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bc4066e454
putty-source/pageant.c
Simon Tatham bc4066e454 Put proper logging into Pageant. 
Now it actually logs all its requests and responses, the fingerprints
of keys mentioned in all messages, and so on.

I've also added the -v option, which causes Pageant in any mode to
direct that logging information to standard error. In --debug mode,
however, the logging output goes to standard output instead (because
when debugging, that information changes from a side effect to the
thing you actually wanted in the first place :-).

An internal tweak: the logging functions now take a va_list rather
than an actual variadic argument list, so that I can pass it through
several functions.
2015-05-06 19:45:04 +01:00

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/*
* pageant.c: cross-platform code to implement Pageant.
*/
#include <stddef.h>
#include <stdlib.h>
#include <assert.h>
#include "putty.h"
#include "ssh.h"
#include "pageant.h"
/*
* We need this to link with the RSA code, because rsaencrypt()
* pads its data with random bytes. Since we only use rsadecrypt()
* and the signing functions, which are deterministic, this should
* never be called.
*
* If it _is_ called, there is a _serious_ problem, because it
* won't generate true random numbers. So we must scream, panic,
* and exit immediately if that should happen.
*/
int random_byte(void)
{
modalfatalbox("Internal error: attempt to use random numbers in Pageant");
exit(0);
return 0; /* unreachable, but placate optimiser */
}
/*
* rsakeys stores SSH-1 RSA keys. ssh2keys stores all SSH-2 keys.
*/
static tree234 *rsakeys, *ssh2keys;
/*
* Blob structure for passing to the asymmetric SSH-2 key compare
* function, prototyped here.
*/
struct blob {
const unsigned char *blob;
int len;
};
static int cmpkeys_ssh2_asymm(void *av, void *bv);
/*
* Key comparison function for the 2-3-4 tree of RSA keys.
*/
static int cmpkeys_rsa(void *av, void *bv)
{
struct RSAKey *a = (struct RSAKey *) av;
struct RSAKey *b = (struct RSAKey *) bv;
Bignum am, bm;
int alen, blen;
am = a->modulus;
bm = b->modulus;
/*
* Compare by length of moduli.
*/
alen = bignum_bitcount(am);
blen = bignum_bitcount(bm);
if (alen > blen)
return +1;
else if (alen < blen)
return -1;
/*
* Now compare by moduli themselves.
*/
alen = (alen + 7) / 8; /* byte count */
while (alen-- > 0) {
int abyte, bbyte;
abyte = bignum_byte(am, alen);
bbyte = bignum_byte(bm, alen);
if (abyte > bbyte)
return +1;
else if (abyte < bbyte)
return -1;
}
/*
* Give up.
*/
return 0;
}
/*
* Key comparison function for the 2-3-4 tree of SSH-2 keys.
*/
static int cmpkeys_ssh2(void *av, void *bv)
{
struct ssh2_userkey *a = (struct ssh2_userkey *) av;
struct ssh2_userkey *b = (struct ssh2_userkey *) bv;
int i;
int alen, blen;
unsigned char *ablob, *bblob;
int c;
/*
* Compare purely by public blob.
*/
ablob = a->alg->public_blob(a->data, &alen);
bblob = b->alg->public_blob(b->data, &blen);
c = 0;
for (i = 0; i < alen && i < blen; i++) {
if (ablob[i] < bblob[i]) {
c = -1;
break;
} else if (ablob[i] > bblob[i]) {
c = +1;
break;
}
}
if (c == 0 && i < alen)
c = +1; /* a is longer */
if (c == 0 && i < blen)
c = -1; /* a is longer */
sfree(ablob);
sfree(bblob);
return c;
}
/*
* Key comparison function for looking up a blob in the 2-3-4 tree
* of SSH-2 keys.
*/
static int cmpkeys_ssh2_asymm(void *av, void *bv)
{
struct blob *a = (struct blob *) av;
struct ssh2_userkey *b = (struct ssh2_userkey *) bv;
int i;
int alen, blen;
const unsigned char *ablob;
unsigned char *bblob;
int c;
/*
* Compare purely by public blob.
*/
ablob = a->blob;
alen = a->len;
bblob = b->alg->public_blob(b->data, &blen);
c = 0;
for (i = 0; i < alen && i < blen; i++) {
if (ablob[i] < bblob[i]) {
c = -1;
break;
} else if (ablob[i] > bblob[i]) {
c = +1;
break;
}
}
if (c == 0 && i < alen)
c = +1; /* a is longer */
if (c == 0 && i < blen)
c = -1; /* a is longer */
sfree(bblob);
return c;
}
/*
* Create an SSH-1 key list in a malloc'ed buffer; return its
* length.
*/
void *pageant_make_keylist1(int *length)
{
int i, nkeys, len;
struct RSAKey *key;
unsigned char *blob, *p, *ret;
int bloblen;
/*
* Count up the number and length of keys we hold.
*/
len = 4;
nkeys = 0;
for (i = 0; NULL != (key = index234(rsakeys, i)); i++) {
nkeys++;
blob = rsa_public_blob(key, &bloblen);
len += bloblen;
sfree(blob);
len += 4 + strlen(key->comment);
}
/* Allocate the buffer. */
p = ret = snewn(len, unsigned char);
if (length) *length = len;
PUT_32BIT(p, nkeys);
p += 4;
for (i = 0; NULL != (key = index234(rsakeys, i)); i++) {
blob = rsa_public_blob(key, &bloblen);
memcpy(p, blob, bloblen);
p += bloblen;
sfree(blob);
PUT_32BIT(p, strlen(key->comment));
memcpy(p + 4, key->comment, strlen(key->comment));
p += 4 + strlen(key->comment);
}
assert(p - ret == len);
return ret;
}
/*
* Create an SSH-2 key list in a malloc'ed buffer; return its
* length.
*/
void *pageant_make_keylist2(int *length)
{
struct ssh2_userkey *key;
int i, len, nkeys;
unsigned char *blob, *p, *ret;
int bloblen;
/*
* Count up the number and length of keys we hold.
*/
len = 4;
nkeys = 0;
for (i = 0; NULL != (key = index234(ssh2keys, i)); i++) {
nkeys++;
len += 4; /* length field */
blob = key->alg->public_blob(key->data, &bloblen);
len += bloblen;
sfree(blob);
len += 4 + strlen(key->comment);
}
/* Allocate the buffer. */
p = ret = snewn(len, unsigned char);
if (length) *length = len;
/*
* Packet header is the obvious five bytes, plus four
* bytes for the key count.
*/
PUT_32BIT(p, nkeys);
p += 4;
for (i = 0; NULL != (key = index234(ssh2keys, i)); i++) {
blob = key->alg->public_blob(key->data, &bloblen);
PUT_32BIT(p, bloblen);
p += 4;
memcpy(p, blob, bloblen);
p += bloblen;
sfree(blob);
PUT_32BIT(p, strlen(key->comment));
memcpy(p + 4, key->comment, strlen(key->comment));
p += 4 + strlen(key->comment);
}
assert(p - ret == len);
return ret;
}
char *fingerprint_ssh2_blob(const void *blob, int bloblen)
{
unsigned char digest[16];
char fingerprint_str[16*3];
unsigned stringlen;
int i;
MD5Simple(blob, bloblen, digest);
for (i = 0; i < 16; i++)
sprintf(fingerprint_str + i*3, "%02x%s", digest[i], i==15 ? "" : ":");
stringlen = GET_32BIT((const unsigned char *)blob);
if (stringlen < bloblen-4)
return dupprintf("%.*s %s", (int)stringlen, (const char *)blob + 4,
fingerprint_str);
else
return dupstr(fingerprint_str);
}
static void plog(void *logctx, pageant_logfn_t logfn, const char *fmt, ...)
#ifdef __GNUC__
__attribute__ ((format (printf, 3, 4)))
#endif
;
static void plog(void *logctx, pageant_logfn_t logfn, const char *fmt, ...)
{
/*
* This is the wrapper that takes a variadic argument list and
* turns it into the va_list that the log function really expects.
* It's safe to call this with logfn==NULL, because we
* double-check that below; but if you're going to do lots of work
* before getting here (such as looping, or hashing things) then
* you should probably check logfn manually before doing that.
*/
if (logfn) {
va_list ap;
va_start(ap, fmt);
logfn(logctx, fmt, ap);
va_end(ap);
}
}
void *pageant_handle_msg(const void *msg, int msglen, int *outlen,
void *logctx, pageant_logfn_t logfn)
{
const unsigned char *p = msg;
const unsigned char *msgend;
unsigned char *ret = snewn(AGENT_MAX_MSGLEN, unsigned char);
int type;
const char *fail_reason;
msgend = p + msglen;
/*
* Get the message type.
*/
if (msgend < p+1) {
fail_reason = "message contained no type code";
goto failure;
}
type = *p++;
switch (type) {
case SSH1_AGENTC_REQUEST_RSA_IDENTITIES:
/*
* Reply with SSH1_AGENT_RSA_IDENTITIES_ANSWER.
*/
{
int len;
void *keylist;
plog(logctx, logfn, "request: SSH1_AGENTC_REQUEST_RSA_IDENTITIES");
ret[4] = SSH1_AGENT_RSA_IDENTITIES_ANSWER;
keylist = pageant_make_keylist1(&len);
if (len + 5 > AGENT_MAX_MSGLEN) {
sfree(keylist);
fail_reason = "output would exceed max msglen";
goto failure;
}
PUT_32BIT(ret, len + 1);
memcpy(ret + 5, keylist, len);
plog(logctx, logfn, "reply: SSH1_AGENT_RSA_IDENTITIES_ANSWER");
if (logfn) { /* skip this loop if not logging */
int i;
struct RSAKey *rkey;
for (i = 0; NULL != (rkey = pageant_nth_ssh1_key(i)); i++) {
char fingerprint[128];
rsa_fingerprint(fingerprint, sizeof(fingerprint), rkey);
plog(logctx, logfn, "returned key: %s", fingerprint);
}
}
sfree(keylist);
}
break;
case SSH2_AGENTC_REQUEST_IDENTITIES:
/*
* Reply with SSH2_AGENT_IDENTITIES_ANSWER.
*/
{
int len;
void *keylist;
plog(logctx, logfn, "request: SSH2_AGENTC_REQUEST_IDENTITIES");
ret[4] = SSH2_AGENT_IDENTITIES_ANSWER;
keylist = pageant_make_keylist2(&len);
if (len + 5 > AGENT_MAX_MSGLEN) {
sfree(keylist);
fail_reason = "output would exceed max msglen";
goto failure;
}
PUT_32BIT(ret, len + 1);
memcpy(ret + 5, keylist, len);
plog(logctx, logfn, "reply: SSH2_AGENT_IDENTITIES_ANSWER");
if (logfn) { /* skip this loop if not logging */
int i;
struct ssh2_userkey *skey;
for (i = 0; NULL != (skey = pageant_nth_ssh2_key(i)); i++) {
char *fingerprint = skey->alg->fingerprint(skey->data);
plog(logctx, logfn, "returned key: %s %s",
fingerprint, skey->comment);
sfree(fingerprint);
}
}
sfree(keylist);
}
break;
case SSH1_AGENTC_RSA_CHALLENGE:
/*
* Reply with either SSH1_AGENT_RSA_RESPONSE or
* SSH_AGENT_FAILURE, depending on whether we have that key
* or not.
*/
{
struct RSAKey reqkey, *key;
Bignum challenge, response;
unsigned char response_source[48], response_md5[16];
struct MD5Context md5c;
int i, len;
plog(logctx, logfn, "request: SSH1_AGENTC_RSA_CHALLENGE");
p += 4;
i = ssh1_read_bignum(p, msgend - p, &reqkey.exponent);
if (i < 0) {
fail_reason = "request truncated before key exponent";
goto failure;
}
p += i;
i = ssh1_read_bignum(p, msgend - p, &reqkey.modulus);
if (i < 0) {
freebn(reqkey.exponent);
fail_reason = "request truncated before key modulus";
goto failure;
}
p += i;
i = ssh1_read_bignum(p, msgend - p, &challenge);
if (i < 0) {
freebn(reqkey.exponent);
freebn(reqkey.modulus);
fail_reason = "request truncated before challenge";
goto failure;
}
p += i;
if (msgend < p+16) {
freebn(reqkey.exponent);
freebn(reqkey.modulus);
freebn(challenge);
fail_reason = "request truncated before session id";
goto failure;
}
memcpy(response_source + 32, p, 16);
p += 16;
if (msgend < p+4) {
freebn(reqkey.exponent);
freebn(reqkey.modulus);
freebn(challenge);
fail_reason = "request truncated before response type";
goto failure;
}
if (GET_32BIT(p) != 1) {
freebn(reqkey.exponent);
freebn(reqkey.modulus);
freebn(challenge);
fail_reason = "response type other than 1 not supported";
goto failure;
}
if (logfn) {
char fingerprint[128];
reqkey.comment = NULL;
rsa_fingerprint(fingerprint, sizeof(fingerprint), &reqkey);
plog(logctx, logfn, "requested key: %s", fingerprint);
}
if ((key = find234(rsakeys, &reqkey, NULL)) == NULL) {
freebn(reqkey.exponent);
freebn(reqkey.modulus);
freebn(challenge);
fail_reason = "key not found";
goto failure;
}
response = rsadecrypt(challenge, key);
for (i = 0; i < 32; i++)
response_source[i] = bignum_byte(response, 31 - i);
MD5Init(&md5c);
MD5Update(&md5c, response_source, 48);
MD5Final(response_md5, &md5c);
smemclr(response_source, 48); /* burn the evidence */
freebn(response); /* and that evidence */
freebn(challenge); /* yes, and that evidence */
freebn(reqkey.exponent); /* and free some memory ... */
freebn(reqkey.modulus); /* ... while we're at it. */
/*
* Packet is the obvious five byte header, plus sixteen
* bytes of MD5.
*/
len = 5 + 16;
PUT_32BIT(ret, len - 4);
ret[4] = SSH1_AGENT_RSA_RESPONSE;
memcpy(ret + 5, response_md5, 16);
plog(logctx, logfn, "reply: SSH1_AGENT_RSA_RESPONSE");
}
break;
case SSH2_AGENTC_SIGN_REQUEST:
/*
* Reply with either SSH2_AGENT_SIGN_RESPONSE or
* SSH_AGENT_FAILURE, depending on whether we have that key
* or not.
*/
{
struct ssh2_userkey *key;
struct blob b;
const unsigned char *data;
unsigned char *signature;
int datalen, siglen, len;
plog(logctx, logfn, "request: SSH2_AGENTC_SIGN_REQUEST");
if (msgend < p+4) {
fail_reason = "request truncated before public key";
goto failure;
}
b.len = toint(GET_32BIT(p));
if (b.len < 0 || b.len > msgend - (p+4)) {
fail_reason = "request truncated before public key";
goto failure;
}
p += 4;
b.blob = p;
p += b.len;
if (msgend < p+4) {
fail_reason = "request truncated before string to sign";
goto failure;
}
datalen = toint(GET_32BIT(p));
p += 4;
if (datalen < 0 || datalen > msgend - p) {
fail_reason = "request truncated before string to sign";
goto failure;
}
data = p;
if (logfn) {
char *fingerprint = fingerprint_ssh2_blob(b.blob, b.len);
plog(logctx, logfn, "requested key: %s", fingerprint);
sfree(fingerprint);
}
key = find234(ssh2keys, &b, cmpkeys_ssh2_asymm);
if (!key) {
fail_reason = "key not found";
goto failure;
}
signature = key->alg->sign(key->data, (const char *)data,
datalen, &siglen);
len = 5 + 4 + siglen;
PUT_32BIT(ret, len - 4);
ret[4] = SSH2_AGENT_SIGN_RESPONSE;
PUT_32BIT(ret + 5, siglen);
memcpy(ret + 5 + 4, signature, siglen);
sfree(signature);
plog(logctx, logfn, "reply: SSH2_AGENT_SIGN_RESPONSE");
}
break;
case SSH1_AGENTC_ADD_RSA_IDENTITY:
/*
* Add to the list and return SSH_AGENT_SUCCESS, or
* SSH_AGENT_FAILURE if the key was malformed.
*/
{
struct RSAKey *key;
char *comment;
int n, commentlen;
plog(logctx, logfn, "request: SSH1_AGENTC_ADD_RSA_IDENTITY");
key = snew(struct RSAKey);
memset(key, 0, sizeof(struct RSAKey));
n = makekey(p, msgend - p, key, NULL, 1);
if (n < 0) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before public key";
goto failure;
}
p += n;
n = makeprivate(p, msgend - p, key);
if (n < 0) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before private key";
goto failure;
}
p += n;
n = ssh1_read_bignum(p, msgend - p, &key->iqmp); /* p^-1 mod q */
if (n < 0) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before iqmp";
goto failure;
}
p += n;
n = ssh1_read_bignum(p, msgend - p, &key->p); /* p */
if (n < 0) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before p";
goto failure;
}
p += n;
n = ssh1_read_bignum(p, msgend - p, &key->q); /* q */
if (n < 0) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before q";
goto failure;
}
p += n;
if (msgend < p+4) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before key comment";
goto failure;
}
commentlen = toint(GET_32BIT(p));
if (commentlen < 0 || commentlen > msgend - p) {
freersakey(key);
sfree(key);
fail_reason = "request truncated before key comment";
goto failure;
}
comment = snewn(commentlen+1, char);
if (comment) {
memcpy(comment, p + 4, commentlen);
comment[commentlen] = '\0';
key->comment = comment;
}
if (logfn) {
char fingerprint[128];
rsa_fingerprint(fingerprint, sizeof(fingerprint), key);
plog(logctx, logfn, "submitted key: %s", fingerprint);
}
if (add234(rsakeys, key) == key) {
keylist_update();
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
} else {
freersakey(key);
sfree(key);
fail_reason = "key already present";
goto failure;
}
}
break;
case SSH2_AGENTC_ADD_IDENTITY:
/*
* Add to the list and return SSH_AGENT_SUCCESS, or
* SSH_AGENT_FAILURE if the key was malformed.
*/
{
struct ssh2_userkey *key;
char *comment;
const char *alg;
int alglen, commlen;
int bloblen;
plog(logctx, logfn, "request: SSH2_AGENTC_ADD_IDENTITY");
if (msgend < p+4) {
fail_reason = "request truncated before key algorithm";
goto failure;
}
alglen = toint(GET_32BIT(p));
p += 4;
if (alglen < 0 || alglen > msgend - p) {
fail_reason = "request truncated before key algorithm";
goto failure;
}
alg = (const char *)p;
p += alglen;
key = snew(struct ssh2_userkey);
/* Add further algorithm names here. */
if (alglen == 7 && !memcmp(alg, "ssh-rsa", 7))
key->alg = &ssh_rsa;
else if (alglen == 7 && !memcmp(alg, "ssh-dss", 7))
key->alg = &ssh_dss;
else if (alglen == 19 && memcmp(alg, "ecdsa-sha2-nistp256", 19))
key->alg = &ssh_ecdsa_nistp256;
else if (alglen == 19 && memcmp(alg, "ecdsa-sha2-nistp384", 19))
key->alg = &ssh_ecdsa_nistp384;
else if (alglen == 19 && memcmp(alg, "ecdsa-sha2-nistp521", 19))
key->alg = &ssh_ecdsa_nistp521;
else {
sfree(key);
fail_reason = "algorithm unknown";
goto failure;
}
bloblen = msgend - p;
key->data = key->alg->openssh_createkey(&p, &bloblen);
if (!key->data) {
sfree(key);
fail_reason = "key setup failed";
goto failure;
}
/*
* p has been advanced by openssh_createkey, but
* certainly not _beyond_ the end of the buffer.
*/
assert(p <= msgend);
if (msgend < p+4) {
key->alg->freekey(key->data);
sfree(key);
fail_reason = "request truncated before key comment";
goto failure;
}
commlen = toint(GET_32BIT(p));
p += 4;
if (commlen < 0 || commlen > msgend - p) {
key->alg->freekey(key->data);
sfree(key);
fail_reason = "request truncated before key comment";
goto failure;
}
comment = snewn(commlen + 1, char);
if (comment) {
memcpy(comment, p, commlen);
comment[commlen] = '\0';
}
key->comment = comment;
if (logfn) {
char *fingerprint = key->alg->fingerprint(key->data);
plog(logctx, logfn, "submitted key: %s %s",
fingerprint, key->comment);
sfree(fingerprint);
}
if (add234(ssh2keys, key) == key) {
keylist_update();
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
} else {
key->alg->freekey(key->data);
sfree(key->comment);
sfree(key);
fail_reason = "key already present";
goto failure;
}
}
break;
case SSH1_AGENTC_REMOVE_RSA_IDENTITY:
/*
* Remove from the list and return SSH_AGENT_SUCCESS, or
* perhaps SSH_AGENT_FAILURE if it wasn't in the list to
* start with.
*/
{
struct RSAKey reqkey, *key;
int n;
plog(logctx, logfn, "request: SSH1_AGENTC_REMOVE_RSA_IDENTITY");
n = makekey(p, msgend - p, &reqkey, NULL, 0);
if (n < 0) {
fail_reason = "request truncated before public key";
goto failure;
}
if (logfn) {
char fingerprint[128];
reqkey.comment = NULL;
rsa_fingerprint(fingerprint, sizeof(fingerprint), &reqkey);
plog(logctx, logfn, "unwanted key: %s", fingerprint);
}
key = find234(rsakeys, &reqkey, NULL);
freebn(reqkey.exponent);
freebn(reqkey.modulus);
PUT_32BIT(ret, 1);
if (key) {
plog(logctx, logfn, "found with comment: %s", key->comment);
del234(rsakeys, key);
keylist_update();
freersakey(key);
sfree(key);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
} else {
fail_reason = "key not found";
goto failure;
}
}
break;
case SSH2_AGENTC_REMOVE_IDENTITY:
/*
* Remove from the list and return SSH_AGENT_SUCCESS, or
* perhaps SSH_AGENT_FAILURE if it wasn't in the list to
* start with.
*/
{
struct ssh2_userkey *key;
struct blob b;
plog(logctx, logfn, "request: SSH2_AGENTC_REMOVE_IDENTITY");
if (msgend < p+4) {
fail_reason = "request truncated before public key";
goto failure;
}
b.len = toint(GET_32BIT(p));
p += 4;
if (b.len < 0 || b.len > msgend - p) {
fail_reason = "request truncated before public key";
goto failure;
}
b.blob = p;
p += b.len;
if (logfn) {
char *fingerprint = fingerprint_ssh2_blob(b.blob, b.len);
plog(logctx, logfn, "unwanted key: %s", fingerprint);
sfree(fingerprint);
}
key = find234(ssh2keys, &b, cmpkeys_ssh2_asymm);
if (!key) {
fail_reason = "key not found";
goto failure;
}
plog(logctx, logfn, "found with comment: %s", key->comment);
del234(ssh2keys, key);
keylist_update();
key->alg->freekey(key->data);
sfree(key);
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
}
break;
case SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
/*
* Remove all SSH-1 keys. Always returns success.
*/
{
struct RSAKey *rkey;
plog(logctx, logfn, "request:"
" SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES");
while ((rkey = index234(rsakeys, 0)) != NULL) {
del234(rsakeys, rkey);
freersakey(rkey);
sfree(rkey);
}
keylist_update();
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
}
break;
case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
/*
* Remove all SSH-2 keys. Always returns success.
*/
{
struct ssh2_userkey *skey;
plog(logctx, logfn, "request: SSH2_AGENTC_REMOVE_ALL_IDENTITIES");
while ((skey = index234(ssh2keys, 0)) != NULL) {
del234(ssh2keys, skey);
skey->alg->freekey(skey->data);
sfree(skey);
}
keylist_update();
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_SUCCESS;
plog(logctx, logfn, "reply: SSH_AGENT_SUCCESS");
}
break;
default:
plog(logctx, logfn, "request: unknown message type %d", type);
fail_reason = "unrecognised message";
/* fall through */
failure:
/*
* Unrecognised message. Return SSH_AGENT_FAILURE.
*/
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_FAILURE;
plog(logctx, logfn, "reply: SSH_AGENT_FAILURE (%s)", fail_reason);
break;
}
*outlen = 4 + GET_32BIT(ret);
return ret;
}
void *pageant_failure_msg(int *outlen)
{
unsigned char *ret = snewn(5, unsigned char);
PUT_32BIT(ret, 1);
ret[4] = SSH_AGENT_FAILURE;
*outlen = 5;
return ret;
}
void pageant_init(void)
{
rsakeys = newtree234(cmpkeys_rsa);
ssh2keys = newtree234(cmpkeys_ssh2);
}
struct RSAKey *pageant_nth_ssh1_key(int i)
{
return index234(rsakeys, i);
}
struct ssh2_userkey *pageant_nth_ssh2_key(int i)
{
return index234(ssh2keys, i);
}
int pageant_count_ssh1_keys(void)
{
return count234(rsakeys);
}
int pageant_count_ssh2_keys(void)
{
return count234(ssh2keys);
}
int pageant_add_ssh1_key(struct RSAKey *rkey)
{
return add234(rsakeys, rkey) != rkey;
}
int pageant_add_ssh2_key(struct ssh2_userkey *skey)
{
return add234(ssh2keys, skey) != skey;
}
int pageant_delete_ssh1_key(struct RSAKey *rkey)
{
struct RSAKey *deleted = del234(rsakeys, rkey);
if (!deleted)
return FALSE;
assert(deleted == rkey);
return TRUE;
}
int pageant_delete_ssh2_key(struct ssh2_userkey *skey)
{
struct ssh2_userkey *deleted = del234(ssh2keys, skey);
if (!deleted)
return FALSE;
assert(deleted == skey);
return TRUE;
}
/* ----------------------------------------------------------------------
* The agent plug.
*/
/*
* Coroutine macros similar to, but simplified from, those in ssh.c.
*/
#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
#define crFinish(z) } *crLine = 0; return (z); }
#define crGetChar(c) do \
{ \
while (len == 0) { \
*crLine =__LINE__; return 1; case __LINE__:; \
} \
len--; \
(c) = (unsigned char)*data++; \
} while (0)
struct pageant_conn_state {
const struct plug_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
Socket connsock;
void *logctx;
pageant_logfn_t logfn;
unsigned char lenbuf[4], pktbuf[AGENT_MAX_MSGLEN];
unsigned len, got;
int real_packet;
int crLine; /* for coroutine in pageant_conn_receive */
};
static int pageant_conn_closing(Plug plug, const char *error_msg,
int error_code, int calling_back)
{
struct pageant_conn_state *pc = (struct pageant_conn_state *)plug;
if (error_msg)
plog(pc->logctx, pc->logfn, "%p: error: %s", pc, error_msg);
else
plog(pc->logctx, pc->logfn, "%p: connection closed", pc);
sk_close(pc->connsock);
sfree(pc);
return 1;
}
static void pageant_conn_sent(Plug plug, int bufsize)
{
/* struct pageant_conn_state *pc = (struct pageant_conn_state *)plug; */
/*
* We do nothing here, because we expect that there won't be a
* need to throttle and unthrottle the connection to an agent -
* clients will typically not send many requests, and will wait
* until they receive each reply before sending a new request.
*/
}
static void pageant_conn_log(void *logctx, const char *fmt, va_list ap)
{
/* Wrapper on pc->logfn that prefixes the connection identifier */
struct pageant_conn_state *pc = (struct pageant_conn_state *)logctx;
char *formatted = dupvprintf(fmt, ap);
plog(pc->logctx, pc->logfn, "%p: %s", pc, formatted);
sfree(formatted);
}
static int pageant_conn_receive(Plug plug, int urgent, char *data, int len)
{
struct pageant_conn_state *pc = (struct pageant_conn_state *)plug;
char c;
crBegin(pc->crLine);
while (len > 0) {
pc->got = 0;
while (pc->got < 4) {
crGetChar(c);
pc->lenbuf[pc->got++] = c;
}
pc->len = GET_32BIT(pc->lenbuf);
pc->got = 0;
pc->real_packet = (pc->len < AGENT_MAX_MSGLEN-4);
while (pc->got < pc->len) {
crGetChar(c);
if (pc->real_packet)
pc->pktbuf[pc->got] = c;
pc->got++;
}
{
void *reply;
int replylen;
if (pc->real_packet) {
reply = pageant_handle_msg(pc->pktbuf, pc->len, &replylen, pc,
pc->logfn?pageant_conn_log:NULL);
} else {
plog(pc->logctx, pc->logfn, "%p: overlong message (%u)",
pc, pc->len);
plog(pc->logctx, pc->logfn, "%p: reply: SSH_AGENT_FAILURE "
"(message too long)", pc);
reply = pageant_failure_msg(&replylen);
}
sk_write(pc->connsock, reply, replylen);
smemclr(reply, replylen);
}
}
crFinish(1);
}
struct pageant_listen_state {
const struct plug_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
Socket listensock;
void *logctx;
pageant_logfn_t logfn;
};
static int pageant_listen_closing(Plug plug, const char *error_msg,
int error_code, int calling_back)
{
struct pageant_listen_state *pl = (struct pageant_listen_state *)plug;
if (error_msg)
plog(pl->logctx, pl->logfn, "listening socket: error: %s", error_msg);
sk_close(pl->listensock);
pl->listensock = NULL;
return 1;
}
static int pageant_listen_accepting(Plug plug,
accept_fn_t constructor, accept_ctx_t ctx)
{
static const struct plug_function_table connection_fn_table = {
NULL, /* no log function, because that's for outgoing connections */
pageant_conn_closing,
pageant_conn_receive,
pageant_conn_sent,
NULL /* no accepting function, because we've already done it */
};
struct pageant_listen_state *pl = (struct pageant_listen_state *)plug;
struct pageant_conn_state *pc;
const char *err;
pc = snew(struct pageant_conn_state);
pc->fn = &connection_fn_table;
pc->logfn = pl->logfn;
pc->logctx = pl->logctx;
pc->crLine = 0;
pc->connsock = constructor(ctx, (Plug) pc);
if ((err = sk_socket_error(pc->connsock)) != NULL) {
sk_close(pc->connsock);
sfree(pc);
return TRUE;
}
sk_set_frozen(pc->connsock, 0);
/* FIXME: can we get any useful peer id info? */
plog(pl->logctx, pl->logfn, "%p: new connection", pc);
return 0;
}
struct pageant_listen_state *pageant_listener_new(void *logctx,
pageant_logfn_t logfn)
{
static const struct plug_function_table listener_fn_table = {
NULL, /* no log function, because that's for outgoing connections */
pageant_listen_closing,
NULL, /* no receive function on a listening socket */
NULL, /* no sent function on a listening socket */
pageant_listen_accepting
};
struct pageant_listen_state *pl = snew(struct pageant_listen_state);
pl->fn = &listener_fn_table;
pl->logctx = logctx;
pl->logfn = logfn;
pl->listensock = NULL;
return pl;
}
void pageant_listener_got_socket(struct pageant_listen_state *pl, Socket sock)
{
pl->listensock = sock;
}
void pageant_listener_free(struct pageant_listen_state *pl)
{
if (pl->listensock)
sk_close(pl->listensock);
sfree(pl);
}
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