version 1.116, 2003/04/08 20:21:29 |
version 1.117, 2003/05/12 16:55:37 |
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typedef struct Authctxt Authctxt; |
typedef struct Authctxt Authctxt; |
typedef struct Authmethod Authmethod; |
typedef struct Authmethod Authmethod; |
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typedef struct identity Identity; |
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typedef struct idlist Idlist; |
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typedef int sign_cb_fn( |
struct identity { |
Authctxt *authctxt, Key *key, |
TAILQ_ENTRY(identity) next; |
u_char **sigp, u_int *lenp, u_char *data, u_int datalen); |
AuthenticationConnection *ac; /* set if agent supports key */ |
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Key *key; /* public/private key */ |
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char *filename; /* comment for agent-only keys */ |
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int tried; |
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int isprivate; /* key points to the private key */ |
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}; |
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TAILQ_HEAD(idlist, identity); |
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struct Authctxt { |
struct Authctxt { |
const char *server_user; |
const char *server_user; |
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int success; |
int success; |
char *authlist; |
char *authlist; |
/* pubkey */ |
/* pubkey */ |
Key *last_key; |
Idlist keys; |
sign_cb_fn *last_key_sign; |
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int last_key_hint; |
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AuthenticationConnection *agent; |
AuthenticationConnection *agent; |
/* hostbased */ |
/* hostbased */ |
Sensitive *sensitive; |
Sensitive *sensitive; |
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void userauth(Authctxt *, char *); |
void userauth(Authctxt *, char *); |
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static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *); |
static int sign_and_send_pubkey(Authctxt *, Identity *); |
static void clear_auth_state(Authctxt *); |
static void clear_auth_state(Authctxt *); |
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static void pubkey_prepare(Authctxt *); |
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static void pubkey_cleanup(Authctxt *); |
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static Key *load_identity_file(char *); |
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static Authmethod *authmethod_get(char *authlist); |
static Authmethod *authmethod_get(char *authlist); |
static Authmethod *authmethod_lookup(const char *name); |
static Authmethod *authmethod_lookup(const char *name); |
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/* setup authentication context */ |
/* setup authentication context */ |
memset(&authctxt, 0, sizeof(authctxt)); |
memset(&authctxt, 0, sizeof(authctxt)); |
authctxt.agent = ssh_get_authentication_connection(); |
pubkey_prepare(&authctxt); |
authctxt.server_user = server_user; |
authctxt.server_user = server_user; |
authctxt.local_user = local_user; |
authctxt.local_user = local_user; |
authctxt.host = host; |
authctxt.host = host; |
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dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
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if (authctxt.agent != NULL) |
pubkey_cleanup(&authctxt); |
ssh_close_authentication_connection(authctxt.agent); |
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debug("Authentication succeeded (%s).", authctxt.method->name); |
debug("Authentication succeeded (%s).", authctxt.method->name); |
} |
} |
void |
void |
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{ |
{ |
Authctxt *authctxt = ctxt; |
Authctxt *authctxt = ctxt; |
Key *key = NULL; |
Key *key = NULL; |
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Identity *id = NULL; |
Buffer b; |
Buffer b; |
int pktype, sent = 0; |
int pktype, sent = 0; |
u_int alen, blen; |
u_int alen, blen; |
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} |
} |
packet_check_eom(); |
packet_check_eom(); |
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debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d", |
debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
pkalg, blen, authctxt->last_key, authctxt->last_key_hint); |
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do { |
if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
if (authctxt->last_key == NULL || |
debug("unknown pkalg %s", pkalg); |
authctxt->last_key_sign == NULL) { |
goto done; |
debug("no last key or no sign cb"); |
} |
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if ((key = key_from_blob(pkblob, blen)) == NULL) { |
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debug("no key from blob. pkalg %s", pkalg); |
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goto done; |
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} |
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if (key->type != pktype) { |
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error("input_userauth_pk_ok: type mismatch " |
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"for decoded key (received %d, expected %d)", |
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key->type, pktype); |
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goto done; |
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} |
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fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
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debug2("input_userauth_pk_ok: fp %s", fp); |
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xfree(fp); |
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TAILQ_FOREACH(id, &authctxt->keys, next) { |
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if (key_equal(key, id->key)) { |
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sent = sign_and_send_pubkey(authctxt, id); |
break; |
break; |
} |
} |
if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
} |
debug("unknown pkalg %s", pkalg); |
done: |
break; |
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} |
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if ((key = key_from_blob(pkblob, blen)) == NULL) { |
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debug("no key from blob. pkalg %s", pkalg); |
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break; |
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} |
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if (key->type != pktype) { |
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error("input_userauth_pk_ok: type mismatch " |
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"for decoded key (received %d, expected %d)", |
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key->type, pktype); |
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break; |
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} |
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fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
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debug2("input_userauth_pk_ok: fp %s", fp); |
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xfree(fp); |
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if (!key_equal(key, authctxt->last_key)) { |
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debug("key != last_key"); |
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break; |
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} |
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sent = sign_and_send_pubkey(authctxt, key, |
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authctxt->last_key_sign); |
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} while (0); |
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if (key != NULL) |
if (key != NULL) |
key_free(key); |
key_free(key); |
xfree(pkalg); |
xfree(pkalg); |
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/* try another method if we did not send a packet */ |
/* try another method if we did not send a packet */ |
if (sent == 0) |
if (sent == 0) |
userauth(authctxt, NULL); |
userauth(authctxt, NULL); |
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} |
} |
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int |
int |
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{ |
{ |
/* XXX clear authentication state */ |
/* XXX clear authentication state */ |
dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL); |
dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL); |
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} |
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if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { |
static int |
debug3("clear_auth_state: key_free %p", authctxt->last_key); |
identity_sign(Identity *id, u_char **sigp, u_int *lenp, |
key_free(authctxt->last_key); |
u_char *data, u_int datalen) |
} |
{ |
authctxt->last_key = NULL; |
Key *prv; |
authctxt->last_key_hint = -2; |
int ret; |
authctxt->last_key_sign = NULL; |
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/* the agent supports this key */ |
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if (id->ac) |
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return (ssh_agent_sign(id->ac, id->key, sigp, lenp, |
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data, datalen)); |
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/* |
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* we have already loaded the private key or |
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* the private key is stored in external hardware |
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*/ |
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if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) |
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return (key_sign(id->key, sigp, lenp, data, datalen)); |
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/* load the private key from the file */ |
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if ((prv = load_identity_file(id->filename)) == NULL) |
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return (-1); |
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ret = key_sign(prv, sigp, lenp, data, datalen); |
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key_free(prv); |
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return (ret); |
} |
} |
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static int |
static int |
sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
{ |
{ |
Buffer b; |
Buffer b; |
u_char *blob, *signature; |
u_char *blob, *signature; |
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debug3("sign_and_send_pubkey"); |
debug3("sign_and_send_pubkey"); |
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if (key_to_blob(k, &blob, &bloblen) == 0) { |
if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
/* we cannot handle this key */ |
/* we cannot handle this key */ |
debug3("sign_and_send_pubkey: cannot handle key"); |
debug3("sign_and_send_pubkey: cannot handle key"); |
return 0; |
return 0; |
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} else { |
} else { |
buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_char(&b, have_sig); |
buffer_put_char(&b, have_sig); |
buffer_put_cstring(&b, key_ssh_name(k)); |
buffer_put_cstring(&b, key_ssh_name(id->key)); |
} |
} |
buffer_put_string(&b, blob, bloblen); |
buffer_put_string(&b, blob, bloblen); |
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/* generate signature */ |
/* generate signature */ |
ret = (*sign_callback)(authctxt, k, &signature, &slen, |
ret = identity_sign(id, &signature, &slen, |
buffer_ptr(&b), buffer_len(&b)); |
buffer_ptr(&b), buffer_len(&b)); |
if (ret == -1) { |
if (ret == -1) { |
xfree(blob); |
xfree(blob); |
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buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_cstring(&b, authctxt->method->name); |
buffer_put_char(&b, have_sig); |
buffer_put_char(&b, have_sig); |
if (!(datafellows & SSH_BUG_PKAUTH)) |
if (!(datafellows & SSH_BUG_PKAUTH)) |
buffer_put_cstring(&b, key_ssh_name(k)); |
buffer_put_cstring(&b, key_ssh_name(id->key)); |
buffer_put_string(&b, blob, bloblen); |
buffer_put_string(&b, blob, bloblen); |
} |
} |
xfree(blob); |
xfree(blob); |
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} |
} |
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static int |
static int |
send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, |
send_pubkey_test(Authctxt *authctxt, Identity *id) |
int hint) |
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{ |
{ |
u_char *blob; |
u_char *blob; |
u_int bloblen, have_sig = 0; |
u_int bloblen, have_sig = 0; |
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debug3("send_pubkey_test"); |
debug3("send_pubkey_test"); |
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if (key_to_blob(k, &blob, &bloblen) == 0) { |
if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
/* we cannot handle this key */ |
/* we cannot handle this key */ |
debug3("send_pubkey_test: cannot handle key"); |
debug3("send_pubkey_test: cannot handle key"); |
return 0; |
return 0; |
} |
} |
/* register callback for USERAUTH_PK_OK message */ |
/* register callback for USERAUTH_PK_OK message */ |
authctxt->last_key_sign = sign_callback; |
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authctxt->last_key_hint = hint; |
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authctxt->last_key = k; |
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dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
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packet_start(SSH2_MSG_USERAUTH_REQUEST); |
packet_start(SSH2_MSG_USERAUTH_REQUEST); |
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packet_put_cstring(authctxt->method->name); |
packet_put_cstring(authctxt->method->name); |
packet_put_char(have_sig); |
packet_put_char(have_sig); |
if (!(datafellows & SSH_BUG_PKAUTH)) |
if (!(datafellows & SSH_BUG_PKAUTH)) |
packet_put_cstring(key_ssh_name(k)); |
packet_put_cstring(key_ssh_name(id->key)); |
packet_put_string(blob, bloblen); |
packet_put_string(blob, bloblen); |
xfree(blob); |
xfree(blob); |
packet_send(); |
packet_send(); |
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return private; |
return private; |
} |
} |
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static int |
/* |
identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
* try keys in the following order: |
u_char *data, u_int datalen) |
* 1. agent keys that are found in the config file |
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* 2. other agent keys |
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* 3. keys that are only listed in the config file |
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*/ |
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static void |
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pubkey_prepare(Authctxt *authctxt) |
{ |
{ |
Key *private; |
Identity *id; |
int idx, ret; |
Idlist agent, files, *preferred; |
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Key *key; |
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AuthenticationConnection *ac; |
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char *comment; |
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int i, found; |
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idx = authctxt->last_key_hint; |
TAILQ_INIT(&agent); /* keys from the agent */ |
if (idx < 0) |
TAILQ_INIT(&files); /* keys from the config file */ |
return -1; |
preferred = &authctxt->keys; |
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TAILQ_INIT(preferred); /* preferred order of keys */ |
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/* private key is stored in external hardware */ |
/* list of keys stored in the filesystem */ |
if (options.identity_keys[idx]->flags & KEY_FLAG_EXT) |
for (i = 0; i < options.num_identity_files; i++) { |
return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen); |
key = options.identity_keys[i]; |
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if (key && key->type == KEY_RSA1) |
private = load_identity_file(options.identity_files[idx]); |
continue; |
if (private == NULL) |
options.identity_keys[i] = NULL; |
return -1; |
id = xmalloc(sizeof(*id)); |
ret = key_sign(private, sigp, lenp, data, datalen); |
memset(id, 0, sizeof(*id)); |
key_free(private); |
id->key = key; |
return ret; |
id->filename = xstrdup(options.identity_files[i]); |
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TAILQ_INSERT_TAIL(&files, id, next); |
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} |
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/* list of keys supported by the agent */ |
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if ((ac = ssh_get_authentication_connection())) { |
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for (key = ssh_get_first_identity(ac, &comment, 2); |
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key != NULL; |
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key = ssh_get_next_identity(ac, &comment, 2)) { |
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found = 0; |
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TAILQ_FOREACH(id, &files, next) { |
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/* agent keys from the config file are preferred */ |
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if (key_equal(key, id->key)) { |
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key_free(key); |
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xfree(comment); |
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TAILQ_REMOVE(&files, id, next); |
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TAILQ_INSERT_TAIL(preferred, id, next); |
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id->ac = ac; |
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found = 1; |
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break; |
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} |
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} |
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if (!found) { |
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id = xmalloc(sizeof(*id)); |
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memset(id, 0, sizeof(*id)); |
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id->key = key; |
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id->filename = comment; |
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id->ac = ac; |
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TAILQ_INSERT_TAIL(&agent, id, next); |
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} |
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} |
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/* append remaining agent keys */ |
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for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { |
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TAILQ_REMOVE(&agent, id, next); |
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TAILQ_INSERT_TAIL(preferred, id, next); |
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} |
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authctxt->agent = ac; |
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} |
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/* append remaining keys from the config file */ |
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for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { |
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TAILQ_REMOVE(&files, id, next); |
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TAILQ_INSERT_TAIL(preferred, id, next); |
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} |
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TAILQ_FOREACH(id, preferred, next) { |
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debug2("key: %s (%p)", id->filename, id->key); |
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} |
} |
} |
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static int |
static void |
agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
pubkey_cleanup(Authctxt *authctxt) |
u_char *data, u_int datalen) |
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{ |
{ |
return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
Identity *id; |
} |
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static int |
if (authctxt->agent != NULL) |
key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
ssh_close_authentication_connection(authctxt->agent); |
u_char *data, u_int datalen) |
for (id = TAILQ_FIRST(&authctxt->keys); id; |
{ |
id = TAILQ_FIRST(&authctxt->keys)) { |
return key_sign(key, sigp, lenp, data, datalen); |
TAILQ_REMOVE(&authctxt->keys, id, next); |
} |
if (id->key) |
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key_free(id->key); |
static int |
if (id->filename) |
userauth_pubkey_agent(Authctxt *authctxt) |
xfree(id->filename); |
{ |
xfree(id); |
static int called = 0; |
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int ret = 0; |
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char *comment; |
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Key *k; |
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if (called == 0) { |
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if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
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debug2("userauth_pubkey_agent: no keys at all"); |
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called = 1; |
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} |
} |
k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
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if (k == NULL) { |
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debug2("userauth_pubkey_agent: no more keys"); |
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} else { |
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debug("Offering agent key: %s", comment); |
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xfree(comment); |
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ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); |
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if (ret == 0) |
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key_free(k); |
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} |
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if (ret == 0) |
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debug2("userauth_pubkey_agent: no message sent"); |
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return ret; |
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} |
} |
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int |
int |
userauth_pubkey(Authctxt *authctxt) |
userauth_pubkey(Authctxt *authctxt) |
{ |
{ |
static int idx = 0; |
Identity *id; |
int sent = 0; |
int sent = 0; |
Key *key; |
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char *filename; |
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if (authctxt->agent != NULL) { |
while ((id = TAILQ_FIRST(&authctxt->keys))) { |
do { |
if (id->tried++) |
sent = userauth_pubkey_agent(authctxt); |
return (0); |
} while (!sent && authctxt->agent->howmany > 0); |
TAILQ_REMOVE(&authctxt->keys, id, next); |
} |
TAILQ_INSERT_TAIL(&authctxt->keys, id, next); |
while (!sent && idx < options.num_identity_files) { |
/* |
key = options.identity_keys[idx]; |
* send a test message if we have the public key. for |
filename = options.identity_files[idx]; |
* encrypted keys we cannot do this and have to load the |
if (key == NULL) { |
* private key instead |
debug("Trying private key: %s", filename); |
*/ |
key = load_identity_file(filename); |
if (id->key && id->key->type != KEY_RSA1) { |
if (key != NULL) { |
debug("Offering public key: %s", id->filename); |
sent = sign_and_send_pubkey(authctxt, key, |
sent = send_pubkey_test(authctxt, id); |
key_sign_cb); |
} else if (id->key == NULL) { |
key_free(key); |
debug("Trying private key: %s", id->filename); |
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id->key = load_identity_file(id->filename); |
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if (id->key != NULL) { |
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id->isprivate = 1; |
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sent = sign_and_send_pubkey(authctxt, id); |
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key_free(id->key); |
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id->key = NULL; |
} |
} |
} else if (key->type != KEY_RSA1) { |
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debug("Offering public key: %s", filename); |
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sent = send_pubkey_test(authctxt, key, |
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identity_sign_cb, idx); |
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} |
} |
idx++; |
if (sent) |
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return (sent); |
} |
} |
return sent; |
return (0); |
} |
} |
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/* |
/* |