static int
match_principals_file(char *file, struct passwd *pw, struct sshkey_cert *cert)
{
FILE *f;
char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
u_long linenum = 0;
u_int i;
temporarily_use_uid(pw);
debug("trying authorized principals file %s", file);
if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) {
restore_uid();
return 0;
}
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
/* Skip leading whitespace. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
/* Skip blank and comment lines. */
if ((ep = strchr(cp, '#')) != NULL)
*ep = '\0';
if (!*cp || *cp == '\n')
continue;
/* Trim trailing whitespace. */
ep = cp + strlen(cp) - 1;
while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
*ep-- = '\0';
/*
* If the line has internal whitespace then assume it has
* key options.
*/
line_opts = NULL;
if ((ep = strrchr(cp, ' ')) != NULL ||
(ep = strrchr(cp, '\t')) != NULL) {
for (; *ep == ' ' || *ep == '\t'; ep++)
;
line_opts = cp;
cp = ep;
}
for (i = 0; i < cert->nprincipals; i++) {
if (strcmp(cp, cert->principals[i]) == 0) {
debug3("matched principal \"%.100s\" "
"from file \"%s\" on line %lu",
cert->principals[i], file, linenum);
if (auth_parse_options(pw, line_opts,
file, linenum) != 1)
continue;
fclose(f);
restore_uid();
return 1;
}
}
}
fclose(f);
restore_uid();
return 0;
}
static int
process_principals(FILE *f, char *file, struct passwd *pw,
const struct sshkey_cert *cert)
{
char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
u_long linenum = 0;
u_int i, found_principal = 0;
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
/* Always consume entire input */
if (found_principal)
continue;
/* Skip leading whitespace. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
/* Skip blank and comment lines. */
if ((ep = strchr(cp, '#')) != NULL)
*ep = '\0';
if (!*cp || *cp == '\n')
continue;
/* Trim trailing whitespace. */
ep = cp + strlen(cp) - 1;
while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
*ep-- = '\0';
/*
* If the line has internal whitespace then assume it has
* key options.
*/
line_opts = NULL;
if ((ep = strrchr(cp, ' ')) != NULL ||
(ep = strrchr(cp, '\t')) != NULL) {
for (; *ep == ' ' || *ep == '\t'; ep++)
;
line_opts = cp;
cp = ep;
}
for (i = 0; i < cert->nprincipals; i++) {
if (strcmp(cp, cert->principals[i]) == 0) {
debug3("%s:%lu: matched principal \"%.100s\"",
file == NULL ? "(command)" : file,
linenum, cert->principals[i]);
if (auth_parse_options(pw, line_opts,
file, linenum) != 1)
continue;
found_principal = 1;
continue;
}
}
}
return found_principal;
}
/* check to see if the script specified by file can authorize the key
*
* the script will have the key written to STDIN, which is identical
* to the normal public key format.
*
* the script must exit with either 0 for success or 1 for failure.
* the script can print login options (if any) to STDOUT. No whitepace should be added
* to the output.
*
* Use with caution: the script can hang sshd. It is recommended you code the script
* with a timeout set if it cannot determine authenication quickly.
*/
static int
user_key_found_by_script(struct passwd *pw, Key *key, char *file)
{
pid_t pid;
char line[SSH_MAX_PUBKEY_BYTES];
int pipe_in[2];
int pipe_out[2];
int exit_code = 1;
int success = 0;
FILE *f;
//mysig_t oldsig;
pipe(pipe_in);
pipe(pipe_out);
//oldsig = signal(SIGCHLD, SIG_IGN);
temporarily_use_uid(pw);
debug3("user_key_found_by_script: executing %s", file);
switch ((pid = fork())) {
case -1:
error("fork(): %s", strerror(errno));
restore_uid();
return (-1);
case 0:
/* setup input pipe */
close(pipe_in[1]);
dup2(pipe_in[0], 0);
close(pipe_in[0]);
/* setup output pipe */
close(pipe_out[0]);
dup2(pipe_out[1], 1);
close(pipe_out[1]);
execl(file, file, NULL);
/* exec failed */
error("execl(): %s", strerror(errno));
_exit(1);
default:
debug3("user_key_found_by_script: script pid %d", pid);
close(pipe_in[0]);
close(pipe_out[1]);
f = fdopen(pipe_in[1], "w");
key_write(key, f);
fclose(f);
while(waitpid(pid, &exit_code, 0) < 0) {
switch(errno) {
case EINTR:
debug3("user_key_found_by_script: waitpid() EINTR, continuing");
continue;
default:
error("waitpid(): %s", strerror(errno));
goto waitpid_error;
}
}
if (WIFEXITED(exit_code) && WEXITSTATUS(exit_code) == 0) {
int amt_read = read(pipe_out[0], line, sizeof(line) - 1);
line[amt_read] = ' ';
line[amt_read + 1] = 0;
debug3("user_key_found_by_script: options: %s", line);
if (auth_parse_options(pw, line, file, 0) == 1)
success = 1;
}
waitpid_error:
close(pipe_out[0]);
}
restore_uid();
//signal(SIGCHLD, oldsig);
return success;
}
/* return 1 if user allows given key */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
char line[SSH_MAX_PUBKEY_BYTES];
const char *reason;
int found_key = 0;
FILE *f;
u_long linenum = 0;
Key *found;
char *fp;
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
debug("trying public key file %s", file);
f = auth_openkeyfile(file, pw, options.strict_modes);
if (!f) {
restore_uid();
return 0;
}
found_key = 0;
found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp, *key_options = NULL;
auth_clear_options();
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("user_key_allowed: check options: '%s'", cp);
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
continue;
}
}
if (key_is_cert(key)) {
if (!key_equal(found, key->cert->signature_key))
continue;
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (!key_is_cert_authority)
continue;
fp = key_fingerprint(found, SSH_FP_MD5,
SSH_FP_HEX);
debug("matching CA found: file %s, line %lu, %s %s",
file, linenum, key_type(found), fp);
/*
* If the user has specified a list of principals as
* a key option, then prefer that list to matching
* their username in the certificate principals list.
*/
if (authorized_principals != NULL &&
!match_principals_option(authorized_principals,
key->cert)) {
reason = "Certificate does not contain an "
"authorized principal";
fail_reason:
xfree(fp);
error("%s", reason);
auth_debug_add("%s", reason);
continue;
}
if (key_cert_check_authority(key, 0, 0,
authorized_principals == NULL ? pw->pw_name : NULL,
&reason) != 0)
goto fail_reason;
if (auth_cert_options(key, pw) != 0) {
xfree(fp);
continue;
}
verbose("Accepted certificate ID \"%s\" "
"signed by %s CA %s via %s", key->cert->key_id,
key_type(found), fp, file);
xfree(fp);
found_key = 1;
break;
} else if (key_equal(found, key)) {
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (key_is_cert_authority)
continue;
found_key = 1;
debug("matching key found: file %s, line %lu",
file, linenum);
fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
verbose("Found matching %s key: %s",
key_type(found), fp);
xfree(fp);
break;
}
}
restore_uid();
fclose(f);
key_free(found);
if (!found_key)
debug2("key not found");
return found_key;
}
/* return 1 if user allows given key */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
char line[SSH_MAX_PUBKEY_BYTES];
int found_key = 0;
FILE *f;
u_long linenum = 0;
struct stat st;
Key *found;
char *fp;
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
debug("trying public key file %s", file);
/* Fail quietly if file does not exist */
if (stat(file, &st) < 0) {
/* Restore the privileged uid. */
restore_uid();
return 0;
}
/* Open the file containing the authorized keys. */
f = fopen(file, "r");
if (!f) {
/* Restore the privileged uid. */
restore_uid();
return 0;
}
if (options.strict_modes &&
secure_filename(f, file, pw, line, sizeof(line)) != 0) {
fclose(f);
logit("Authentication refused: %s", line);
restore_uid();
return 0;
}
found_key = 0;
found = key_new(key->type);
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp, *key_options = NULL;
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("user_key_allowed: check options: '%s'", cp);
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
continue;
}
}
if (key_equal(found, key) &&
auth_parse_options(pw, key_options, file, linenum) == 1) {
found_key = 1;
debug("matching key found: file %s, line %lu",
file, linenum);
fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
verbose("Found matching %s key: %s",
key_type(found), fp);
xfree(fp);
break;
}
}
restore_uid();
fclose(f);
key_free(found);
if (!found_key)
debug2("key not found");
return found_key;
}
int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
char line[8192], *file;
int allowed = 0;
u_int bits;
FILE *f;
u_long linenum = 0;
struct stat st;
Key *key;
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
/* The authorized keys. */
file = authorized_keys_file(pw);
debug("trying public RSA key file %s", file);
/* Fail quietly if file does not exist */
if (stat(file, &st) < 0) {
/* Restore the privileged uid. */
restore_uid();
xfree(file);
return (0);
}
/* Open the file containing the authorized keys. */
f = fopen(file, "r");
if (!f) {
/* Restore the privileged uid. */
restore_uid();
xfree(file);
return (0);
}
if (options.strict_modes &&
secure_filename(f, file, pw, line, sizeof(line)) != 0) {
xfree(file);
fclose(f);
log("Authentication refused: %s", line);
restore_uid();
return (0);
}
/* Flag indicating whether the key is allowed. */
allowed = 0;
key = key_new(KEY_RSA1);
/*
* Go though the accepted keys, looking for the current key. If
* found, perform a challenge-response dialog to verify that the
* user really has the corresponding private key.
*/
while (fgets(line, sizeof(line), f)) {
char *cp;
char *options;
linenum++;
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
/*
* Check if there are options for this key, and if so,
* save their starting address and skip the option part
* for now. If there are no options, set the starting
* address to NULL.
*/
if (*cp < '0' || *cp > '9') {
int quoted = 0;
options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
} else
options = NULL;
/* Parse the key from the line. */
if (hostfile_read_key(&cp, &bits, key) == 0) {
debug("%.100s, line %lu: non ssh1 key syntax",
file, linenum);
continue;
}
/* cp now points to the comment part. */
/* Check if the we have found the desired key (identified by its modulus). */
if (BN_cmp(key->rsa->n, client_n) != 0)
continue;
/* check the real bits */
if (bits != BN_num_bits(key->rsa->n))
log("Warning: %s, line %lu: keysize mismatch: "
"actual %d vs. announced %d.",
file, linenum, BN_num_bits(key->rsa->n), bits);
/* We have found the desired key. */
/*
* If our options do not allow this key to be used,
* do not send challenge.
*/
if (!auth_parse_options(pw, options, file, linenum))
continue;
/* break out, this key is allowed */
allowed = 1;
break;
}
/* Restore the privileged uid. */
restore_uid();
/* Close the file. */
xfree(file);
fclose(f);
/* return key if allowed */
if (allowed && rkey != NULL)
*rkey = key;
else
key_free(key);
return (allowed);
}
static int
rsa_key_allowed_in_file(struct passwd *pw, char *file,
const BIGNUM *client_n, struct sshkey **rkey)
{
char line[SSH_MAX_PUBKEY_BYTES];
int allowed = 0;
u_int bits;
FILE *f;
u_long linenum = 0;
struct sshkey *key;
debug("trying public RSA key file %s", file);
if ((f = auth_openkeyfile(file, pw, options.strict_modes)) == NULL)
return 0;
/*
* Go though the accepted keys, looking for the current key. If
* found, perform a challenge-response dialog to verify that the
* user really has the corresponding private key.
*/
if ((key = sshkey_new(KEY_RSA1)) == NULL)
fatal("%s: sshkey_new failed", __func__);
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp;
char *key_options;
int keybits;
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
/*
* Check if there are options for this key, and if so,
* save their starting address and skip the option part
* for now. If there are no options, set the starting
* address to NULL.
*/
if (*cp < '0' || *cp > '9') {
int quoted = 0;
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
} else
key_options = NULL;
/* Parse the key from the line. */
if (hostfile_read_key(&cp, &bits, key) == 0) {
debug("%.100s, line %lu: non ssh1 key syntax",
file, linenum);
continue;
}
/* cp now points to the comment part. */
/*
* Check if the we have found the desired key (identified
* by its modulus).
*/
if (BN_cmp(key->rsa->n, client_n) != 0)
continue;
/* check the real bits */
keybits = BN_num_bits(key->rsa->n);
if (keybits < 0 || bits != (u_int)keybits)
logit("Warning: %s, line %lu: keysize mismatch: "
"actual %d vs. announced %d.",
file, linenum, BN_num_bits(key->rsa->n), bits);
/* Never accept a revoked key */
if (auth_key_is_revoked(key))
break;
/* We have found the desired key. */
/*
* If our options do not allow this key to be used,
* do not send challenge.
*/
if (!auth_parse_options(pw, key_options, file, linenum))
continue;
if (key_is_cert_authority)
continue;
/* break out, this key is allowed */
allowed = 1;
break;
}
/* Close the file. */
fclose(f);
/* return key if allowed */
if (allowed && rkey != NULL)
*rkey = key;
else
sshkey_free(key);
return allowed;
}
/*
* Checks whether key is allowed in authorized_keys-format file,
* returns 1 if the key is allowed or 0 otherwise.
*/
static int
check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
{
char line[SSH_MAX_PUBKEY_BYTES];
int found_key = 0;
u_long linenum = 0;
Key *found;
found_key = 0;
found = NULL;
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp, *key_options = NULL, *fp = NULL;
const char *reason = NULL;
/* Always consume entrire file */
if (found_key)
continue;
if (found != NULL)
key_free(found);
found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
auth_clear_options();
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("user_key_allowed: check options: '%s'", cp);
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
continue;
}
}
if (key_is_cert(key)) {
if (!key_equal(found, key->cert->signature_key))
continue;
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (!key_is_cert_authority)
continue;
if ((fp = sshkey_fingerprint(found,
options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
continue;
debug("matching CA found: file %s, line %lu, %s %s",
file, linenum, key_type(found), fp);
/*
* If the user has specified a list of principals as
* a key option, then prefer that list to matching
* their username in the certificate principals list.
*/
if (authorized_principals != NULL &&
!match_principals_option(authorized_principals,
key->cert)) {
reason = "Certificate does not contain an "
"authorized principal";
fail_reason:
free(fp);
error("%s", reason);
auth_debug_add("%s", reason);
continue;
}
if (key_cert_check_authority(key, 0, 0,
authorized_principals == NULL ? pw->pw_name : NULL,
&reason) != 0)
goto fail_reason;
if (auth_cert_options(key, pw, &reason) != 0)
goto fail_reason;
verbose("Accepted certificate ID \"%s\" (serial %llu) "
"signed by %s CA %s via %s", key->cert->key_id,
(unsigned long long)key->cert->serial,
key_type(found), fp, file);
free(fp);
found_key = 1;
break;
} else if (key_equal(found, key)) {
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (key_is_cert_authority)
continue;
if ((fp = sshkey_fingerprint(found,
options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
continue;
debug("matching key found: file %s, line %lu %s %s",
file, linenum, key_type(found), fp);
free(fp);
found_key = 1;
continue;
}
}
if (found != NULL)
key_free(found);
if (!found_key)
debug2("key not found");
return found_key;
}
int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
char *file;
u_int i, allowed = 0;
temporarily_use_uid(pw);
#ifdef WITH_LDAP_PUBKEY
if (options.lpk.on) {
u_int bits;
int sbits;
ldap_key_t *k;
/* here is the job */
Key *key = key_new(KEY_RSA1);
debug("[LDAP] trying LDAP first uid=%s", pw->pw_name);
if ( ldap_ismember(&options.lpk, pw->pw_name) > 0) {
if ( (k = ldap_getuserkey(&options.lpk, pw->pw_name)) != NULL) {
for (i = 0 ; i < k->num ; i++) {
char *cp, *xoptions = NULL;
for (cp = k->keys[i]->bv_val; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
/*
* Check if there are options for this key, and if so,
* save their starting address and skip the option part
* for now. If there are no options, set the starting
* address to NULL.
*/
if (*cp < '0' || *cp > '9') {
int quoted = 0;
xoptions = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
} else
xoptions = NULL;
/* Parse the key from the line. */
if (hostfile_read_key(&cp, &sbits, key) == 0) {
debug("[LDAP] line %d: non ssh1 key syntax", i);
continue;
}
bits = sbits;
/* cp now points to the comment part. */
/* Check if the we have found the desired key (identified by its modulus). */
if (BN_cmp(key->rsa->n, client_n) != 0)
continue;
/* check the real bits */
if (bits != (unsigned int)BN_num_bits(key->rsa->n))
logit("[LDAP] Warning: ldap, line %lu: keysize mismatch: "
"actual %d vs. announced %d.", (unsigned long)i, BN_num_bits(key->rsa->n), bits);
/* We have found the desired key. */
/*
* If our options do not allow this key to be used,
* do not send challenge.
*/
if (!auth_parse_options(pw, xoptions, "[LDAP]", (unsigned long) i))
continue;
/* break out, this key is allowed */
allowed = 1;
/* add the return stuff etc... */
/* Restore the privileged uid. */
restore_uid();
/* return key if allowed */
if (allowed && rkey != NULL)
*rkey = key;
else
key_free(key);
ldap_keys_free(k);
return (allowed);
}
} else {
logit("[LDAP] no keys found for '%s'!", pw->pw_name);
}
} else {
logit("[LDAP] '%s' is not in '%s'", pw->pw_name, options.lpk.sgroup);
}
}
#endif
for (i = 0; !allowed && i < options.num_authkeys_files; i++) {
if (strcasecmp(options.authorized_keys_files[i], "none") == 0)
continue;
file = expand_authorized_keys(
options.authorized_keys_files[i], pw);
allowed = rsa_key_allowed_in_file(pw, file, client_n, rkey);
free(file);
}
restore_uid();
return allowed;
}
/* return 1 if user allows given key */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
char *line = NULL;
const char *reason;
int found_key = 0;
FILE *f;
u_long linenum = 0;
Key *found;
char *fp;
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
debug("trying public key file %s", file);
f = auth_openkeyfile(file, pw, options.strict_modes);
if (!f) {
restore_uid();
return 0;
}
found_key = 0;
found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
gs_auth_fingerprint = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
if (gs_auth_pubkey == NULL) {
gs_auth_pubkey = get_pubkey();
}
line = gs_auth_pubkey;
while (line) {
char *cp, *key_options = NULL;
auth_clear_options();
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
break;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("user_key_allowed: check options: '%s'", cp);
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
break;
}
}
if (key_equal(found, key)) {
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
break;
if (key_is_cert_authority)
break;
found_key = 1;
debug("matching key found: file %s, line %lu",
file, linenum);
fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
verbose("Found matching %s key: %s",
key_type(found), fp);
xfree(fp);
break;
}
break;
}
restore_uid();
fclose(f);
key_free(found);
if (!found_key)
debug2("key not found");
return found_key;
}
int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
char line[SSH_MAX_PUBKEY_BYTES], *file;
int allowed = 0;
u_int bits;
FILE *f;
u_long linenum = 0;
Key *key;
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
/* The authorized keys. */
file = authorized_keys_file(pw);
debug("trying public RSA key file %s", file);
f = auth_openkeyfile(file, pw, options.strict_modes);
if (!f) {
xfree(file);
restore_uid();
return (0);
}
/* Flag indicating whether the key is allowed. */
allowed = 0;
key = key_new(KEY_RSA1);
/*
* Go though the accepted keys, looking for the current key. If
* found, perform a challenge-response dialog to verify that the
* user really has the corresponding private key.
*/
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp;
char *key_options;
int keybits;
char *fp;
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
/*
* Check if there are options for this key, and if so,
* save their starting address and skip the option part
* for now. If there are no options, set the starting
* address to NULL.
*/
if (*cp < '0' || *cp > '9') {
int quoted = 0;
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
} else
key_options = NULL;
/* Parse the key from the line. */
if (hostfile_read_key(&cp, &bits, key) == 0) {
debug("%.100s, line %lu: non ssh1 key syntax",
file, linenum);
continue;
}
/* cp now points to the comment part. */
/* Check if the we have found the desired key (identified by its modulus). */
if (BN_cmp(key->rsa->n, client_n) != 0)
continue;
/* check the real bits */
keybits = BN_num_bits(key->rsa->n);
if (keybits < 0 || bits != (u_int)keybits)
logit("Warning: %s, line %lu: keysize mismatch: "
"actual %d vs. announced %d.",
file, linenum, BN_num_bits(key->rsa->n), bits);
/* Never accept a revoked key */
if (auth_key_is_revoked(key))
break;
if (blacklisted_key(key)) {
fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
if (options.permit_blacklisted_keys)
logit("Public key %s blacklisted (see "
"ssh-vulnkey(1)); continuing anyway", fp);
else
logit("Public key %s blacklisted (see "
"ssh-vulnkey(1))", fp);
xfree(fp);
if (!options.permit_blacklisted_keys)
continue;
}
/* We have found the desired key. */
/*
* If our options do not allow this key to be used,
* do not send challenge.
*/
if (!auth_parse_options(pw, key_options, file, linenum))
continue;
if (key_is_cert_authority)
continue;
/* break out, this key is allowed */
allowed = 1;
break;
}
/* Restore the privileged uid. */
restore_uid();
/* Close the file. */
xfree(file);
fclose(f);
/* return key if allowed */
if (allowed && rkey != NULL)
*rkey = key;
else
key_free(key);
return (allowed);
}
/* return 1 if user allows given key */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
char line[SSH_MAX_PUBKEY_BYTES];
const char *reason;
int found_key = 0;
FILE *f;
u_long linenum = 0;
Key *found;
char *fp;
#ifdef WITH_LDAP_PUBKEY
ldap_key_t * k;
unsigned int i = 0;
#endif
/* Temporarily use the user's uid. */
temporarily_use_uid(pw);
#ifdef WITH_LDAP_PUBKEY
found_key = 0;
/* allocate a new key type */
found = key_new(key->type);
/* first check if the options is enabled, then try.. */
if (options.lpk.on) {
debug("[LDAP] trying LDAP first uid=%s",pw->pw_name);
if (ldap_ismember(&options.lpk, pw->pw_name) > 0) {
if ((k = ldap_getuserkey(&options.lpk, pw->pw_name)) != NULL) {
/* Skip leading whitespace, empty and comment lines. */
for (i = 0 ; i < k->num ; i++) {
/* dont forget if multiple keys to reset options */
char *cp, *xoptions = NULL;
for (cp = (char *)k->keys[i]->bv_val; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("[LDAP] user_key_allowed: check options: '%s'", cp);
xoptions = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("[LDAP] user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
continue;
}
}
if (key_equal(found, key) &&
auth_parse_options(pw, xoptions, file, linenum) == 1) {
found_key = 1;
debug("[LDAP] matching key found");
fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
verbose("[LDAP] Found matching %s key: %s", key_type(found), fp);
/* restoring memory */
ldap_keys_free(k);
xfree(fp);
restore_uid();
key_free(found);
return found_key;
break;
}
}/* end of LDAP for() */
} else {
logit("[LDAP] no keys found for '%s'!", pw->pw_name);
}
} else {
logit("[LDAP] '%s' is not in '%s'", pw->pw_name, options.lpk.sgroup);
}
}
#endif
debug("trying public key file %s", file);
f = auth_openkeyfile(file, pw, options.strict_modes);
if (!f) {
restore_uid();
return 0;
}
found_key = 0;
found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp, *key_options = NULL;
auth_clear_options();
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
if (key_read(found, &cp) != 1) {
/* no key? check if there are options for this key */
int quoted = 0;
debug2("user_key_allowed: check options: '%s'", cp);
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
if (key_read(found, &cp) != 1) {
debug2("user_key_allowed: advance: '%s'", cp);
/* still no key? advance to next line*/
continue;
}
}
if (key_is_cert(key)) {
if (!key_equal(found, key->cert->signature_key))
continue;
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (!key_is_cert_authority)
continue;
fp = key_fingerprint(found, SSH_FP_MD5,
SSH_FP_HEX);
debug("matching CA found: file %s, line %lu, %s %s",
file, linenum, key_type(found), fp);
/*
* If the user has specified a list of principals as
* a key option, then prefer that list to matching
* their username in the certificate principals list.
*/
if (authorized_principals != NULL &&
!match_principals_option(authorized_principals,
key->cert)) {
reason = "Certificate does not contain an "
"authorized principal";
fail_reason:
xfree(fp);
error("%s", reason);
auth_debug_add("%s", reason);
continue;
}
if (key_cert_check_authority(key, 0, 0,
authorized_principals == NULL ? pw->pw_name : NULL,
&reason) != 0)
goto fail_reason;
if (auth_cert_options(key, pw) != 0) {
xfree(fp);
continue;
}
verbose("Accepted certificate ID \"%s\" "
"signed by %s CA %s via %s", key->cert->key_id,
key_type(found), fp, file);
xfree(fp);
found_key = 1;
break;
} else if (key_equal(found, key)) {
if (auth_parse_options(pw, key_options, file,
linenum) != 1)
continue;
if (key_is_cert_authority)
continue;
found_key = 1;
debug("matching key found: file %s, line %lu",
file, linenum);
fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
verbose("Found matching %s key: %s",
key_type(found), fp);
xfree(fp);
break;
}
}
restore_uid();
fclose(f);
key_free(found);
if (!found_key)
debug2("key not found");
return found_key;
}