/*
* pageant.c: cross-platform code to implement Pageant.
*/
#include <stddef.h>
#include <stdlib.h>
#include <assert.h>
#include "putty.h"
#include "mpint.h"
#include "ssh.h"
#include "sshcr.h"
#include "pageant.h"
/*
* We need this to link with the RSA code, because rsa_ssh1_encrypt()
* pads its data with random bytes. Since we only use rsa_ssh1_decrypt()
* 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.
*/
void random_read(void *buf, size_t size)
{
modalfatalbox("Internal error: attempt to use random numbers in Pageant");
}
static bool pageant_local = false;
struct PageantClientDialogId {
int dummy;
};
typedef struct PageantKeySort PageantKeySort;
typedef struct PageantKey PageantKey;
typedef struct PageantAsyncOp PageantAsyncOp;
typedef struct PageantAsyncOpVtable PageantAsyncOpVtable;
typedef struct PageantClientRequestNode PageantClientRequestNode;
typedef struct PageantKeyRequestNode PageantKeyRequestNode;
struct PageantClientRequestNode {
PageantClientRequestNode *prev, *next;
};
struct PageantKeyRequestNode {
PageantKeyRequestNode *prev, *next;
};
struct PageantClientInfo {
PageantClient *pc; /* goes to NULL when client is unregistered */
PageantClientRequestNode head;
};
struct PageantAsyncOp {
const PageantAsyncOpVtable *vt;
PageantClientInfo *info;
PageantClientRequestNode cr;
PageantClientRequestId *reqid;
};
struct PageantAsyncOpVtable {
void (*coroutine)(PageantAsyncOp *pao);
void (*free)(PageantAsyncOp *pao);
};
static inline void pageant_async_op_coroutine(PageantAsyncOp *pao)
{ pao->vt->coroutine(pao); }
static inline void pageant_async_op_free(PageantAsyncOp *pao)
{
delete_callbacks_for_context(pao);
pao->vt->free(pao);
}
static inline void pageant_async_op_unlink(PageantAsyncOp *pao)
{
pao->cr.prev->next = pao->cr.next;
pao->cr.next->prev = pao->cr.prev;
}
static inline void pageant_async_op_unlink_and_free(PageantAsyncOp *pao)
{
pageant_async_op_unlink(pao);
pageant_async_op_free(pao);
}
static void pageant_async_op_callback(void *vctx)
{
pageant_async_op_coroutine((PageantAsyncOp *)vctx);
}
/*
* Master list of all the keys we have stored, in any form at all.
*/
static tree234 *keytree;
struct PageantKeySort {
/* Prefix of the main PageantKey structure which contains all the
* data that the sorting order depends on. Also simple enough that
* you can construct one for lookup purposes. */
int ssh_version; /* 1 or 2; primary sort key */
ptrlen public_blob; /* secondary sort key */
};
struct PageantKey {
PageantKeySort sort;
strbuf *public_blob; /* the true owner of sort.public_blob */
char *comment; /* stored separately, whether or not in rkey/skey */
union {
RSAKey *rkey; /* if ssh_version == 1 */
ssh2_userkey *skey; /* if ssh_version == 2 */
};
strbuf *encrypted_key_file;
bool decryption_prompt_active;
PageantKeyRequestNode blocked_requests;
PageantClientDialogId dlgid;
};
typedef struct PageantSignOp PageantSignOp;
struct PageantSignOp {
PageantKey *pk;
strbuf *data_to_sign;
unsigned flags;
int crLine;
unsigned char failure_type;
PageantKeyRequestNode pkr;
PageantAsyncOp pao;
};
/* Master lock that indicates whether a GUI request is currently in
* progress */
static bool gui_request_in_progress = false;
static void failure(PageantClient *pc, PageantClientRequestId *reqid,
strbuf *sb, unsigned char type, const char *fmt, ...);
static void fail_requests_for_key(PageantKey *pk, const char *reason);
static void pk_free(PageantKey *pk)
{
if (pk->public_blob) strbuf_free(pk->public_blob);
sfree(pk->comment);
if (pk->sort.ssh_version == 1 && pk->rkey) {
freersakey(pk->rkey);
sfree(pk->rkey);
}
if (pk->sort.ssh_version == 2 && pk->skey) {
sfree(pk->skey->comment);
ssh_key_free(pk->skey->key);
sfree(pk->skey);
}
if (pk->encrypted_key_file) strbuf_free(pk->encrypted_key_file);
fail_requests_for_key(pk, "key deleted from Pageant while signing "
"request was pending");
sfree(pk);
}
static int cmpkeys(void *av, void *bv)
{
PageantKeySort *a = (PageantKeySort *)av, *b = (PageantKeySort *)bv;
if (a->ssh_version != b->ssh_version)
return a->ssh_version < b->ssh_version ? -1 : +1;
else
return ptrlen_strcmp(a->public_blob, b->public_blob);
}
static inline PageantKeySort keysort(int version, ptrlen blob)
{
PageantKeySort sort;
sort.ssh_version = version;
sort.public_blob = blob;
return sort;
}
static strbuf *makeblob1(RSAKey *rkey)
{
strbuf *blob = strbuf_new();
rsa_ssh1_public_blob(BinarySink_UPCAST(blob), rkey,
RSA_SSH1_EXPONENT_FIRST);
return blob;
}
static strbuf *makeblob2(ssh2_userkey *skey)
{
strbuf *blob = strbuf_new();
ssh_key_public_blob(skey->key, BinarySink_UPCAST(blob));
return blob;
}
static PageantKey *findkey1(RSAKey *reqkey)
{
strbuf *blob = makeblob1(reqkey);
PageantKeySort sort = keysort(1, ptrlen_from_strbuf(blob));
PageantKey *toret = find234(keytree, &sort, NULL);
strbuf_free(blob);
return toret;
}
static PageantKey *findkey2(ptrlen blob)
{
PageantKeySort sort = keysort(2, blob);
return find234(keytree, &sort, NULL);
}
static int find_first_key_for_version(int ssh_version)
{
PageantKeySort sort = keysort(ssh_version, PTRLEN_LITERAL(""));
int pos;
if (findrelpos234(keytree, &sort, NULL, REL234_GE, &pos))
return pos;
return count234(keytree);
}
static int count_keys(int ssh_version)
{
return (find_first_key_for_version(ssh_version + 1) -
find_first_key_for_version(ssh_version));
}
int pageant_count_ssh1_keys(void) { return count_keys(1); }
int pageant_count_ssh2_keys(void) { return count_keys(2); }
bool pageant_add_ssh1_key(RSAKey *rkey)
{
PageantKey *pk = snew(PageantKey);
memset(pk, 0, sizeof(PageantKey));
pk->sort.ssh_version = 1;
pk->public_blob = makeblob1(rkey);
pk->sort.public_blob = ptrlen_from_strbuf(pk->public_blob);
pk->blocked_requests.next = pk->blocked_requests.prev =
&pk->blocked_requests;
if (add234(keytree, pk) == pk) {
pk->rkey = rkey;
if (rkey->comment)
pk->comment = dupstr(rkey->comment);
return true;
} else {
pk_free(pk);
return false;
}
}
bool pageant_add_ssh2_key(ssh2_userkey *skey)
{
PageantKey *pk = snew(PageantKey);
memset(pk, 0, sizeof(PageantKey));
pk->sort.ssh_version = 2;
pk->public_blob = makeblob2(skey);
pk->sort.public_blob = ptrlen_from_strbuf(pk->public_blob);
pk->blocked_requests.next = pk->blocked_requests.prev =
&pk->blocked_requests;
if (add234(keytree, pk) == pk) {
pk->skey = skey;
if (skey->comment)
pk->comment = dupstr(skey->comment);
return true;
} else {
pk_free(pk);
return false;
}
}
static void remove_all_keys(int ssh_version)
{
int start = find_first_key_for_version(ssh_version);
int end = find_first_key_for_version(ssh_version + 1);
while (end > start) {
PageantKey *pk = delpos234(keytree, --end);
assert(pk->sort.ssh_version == ssh_version);
pk_free(pk);
}
}
static void list_keys(BinarySink *bs, int ssh_version)
{
int i;
PageantKey *pk;
put_uint32(bs, count_keys(ssh_version));
for (i = find_first_key_for_version(ssh_version);
NULL != (pk = index234(keytree, i)); i++) {
if (pk->sort.ssh_version != ssh_version)
break;
if (ssh_version > 1)
put_stringpl(bs, pk->sort.public_blob);
else
put_datapl(bs, pk->sort.public_blob); /* no header */
put_stringpl(bs, ptrlen_from_asciz(pk->comment));
}
}
void pageant_make_keylist1(BinarySink *bs) { list_keys(bs, 1); }
void pageant_make_keylist2(BinarySink *bs) { list_keys(bs, 2); }
void pageant_register_client(PageantClient *pc)
{
pc->info = snew(PageantClientInfo);
pc->info->pc = pc;
pc->info->head.prev = pc->info->head.next = &pc->info->head;
}
void pageant_unregister_client(PageantClient *pc)
{
PageantClientInfo *info = pc->info;
assert(info);
assert(info->pc == pc);
while (pc->info->head.next != &pc->info->head) {
PageantAsyncOp *pao = container_of(pc->info->head.next,
PageantAsyncOp, cr);
pageant_async_op_unlink_and_free(pao);
}
sfree(pc->info);
}
static PRINTF_LIKE(5, 6) void failure(
PageantClient *pc, PageantClientRequestId *reqid, strbuf *sb,
unsigned char type, const char *fmt, ...)
{
strbuf_clear(sb);
put_byte(sb, type);
if (!pc->suppress_logging) {
va_list ap;
va_start(ap, fmt);
char *msg = dupvprintf(fmt, ap);
va_end(ap);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_FAILURE (%s)", msg);
sfree(msg);
}
}
static void signop_link(PageantSignOp *so)
{
assert(!so->pkr.prev);
assert(!so->pkr.next);
so->pkr.prev = so->pk->blocked_requests.prev;
so->pkr.next = &so->pk->blocked_requests;
so->pkr.prev->next = &so->pkr;
so->pkr.next->prev = &so->pkr;
}
static void signop_unlink(PageantSignOp *so)
{
if (so->pkr.next) {
assert(so->pkr.prev);
so->pkr.next->prev = so->pkr.prev;
so->pkr.prev->next = so->pkr.next;
} else {
assert(!so->pkr.prev);
}
}
static void signop_free(PageantAsyncOp *pao)
{
PageantSignOp *so = container_of(pao, PageantSignOp, pao);
strbuf_free(so->data_to_sign);
sfree(so);
}
static bool request_passphrase(PageantClient *pc, PageantKey *pk)
{
if (!pk->decryption_prompt_active) {
assert(!gui_request_in_progress);
strbuf *sb = strbuf_new();
strbuf_catf(sb, "Enter passphrase to decrypt key '%s'", pk->comment);
bool created_dlg = pageant_client_ask_passphrase(
pc, &pk->dlgid, sb->s);
strbuf_free(sb);
if (!created_dlg)
return false;
gui_request_in_progress = true;
pk->decryption_prompt_active = true;
}
return true;
}
static void signop_coroutine(PageantAsyncOp *pao)
{
PageantSignOp *so = container_of(pao, PageantSignOp, pao);
strbuf *response;
crBegin(so->crLine);
while (!so->pk->skey && gui_request_in_progress)
crReturnV;
if (!so->pk->skey) {
assert(so->pk->encrypted_key_file);
if (!request_passphrase(so->pao.info->pc, so->pk)) {
response = strbuf_new();
failure(so->pao.info->pc, so->pao.reqid, response,
so->failure_type, "on-demand decryption could not "
"prompt for a passphrase");
goto respond;
}
signop_link(so);
crReturnV;
signop_unlink(so);
}
uint32_t supported_flags = ssh_key_alg(so->pk->skey->key)->supported_flags;
if (so->flags & ~supported_flags) {
/*
* We MUST reject any message containing flags we don't
* understand.
*/
response = strbuf_new();
failure(so->pao.info->pc, so->pao.reqid, response, so->failure_type,
"unsupported flag bits 0x%08"PRIx32,
so->flags & ~supported_flags);
goto respond;
}
char *invalid = ssh_key_invalid(so->pk->skey->key, so->flags);
if (invalid) {
response = strbuf_new();
failure(so->pao.info->pc, so->pao.reqid, response, so->failure_type,
"key invalid: %s", invalid);
sfree(invalid);
goto respond;
}
strbuf *signature = strbuf_new();
ssh_key_sign(so->pk->skey->key, ptrlen_from_strbuf(so->data_to_sign),
so->flags, BinarySink_UPCAST(signature));
response = strbuf_new();
put_byte(response, SSH2_AGENT_SIGN_RESPONSE);
put_stringsb(response, signature);
respond:
pageant_client_got_response(so->pao.info->pc, so->pao.reqid,
ptrlen_from_strbuf(response));
strbuf_free(response);
pageant_async_op_unlink_and_free(&so->pao);
crFinishFreedV;
}
static struct PageantAsyncOpVtable signop_vtable = {
signop_coroutine,
signop_free,
};
static void fail_requests_for_key(PageantKey *pk, const char *reason)
{
while (pk->blocked_requests.next != &pk->blocked_requests) {
PageantSignOp *so = container_of(pk->blocked_requests.next,
PageantSignOp, pkr);
signop_unlink(so);
strbuf *sb = strbuf_new();
failure(so->pao.info->pc, so->pao.reqid, sb, so->failure_type,
"%s", reason);
pageant_client_got_response(so->pao.info->pc, so->pao.reqid,
ptrlen_from_strbuf(sb));
strbuf_free(sb);
pageant_async_op_unlink_and_free(&so->pao);
}
}
static void unblock_requests_for_key(PageantKey *pk)
{
for (PageantKeyRequestNode *pkr = pk->blocked_requests.next;
pkr != &pk->blocked_requests; pkr = pkr->next) {
PageantSignOp *so = container_of(pk->blocked_requests.next,
PageantSignOp, pkr);
queue_toplevel_callback(pageant_async_op_callback, &so->pao);
}
}
void pageant_passphrase_request_success(PageantClientDialogId *dlgid,
ptrlen passphrase)
{
PageantKey *pk = container_of(dlgid, PageantKey, dlgid);
assert(gui_request_in_progress);
gui_request_in_progress = false;
pk->decryption_prompt_active = false;
if (!pk->skey) {
const char *error;
BinarySource src[1];
BinarySource_BARE_INIT_PL(src, ptrlen_from_strbuf(
pk->encrypted_key_file));
strbuf *ppsb = strbuf_new_nm();
put_datapl(ppsb, passphrase);
pk->skey = ppk_load_s(src, ppsb->s, &error);
strbuf_free(ppsb);
if (!pk->skey) {
fail_requests_for_key(pk, "unable to decrypt key");
return;
} else if (pk->skey == SSH2_WRONG_PASSPHRASE) {
pk->skey = NULL;
/*
* Find a PageantClient to use for another attempt at
* request_passphrase.
*/
PageantKeyRequestNode *pkr = pk->blocked_requests.next;
if (pkr == &pk->blocked_requests) {
/*
* Special case: if all the requests have gone away at
* this point, we need not bother putting up a request
* at all any more.
*/
return;
}
PageantSignOp *so = container_of(pk->blocked_requests.next,
PageantSignOp, pkr);
pk->decryption_prompt_active = false;
if (!request_passphrase(so->pao.info->pc, pk)) {
fail_requests_for_key(pk, "unable to continue creating "
"passphrase prompts");
}
return;
}
}
unblock_requests_for_key(pk);
}
void pageant_passphrase_request_refused(PageantClientDialogId *dlgid)
{
PageantKey *pk = container_of(dlgid, PageantKey, dlgid);
assert(gui_request_in_progress);
gui_request_in_progress = false;
pk->decryption_prompt_active = false;
fail_requests_for_key(pk, "user refused to supply passphrase");
}
typedef struct PageantImmOp PageantImmOp;
struct PageantImmOp {
int crLine;
strbuf *response;
PageantAsyncOp pao;
};
static void immop_free(PageantAsyncOp *pao)
{
PageantImmOp *io = container_of(pao, PageantImmOp, pao);
if (io->response)
strbuf_free(io->response);
sfree(io);
}
static void immop_coroutine(PageantAsyncOp *pao)
{
PageantImmOp *io = container_of(pao, PageantImmOp, pao);
crBegin(io->crLine);
if (0) crReturnV;
pageant_client_got_response(io->pao.info->pc, io->pao.reqid,
ptrlen_from_strbuf(io->response));
pageant_async_op_unlink_and_free(&io->pao);
crFinishFreedV;
}
static struct PageantAsyncOpVtable immop_vtable = {
immop_coroutine,
immop_free,
};
static bool reencrypt_key(PageantKey *pk)
{
if (pk->sort.ssh_version != 2) {
/*
* We don't support storing SSH-1 keys in encrypted form at
* all.
*/
return false;
}
if (!pk->encrypted_key_file) {
/*
* We can't re-encrypt a key if it doesn't have an encrypted
* form. (We could make one up, of course - but with what
* passphrase that we could expect the user to know later?)
*/
return false;
}
/* Only actually free pk->skey if it exists. But we return success
* regardless, so that 'please ensure this key isn't stored
* decrypted' is idempotent. */
if (pk->skey) {
sfree(pk->skey->comment);
ssh_key_free(pk->skey->key);
sfree(pk->skey);
pk->skey = NULL;
}
return true;
}
#define PUTTYEXT(base) base "@putty.projects.tartarus.org"
#define KNOWN_EXTENSIONS(X) \
X(EXT_QUERY, "query") \
X(EXT_ADD_PPK, PUTTYEXT("add-ppk")) \
X(EXT_REENCRYPT, PUTTYEXT("reencrypt")) \
X(EXT_REENCRYPT_ALL, PUTTYEXT("reencrypt-all")) \
/* end of list */
#define DECL_EXT_ENUM(id, name) id,
enum Extension { KNOWN_EXTENSIONS(DECL_EXT_ENUM) EXT_UNKNOWN };
#define DEF_EXT_NAMES(id, name) PTRLEN_DECL_LITERAL(name),
static const ptrlen extension_names[] = { KNOWN_EXTENSIONS(DEF_EXT_NAMES) };
static PageantAsyncOp *pageant_make_op(
PageantClient *pc, PageantClientRequestId *reqid, ptrlen msgpl)
{
BinarySource msg[1];
strbuf *sb = strbuf_new_nm();
unsigned char failure_type = SSH_AGENT_FAILURE;
int type;
#define fail(...) failure(pc, reqid, sb, failure_type, __VA_ARGS__)
BinarySource_BARE_INIT_PL(msg, msgpl);
type = get_byte(msg);
if (get_err(msg)) {
fail("message contained no type code");
goto responded;
}
switch (type) {
case SSH1_AGENTC_REQUEST_RSA_IDENTITIES: {
/*
* Reply with SSH1_AGENT_RSA_IDENTITIES_ANSWER.
*/
pageant_client_log(pc, reqid,
"request: SSH1_AGENTC_REQUEST_RSA_IDENTITIES");
put_byte(sb, SSH1_AGENT_RSA_IDENTITIES_ANSWER);
pageant_make_keylist1(BinarySink_UPCAST(sb));
pageant_client_log(pc, reqid,
"reply: SSH1_AGENT_RSA_IDENTITIES_ANSWER");
if (!pc->suppress_logging) {
int i;
RSAKey *rkey;
for (i = 0; NULL != (rkey = pageant_nth_ssh1_key(i)); i++) {
char *fingerprint = rsa_ssh1_fingerprint(rkey);
pageant_client_log(pc, reqid, "returned key: %s",
fingerprint);
sfree(fingerprint);
}
}
break;
}
case SSH2_AGENTC_REQUEST_IDENTITIES: {
/*
* Reply with SSH2_AGENT_IDENTITIES_ANSWER.
*/
pageant_client_log(pc, reqid,
"request: SSH2_AGENTC_REQUEST_IDENTITIES");
put_byte(sb, SSH2_AGENT_IDENTITIES_ANSWER);
pageant_make_keylist2(BinarySink_UPCAST(sb));
pageant_client_log(pc, reqid,
"reply: SSH2_AGENT_IDENTITIES_ANSWER");
if (!pc->suppress_logging) {
int i;
ssh2_userkey *skey;
for (i = 0; NULL != (skey = pageant_nth_ssh2_key(i)); i++) {
char *fingerprint = ssh2_fingerprint(skey->key);
pageant_client_log(pc, reqid, "returned key: %s %s",
fingerprint, skey->comment);
sfree(fingerprint);
}
}
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.
*/
RSAKey reqkey;
PageantKey *pk;
mp_int *challenge, *response;
ptrlen session_id;
unsigned response_type;
unsigned char response_md5[16];
int i;
pageant_client_log(pc, reqid,
"request: SSH1_AGENTC_RSA_CHALLENGE");
response = NULL;
memset(&reqkey, 0, sizeof(reqkey));
get_rsa_ssh1_pub(msg, &reqkey, RSA_SSH1_EXPONENT_FIRST);
challenge = get_mp_ssh1(msg);
session_id = get_data(msg, 16);
response_type = get_uint32(msg);
if (get_err(msg)) {
fail("unable to decode request");
goto challenge1_cleanup;
}
if (response_type != 1) {
fail("response type other than 1 not supported");
goto challenge1_cleanup;
}
if (!pc->suppress_logging) {
char *fingerprint;
reqkey.comment = NULL;
fingerprint = rsa_ssh1_fingerprint(&reqkey);
pageant_client_log(pc, reqid, "requested key: %s",
fingerprint);
sfree(fingerprint);
}
if ((pk = findkey1(&reqkey)) == NULL) {
fail("key not found");
goto challenge1_cleanup;
}
response = rsa_ssh1_decrypt(challenge, pk->rkey);
{
ssh_hash *h = ssh_hash_new(&ssh_md5);
for (i = 0; i < 32; i++)
put_byte(h, mp_get_byte(response, 31 - i));
put_datapl(h, session_id);
ssh_hash_final(h, response_md5);
}
put_byte(sb, SSH1_AGENT_RSA_RESPONSE);
put_data(sb, response_md5, 16);
pageant_client_log(pc, reqid, "reply: SSH1_AGENT_RSA_RESPONSE");
challenge1_cleanup:
if (response)
mp_free(response);
mp_free(challenge);
freersakey(&reqkey);
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.
*/
PageantKey *pk;
ptrlen keyblob, sigdata;
uint32_t flags;
pageant_client_log(pc, reqid, "request: SSH2_AGENTC_SIGN_REQUEST");
keyblob = get_string(msg);
sigdata = get_string(msg);
if (get_err(msg)) {
fail("unable to decode request");
goto responded;
}
/*
* Later versions of the agent protocol added a flags word
* on the end of the sign request. That hasn't always been
* there, so we don't complain if we don't find it.
*
* get_uint32 will default to returning zero if no data is
* available.
*/
bool have_flags = false;
flags = get_uint32(msg);
if (!get_err(msg))
have_flags = true;
if (!pc->suppress_logging) {
char *fingerprint = ssh2_fingerprint_blob(keyblob);
pageant_client_log(pc, reqid, "requested key: %s",
fingerprint);
sfree(fingerprint);
}
if ((pk = findkey2(keyblob)) == NULL) {
fail("key not found");
goto responded;
}
if (have_flags)
pageant_client_log(pc, reqid, "signature flags = 0x%08"PRIx32,
flags);
else
pageant_client_log(pc, reqid, "no signature flags");
strbuf_free(sb); /* no immediate response */
PageantSignOp *so = snew(PageantSignOp);
so->pao.vt = &signop_vtable;
so->pao.info = pc->info;
so->pao.cr.prev = pc->info->head.prev;
so->pao.cr.next = &pc->info->head;
so->pao.reqid = reqid;
so->pk = pk;
so->pkr.prev = so->pkr.next = NULL;
so->data_to_sign = strbuf_new();
put_datapl(so->data_to_sign, sigdata);
so->flags = flags;
so->failure_type = failure_type;
so->crLine = 0;
return &so->pao;
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.
*/
RSAKey *key;
pageant_client_log(pc, reqid,
"request: SSH1_AGENTC_ADD_RSA_IDENTITY");
key = get_rsa_ssh1_priv_agent(msg);
key->comment = mkstr(get_string(msg));
if (get_err(msg)) {
fail("unable to decode request");
goto add1_cleanup;
}
if (!rsa_verify(key)) {
fail("key is invalid");
goto add1_cleanup;
}
if (!pc->suppress_logging) {
char *fingerprint = rsa_ssh1_fingerprint(key);
pageant_client_log(pc, reqid,
"submitted key: %s", fingerprint);
sfree(fingerprint);
}
if (pageant_add_ssh1_key(key)) {
keylist_update();
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
key = NULL; /* don't free it in cleanup */
} else {
fail("key already present");
}
add1_cleanup:
if (key) {
freersakey(key);
sfree(key);
}
break;
}
case SSH2_AGENTC_ADD_IDENTITY: {
/*
* Add to the list and return SSH_AGENT_SUCCESS, or
* SSH_AGENT_FAILURE if the key was malformed.
*/
ssh2_userkey *key = NULL;
ptrlen algpl;
const ssh_keyalg *alg;
pageant_client_log(pc, reqid, "request: SSH2_AGENTC_ADD_IDENTITY");
algpl = get_string(msg);
key = snew(ssh2_userkey);
key->key = NULL;
key->comment = NULL;
alg = find_pubkey_alg_len(algpl);
if (!alg) {
fail("algorithm unknown");
goto add2_cleanup;
}
key->key = ssh_key_new_priv_openssh(alg, msg);
if (!key->key) {
fail("key setup failed");
goto add2_cleanup;
}
key->comment = mkstr(get_string(msg));
if (get_err(msg)) {
fail("unable to decode request");
goto add2_cleanup;
}
if (!pc->suppress_logging) {
char *fingerprint = ssh2_fingerprint(key->key);
pageant_client_log(pc, reqid, "submitted key: %s %s",
fingerprint, key->comment);
sfree(fingerprint);
}
if (pageant_add_ssh2_key(key)) {
keylist_update();
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
key = NULL; /* don't clean it up */
} else {
fail("key already present");
}
add2_cleanup:
if (key) {
if (key->key)
ssh_key_free(key->key);
if (key->comment)
sfree(key->comment);
sfree(key);
}
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.
*/
RSAKey reqkey;
PageantKey *pk;
pageant_client_log(pc, reqid,
"request: SSH1_AGENTC_REMOVE_RSA_IDENTITY");
memset(&reqkey, 0, sizeof(reqkey));
get_rsa_ssh1_pub(msg, &reqkey, RSA_SSH1_EXPONENT_FIRST);
if (get_err(msg)) {
fail("unable to decode request");
freersakey(&reqkey);
goto responded;
}
if (!pc->suppress_logging) {
char *fingerprint;
reqkey.comment = NULL;
fingerprint = rsa_ssh1_fingerprint(&reqkey);
pageant_client_log(pc, reqid, "unwanted key: %s", fingerprint);
sfree(fingerprint);
}
pk = findkey1(&reqkey);
freersakey(&reqkey);
if (pk) {
pageant_client_log(pc, reqid, "found with comment: %s",
pk->rkey->comment);
del234(keytree, pk);
keylist_update();
pk_free(pk);
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
} else {
fail("key not found");
}
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.
*/
PageantKey *pk;
ptrlen blob;
pageant_client_log(pc, reqid,
"request: SSH2_AGENTC_REMOVE_IDENTITY");
blob = get_string(msg);
if (get_err(msg)) {
fail("unable to decode request");
goto responded;
}
if (!pc->suppress_logging) {
char *fingerprint = ssh2_fingerprint_blob(blob);
pageant_client_log(pc, reqid, "unwanted key: %s", fingerprint);
sfree(fingerprint);
}
pk = findkey2(blob);
if (!pk) {
fail("key not found");
goto responded;
}
pageant_client_log(pc, reqid,
"found with comment: %s", pk->comment);
del234(keytree, pk);
keylist_update();
pk_free(pk);
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
break;
}
case SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES: {
/*
* Remove all SSH-1 keys. Always returns success.
*/
pageant_client_log(pc, reqid, "request:"
" SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES");
remove_all_keys(1);
keylist_update();
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
break;
}
case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: {
/*
* Remove all SSH-2 keys. Always returns success.
*/
pageant_client_log(pc, reqid,
"request: SSH2_AGENTC_REMOVE_ALL_IDENTITIES");
remove_all_keys(2);
keylist_update();
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
break;
}
case SSH2_AGENTC_EXTENSION: {
enum Extension exttype = EXT_UNKNOWN;
ptrlen extname = get_string(msg);
pageant_client_log(pc, reqid,
"request: SSH2_AGENTC_EXTENSION \"%.*s\"",
PTRLEN_PRINTF(extname));
for (size_t i = 0; i < lenof(extension_names); i++)
if (ptrlen_eq_ptrlen(extname, extension_names[i])) {
exttype = i;
/*
* For SSH_AGENTC_EXTENSION requests, the message
* code SSH_AGENT_FAILURE is reserved for "I don't
* recognise this extension name at all". For any
* other kind of failure while processing an
* extension we _do_ recognise, we must switch to
* returning a different failure code, with
* semantics "I understood the extension name, but
* something else went wrong".
*/
failure_type = SSH_AGENT_EXTENSION_FAILURE;
break;
}
switch (exttype) {
case EXT_UNKNOWN:
fail("unrecognised extension name '%.*s'",
PTRLEN_PRINTF(extname));
break;
case EXT_QUERY:
/* Standard request to list the supported extensions. */
put_byte(sb, SSH_AGENT_SUCCESS);
for (size_t i = 0; i < lenof(extension_names); i++)
put_stringpl(sb, extension_names[i]);
pageant_client_log(pc, reqid,
"reply: SSH_AGENT_SUCCESS + names");
break;
case EXT_ADD_PPK: {
ptrlen keyfile = get_string(msg);
if (get_err(msg)) {
fail("unable to decode request");
goto responded;
}
BinarySource src[1];
const char *error;
strbuf *public_blob = strbuf_new();
char *comment;
BinarySource_BARE_INIT_PL(src, keyfile);
if (!ppk_loadpub_s(src, NULL,
BinarySink_UPCAST(public_blob),
&comment, &error)) {
fail("failed to extract public key blob: %s", error);
goto add_ppk_cleanup;
}
if (!pc->suppress_logging) {
char *fingerprint = ssh2_fingerprint_blob(
ptrlen_from_strbuf(public_blob));
pageant_client_log(pc, reqid, "add-ppk: %s %s",
fingerprint, comment);
sfree(fingerprint);
}
BinarySource_BARE_INIT_PL(src, keyfile);
bool encrypted = ppk_encrypted_s(src, NULL);
if (!encrypted) {
/* If the key isn't encrypted, then we should just
* load and add it in the obvious way. */
BinarySource_BARE_INIT_PL(src, keyfile);
ssh2_userkey *skey = ppk_load_s(src, NULL, &error);
if (!skey) {
fail("failed to decode private key: %s", error);
} else if (pageant_add_ssh2_key(skey)) {
keylist_update();
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid,
"reply: SSH_AGENT_SUCCESS"
" (loaded unencrypted PPK)");
} else {
fail("key already present");
if (skey->key)
ssh_key_free(skey->key);
if (skey->comment)
sfree(skey->comment);
sfree(skey);
}
goto add_ppk_cleanup;
}
PageantKeySort sort =
keysort(2, ptrlen_from_strbuf(public_blob));
PageantKey *pk = find234(keytree, &sort, NULL);
if (pk) {
/*
* This public key blob already exists in the
* keytree. Add the encrypted key file to the
* existing record, if it doesn't have one already.
*/
if (!pk->encrypted_key_file) {
pk->encrypted_key_file = strbuf_new_nm();
put_datapl(pk->encrypted_key_file, keyfile);
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid,
"reply: SSH_AGENT_SUCCESS (added"
" encrypted PPK to existing key"
" record)");
} else {
fail("key already present");
}
} else {
/*
* We're adding a new key record containing only
* an encrypted key file.
*/
PageantKey *pk = snew(PageantKey);
memset(pk, 0, sizeof(PageantKey));
pk->blocked_requests.next = pk->blocked_requests.prev =
&pk->blocked_requests;
pk->sort.ssh_version = 2;
pk->public_blob = public_blob;
public_blob = NULL;
pk->sort.public_blob = ptrlen_from_strbuf(pk->public_blob);
pk->comment = dupstr(comment);
pk->encrypted_key_file = strbuf_new_nm();
put_datapl(pk->encrypted_key_file, keyfile);
PageantKey *added = add234(keytree, pk);
assert(added == pk); (void)added;
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS"
" (made new encrypted-only key"
" record)");
}
add_ppk_cleanup:
if (public_blob)
strbuf_free(public_blob);
sfree(comment);
break;
}
case EXT_REENCRYPT: {
/*
* Re-encrypt a single key, in the sense of deleting
* its unencrypted copy, returning it to the state of
* only having the encrypted PPK form stored, so that
* the next attempt to use it will have to re-prompt
* for the passphrase.
*/
ptrlen blob = get_string(msg);
if (get_err(msg)) {
fail("unable to decode request");
goto responded;
}
if (!pc->suppress_logging) {
char *fingerprint = ssh2_fingerprint_blob(blob);
pageant_client_log(pc, reqid, "key to re-encrypt: %s",
fingerprint);
sfree(fingerprint);
}
PageantKey *pk = findkey2(blob);
if (!pk) {
fail("key not found");
goto responded;
}
pageant_client_log(pc, reqid,
"found with comment: %s", pk->comment);
if (!reencrypt_key(pk)) {
fail("this key couldn't be re-encrypted");
goto responded;
}
put_byte(sb, SSH_AGENT_SUCCESS);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS");
break;
}
case EXT_REENCRYPT_ALL: {
/*
* Re-encrypt all keys that have an encrypted form
* stored. Usually, returns success, but with a uint32
* appended indicating how many keys remain
* unencrypted. The exception is if there is at least
* one key in the agent and _no_ key was successfully
* re-encrypted; in that situation we've done nothing,
* and the client didn't _want_ us to do nothing, so
* we return failure.
*
* (Rationale: the 'failure' message ought to be
* atomic, that is, you shouldn't return failure
* having made a state change.)
*/
unsigned nfailures = 0, nsuccesses = 0;
PageantKey *pk;
for (int i = 0; (pk = index234(keytree, i)) != NULL; i++) {
if (reencrypt_key(pk))
nsuccesses++;
else
nfailures++;
}
if (nsuccesses == 0 && nfailures > 0) {
fail("no key could be re-encrypted");
} else {
put_byte(sb, SSH_AGENT_SUCCESS);
put_uint32(sb, nfailures);
pageant_client_log(pc, reqid, "reply: SSH_AGENT_SUCCESS "
"(%u keys re-encrypted, %u failures)",
nsuccesses, nfailures);
}
break;
}
}
break;
}
default:
pageant_client_log(pc, reqid, "request: unknown message type %d",
type);
fail("unrecognised message");
break;
}
#undef fail
responded:;
PageantImmOp *io = snew(PageantImmOp);
io->pao.vt = &immop_vtable;
io->pao.info = pc->info;
io->pao.cr.prev = pc->info->head.prev;
io->pao.cr.next = &pc->info->head;
io->pao.reqid = reqid;
io->response = sb;
io->crLine = 0;
return &io->pao;
}
void pageant_handle_msg(PageantClient *pc, PageantClientRequestId *reqid,
ptrlen msgpl)
{
PageantAsyncOp *pao = pageant_make_op(pc, reqid, msgpl);
queue_toplevel_callback(pageant_async_op_callback, pao);
}
void pageant_init(void)
{
pageant_local = true;
keytree = newtree234(cmpkeys);
}
RSAKey *pageant_nth_ssh1_key(int i)
{
PageantKey *pk = index234(keytree, find_first_key_for_version(1) + i);
if (pk && pk->sort.ssh_version == 1)
return pk->rkey;
else
return NULL;
}
ssh2_userkey *pageant_nth_ssh2_key(int i)
{
PageantKey *pk = index234(keytree, find_first_key_for_version(2) + i);
if (pk && pk->sort.ssh_version == 2)
return pk->skey;
else
return NULL;
}
bool pageant_delete_ssh1_key(RSAKey *rkey)
{
strbuf *blob = makeblob1(rkey);
PageantKeySort sort = keysort(1, ptrlen_from_strbuf(blob));
PageantKey *deleted = del234(keytree, &sort);
strbuf_free(blob);
if (!deleted)
return false;
assert(deleted->sort.ssh_version == 1);
assert(deleted->rkey == rkey);
return true;
}
bool pageant_delete_ssh2_key(ssh2_userkey *skey)
{
strbuf *blob = makeblob2(skey);
PageantKeySort sort = keysort(2, ptrlen_from_strbuf(blob));
PageantKey *deleted = del234(keytree, &sort);
strbuf_free(blob);
if (!deleted)
return false;
assert(deleted->sort.ssh_version == 2);
assert(deleted->skey == skey);
return true;
}
/* ----------------------------------------------------------------------
* The agent plug.
*/
/*
* An extra coroutine macro, specific to this code which is consuming
* 'const char *data'.
*/
#define crGetChar(c) do \
{ \
while (len == 0) { \
*crLine =__LINE__; return; case __LINE__:; \
} \
len--; \
(c) = (unsigned char)*data++; \
} while (0)
struct pageant_conn_queued_response {
struct pageant_conn_queued_response *next, *prev;
size_t req_index; /* for indexing requests in log messages */
strbuf *sb;
PageantClientRequestId reqid;
};
struct pageant_conn_state {
Socket *connsock;
PageantListenerClient *plc;
unsigned char lenbuf[4], pktbuf[AGENT_MAX_MSGLEN];
unsigned len, got;
bool real_packet;
size_t conn_index; /* for indexing connections in log messages */
size_t req_index; /* for indexing requests in log messages */
int crLine; /* for coroutine in pageant_conn_receive */
struct pageant_conn_queued_response response_queue;
PageantClient pc;
Plug plug;
};
static void pageant_conn_closing(Plug *plug, const char *error_msg,
int error_code, bool calling_back)
{
struct pageant_conn_state *pc = container_of(
plug, struct pageant_conn_state, plug);
if (error_msg)
pageant_listener_client_log(pc->plc, "c#%"SIZEu": error: %s",
pc->conn_index, error_msg);
else
pageant_listener_client_log(pc->plc, "c#%"SIZEu": connection closed",
pc->conn_index);
sk_close(pc->connsock);
pageant_unregister_client(&pc->pc);
sfree(pc);
}
static void pageant_conn_sent(Plug *plug, size_t bufsize)
{
/* struct pageant_conn_state *pc = container_of(
plug, 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(PageantClient *pc, PageantClientRequestId *reqid,
const char *fmt, va_list ap)
{
struct pageant_conn_state *pcs =
container_of(pc, struct pageant_conn_state, pc);
struct pageant_conn_queued_response *qr =
container_of(reqid, struct pageant_conn_queued_response, reqid);
char *formatted = dupvprintf(fmt, ap);
pageant_listener_client_log(pcs->plc, "c#%"SIZEu",r#%"SIZEu": %s",
pcs->conn_index, qr->req_index, formatted);
sfree(formatted);
}
static void pageant_conn_got_response(
PageantClient *pc, PageantClientRequestId *reqid, ptrlen response)
{
struct pageant_conn_state *pcs =
container_of(pc, struct pageant_conn_state, pc);
struct pageant_conn_queued_response *qr =
container_of(reqid, struct pageant_conn_queued_response, reqid);
qr->sb = strbuf_new_nm();
put_stringpl(qr->sb, response);
while (pcs->response_queue.next != &pcs->response_queue &&
pcs->response_queue.next->sb) {
qr = pcs->response_queue.next;
sk_write(pcs->connsock, qr->sb->u, qr->sb->len);
qr->next->prev = qr->prev;
qr->prev->next = qr->next;
strbuf_free(qr->sb);
sfree(qr);
}
}
static bool pageant_conn_ask_passphrase(
PageantClient *pc, PageantClientDialogId *dlgid, const char *msg)
{
struct pageant_conn_state *pcs =
container_of(pc, struct pageant_conn_state, pc);
return pageant_listener_client_ask_passphrase(pcs->plc, dlgid, msg);
}
static const struct PageantClientVtable pageant_connection_clientvt = {
pageant_conn_log,
pageant_conn_got_response,
pageant_conn_ask_passphrase,
};
static void pageant_conn_receive(
Plug *plug, int urgent, const char *data, size_t len)
{
struct pageant_conn_state *pc = container_of(
plug, 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_MSB_FIRST(pc->lenbuf);
pc->got = 0;
pc->real_packet = (pc->len < AGENT_MAX_MSGLEN-4);
{
struct pageant_conn_queued_response *qr =
snew(struct pageant_conn_queued_response);
qr->prev = pc->response_queue.prev;
qr->next = &pc->response_queue;
qr->prev->next = qr->next->prev = qr;
qr->sb = NULL;
qr->req_index = pc->req_index++;
}
if (!pc->real_packet) {
/*
* Send failure immediately, before consuming the packet
* data. That way we notify the client reasonably early
* even if the data channel has just started spewing
* nonsense.
*/
pageant_client_log(&pc->pc, &pc->response_queue.prev->reqid,
"early reply: SSH_AGENT_FAILURE "
"(overlong message, length %u)", pc->len);
static const unsigned char failure[] = { SSH_AGENT_FAILURE };
pageant_conn_got_response(&pc->pc, &pc->response_queue.prev->reqid,
make_ptrlen(failure, lenof(failure)));
}
while (pc->got < pc->len) {
crGetChar(c);
if (pc->real_packet)
pc->pktbuf[pc->got] = c;
pc->got++;
}
if (pc->real_packet)
pageant_handle_msg(&pc->pc, &pc->response_queue.prev->reqid,
make_ptrlen(pc->pktbuf, pc->len));
}
crFinishV;
}
struct pageant_listen_state {
Socket *listensock;
PageantListenerClient *plc;
size_t conn_index; /* for indexing connections in log messages */
Plug plug;
};
static void pageant_listen_closing(Plug *plug, const char *error_msg,
int error_code, bool calling_back)
{
struct pageant_listen_state *pl = container_of(
plug, struct pageant_listen_state, plug);
if (error_msg)
pageant_listener_client_log(pl->plc, "listening socket: error: %s",
error_msg);
sk_close(pl->listensock);
pl->listensock = NULL;
}
static const PlugVtable pageant_connection_plugvt = {
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 */
};
static int pageant_listen_accepting(Plug *plug,
accept_fn_t constructor, accept_ctx_t ctx)
{
struct pageant_listen_state *pl = container_of(
plug, struct pageant_listen_state, plug);
struct pageant_conn_state *pc;
const char *err;
SocketPeerInfo *peerinfo;
pc = snew(struct pageant_conn_state);
pc->plug.vt = &pageant_connection_plugvt;
pc->pc.vt = &pageant_connection_clientvt;
pc->plc = pl->plc;
pc->response_queue.next = pc->response_queue.prev = &pc->response_queue;
pc->conn_index = pl->conn_index++;
pc->req_index = 0;
pc->crLine = 0;
pc->connsock = constructor(ctx, &pc->plug);
if ((err = sk_socket_error(pc->connsock)) != NULL) {
sk_close(pc->connsock);
sfree(pc);
return 1;
}
sk_set_frozen(pc->connsock, false);
peerinfo = sk_peer_info(pc->connsock);
if (peerinfo && peerinfo->log_text) {
pageant_listener_client_log(pl->plc,
"c#%"SIZEu": new connection from %s",
pc->conn_index, peerinfo->log_text);
} else {
pageant_listener_client_log(pl->plc, "c#%"SIZEu": new connection",
pc->conn_index);
}
sk_free_peer_info(peerinfo);
pageant_register_client(&pc->pc);
return 0;
}
static const PlugVtable pageant_listener_plugvt = {
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 *pageant_listener_new(
Plug **plug, PageantListenerClient *plc)
{
struct pageant_listen_state *pl = snew(struct pageant_listen_state);
pl->plug.vt = &pageant_listener_plugvt;
pl->plc = plc;
pl->listensock = NULL;
pl->conn_index = 0;
*plug = &pl->plug;
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);
}
/* ----------------------------------------------------------------------
* Code to perform agent operations either as a client, or within the
* same process as the running agent.
*/
static tree234 *passphrases = NULL;
typedef struct PageantInternalClient {
strbuf *response;
bool got_response;
PageantClient pc;
} PageantInternalClient;
static void internal_client_got_response(
PageantClient *pc, PageantClientRequestId *reqid, ptrlen response)
{
PageantInternalClient *pic = container_of(pc, PageantInternalClient, pc);
strbuf_clear(pic->response);
put_datapl(pic->response, response);
pic->got_response = true;
}
static bool internal_client_ask_passphrase(
PageantClient *pc, PageantClientDialogId *dlgid, const char *msg)
{
/* No delaying operations are permitted in this mode */
return false;
}
static const struct PageantClientVtable internal_clientvt = {
NULL /* log */,
internal_client_got_response,
internal_client_ask_passphrase,
};
typedef struct PageantClientOp {
strbuf *buf;
bool request_made;
BinarySink_DELEGATE_IMPLEMENTATION;
BinarySource_IMPLEMENTATION;
} PageantClientOp;
static PageantClientOp *pageant_client_op_new(void)
{
PageantClientOp *pco = snew(PageantClientOp);
pco->buf = strbuf_new_for_agent_query();
pco->request_made = false;
BinarySink_DELEGATE_INIT(pco, pco->buf);
BinarySource_INIT(pco, "", 0);
return pco;
}
static void pageant_client_op_free(PageantClientOp *pco)
{
if (pco->buf)
strbuf_free(pco->buf);
sfree(pco);
}
static unsigned pageant_client_op_query(PageantClientOp *pco)
{
/* Since we use the same strbuf for the request and the response,
* check by assertion that we aren't embarrassingly sending a
* previous response back to the agent */
assert(!pco->request_made);
pco->request_made = true;
if (!pageant_local) {
void *response_raw;
int resplen_raw;
agent_query_synchronous(pco->buf, &response_raw, &resplen_raw);
strbuf_clear(pco->buf);
put_data(pco->buf, response_raw, resplen_raw);
sfree(response_raw);
/* The data coming back from agent_query_synchronous will have
* its length field prepended. So we start by parsing it as an
* SSH-formatted string, and then reinitialise our
* BinarySource with the interior of that string. */
BinarySource_INIT_PL(pco, ptrlen_from_strbuf(pco->buf));
BinarySource_INIT_PL(pco, get_string(pco));
} else {
PageantInternalClient pic;
PageantClientRequestId reqid;
pic.pc.vt = &internal_clientvt;
pic.pc.suppress_logging = true;
pic.response = pco->buf;
pic.got_response = false;
pageant_register_client(&pic.pc);
assert(pco->buf->len > 4);
PageantAsyncOp *pao = pageant_make_op(
&pic.pc, &reqid, make_ptrlen(pco->buf->s + 4, pco->buf->len - 4));
while (!pic.got_response)
pageant_async_op_coroutine(pao);
pageant_unregister_client(&pic.pc);
BinarySource_INIT_PL(pco, ptrlen_from_strbuf(pco->buf));
}
/* Strip off and directly return the type byte, which every client
* will need, to save a boilerplate get_byte at each call site */
unsigned reply_type = get_byte(pco);
if (get_err(pco))
reply_type = 256; /* out-of-range code */
return reply_type;
}
/*
* After processing a list of filenames, we want to forget the
* passphrases.
*/
void pageant_forget_passphrases(void)
{
if (!passphrases) /* in case we never set it up at all */
return;
while (count234(passphrases) > 0) {
char *pp = index234(passphrases, 0);
smemclr(pp, strlen(pp));
delpos234(passphrases, 0);
sfree(pp);
}
}
typedef struct KeyListEntry {
ptrlen blob, comment;
} KeyListEntry;
typedef struct KeyList {
strbuf *raw_data;
KeyListEntry *keys;
size_t nkeys;
bool broken;
} KeyList;
static void keylist_free(KeyList *kl)
{
sfree(kl->keys);
strbuf_free(kl->raw_data);
sfree(kl);
}
static KeyList *pageant_get_keylist(unsigned ssh_version)
{
static const unsigned char requests[] = {
0, SSH1_AGENTC_REQUEST_RSA_IDENTITIES, SSH2_AGENTC_REQUEST_IDENTITIES
}, responses[] = {
0, SSH1_AGENT_RSA_IDENTITIES_ANSWER, SSH2_AGENT_IDENTITIES_ANSWER
};
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, requests[ssh_version]);
unsigned reply = pageant_client_op_query(pco);
if (reply != responses[ssh_version]) {
pageant_client_op_free(pco);
return NULL;
}
KeyList *kl = snew(KeyList);
kl->nkeys = get_uint32(pco);
kl->keys = snewn(kl->nkeys, struct KeyListEntry);
for (size_t i = 0; i < kl->nkeys && !get_err(pco); i++) {
if (ssh_version == 1) {
kl->keys[i].blob = get_data(pco, rsa_ssh1_public_blob_len(
make_ptrlen(get_ptr(pco), get_avail(pco))));
} else {
kl->keys[i].blob = get_string(pco);
}
kl->keys[i].comment = get_string(pco);
}
kl->broken = get_err(pco);
kl->raw_data = pco->buf;
pco->buf = NULL;
pageant_client_op_free(pco);
return kl;
}
int pageant_add_keyfile(Filename *filename, const char *passphrase,
char **retstr, bool add_encrypted)
{
RSAKey *rkey = NULL;
ssh2_userkey *skey = NULL;
bool needs_pass;
int ret;
int attempts;
char *comment;
const char *this_passphrase;
const char *error = NULL;
int type;
if (!passphrases) {
passphrases = newtree234(NULL);
}
*retstr = NULL;
type = key_type(filename);
if (type != SSH_KEYTYPE_SSH1 && type != SSH_KEYTYPE_SSH2) {
*retstr = dupprintf("Couldn't load this key (%s)",
key_type_to_str(type));
return PAGEANT_ACTION_FAILURE;
}
if (add_encrypted && type == SSH_KEYTYPE_SSH1) {
*retstr = dupprintf("Can't add SSH-1 keys in encrypted form");
return PAGEANT_ACTION_FAILURE;
}
/*
* See if the key is already loaded (in the primary Pageant,
* which may or may not be us).
*/
{
strbuf *blob = strbuf_new();
KeyList *kl;
if (type == SSH_KEYTYPE_SSH1) {
if (!rsa1_loadpub_f(filename, BinarySink_UPCAST(blob),
NULL, &error)) {
*retstr = dupprintf("Couldn't load private key (%s)", error);
strbuf_free(blob);
return PAGEANT_ACTION_FAILURE;
}
kl = pageant_get_keylist(1);
} else {
if (!ppk_loadpub_f(filename, NULL, BinarySink_UPCAST(blob),
NULL, &error)) {
*retstr = dupprintf("Couldn't load private key (%s)", error);
strbuf_free(blob);
return PAGEANT_ACTION_FAILURE;
}
kl = pageant_get_keylist(2);
}
if (kl) {
if (kl->broken) {
*retstr = dupstr("Received broken key list from agent");
keylist_free(kl);
strbuf_free(blob);
return PAGEANT_ACTION_FAILURE;
}
for (size_t i = 0; i < kl->nkeys; i++) {
if (ptrlen_eq_ptrlen(ptrlen_from_strbuf(blob),
kl->keys[i].blob)) {
/* Key is already present; we can now leave. */
keylist_free(kl);
strbuf_free(blob);
return PAGEANT_ACTION_OK;
}
}
keylist_free(kl);
}
strbuf_free(blob);
}
if (add_encrypted) {
const char *load_error;
LoadedFile *lf = lf_load_keyfile(filename, &load_error);
if (!lf) {
*retstr = dupstr(load_error);
return PAGEANT_ACTION_FAILURE;
}
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, SSH2_AGENTC_EXTENSION);
put_stringpl(pco, extension_names[EXT_ADD_PPK]);
put_string(pco, lf->data, lf->len);
lf_free(lf);
unsigned reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("The already running Pageant "
"refused to add the key.");
return PAGEANT_ACTION_FAILURE;
}
return PAGEANT_ACTION_OK;
}
error = NULL;
if (type == SSH_KEYTYPE_SSH1)
needs_pass = rsa1_encrypted_f(filename, &comment);
else
needs_pass = ppk_encrypted_f(filename, &comment);
attempts = 0;
if (type == SSH_KEYTYPE_SSH1)
rkey = snew(RSAKey);
/*
* Loop round repeatedly trying to load the key, until we either
* succeed, fail for some serious reason, or run out of
* passphrases to try.
*/
while (1) {
if (needs_pass) {
/*
* If we've been given a passphrase on input, try using
* it. Otherwise, try one from our tree234 of previously
* useful passphrases.
*/
if (passphrase) {
this_passphrase = (attempts == 0 ? passphrase : NULL);
} else {
this_passphrase = (const char *)index234(passphrases, attempts);
}
if (!this_passphrase) {
/*
* Run out of passphrases to try.
*/
*retstr = comment;
sfree(rkey);
return PAGEANT_ACTION_NEED_PP;
}
} else
this_passphrase = "";
if (type == SSH_KEYTYPE_SSH1)
ret = rsa1_load_f(filename, rkey, this_passphrase, &error);
else {
skey = ppk_load_f(filename, this_passphrase, &error);
if (skey == SSH2_WRONG_PASSPHRASE)
ret = -1;
else if (!skey)
ret = 0;
else
ret = 1;
}
if (ret == 0) {
/*
* Failed to load the key file, for some reason other than
* a bad passphrase.
*/
*retstr = dupstr(error);
sfree(rkey);
if (comment)
sfree(comment);
return PAGEANT_ACTION_FAILURE;
} else if (ret == 1) {
/*
* Successfully loaded the key file.
*/
break;
} else {
/*
* Passphrase wasn't right; go round again.
*/
attempts++;
}
}
/*
* If we get here, we've successfully loaded the key into
* rkey/skey, but not yet added it to the agent.
*/
/*
* If the key was successfully decrypted, save the passphrase for
* use with other keys we try to load.
*/
{
char *pp_copy = dupstr(this_passphrase);
if (addpos234(passphrases, pp_copy, 0) != pp_copy) {
/* No need; it was already there. */
smemclr(pp_copy, strlen(pp_copy));
sfree(pp_copy);
}
}
if (comment)
sfree(comment);
if (type == SSH_KEYTYPE_SSH1) {
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, SSH1_AGENTC_ADD_RSA_IDENTITY);
rsa_ssh1_private_blob_agent(BinarySink_UPCAST(pco), rkey);
put_stringz(pco, rkey->comment);
unsigned reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
freersakey(rkey);
sfree(rkey);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("The already running Pageant "
"refused to add the key.");
return PAGEANT_ACTION_FAILURE;
}
} else {
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, SSH2_AGENTC_ADD_IDENTITY);
put_stringz(pco, ssh_key_ssh_id(skey->key));
ssh_key_openssh_blob(skey->key, BinarySink_UPCAST(pco));
put_stringz(pco, skey->comment);
unsigned reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
sfree(skey->comment);
ssh_key_free(skey->key);
sfree(skey);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("The already running Pageant "
"refused to add the key.");
return PAGEANT_ACTION_FAILURE;
}
}
return PAGEANT_ACTION_OK;
}
int pageant_enum_keys(pageant_key_enum_fn_t callback, void *callback_ctx,
char **retstr)
{
KeyList *kl1 = NULL, *kl2 = NULL;
struct pageant_pubkey cbkey;
int toret = PAGEANT_ACTION_FAILURE;
kl1 = pageant_get_keylist(1);
if (!kl1) {
*retstr = dupstr("Did not receive an SSH-1 key list from agent");
goto out;
}
if (kl1->broken) {
*retstr = dupstr("Received broken SSH-1 key list from agent");
goto out;
}
kl2 = pageant_get_keylist(2);
if (!kl2) {
*retstr = dupstr("Did not receive an SSH-2 key list from agent");
goto out;
}
if (kl2->broken) {
*retstr = dupstr("Received broken SSH-2 key list from agent");
goto out;
}
for (size_t i = 0; i < kl1->nkeys; i++) {
cbkey.blob = strbuf_new();
put_datapl(cbkey.blob, kl1->keys[i].blob);
cbkey.comment = mkstr(kl1->keys[i].comment);
cbkey.ssh_version = 1;
/* Decode public blob into a key in order to fingerprint it */
RSAKey rkey;
memset(&rkey, 0, sizeof(rkey));
{
BinarySource src[1];
BinarySource_BARE_INIT_PL(src, kl1->keys[i].blob);
get_rsa_ssh1_pub(src, &rkey, RSA_SSH1_EXPONENT_FIRST);
if (get_err(src)) {
*retstr = dupstr("Received an invalid SSH-1 key from agent");
goto out;
}
}
char *fingerprint = rsa_ssh1_fingerprint(&rkey);
freersakey(&rkey);
callback(callback_ctx, fingerprint, cbkey.comment, &cbkey);
strbuf_free(cbkey.blob);
sfree(cbkey.comment);
sfree(fingerprint);
}
for (size_t i = 0; i < kl2->nkeys; i++) {
cbkey.blob = strbuf_new();
put_datapl(cbkey.blob, kl2->keys[i].blob);
cbkey.comment = mkstr(kl2->keys[i].comment);
cbkey.ssh_version = 2;
char *fingerprint = ssh2_fingerprint_blob(kl2->keys[i].blob);
callback(callback_ctx, fingerprint, cbkey.comment, &cbkey);
sfree(fingerprint);
sfree(cbkey.comment);
strbuf_free(cbkey.blob);
}
*retstr = NULL;
toret = PAGEANT_ACTION_OK;
out:
if (kl1)
keylist_free(kl1);
if (kl2)
keylist_free(kl2);
return toret;
}
int pageant_delete_key(struct pageant_pubkey *key, char **retstr)
{
PageantClientOp *pco = pageant_client_op_new();
if (key->ssh_version == 1) {
put_byte(pco, SSH1_AGENTC_REMOVE_RSA_IDENTITY);
put_data(pco, key->blob->s, key->blob->len);
} else {
put_byte(pco, SSH2_AGENTC_REMOVE_IDENTITY);
put_string(pco, key->blob->s, key->blob->len);
}
unsigned reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("Agent failed to delete key");
return PAGEANT_ACTION_FAILURE;
} else {
*retstr = NULL;
return PAGEANT_ACTION_OK;
}
}
int pageant_delete_all_keys(char **retstr)
{
PageantClientOp *pco;
unsigned reply;
pco = pageant_client_op_new();
put_byte(pco, SSH2_AGENTC_REMOVE_ALL_IDENTITIES);
reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("Agent failed to delete SSH-2 keys");
return PAGEANT_ACTION_FAILURE;
}
pco = pageant_client_op_new();
put_byte(pco, SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES);
reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("Agent failed to delete SSH-1 keys");
return PAGEANT_ACTION_FAILURE;
}
*retstr = NULL;
return PAGEANT_ACTION_OK;
}
int pageant_reencrypt_key(struct pageant_pubkey *key, char **retstr)
{
PageantClientOp *pco = pageant_client_op_new();
if (key->ssh_version == 1) {
*retstr = dupstr("Can't re-encrypt an SSH-1 key");
return PAGEANT_ACTION_FAILURE;
} else {
put_byte(pco, SSH2_AGENTC_EXTENSION);
put_stringpl(pco, extension_names[EXT_REENCRYPT]);
put_string(pco, key->blob->s, key->blob->len);
}
unsigned reply = pageant_client_op_query(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("Agent failed to re-encrypt key");
return PAGEANT_ACTION_FAILURE;
} else {
*retstr = NULL;
return PAGEANT_ACTION_OK;
}
}
int pageant_reencrypt_all_keys(char **retstr)
{
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, SSH2_AGENTC_EXTENSION);
put_stringpl(pco, extension_names[EXT_REENCRYPT_ALL]);
unsigned reply = pageant_client_op_query(pco);
uint32_t failures = get_uint32(pco);
pageant_client_op_free(pco);
if (reply != SSH_AGENT_SUCCESS) {
*retstr = dupstr("Agent failed to re-encrypt any keys");
return PAGEANT_ACTION_FAILURE;
} else if (failures == 1) {
/* special case for English grammar */
*retstr = dupstr("1 key remains unencrypted");
return PAGEANT_ACTION_WARNING;
} else if (failures > 0) {
*retstr = dupprintf("%"PRIu32" keys remain unencrypted", failures);
return PAGEANT_ACTION_WARNING;
} else {
*retstr = NULL;
return PAGEANT_ACTION_OK;
}
}
int pageant_sign(struct pageant_pubkey *key, ptrlen message, strbuf *out,
uint32_t flags, char **retstr)
{
PageantClientOp *pco = pageant_client_op_new();
put_byte(pco, SSH2_AGENTC_SIGN_REQUEST);
put_string(pco, key->blob->s, key->blob->len);
put_stringpl(pco, message);
put_uint32(pco, flags);
unsigned reply = pageant_client_op_query(pco);
ptrlen signature = get_string(pco);
if (reply == SSH2_AGENT_SIGN_RESPONSE && !get_err(pco)) {
*retstr = NULL;
put_datapl(out, signature);
pageant_client_op_free(pco);
return PAGEANT_ACTION_OK;
} else {
*retstr = dupstr("Agent failed to create signature");
pageant_client_op_free(pco);
return PAGEANT_ACTION_FAILURE;
}
}
struct pageant_pubkey *pageant_pubkey_copy(struct pageant_pubkey *key)
{
struct pageant_pubkey *ret = snew(struct pageant_pubkey);
ret->blob = strbuf_new();
put_data(ret->blob, key->blob->s, key->blob->len);
ret->comment = key->comment ? dupstr(key->comment) : NULL;
ret->ssh_version = key->ssh_version;
return ret;
}
void pageant_pubkey_free(struct pageant_pubkey *key)
{
sfree(key->comment);
strbuf_free(key->blob);
sfree(key);
}