1VERIFY(1) OpenSSL VERIFY(1)
2
6 verify - Utility to verify certificates.
7
9 openssl verify [-CApath directory] [-CAfile file] [-purpose purpose]
10 [-untrusted file] [-help] [-issuer_checks] [-verbose] [-] [certifi‐
11 cates]
12
14 The verify command verifies certificate chains.
15
17 -CApath directory
18 A directory of trusted certificates. The certificates should have
19 names of the form: hash.0 or have symbolic links to them of this
20 form ("hash" is the hashed certificate subject name: see the -hash
21 option of the x509 utility). Under Unix the c_rehash script will
22 automatically create symbolic links to a directory of certificates.
23 -CAfile file
25 A file of trusted certificates. The file should contain multiple
26 certificates in PEM format concatenated together.
27 -untrusted file
29 A file of untrusted certificates. The file should contain multiple
30 certificates
31 -purpose purpose
33 the intended use for the certificate. Without this option no chain
34 verification will be done. Currently accepted uses are sslclient,
35 sslserver, nssslserver, smimesign, smimeencrypt. See the VERIFY
36 OPERATION section for more information.
37 -help
39 prints out a usage message.
40 -verbose
42 print extra information about the operations being performed.
43 -issuer_checks
45 print out diagnostics relating to searches for the issuer certifi‐
46 cate of the current certificate. This shows why each candidate
47 issuer certificate was rejected. However the presence of rejection
48 messages does not itself imply that anything is wrong: during the
49 normal verify process several rejections may take place.
50 - marks the last option. All arguments following this are assumed to
52 be certificate files. This is useful if the first certificate file‐
53 name begins with a -.
54 certificates
56 one or more certificates to verify. If no certificate filenames are
57 included then an attempt is made to read a certificate from stan‐
58 dard input. They should all be in PEM format.
59
61 The verify program uses the same functions as the internal SSL and
62 S/MIME verification, therefore this description applies to these verify
63 operations too.
64 There is one crucial difference between the verify operations performed
66 by the verify program: wherever possible an attempt is made to continue
67 after an error whereas normally the verify operation would halt on the
68 first error. This allows all the problems with a certificate chain to
69 be determined.
70 The verify operation consists of a number of separate steps.
72 Firstly a certificate chain is built up starting from the supplied cer‐
74 tificate and ending in the root CA. It is an error if the whole chain
75 cannot be built up. The chain is built up by looking up the issuers
76 certificate of the current certificate. If a certificate is found which
77 is its own issuer it is assumed to be the root CA.
78 The process of 'looking up the issuers certificate' itself involves a
80 number of steps. In versions of OpenSSL before 0.9.5a the first cer‐
81 tificate whose subject name matched the issuer of the current certifi‐
82 cate was assumed to be the issuers certificate. In OpenSSL 0.9.6 and
83 later all certificates whose subject name matches the issuer name of
84 the current certificate are subject to further tests. The relevant
85 authority key identifier components of the current certificate (if
86 present) must match the subject key identifier (if present) and issuer
87 and serial number of the candidate issuer, in addition the keyUsage
88 extension of the candidate issuer (if present) must permit certificate
89 signing.
90 The lookup first looks in the list of untrusted certificates and if no
92 match is found the remaining lookups are from the trusted certificates.
93 The root CA is always looked up in the trusted certificate list: if the
94 certificate to verify is a root certificate then an exact match must be
95 found in the trusted list.
96 The second operation is to check every untrusted certificate's exten‐
98 sions for consistency with the supplied purpose. If the -purpose option
99 is not included then no checks are done. The supplied or "leaf" cer‐
100 tificate must have extensions compatible with the supplied purpose and
101 all other certificates must also be valid CA certificates. The precise
102 extensions required are described in more detail in the CERTIFICATE
103 EXTENSIONS section of the x509 utility.
104 The third operation is to check the trust settings on the root CA. The
106 root CA should be trusted for the supplied purpose. For compatibility
107 with previous versions of SSLeay and OpenSSL a certificate with no
108 trust settings is considered to be valid for all purposes.
109 The final operation is to check the validity of the certificate chain.
111 The validity period is checked against the current system time and the
112 notBefore and notAfter dates in the certificate. The certificate signa‐
113 tures are also checked at this point.
114 If all operations complete successfully then certificate is considered
116 valid. If any operation fails then the certificate is not valid.
117
119 When a verify operation fails the output messages can be somewhat cryp‐
120 tic. The general form of the error message is:
121 server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
123 error 24 at 1 depth lookup:invalid CA certificate
124 The first line contains the name of the certificate being verified fol‐
126 lowed by the subject name of the certificate. The second line contains
127 the error number and the depth. The depth is number of the certificate
128 being verified when a problem was detected starting with zero for the
129 certificate being verified itself then 1 for the CA that signed the
130 certificate and so on. Finally a text version of the error number is
131 presented.
132 An exhaustive list of the error codes and messages is shown below, this
134 also includes the name of the error code as defined in the header file
135 x509_vfy.h Some of the error codes are defined but never returned:
136 these are described as "unused".
137 0 X509_V_OK: ok
139 the operation was successful.
140 2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certifi‐
142 cate
143 the issuer certificate could not be found: this occurs if the
144 issuer certificate of an untrusted certificate cannot be found.
145 3 X509_V_ERR_UNABLE_TO_GET_CRL unable to get certificate CRL
147 the CRL of a certificate could not be found. Unused.
148 4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt cer‐
150 tificate's signature
151 the certificate signature could not be decrypted. This means that
152 the actual signature value could not be determined rather than it
153 not matching the expected value, this is only meaningful for RSA
154 keys.
155 5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's
157 signature
158 the CRL signature could not be decrypted: this means that the
159 actual signature value could not be determined rather than it not
160 matching the expected value. Unused.
161 6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode
163 issuer public key
164 the public key in the certificate SubjectPublicKeyInfo could not be
165 read.
166 7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure
168 the signature of the certificate is invalid.
169 8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure
171 the signature of the certificate is invalid. Unused.
172 9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid
174 the certificate is not yet valid: the notBefore date is after the
175 current time.
176 10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired
178 the certificate has expired: that is the notAfter date is before
179 the current time.
180 11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid
182 the CRL is not yet valid. Unused.
183 12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired
185 the CRL has expired. Unused.
186 13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certifi‐
188 cate's notBefore field
189 the certificate notBefore field contains an invalid time.
190 14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certifi‐
192 cate's notAfter field
193 the certificate notAfter field contains an invalid time.
194 15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's
196 lastUpdate field
197 the CRL lastUpdate field contains an invalid time. Unused.
198 16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's
200 nextUpdate field
201 the CRL nextUpdate field contains an invalid time. Unused.
202 17 X509_V_ERR_OUT_OF_MEM: out of memory
204 an error occurred trying to allocate memory. This should never hap‐
205 pen.
206 18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate
208 the passed certificate is self signed and the same certificate can‐
209 not be found in the list of trusted certificates.
210 19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in
212 certificate chain
213 the certificate chain could be built up using the untrusted cer‐
214 tificates but the root could not be found locally.
215 20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local
217 issuer certificate
218 the issuer certificate of a locally looked up certificate could not
219 be found. This normally means the list of trusted certificates is
220 not complete.
221 21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the
223 first certificate
224 no signatures could be verified because the chain contains only one
225 certificate and it is not self signed.
226 22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long
228 the certificate chain length is greater than the supplied maximum
229 depth. Unused.
230 23 X509_V_ERR_CERT_REVOKED: certificate revoked
232 the certificate has been revoked. Unused.
233 24 X509_V_ERR_INVALID_CA: invalid CA certificate
235 a CA certificate is invalid. Either it is not a CA or its exten‐
236 sions are not consistent with the supplied purpose.
237 25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded
239 the basicConstraints pathlength parameter has been exceeded.
240 26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose
242 the supplied certificate cannot be used for the specified purpose.
243 27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted
245 the root CA is not marked as trusted for the specified purpose.
246 28 X509_V_ERR_CERT_REJECTED: certificate rejected
248 the root CA is marked to reject the specified purpose.
249 29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch
251 the current candidate issuer certificate was rejected because its
252 subject name did not match the issuer name of the current certifi‐
253 cate. Only displayed when the -issuer_checks option is set.
254 30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier
256 mismatch
257 the current candidate issuer certificate was rejected because its
258 subject key identifier was present and did not match the authority
259 key identifier current certificate. Only displayed when the
260 -issuer_checks option is set.
261 31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial
263 number mismatch
264 the current candidate issuer certificate was rejected because its
265 issuer name and serial number was present and did not match the
266 authority key identifier of the current certificate. Only displayed
267 when the -issuer_checks option is set.
268 32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certifi‐
270 cate signing
271 the current candidate issuer certificate was rejected because its
272 keyUsage extension does not permit certificate signing.
273 50 X509_V_ERR_APPLICATION_VERIFICATION: application verification fail‐
275 ure
276 an application specific error. Unused.
277
279 Although the issuer checks are a considerably improvement over the old
280 technique they still suffer from limitations in the underlying
281 X509_LOOKUP API. One consequence of this is that trusted certificates
282 with matching subject name must either appear in a file (as specified
283 by the -CAfile option) or a directory (as specified by -CApath. If they
284 occur in both then only the certificates in the file will be recog‐
285 nised.
286 Previous versions of OpenSSL assume certificates with matching subject
288 name are identical and mishandled them.
289
291 x509(1)
2920.9.8b 2001-10-08 VERIFY(1)