1 |
9e22e20c
|
David Friesecký
|
from typing import Dict, List
|
2 |
f8b23532
|
David Friesecký
|
from sqlite3 import Connection, Cursor, Error
|
3 |
1636aefe
|
David Friesecký
|
|
4 |
181e1196
|
Jan Pašek
|
from src.model.certificate import Certificate
|
5 |
f8b23532
|
David Friesecký
|
from src.constants import *
|
6 |
e9e55282
|
David Friesecký
|
|
7 |
|
|
|
8 |
f8b23532
|
David Friesecký
|
class CertificateRepository:
|
9 |
25053504
|
David Friesecký
|
|
10 |
f8b23532
|
David Friesecký
|
def __init__(self, connection: Connection, cursor: Cursor):
|
11 |
a0602bad
|
David Friesecký
|
"""
|
12 |
f8b23532
|
David Friesecký
|
Constructor of the CertificateRepository object
|
13 |
a0602bad
|
David Friesecký
|
|
14 |
f8b23532
|
David Friesecký
|
:param connection: Instance of the Connection object
|
15 |
|
|
:param cursor: Instance of the Cursor object
|
16 |
a0602bad
|
David Friesecký
|
"""
|
17 |
|
|
|
18 |
f8b23532
|
David Friesecký
|
self.connection = connection
|
19 |
|
|
self.cursor = cursor
|
20 |
e9e55282
|
David Friesecký
|
|
21 |
805077f5
|
David Friesecký
|
def create(self, certificate: Certificate):
|
22 |
a0602bad
|
David Friesecký
|
"""
|
23 |
f8b23532
|
David Friesecký
|
Creates a certificate.
|
24 |
|
|
For root certificate (CA) the parent certificate id is modified to the same id (id == parent_id).
|
25 |
a0602bad
|
David Friesecký
|
|
26 |
f8b23532
|
David Friesecký
|
:param certificate: Instance of the Certificate object
|
27 |
a0602bad
|
David Friesecký
|
|
28 |
f8b23532
|
David Friesecký
|
:return: the result of whether the creation was successful
|
29 |
a0602bad
|
David Friesecký
|
"""
|
30 |
|
|
|
31 |
f8b23532
|
David Friesecký
|
try:
|
32 |
8b049f43
|
David Friesecký
|
if certificate.revocation_date != "" and certificate.revocation_reason == "":
|
33 |
|
|
certificate.revocation_reason = REV_REASON_UNSPECIFIED
|
34 |
|
|
elif certificate.revocation_date == "":
|
35 |
|
|
certificate.revocation_reason = ""
|
36 |
|
|
|
37 |
f8b23532
|
David Friesecký
|
sql = (f"INSERT INTO {TAB_CERTIFICATES} "
|
38 |
|
|
f"({COL_COMMON_NAME},"
|
39 |
|
|
f"{COL_VALID_FROM},"
|
40 |
|
|
f"{COL_VALID_TO},"
|
41 |
|
|
f"{COL_PEM_DATA},"
|
42 |
|
|
f"{COL_PRIVATE_KEY_ID},"
|
43 |
|
|
f"{COL_TYPE_ID},"
|
44 |
|
|
f"{COL_PARENT_ID})"
|
45 |
|
|
f"VALUES(?,?,?,?,?,?,?)")
|
46 |
|
|
values = [certificate.common_name,
|
47 |
|
|
certificate.valid_from,
|
48 |
|
|
certificate.valid_to,
|
49 |
|
|
certificate.pem_data,
|
50 |
|
|
certificate.private_key_id,
|
51 |
|
|
certificate.type_id,
|
52 |
|
|
certificate.parent_id]
|
53 |
|
|
self.cursor.execute(sql, values)
|
54 |
|
|
self.connection.commit()
|
55 |
|
|
|
56 |
|
|
last_id: int = self.cursor.lastrowid
|
57 |
|
|
|
58 |
f3125948
|
Stanislav Král
|
# TODO assure that this is correct
|
59 |
|
|
if certificate.type_id == ROOT_CA_ID:
|
60 |
f8b23532
|
David Friesecký
|
certificate.parent_id = last_id
|
61 |
093d06df
|
Stanislav Král
|
self.update(last_id, certificate)
|
62 |
f8b23532
|
David Friesecký
|
else:
|
63 |
fa72c969
|
Stanislav Král
|
for usage_id, usage_value in certificate.usages.items():
|
64 |
f8b23532
|
David Friesecký
|
if usage_value:
|
65 |
|
|
sql = (f"INSERT INTO {TAB_CERTIFICATE_USAGES} "
|
66 |
|
|
f"({COL_CERTIFICATE_ID},"
|
67 |
|
|
f"{COL_USAGE_TYPE_ID}) "
|
68 |
|
|
f"VALUES (?,?)")
|
69 |
|
|
values = [last_id, usage_id]
|
70 |
|
|
self.cursor.execute(sql, values)
|
71 |
|
|
self.connection.commit()
|
72 |
|
|
except Error as e:
|
73 |
58051326
|
David Friesecký
|
return e
|
74 |
f8b23532
|
David Friesecký
|
|
75 |
805077f5
|
David Friesecký
|
return last_id
|
76 |
f8b23532
|
David Friesecký
|
|
77 |
805077f5
|
David Friesecký
|
def read(self, certificate_id: int):
|
78 |
f8b23532
|
David Friesecký
|
"""
|
79 |
|
|
Reads (selects) a certificate.
|
80 |
e9e55282
|
David Friesecký
|
|
81 |
f8b23532
|
David Friesecký
|
:param certificate_id: ID of specific certificate
|
82 |
e9e55282
|
David Friesecký
|
|
83 |
f8b23532
|
David Friesecký
|
:return: instance of the Certificate object
|
84 |
|
|
"""
|
85 |
e9e55282
|
David Friesecký
|
|
86 |
f8b23532
|
David Friesecký
|
try:
|
87 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATES} "
|
88 |
|
|
f"WHERE {COL_ID} = ?")
|
89 |
|
|
values = [certificate_id]
|
90 |
|
|
self.cursor.execute(sql, values)
|
91 |
a7411982
|
Stanislav Král
|
certificate_row = self.cursor.fetchone()
|
92 |
e9e55282
|
David Friesecký
|
|
93 |
6f4a5f24
|
Captain_Trojan
|
if certificate_row is None:
|
94 |
|
|
return None
|
95 |
|
|
|
96 |
f8b23532
|
David Friesecký
|
sql = (f"SELECT * FROM {TAB_CERTIFICATE_USAGES} "
|
97 |
|
|
f"WHERE {COL_CERTIFICATE_ID} = ?")
|
98 |
|
|
self.cursor.execute(sql, values)
|
99 |
|
|
usage_rows = self.cursor.fetchall()
|
100 |
1636aefe
|
David Friesecký
|
|
101 |
|
|
usage_dict: Dict[int, bool] = {}
|
102 |
|
|
for usage_row in usage_rows:
|
103 |
f8b23532
|
David Friesecký
|
usage_dict[usage_row[2]] = True
|
104 |
|
|
|
105 |
|
|
certificate: Certificate = Certificate(certificate_row[0],
|
106 |
|
|
certificate_row[1],
|
107 |
|
|
certificate_row[2],
|
108 |
|
|
certificate_row[3],
|
109 |
|
|
certificate_row[4],
|
110 |
|
|
certificate_row[7],
|
111 |
58051326
|
David Friesecký
|
certificate_row[8],
|
112 |
|
|
certificate_row[9],
|
113 |
|
|
usage_dict,
|
114 |
|
|
certificate_row[5],
|
115 |
|
|
certificate_row[6])
|
116 |
f8b23532
|
David Friesecký
|
except Error as e:
|
117 |
58051326
|
David Friesecký
|
return e
|
118 |
f8b23532
|
David Friesecký
|
|
119 |
805077f5
|
David Friesecký
|
if len(certificate_row) > 0:
|
120 |
|
|
return certificate
|
121 |
|
|
else:
|
122 |
|
|
return None
|
123 |
f8b23532
|
David Friesecký
|
|
124 |
58051326
|
David Friesecký
|
def read_all(self, filter_type: int = None):
|
125 |
9e22e20c
|
David Friesecký
|
"""
|
126 |
|
|
Reads (selects) all certificates (with type).
|
127 |
|
|
|
128 |
|
|
:param filter_type: ID of certificate type from CertificateTypes table
|
129 |
|
|
|
130 |
|
|
:return: list of certificates
|
131 |
|
|
"""
|
132 |
|
|
|
133 |
|
|
try:
|
134 |
|
|
sql_extension = ""
|
135 |
|
|
values = []
|
136 |
|
|
if filter_type is not None:
|
137 |
|
|
sql_extension = (f" WHERE {COL_TYPE_ID} = ("
|
138 |
6f64f062
|
Stanislav Král
|
f"SELECT {COL_ID} FROM {TAB_CERTIFICATE_TYPES} WHERE {COL_ID} = ?)")
|
139 |
9e22e20c
|
David Friesecký
|
values = [filter_type]
|
140 |
|
|
|
141 |
8b049f43
|
David Friesecký
|
sql = f"SELECT * FROM {TAB_CERTIFICATES}{sql_extension}"
|
142 |
9e22e20c
|
David Friesecký
|
self.cursor.execute(sql, values)
|
143 |
|
|
certificate_rows = self.cursor.fetchall()
|
144 |
|
|
|
145 |
|
|
certificates: List[Certificate] = []
|
146 |
|
|
for certificate_row in certificate_rows:
|
147 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATE_USAGES} "
|
148 |
|
|
f"WHERE {COL_CERTIFICATE_ID} = ?")
|
149 |
|
|
values = [certificate_row[0]]
|
150 |
|
|
self.cursor.execute(sql, values)
|
151 |
|
|
usage_rows = self.cursor.fetchall()
|
152 |
|
|
|
153 |
|
|
usage_dict: Dict[int, bool] = {}
|
154 |
|
|
for usage_row in usage_rows:
|
155 |
|
|
usage_dict[usage_row[2]] = True
|
156 |
|
|
|
157 |
|
|
certificates.append(Certificate(certificate_row[0],
|
158 |
|
|
certificate_row[1],
|
159 |
|
|
certificate_row[2],
|
160 |
|
|
certificate_row[3],
|
161 |
|
|
certificate_row[4],
|
162 |
|
|
certificate_row[7],
|
163 |
58051326
|
David Friesecký
|
certificate_row[8],
|
164 |
|
|
certificate_row[9],
|
165 |
|
|
usage_dict,
|
166 |
|
|
certificate_row[5],
|
167 |
|
|
certificate_row[6]))
|
168 |
9e22e20c
|
David Friesecký
|
except Error as e:
|
169 |
58051326
|
David Friesecký
|
return e
|
170 |
9e22e20c
|
David Friesecký
|
|
171 |
58051326
|
David Friesecký
|
if len(certificates) > 0:
|
172 |
|
|
return certificates
|
173 |
|
|
else:
|
174 |
|
|
return None
|
175 |
9e22e20c
|
David Friesecký
|
|
176 |
58051326
|
David Friesecký
|
def update(self, certificate_id: int, certificate: Certificate):
|
177 |
a0602bad
|
David Friesecký
|
"""
|
178 |
f8b23532
|
David Friesecký
|
Updates a certificate.
|
179 |
|
|
If the parameter of certificate (Certificate object) is not to be changed,
|
180 |
|
|
the same value must be specified.
|
181 |
a0602bad
|
David Friesecký
|
|
182 |
|
|
:param certificate_id: ID of specific certificate
|
183 |
f8b23532
|
David Friesecký
|
:param certificate: Instance of the Certificate object
|
184 |
a0602bad
|
David Friesecký
|
|
185 |
|
|
:return: the result of whether the updation was successful
|
186 |
|
|
"""
|
187 |
|
|
|
188 |
f8b23532
|
David Friesecký
|
try:
|
189 |
8b049f43
|
David Friesecký
|
if certificate.revocation_date != "" and certificate.revocation_reason == "":
|
190 |
|
|
certificate.revocation_reason = REV_REASON_UNSPECIFIED
|
191 |
|
|
elif certificate.revocation_date == "":
|
192 |
|
|
certificate.revocation_reason = ""
|
193 |
|
|
|
194 |
f8b23532
|
David Friesecký
|
sql = (f"UPDATE {TAB_CERTIFICATES} "
|
195 |
|
|
f"SET {COL_COMMON_NAME} = ?, "
|
196 |
|
|
f"{COL_VALID_FROM} = ?, "
|
197 |
|
|
f"{COL_VALID_TO} = ?, "
|
198 |
|
|
f"{COL_PEM_DATA} = ?, "
|
199 |
|
|
f"{COL_PRIVATE_KEY_ID} = ?, "
|
200 |
|
|
f"{COL_TYPE_ID} = ?, "
|
201 |
|
|
f"{COL_PARENT_ID} = ? "
|
202 |
|
|
f"WHERE {COL_ID} = ?")
|
203 |
|
|
values = [certificate.common_name,
|
204 |
|
|
certificate.valid_from,
|
205 |
|
|
certificate.valid_to,
|
206 |
|
|
certificate.pem_data,
|
207 |
|
|
certificate.private_key_id,
|
208 |
|
|
certificate.type_id,
|
209 |
805077f5
|
David Friesecký
|
certificate.parent_id,
|
210 |
|
|
certificate_id]
|
211 |
f8b23532
|
David Friesecký
|
self.cursor.execute(sql, values)
|
212 |
|
|
self.connection.commit()
|
213 |
|
|
|
214 |
|
|
sql = (f"DELETE FROM {TAB_CERTIFICATE_USAGES} "
|
215 |
|
|
f"WHERE {COL_CERTIFICATE_ID} = ?")
|
216 |
|
|
values = [certificate_id]
|
217 |
|
|
self.cursor.execute(sql, values)
|
218 |
|
|
self.connection.commit()
|
219 |
|
|
|
220 |
f3125948
|
Stanislav Král
|
# iterate over usage pairs
|
221 |
|
|
for usage_id, usage_value in certificate.usages.items():
|
222 |
f8b23532
|
David Friesecký
|
if usage_value:
|
223 |
|
|
sql = (f"INSERT INTO {TAB_CERTIFICATE_USAGES} "
|
224 |
|
|
f"({COL_CERTIFICATE_ID},"
|
225 |
|
|
f"{COL_USAGE_TYPE_ID}) "
|
226 |
|
|
f"VALUES (?,?)")
|
227 |
|
|
values = [certificate_id, usage_id]
|
228 |
|
|
self.cursor.execute(sql, values)
|
229 |
|
|
self.connection.commit()
|
230 |
|
|
except Error as e:
|
231 |
58051326
|
David Friesecký
|
return e
|
232 |
f8b23532
|
David Friesecký
|
|
233 |
8b049f43
|
David Friesecký
|
if self.cursor.rowcount > 0:
|
234 |
|
|
return True
|
235 |
|
|
|
236 |
|
|
return False
|
237 |
e9e55282
|
David Friesecký
|
|
238 |
58051326
|
David Friesecký
|
def delete(self, certificate_id: int):
|
239 |
a0602bad
|
David Friesecký
|
"""
|
240 |
|
|
Deletes a certificate
|
241 |
|
|
|
242 |
|
|
:param certificate_id: ID of specific certificate
|
243 |
|
|
|
244 |
|
|
:return: the result of whether the deletion was successful
|
245 |
|
|
"""
|
246 |
|
|
|
247 |
f8b23532
|
David Friesecký
|
try:
|
248 |
|
|
sql = (f"DELETE FROM {TAB_CERTIFICATES} "
|
249 |
|
|
f"WHERE {COL_ID} = ?")
|
250 |
|
|
values = [certificate_id]
|
251 |
|
|
self.cursor.execute(sql, values)
|
252 |
|
|
self.connection.commit()
|
253 |
|
|
except Error as e:
|
254 |
58051326
|
David Friesecký
|
return e
|
255 |
f8b23532
|
David Friesecký
|
|
256 |
45744020
|
Stanislav Král
|
return self.cursor.rowcount > 0
|
257 |
58051326
|
David Friesecký
|
|
258 |
|
|
def set_certificate_revoked(
|
259 |
8b049f43
|
David Friesecký
|
self, certificate_id: int, revocation_date: str, revocation_reason: str = REV_REASON_UNSPECIFIED):
|
260 |
58051326
|
David Friesecký
|
"""
|
261 |
|
|
Revoke a certificate
|
262 |
|
|
|
263 |
|
|
:param certificate_id: ID of specific certificate
|
264 |
|
|
:param revocation_date: Date, when the certificate is revoked
|
265 |
|
|
:param revocation_reason: Reason of the revocation
|
266 |
|
|
|
267 |
8b049f43
|
David Friesecký
|
:return:
|
268 |
|
|
the result of whether the revocation was successful OR
|
269 |
|
|
sqlite3.Error if an exception is thrown
|
270 |
58051326
|
David Friesecký
|
"""
|
271 |
|
|
|
272 |
|
|
try:
|
273 |
8b049f43
|
David Friesecký
|
if revocation_date != "" and revocation_reason == "":
|
274 |
|
|
revocation_reason = REV_REASON_UNSPECIFIED
|
275 |
|
|
elif revocation_date == "":
|
276 |
|
|
return False
|
277 |
|
|
|
278 |
58051326
|
David Friesecký
|
sql = (f"UPDATE {TAB_CERTIFICATES} "
|
279 |
|
|
f"SET {COL_REVOCATION_DATE} = ?, "
|
280 |
8b049f43
|
David Friesecký
|
f"{COL_REVOCATION_REASON} = ? "
|
281 |
58051326
|
David Friesecký
|
f"WHERE {COL_ID} = ? AND ({COL_REVOCATION_DATE} IS NULL OR {COL_REVOCATION_DATE} = '')")
|
282 |
|
|
values = [revocation_date,
|
283 |
|
|
revocation_reason,
|
284 |
|
|
certificate_id]
|
285 |
|
|
self.cursor.execute(sql, values)
|
286 |
|
|
self.connection.commit()
|
287 |
|
|
except Error as e:
|
288 |
|
|
return e
|
289 |
|
|
|
290 |
8b049f43
|
David Friesecký
|
if self.cursor.rowcount > 0:
|
291 |
|
|
return True
|
292 |
|
|
|
293 |
|
|
return False
|
294 |
58051326
|
David Friesecký
|
|
295 |
|
|
def clear_certificate_revocation(self, certificate_id: int):
|
296 |
|
|
"""
|
297 |
|
|
Clear revocation of a certificate
|
298 |
|
|
|
299 |
|
|
:param certificate_id: ID of specific certificate
|
300 |
|
|
|
301 |
8b049f43
|
David Friesecký
|
:return:
|
302 |
|
|
the result of whether the clear revocation was successful OR
|
303 |
|
|
sqlite3.Error if an exception is thrown
|
304 |
58051326
|
David Friesecký
|
"""
|
305 |
|
|
|
306 |
|
|
try:
|
307 |
|
|
sql = (f"UPDATE {TAB_CERTIFICATES} "
|
308 |
|
|
f"SET {COL_REVOCATION_DATE} = '', "
|
309 |
8b049f43
|
David Friesecký
|
f"{COL_REVOCATION_REASON} = '' "
|
310 |
58051326
|
David Friesecký
|
f"WHERE {COL_ID} = ?")
|
311 |
|
|
values = [certificate_id]
|
312 |
|
|
self.cursor.execute(sql, values)
|
313 |
|
|
self.connection.commit()
|
314 |
|
|
except Error as e:
|
315 |
|
|
return e
|
316 |
|
|
|
317 |
|
|
return True
|
318 |
|
|
|
319 |
|
|
def get_all_revoked_by(self, certificate_id: int):
|
320 |
|
|
"""
|
321 |
|
|
Get list of the revoked certificates that are direct descendants of the certificate with the ID
|
322 |
|
|
|
323 |
|
|
:param certificate_id: ID of specific certificate
|
324 |
|
|
|
325 |
|
|
:return:
|
326 |
8b049f43
|
David Friesecký
|
list of the certificates OR
|
327 |
|
|
None if the list is empty OR
|
328 |
|
|
sqlite3.Error if an exception is thrown
|
329 |
58051326
|
David Friesecký
|
"""
|
330 |
|
|
|
331 |
|
|
try:
|
332 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATES} "
|
333 |
|
|
f"WHERE {COL_PARENT_ID} = ? AND {COL_REVOCATION_DATE} IS NOT NULL AND {COL_REVOCATION_DATE} != ''")
|
334 |
|
|
values = [certificate_id]
|
335 |
|
|
self.cursor.execute(sql, values)
|
336 |
|
|
certificate_rows = self.cursor.fetchall()
|
337 |
|
|
|
338 |
|
|
certificates: List[Certificate] = []
|
339 |
|
|
for certificate_row in certificate_rows:
|
340 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATE_USAGES} "
|
341 |
|
|
f"WHERE {COL_CERTIFICATE_ID} = ?")
|
342 |
|
|
values = [certificate_row[0]]
|
343 |
|
|
self.cursor.execute(sql, values)
|
344 |
|
|
usage_rows = self.cursor.fetchall()
|
345 |
|
|
|
346 |
|
|
usage_dict: Dict[int, bool] = {}
|
347 |
|
|
for usage_row in usage_rows:
|
348 |
|
|
usage_dict[usage_row[2]] = True
|
349 |
|
|
|
350 |
|
|
certificates.append(Certificate(certificate_row[0],
|
351 |
|
|
certificate_row[1],
|
352 |
|
|
certificate_row[2],
|
353 |
|
|
certificate_row[3],
|
354 |
|
|
certificate_row[4],
|
355 |
|
|
certificate_row[7],
|
356 |
|
|
certificate_row[8],
|
357 |
|
|
certificate_row[9],
|
358 |
|
|
usage_dict,
|
359 |
|
|
certificate_row[5],
|
360 |
|
|
certificate_row[6]))
|
361 |
|
|
except Error as e:
|
362 |
|
|
return e
|
363 |
|
|
|
364 |
|
|
if len(certificates) > 0:
|
365 |
|
|
return certificates
|
366 |
|
|
else:
|
367 |
|
|
return None
|
368 |
|
|
|
369 |
|
|
def get_all_issued_by(self, certificate_id: int):
|
370 |
|
|
"""
|
371 |
|
|
Get list of the certificates that are direct descendants of the certificate with the ID
|
372 |
|
|
|
373 |
|
|
:param certificate_id: ID of specific certificate
|
374 |
|
|
|
375 |
|
|
:return:
|
376 |
8b049f43
|
David Friesecký
|
list of the certificates OR
|
377 |
|
|
None if the list is empty OR
|
378 |
|
|
sqlite3.Error if an exception is thrown
|
379 |
58051326
|
David Friesecký
|
"""
|
380 |
|
|
|
381 |
|
|
try:
|
382 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATES} "
|
383 |
8b049f43
|
David Friesecký
|
f"WHERE {COL_PARENT_ID} = ? AND {COL_ID} != ?")
|
384 |
|
|
values = [certificate_id, certificate_id]
|
385 |
58051326
|
David Friesecký
|
self.cursor.execute(sql, values)
|
386 |
|
|
certificate_rows = self.cursor.fetchall()
|
387 |
|
|
|
388 |
|
|
certificates: List[Certificate] = []
|
389 |
|
|
for certificate_row in certificate_rows:
|
390 |
|
|
sql = (f"SELECT * FROM {TAB_CERTIFICATE_USAGES} "
|
391 |
|
|
f"WHERE {COL_CERTIFICATE_ID} = ?")
|
392 |
|
|
values = [certificate_row[0]]
|
393 |
|
|
self.cursor.execute(sql, values)
|
394 |
|
|
usage_rows = self.cursor.fetchall()
|
395 |
|
|
|
396 |
|
|
usage_dict: Dict[int, bool] = {}
|
397 |
|
|
for usage_row in usage_rows:
|
398 |
|
|
usage_dict[usage_row[2]] = True
|
399 |
|
|
|
400 |
|
|
certificates.append(Certificate(certificate_row[0],
|
401 |
|
|
certificate_row[1],
|
402 |
|
|
certificate_row[2],
|
403 |
|
|
certificate_row[3],
|
404 |
|
|
certificate_row[4],
|
405 |
|
|
certificate_row[7],
|
406 |
|
|
certificate_row[8],
|
407 |
|
|
certificate_row[9],
|
408 |
|
|
usage_dict,
|
409 |
|
|
certificate_row[5],
|
410 |
|
|
certificate_row[6]))
|
411 |
|
|
except Error as e:
|
412 |
|
|
return e
|
413 |
|
|
|
414 |
|
|
if len(certificates) > 0:
|
415 |
|
|
return certificates
|
416 |
|
|
else:
|
417 |
|
|
return None
|