back to ssh.c from connection layers */
void ssh_throttle_conn(Ssh *ssh, int adjust);
void ssh_got_exitcode(Ssh *ssh, int status);
void ssh_ldisc_update(Ssh *ssh);
void ssh_check_sendok(Ssh *ssh);
void ssh_got_fallback_cmd(Ssh *ssh);
bool ssh_is_bare(Ssh *ssh);
/* Communications back to ssh.c from the BPP */
void ssh_conn_processed_data(Ssh *ssh);
void ssh_sendbuffer_changed(Ssh *ssh);
void ssh_check_frozen(Ssh *ssh);
/* Functions to abort the connection, for various reasons. */
void ssh_remote_error(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_remote_eof(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_proto_error(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_sw_abort(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_sw_abort_deferred(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_user_close(Ssh *ssh, const char *fmt, ...) PRINTF_LIKE(2, 3);
void ssh_spr_close(Ssh *ssh, SeatPromptResult spr, const char *context);
/* Bit positions in the SSH-1 cipher protocol word */
#define SSH1_CIPHER_IDEA 1
#define SSH1_CIPHER_DES 2
#define SSH1_CIPHER_3DES 3
#define SSH1_CIPHER_BLOWFISH 6
/* The subset of those that we support, with names for selecting them
* on Uppity's command line */
#define SSH1_SUPPORTED_CIPHER_LIST(X) \
X(SSH1_CIPHER_3DES, "3des") \
X(SSH1_CIPHER_BLOWFISH, "blowfish") \
X(SSH1_CIPHER_DES, "des") \
/* end of list */
#define SSH1_CIPHER_LIST_MAKE_MASK(bitpos, name) | (1U << bitpos)
#define SSH1_SUPPORTED_CIPHER_MASK \
(0 SSH1_SUPPORTED_CIPHER_LIST(SSH1_CIPHER_LIST_MAKE_MASK))
struct ssh_key {
const ssh_keyalg *vt;
};
struct RSAKey {
int bits;
int bytes;
mp_int *modulus;
mp_int *exponent;
mp_int *private_exponent;
mp_int *p;
mp_int *q;
mp_int *iqmp;
char *comment;
ssh_key sshk;
};
struct dsa_key {
mp_int *p, *q, *g, *y, *x;
ssh_key sshk;
};
struct ec_curve;
/* Weierstrass form curve */
struct ec_wcurve
{
WeierstrassCurve *wc;
WeierstrassPoint *G;
mp_int *G_order;
};
/* Montgomery form curve */
struct ec_mcurve
{
MontgomeryCurve *mc;
MontgomeryPoint *G;
unsigned log2_cofactor;
};
/* Edwards form curve */
struct ec_ecurve
{
EdwardsCurve *ec;
EdwardsPoint *G;
mp_int *G_order;
unsigned log2_cofactor;
};
typedef enum EllipticCurveType {
EC_WEIERSTRASS, EC_MONTGOMERY, EC_EDWARDS
} EllipticCurveType;
struct ec_curve {
EllipticCurveType type;
/* 'name' is the identifier of the curve when it has to appear in
* wire protocol encodings, as it does in e.g. the public key and
* signature formats for NIST curves. Curves which do not format
* their keys or signatures in this way just have name==NULL.
*
* 'textname' is non-NULL for all curves, and is a human-readable
* identification suitable for putting in log messages. */
const char *name, *textname;
size_t fieldBits, fieldBytes;
mp_int *p;
union {
struct ec_wcurve w;
struct ec_mcurve m;
struct ec_ecurve e;
};
};
const ssh_keyalg *ec_alg_by_oid(int len, const void *oid,
const struct ec_curve **curve);
const unsigned char *ec_alg_oid(const ssh_keyalg *alg, int *oidlen);
extern const int ec_nist_curve_lengths[], n_ec_nist_curve_lengths;
extern const int ec_ed_curve_lengths[], n_ec_ed_curve_lengths;
bool ec_nist_alg_and_curve_by_bits(int bits,
const struct ec_curve **curve,
const ssh_keyalg **alg);
bool ec_ed_alg_and_curve_by_bits(int bits,
const struct ec_curve **curve,
const ssh_keyalg **alg);
struct ecdsa_key {
const struct ec_curve *curve;
WeierstrassPoint *publicKey;
mp_int *privateKey;
ssh_key sshk;
};
struct eddsa_key {
const struct ec_curve *curve;
EdwardsPoint *publicKey;
mp_int *privateKey;
ssh_key sshk;
};
WeierstrassPoint *ecdsa_public(mp_int *private_key, const ssh_keyalg *alg);
EdwardsPoint *eddsa_public(mp_int *private_key, const ssh_keyalg *alg);
typedef enum KeyComponentType {
KCT_TEXT, KCT_BINARY, KCT_MPINT
} KeyComponentType;
typedef struct key_component {
char *name;
KeyComponentType type;
union {
strbuf *str; /* used for KCT_TEXT and KCT_BINARY */
mp_int *mp; /* used for KCT_MPINT */
};
} key_component;
typedef struct key_components {
size_t ncomponents, componentsize;
key_component *components;
} key_components;
key_components *key_components_new(void);
void key_components_add_text(key_components *kc,
const char *name, const char *value);
void key_components_add_text_pl(key_components *kc,
const char *name, ptrlen value);
void key_components_add_binary(key_components *kc,
const char *name, ptrlen value);
void key_components_add_mp(key_components *kc,
const char *name, mp_int *value);
void key_components_add_uint(key_components *kc,
const char *name, uintmax_t value);
void key_components_add_copy(key_components *kc,
const char *name, const key_component *value);
void key_components_free(key_components *kc);
/*
* SSH-1 never quite decided which order to store the two components
* of an RSA key. During connection setup, the server sends its host
* and server keys with the exponent first; private key files store
* the modulus first. The agent protocol is even more confusing,
* because the client specifies a key to the server in one order and
* the server lists the keys it knows about in the other order!
*/
typedef enum { RSA_SSH1_EXPONENT_FIRST, RSA_SSH1_MODULUS_FIRST } RsaSsh1Order;
void BinarySource_get_rsa_ssh1_pub(
BinarySource *src, RSAKey *result, RsaSsh1Order order);
void BinarySource_get_rsa_ssh1_priv(
BinarySource *src, RSAKey *rsa);
RSAKey *BinarySource_get_rsa_ssh1_priv_agent(BinarySource *src);
bool rsa_ssh1_encrypt(unsigned char *data, int length, RSAKey *key);
mp_int *rsa_ssh1_decrypt(mp_int *input, RSAKey *key);
bool rsa_ssh1_decrypt_pkcs1(mp_int *input, RSAKey *key, strbuf *outbuf);
char *rsastr_fmt(RSAKey *key);
char *rsa_ssh1_fingerprint(RSAKey *key);
char **rsa_ssh1_fake_all_fingerprints(RSAKey *key);
bool rsa_verify(RSAKey *key);
void rsa_ssh1_public_blob(BinarySink *bs, RSAKey *key, RsaSsh1Order order);
int rsa_ssh1_public_blob_len(ptrlen data);
void rsa_ssh1_private_blob_agent(BinarySink *bs, RSAKey *key);
void duprsakey(RSAKey *dst, const RSAKey *src);
void freersapriv(RSAKey *key);
void freersakey(RSAKey *key);
key_components *rsa_components(RSAKey *key);
uint32_t crc32_rfc1662(ptrlen data);
uint32_t crc32_ssh1(ptrlen data);
uint32_t crc32_update(uint32_t crc_input, ptrlen data);
/* SSH CRC compensation attack detector */
struct crcda_ctx;
struct crcda_ctx *crcda_make_context(void);
void crcda_free_context(struct crcda_ctx *ctx);
bool detect_attack(struct crcda_ctx *ctx,
const unsigned char *buf, uint32_t len,
const unsigned char *IV);
/*
* SSH2 RSA key exchange functions
*/
struct ssh_rsa_kex_extra {
int minklen;
};
RSAKey *ssh_rsakex_newkey(ptrlen data);
void ssh_rsakex_freekey(RSAKey *key);
int ssh_rsakex_klen(RSAKey *key);
strbuf *ssh_rsakex_encrypt(
RSAKey *key, const ssh_hashalg *h, ptrlen plaintext);
mp_int *ssh_rsakex_decrypt(
RSAKey *key, const ssh_hashalg *h, ptrlen ciphertext);
/*
* System for generating k in DSA and ECDSA.
*/
struct RFC6979Result {
mp_int *k;
unsigned ok;
};
RFC6979 *rfc6979_new(const ssh_hashalg *hashalg, mp_int *q, mp_int *x);
void rfc6979_setup(RFC6979 *s, ptrlen message);
RFC6979Result rfc6979_attempt(RFC6979 *s);
void rfc6979_free(RFC6979 *s);
mp_int *rfc6979(const ssh_hashalg *hashalg, mp_int *modulus,
mp_int *private_key, ptrlen message);
struct ssh_cipher {
const ssh_cipheralg *vt;
};
struct ssh_cipheralg {
ssh_cipher *(*new)(const ssh_cipheralg *alg);
void (*free)(ssh_cipher *);
void (*setiv)(ssh_cipher *, const void *iv);
void (*setkey)(ssh_cipher *, const void *key);
void (*encrypt)(ssh_cipher *, void *blk, int len);
void (*decrypt)(ssh_cipher *, void *blk, int len);
/* Ignored unless SSH_CIPHER_SEPARATE_LENGTH flag set */
void (*encrypt_length)(ssh_cipher *, void *blk, int len,
unsigned long seq);
void (*decrypt_length)(ssh_cipher *, void *blk, int len,
unsigned long seq);
/* For ciphers that update their state per logical message
* (typically, per unit independently MACed) */
void (*next_message)(ssh_cipher *);
const char *ssh2_id;
int blksize;
/* real_keybits is the number of bits of entropy genuinely used by
* the cipher scheme; it's used for deciding how big a
* Diffie-Hellman group is needed to exchange a key for the
* cipher. */
int real_keybits;
/* padded_keybytes is the number of bytes of key data expected as
* input to the setkey function; it's used for deciding how much
* data needs to be generated from the post-kex generation of key
* material. In a sensible cipher which uses all its key bytes for
* real work, this will just be real_keybits/8, but in DES-type
* ciphers which ignore one bit in each byte, it'll be slightly
* different. */
int padded_keybytes;
unsigned int flags;
#define SSH_CIPHER_IS_CBC 1
#define SSH_CIPHER_SEPARATE_LENGTH 2
const char *text_name;
/* If set, this takes priority over other MAC. */
const ssh2_macalg *required_mac;
/* Pointer to any extra data used by a particular implementation. */
const void *extra;
};
static inline ssh_cipher *ssh_cipher_new(const ssh_cipheralg *alg)
{ return alg->new(alg); }
static inline void ssh_cipher_free(ssh_cipher *c)
{ c->vt->free(c); }
static inline void ssh_cipher_setiv(ssh_cipher *c, const void *iv)
{ c->vt->setiv(c, iv); }
static inline void ssh_cipher_setkey(ssh_cipher *c, const void *key)
{ c->vt->setkey(c, key); }
static inline void ssh_cipher_encrypt(ssh_cipher *c, void *blk, int len)
{ c->vt->encrypt(c, blk, len); }
static inline void ssh_cipher_decrypt(ssh_cipher *c, void *blk, int len)
{ c->vt->decrypt(c, blk, len); }
static inline void ssh_cipher_encrypt_length(
ssh_cipher *c, void *blk, int len, unsigned long seq)
{ c->vt->encrypt_length(c, blk, len, seq); }
static inline void ssh_cipher_decrypt_length(
ssh_cipher *c, void *blk, int len, unsigned long seq)
{ c->vt->decrypt_length(c, blk, len, seq); }
static inline void ssh_cipher_next_message(ssh_cipher *c)
{ c->vt->next_message(c); }
static inline const struct ssh_cipheralg *ssh_cipher_alg(ssh_cipher *c)
{ return c->vt; }
void nullcipher_next_message(ssh_cipher *);
struct ssh2_ciphers {
int nciphers;
const ssh_cipheralg *const *list;
};
struct ssh2_mac {
const ssh2_macalg *vt;
BinarySink_DELEGATE_IMPLEMENTATION;
};
struct ssh2_macalg {
/* Passes in the cipher context */
ssh2_mac *(*new)(const ssh2_macalg *alg, ssh_cipher *cipher);
void (*free)(ssh2_mac *);
void (*setkey)(ssh2_mac *, ptrlen key);
void (*start)(ssh2_mac *);
void (*genresult)(ssh2_mac *, unsigned char *);
void (*next_message)(ssh2_mac *);
const char *(*text_name)(ssh2_mac *);
const char *name, *etm_name;
int len, keylen;
/* Pointer to any extra data used by a particular implementation. */
const void *extra;
};
static inline ssh2_mac *ssh2_mac_new(
const ssh2_macalg *alg, ssh_cipher *cipher)
{ return alg->new(alg, cipher); }
static inline void ssh2_mac_free(ssh2_mac *m)
{ m->vt->free(m); }
static inline void ssh2_mac_setkey(ssh2_mac *m, ptrlen key)
{ m->vt->setkey(m, key); }
static inline void ssh2_mac_start(ssh2_mac *m)
{ m->vt->start(m); }
static inline void ssh2_mac_genresult(ssh2_mac *m, unsigned char *out)
{ m->vt->genresult(m, out); }
static inline void ssh2_mac_next_message(ssh2_mac *m)
{ m->vt->next_message(m); }
static inline const char *ssh2_mac_text_name(ssh2_mac *m)
{ return m->vt->text_name(m); }
static inline const ssh2_macalg *ssh2_mac_alg(ssh2_mac *m)
{ return m->vt; }
/* Centralised 'methods' for ssh2_mac, defined in mac.c. These run
* the MAC in a specifically SSH-2 style, i.e. taking account of a
* packet sequence number as well as the data to be authenticated. */
bool ssh2_mac_verresult(ssh2_mac *, const void *);
void ssh2_mac_generate(ssh2_mac *, void *, int, unsigned long seq);
bool ssh2_mac_verify(ssh2_mac *, const void *, int, unsigned long seq);
void nullmac_next_message(ssh2_mac *m);
/* Use a MAC in its raw form, outside SSH-2 context, to MAC a given
* string with a given key in the most obvious way. */
void mac_simple(const ssh2_macalg *alg, ptrlen key, ptrlen data, void *output);
/* Constructor that makes an HMAC object given just a MAC. This object
* will have empty 'name' and 'etm_name' fields, so it's not suitable
* for use in SSH. It's used as a subroutine in RFC 6979. */
ssh2_mac *hmac_new_from_hash(const ssh_hashalg *hash);
struct ssh_hash {
const ssh_hashalg *vt;
BinarySink_DELEGATE_IMPLEMENTATION;
};
struct ssh_hashalg {
ssh_hash *(*new)(const ssh_hashalg *alg);
void (*reset)(ssh_hash *);
void (*copyfrom)(ssh_hash *dest, ssh_hash *src);
void (*digest)(ssh_hash *, unsigned char *);
void (*free)(ssh_hash *);
size_t hlen; /* output length in bytes */
size_t blocklen; /* length of the hash's input block, or 0 for N/A */
const char *text_basename; /* the semantic name of the hash */
const char *annotation; /* extra info, e.g. which of multiple impls */
const char *text_name; /* both combined, e.g. "SHA-n (unaccelerated)" */
const void *extra; /* private to the hash implementation */
};
static inline ssh_hash *ssh_hash_new(const ssh_hashalg *alg)
{ ssh_hash *h = alg->new(alg); if (h) h->vt->reset(h); return h; }
static inline ssh_hash *ssh_hash_copy(ssh_hash *orig)
{ ssh_hash *h = orig->vt->new(orig->vt); h->vt->copyfrom(h, orig); return h; }
static inline void ssh_hash_digest(ssh_hash *h, unsigned char *out)
{ h->vt->digest(h, out); }
static inline void ssh_hash_free(ssh_hash *h)
{ h->vt->free(h); }
static inline const ssh_hashalg *ssh_hash_alg(ssh_hash *h)
{ return h->vt; }
/* The reset and copyfrom vtable methods return void. But for call-site
* convenience, these wrappers return their input pointer. */
static inline ssh_hash *ssh_hash_reset(ssh_hash *h)
{ h->vt->reset(h); return h; }
static inline ssh_hash *ssh_hash_copyfrom(ssh_hash *dest, ssh_hash *src)
{ dest->vt->copyfrom(dest, src); return dest; }
/* ssh_hash_final emits the digest _and_ frees the ssh_hash */
static inline void ssh_hash_final(ssh_hash *h, unsigned char *out)
{ h->vt->digest(h, out); h->vt->free(h); }
/* ssh_hash_digest_nondestructive generates a finalised hash from the
* given object without changing its state, so you can continue
* appending data to get a hash of an extended string. */
static inline void ssh_hash_digest_nondestructive(ssh_hash *h,
unsigned char *out)
{ ssh_hash_final(ssh_hash_copy(h), out); }
/* Handy macros for defining all those text-name fields at once */
#define HASHALG_NAMES_BARE(base) \
.text_basename = base, .annotation = NULL, .text_name = base
#define HASHALG_NAMES_ANNOTATED(base, ann) \
.text_basename = base, .annotation = ann, .text_name = base " (" ann ")"
void hash_simple(const ssh_hashalg *alg, ptrlen data, void *output);
struct ssh_kex {
const char *name, *groupname;
enum { KEXTYPE_DH, KEXTYPE_RSA, KEXTYPE_ECDH,
KEXTYPE_GSS, KEXTYPE_GSS_ECDH } main_type;
const ssh_hashalg *hash;
union { /* publicly visible data for each type */
const ecdh_keyalg *ecdh_vt; /* for KEXTYPE_ECDH, KEXTYPE_GSS_ECDH */
};
const void *extra; /* private to the kex methods */
};
static inline bool kex_is_gss(const struct ssh_kex *kex)
{
return kex->main_type == KEXTYPE_GSS || kex->main_type == KEXTYPE_GSS_ECDH;
}
struct ssh_kexes {
int nkexes;
const ssh_kex *const *list;
};
/* Indices of the negotiation strings in the KEXINIT packet */
enum kexlist {
KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER,
KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP,
NKEXLIST
};
struct ssh_keyalg {
/* Constructors that create an ssh_key */
ssh_key *(*new_pub) (const ssh_keyalg *self, ptrlen pub);
ssh_key *(*new_priv) (const ssh_keyalg *self, ptrlen pub, ptrlen priv);
ssh_key *(*new_priv_openssh) (const ssh_keyalg *self, BinarySource *);
/* Methods that operate on an existing ssh_key */
void (*freekey) (ssh_key *key);
char *(*invalid) (ssh_key *key, unsigned flags);
void (*sign) (ssh_key *key, ptrlen data, unsigned flags, BinarySink *);
bool (*verify) (ssh_key *key, ptrlen sig, ptrlen data);
void (*public_blob)(ssh_key *key, BinarySink *);
void (*private_blob)(ssh_key *key, BinarySink *);
void (*openssh_blob) (ssh_key *key, BinarySink *);
bool (*has_private) (ssh_key *key);
char *(*cache_str) (ssh_key *key);
key_components *(*components) (ssh_key *key);
ssh_key *(*base_key) (ssh_key *key); /* does not confer ownership */
/* The following methods can be NULL if !is_certificate */
void (*ca_public_blob)(ssh_key *key, BinarySink *);
bool (*check_cert)(ssh_key *key, bool host, ptrlen principal,
uint64_t time, const ca_options *opts,
BinarySink *error);
void (*cert_id_string)(ssh_key *key, BinarySink *);
SeatDialogText *(*cert_info)(ssh_key *key);
/* 'Class methods' that don't deal with an ssh_key at all */
int (*pubkey_bits) (const ssh_keyalg *self, ptrlen blob);
unsigned (*supported_flags) (const ssh_keyalg *self);
const char *(*alternate_ssh_id) (const ssh_keyalg *self, unsigned flags);
char *(*alg_desc)(const ssh_keyalg *self);
bool (*variable_size)(const ssh_keyalg *self);
/* The following methods can be NULL if !is_certificate */
const ssh_keyalg *(*related_alg)(const ssh_keyalg *self,
const ssh_keyalg *base);
/* Constant data fields giving information about the key type */
const char *ssh_id; /* string identifier in the SSH protocol */
const char *cache_id; /* identifier used in PuTTY's host key cache */
const void *extra; /* private to the public key methods */
bool is_certificate; /* is this a certified key type? */
const ssh_keyalg *base_alg; /* if so, for what underlying key alg? */
};
static inline ssh_key *ssh_key_new_pub(const ssh_keyalg *self, ptrlen pub)
{ return self->new_pub(self, pub); }
static inline ssh_key *ssh_key_new_priv(
const ssh_keyalg *self, ptrlen pub, ptrlen priv)
{ return self->new_priv(self, pub, priv); }
static inline ssh_key *ssh_key_new_priv_openssh(
const ssh_keyalg *self, BinarySource *src)
{ return self->new_priv_openssh(self, src); }
static inline void ssh_key_free(ssh_key *key)
{ key->vt->freekey(key); }
static inline char *ssh_key_invalid(ssh_key *key, unsigned flags)
{ return key->vt->invalid(key, flags); }
static inline void ssh_key_sign(
ssh_key *key, ptrlen data, unsigned flags, BinarySink *bs)
{ key->vt->sign(key, data, flags, bs); }
static inline bool ssh_key_verify(ssh_key *key, ptrlen sig, ptrlen data)
{ return key->vt->verify(key, sig, data); }
static inline void ssh_key_public_blob(ssh_key *key, BinarySink *bs)
{ key->vt->public_blob(key, bs); }
static inline void ssh_key_private_blob(ssh_key *key, BinarySink *bs)
{ key->vt->private_blob(key, bs); }
static inline void ssh_key_openssh_blob(ssh_key *key, BinarySink *bs)
{ key->vt->openssh_blob(key, bs); }
static inline bool ssh_key_has_private(ssh_key *key)
{ return key->vt->has_private(key); }
static inline char *ssh_key_cache_str(ssh_key *key)
{ return key->vt->cache_str(key); }
static inline key_components *ssh_key_components(ssh_key *key)
{ return key->vt->components(key); }
static inline ssh_key *ssh_key_base_key(ssh_key *key)
{ return key->vt->base_key(key); }
static inline void ssh_key_ca_public_blob(ssh_key *key, BinarySink *bs)
{ key->vt->ca_public_blob(key, bs); }
static inline void ssh_key_cert_id_string(ssh_key *key, BinarySink *bs)
{ key->vt->cert_id_string(key, bs); }
static inline SeatDialogText *ssh_key_cert_info(ssh_key *key)
{ return key->vt->cert_info(key); }
static inline bool ssh_key_check_cert(
ssh_key *key, bool host, ptrlen principal, uint64_t time,
const ca_options *opts, BinarySink *error)
{ return key->vt->check_cert(key, host, principal, time, opts, error); }
static inline int ssh_key_public_bits(const ssh_keyalg *self, ptrlen blob)
{ return self->pubkey_bits(self, blob); }
static inline const ssh_keyalg *ssh_key_alg(ssh_key *key)
{ return key->vt; }
static inline const char *ssh_key_ssh_id(ssh_key *key)
{ return key->vt->ssh_id; }
static inline const char *ssh_key_cache_id(ssh_key *key)
{ return key->vt->cache_id; }
static inline unsigned ssh_key_supported_flags(ssh_key *key)
{ return key->vt->supported_flags(key->vt); }
static inline unsigned ssh_keyalg_supported_flags(const ssh_keyalg *self)
{ return self->supported_flags(self); }
static inline const char *ssh_keyalg_alternate_ssh_id(
const ssh_keyalg *self, unsigned flags)
{ return self->alternate_ssh_id(self, flags); }
static inline char *ssh_keyalg_desc(const ssh_keyalg *self)
{ return self->alg_desc(self); }
static inline bool ssh_keyalg_variable_size(const ssh_keyalg *self)
{ return self->variable_size(self); }
static inline const ssh_keyalg *ssh_keyalg_related_alg(
const ssh_keyalg *self, const ssh_keyalg *base)
{ return self->related_alg(self, base); }
/* Stub functions shared between multiple key types */
unsigned nullkey_supported_flags(const ssh_keyalg *self);
const char *nullkey_alternate_ssh_id(const ssh_keyalg *self, unsigned flags);
ssh_key *nullkey_base_key(ssh_key *key);
bool nullkey_variable_size_no(const ssh_keyalg *self);
bool nullkey_variable_size_yes(const ssh_keyalg *self);
/* Utility functions implemented centrally */
ssh_key *ssh_key_clone(ssh_key *key);
/*
* SSH2 ECDH key exchange vtable
*/
struct ecdh_key {
const ecdh_keyalg *vt;
};
struct ecdh_keyalg {
/* Unusually, the 'new' method here doesn't directly take a vt
* pointer, because it will also need the containing ssh_kex
* structure for top-level parameters, and since that contains a
* vt pointer anyway, we might as well _only_ pass that. */
ecdh_key *(*new)(const ssh_kex *kex, bool is_server);
void (*free)(ecdh_key *key);
void (*getpublic)(ecdh_key *key, BinarySink *bs);
bool (*getkey)(ecdh_key *key, ptrlen remoteKey, BinarySink *bs);
char *(*description)(const ssh_kex *kex);
/* Some things that use this vtable are genuinely elliptic-curve
* Diffie-Hellman. Others are hybrid PQ + classical kex methods.
* Provide a packet-naming context for use in the SSH log. (Purely
* cosmetic.) */