@jay changing it could still be safe as it was completely broken before and thus was never parsed successfully anyway! libcurl had something similar to that for small numbers prior to your change but it would have to be modified to take into account negative numbers. On some other version/environment, serial number can be much shorter). Juraj Sep 7, 2015 @ 15:16. Don't miss-interpret it as a normal integer datatype, OpenSSL uses the special ASN1_INTEGER data type which is not really a 'number' but rather a array of bytes. You can also provide a link from the web. org> Date: 2006-02-26 3:49:42 Message-ID: 20060226034942.GA68453 openssl ! What libcurl is doing right now is the same as the OpenSSL 'serial' format, not the OpenSSL 'Serial Number' format. Another thing that looks strange in that area is output of negative serial numbers. (tested with OpenSSL 1.1.1c. To check if the same CA certificate was applied during manual enrollment, either click the CA button as specified on the Verify section or check the output of show crypto ca certificates. So it doesn't look like much of an issue anymore. Create a certificate using openssl ca -batch -config openssl.cnf -in some.csr -out some.crt; Re-run openssl ca -batch -config openssl.cnf -in some.csr -out some.crt; Expected behaviour: The command should either overwrite some.crt with a new valid certificate or fail and not modify some.crt at all. See the following for details: http://www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml. Verify that the CRL is valid (i.e., signed by the issuer certificate): $ openssl crl -in rapidssl.crl -inform DER -CAfile issuer.crt -noout verify OK. Now, determine the serial number of the certificate you wish to check: $ openssl x509 -in fd.crt -noout -serial serial=0FE760 For other octets retrieved via CURLINFO_CERTINFO like rsa and signature a colon is used as the separator for each octet. Similar to the [ req ] section, the [ ca ] section defines default parameter values for the openssl ca command— the interface to OpenSSL’s minimal CA service. And finally the -out option to tell it to write the certificate to ca-cert.pem file. Look for new_certs_dir definition in the openssl.cnf file of your authority or -outdir option in the scripts). Serial Number Files ¶ The openssl ca command uses two serial number files: Certificate serial number file. Create CA Certificate: Landed in aff153f. 1013, then execute the following command: The -keyfile and -cert mentioned in Nilesh's answer are only required if that deviates from your openssl.cnf settings. (max 2 MiB). Rich Salz recommended me this SSL Cookbook Navigate to Advanced -> Encryption and then click on View Certificates. That's probably fine given that nobody's used it yet, but if you want I can change it to their 'Serial Number' format as seen in X509_print_ex. # Sign the certificate signing request openssl x509 -req -days 365 -in signreq.csr -signkey privkey.pem -out certificate.pem View certificate details. Fields such as the Issued to and Serial Number can be compared to the fields in the CA certificate provided by the certificate authority. Return Values. Already on GitHub? Then we use the -keyout option to tell openssl to write the created private key to ca-key.pem file. Thanks a lot! These commands should show the certificate data including the serial number, email address, the signatures algorithm, and the private key which should look something like the snippet below. I'm not sure why not for serial number. @TobiasKienzler This solved my problem. X509_V_ERR_KEYUSAGE_NO_CERTSIGN . Certificate Authority Functions¶ When setting up a new CA on a system, make sure index.txt and serial exist (empty and set to 01, respectively), and create directories private and newcert. OpenSSL in their output uses the colon as a separator but only for long serial numbers (see openssl x509 -noout -text -in cert). openssl req -text -noout -verify -in testmastersite.csr. You may want to check it to retrieve your certificate. In next section, we will go through OpenSSL commands to decode the contents of the Certificate. This will generate a random 128-bit serial number to start with. To generate a ce r tificate with SAN extension using OpenSSL, we need to create a config first. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. It is therefore piped to cut -d'=' -f2which splits the output on the equal sign and outputs the second part - 0123456709AB. http://curl.haxx.se/docs/adv_20150429.html. Sign in Perhaps it should be a full answer. This command will verify the key and its validity: openssl rsa -in testmastersite.key -check. privacy statement. The snprintf call attempts to create a colon separated string but just the hexadecimal value is being inserted. -CApath option tells openssl where to look for the certificates. X509_set_serialNumber() returns 1 for success and 0 for failure. to your account. In lib/vtls/openssl/c in version 7.41.0 at line 2466 we have: Since bufp gets pushed to return a certificate serial number setting the first character to null will always cause null to be returned, therefore, line 2477 should be removed. Alternatively you can also change /etc/ssl/index.txt.attr to contain the line. > > I don’t understand what attack you are concerned about, but the size of the serial number should not matter for *any* certificate. Unfortunately you need a certificate present to revoke it. Similarly, EJBCA and NSS have the same vulnerability among other 5 open source libraries. Each time a new certificate is created, OpenSSL writes an entry in index.txt. OpenSSL is a CLI (Command Line Tool) which can be used to secure the server to generate public key infrastructure (PKI) and HTTPS. Enter Mozilla Certificate Manager Click the tab Your Certificates or the tab of your choice. As an example, let’s use the openssl to check the SSL certificate expiration date of the https://www.shellhacks.com website: $ echo | openssl s_client -servername www.shellhacks.com -connect www.shellhacks.com:443 2>/dev/null | openssl x509 -noout -dates notBefore=Mar 18 10:55:00 2017 GMT notAfter=Jun 16 10:55:00 2017 GMT If the chosen-prefix collision of so… Thus, the canonical way of doing is something along : However, I add this answer to note that, with current versions, openssl ca -revoke ... seems to only update the index.txt file (it will nevertheless ask for the private key password, which is questioned there) so if you really don't have any certificate backup but still have the index.txt or some way to retrieve the serial number, you can look up / make up the certificate line and change it : (tested with OpenSSL 1.1.1c. That is sent to sed. I should've tested the output of a large negative serial number to be sure. To view the details of a certificate and verify the information, you can use the following command: # Review a certificate openssl x509 -text -noout -in certificate… Now let’s amend openssl.root.cnf with the missing [ ca ] section. I assumed they were based on what I was reading. X509_get_serialNumber() and X509_get0_serialNumber() return an ASN1_INTEGER structure. I also glanced over the negative thing before I ignored it but you're right, we should make sure to output the same serial number that openssl does, even when negative. A smaller number that fits in a long like -2000 shows Serial Number: -2000 (-0x7d0) and serial=-07D0. Edit openssl.cnf - change default_days, certificate and private_key, possibly key size (1024, 1280, 1536, 2048) to whatever is desired. X509_set_serialNumber() sets the serial number of certificate x to serial. These options requires you to have a file called "\demoCA\serial" under the current directory to be used as a serial number register. Data: Version: 3 (0x2) Serial Number: xxxxxxxxxxxxxxxx Signature Algorithm: sha1WithRSAEncryption Issuer: CN=My organisation RootCA Validity Not Before: May 20 13:11:34 2016 GMT Not After : May 20 13:21:34 2021 GMT Subject: DC=org, DC=example, CN=My organisation Issuing CA It is possible to forge certificates based on the method presented by Stevens. Without the "-set_serial" option, the resulting certificate will have random serial number. Depending on what you're looking for. Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks option. Yes, you can sign you own CSR (Certificate Sign Request) with a given serial number using the OpenSSL "req -x509 -set_serial" command as shown below. I haven't tried this but it looks like you need something like this. openssl x509 -noout -serial -in cert.pemwill output the serial number of the certificate, but in the format serial=0123456709AB. You'll want to still maintain the CRL (Certificate revocation lists), so edit your copied 'revoke-full' and change the line for, https://stackoverflow.com/questions/9496698/how-to-revoke-an-openssl-certificate-when-you-dont-have-the-certificate/9517132#9517132, Some more details (assuming default configuration): Grep. Fixing this error is easy. This is the certificate that we want to decode (Part of the certificate displayed below is erased due to security concerns). Though changing it to be consistent with the others at this point may break a user's parsing of it. Certificate: Data: Version: 3 (0x2) Serial Number: For example if the CA certificate file is called "mycacert.pem" it expects to find a serial number file called "mycacert.srl". Shame, the i2c method still looks more correct to me and easier to parse! Finally, we created two files, index.txt and serial. You have to set an initial value like "1000" in the file. The openssl ca -config openssl.cnf -gencrl -crldays 30 -out crl.pem will be the actual step to revoke the certificate, producing a signed list using the private key of the authority. Per standard, the serial number should be unique per CA, however it is up to the CA code to enforce this. Also, if something goes wrong, you’ll probably have a much harder time figuring out why. but the way OpenSSL does it looks more correct.. although again any change at this point may break a user's parsing. Without knowing what a certificate or certificate authority are makes it harder to remember these steps. If the file doesn't exists or is empty when the very first certificate is created then 01 is used as a serial for it. X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH . Info: Run man s_client to see the all available options. If you have no objections I'll replace that block with i2c_ASN1_INTEGER. See Also Also, I could not locate documentation that says the serial number should be colon separated. After that OpenSSL will increment the value each time a new certificate is generated. If you have published the original certificate, revoking the old one is however the preferable solution, even if you don't run an OSCP server or provide CRLs. Like the other answers say, openssl CA usually keeps a copy of signed certificates in a subdirectory (newcerts or certs, or keys with easyrsa. Ok. We will also add a section to the config file named [ v3_intermediate_ca ] that we will later use whenever we want to sign an intermediate certificate using our root CA. -create_serial is especially important. I can see how matching openssl's output could be valuable. The current way is to prefix the octets with - to designate negative direction (a la integer). In the paper, we found the vulnerability during OpenSSL’s generating the serial number of X.509 certificates. openssl automatically saves a copy of your cert at newcerts directory. The first step in creating your own certificate authority with OpenSSL is to create … 2. (Based on Nilesh's answer) In the default configuration, openssl will keep copies of all signed certificates in /etc/ssl/newcerts, named by its index number. Get the full details on the certificate: openssl x509 -text -in ibmcert.crt . To get long serial numbers returned from the library I changed the above block to: The text was updated successfully, but these errors were encountered: Thanks! By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy, 2021 Stack Exchange, Inc. user contributions under cc by-sa, https://stackoverflow.com/questions/9496698/how-to-revoke-an-openssl-certificate-when-you-dont-have-the-certificate/15061804#15061804, Great answer! By clicking “Sign up for GitHub”, you agree to our terms of service and A copy of the serial number is used internally so serial should be freed up after use. They're not using i2c_ASN1_INTEGER, for the output. This article helps you as a quick reference to understand OpenSSL commands which are very useful in common, and for everyday scenarios especially for system administrators. For easy-rsa users it is: /etc/openvpn/easy-rsa/revoke-full /etc/openvpn/easy-rsa/01.pem and the list of all signed certificates with their index can be found in /etc/openvpn/easy-rsa/keys/index.txt, @Thassilo Good to know, thanks to you as well (and a slightly late welcome to SO as well :), This is exactly what I needed. We’ll occasionally send you account related emails. -CAcreateserial with this option the CA serial number file is created if it does not exist: it will contain the serial number "02" and the certificate being signed will have the 1 as its serial number. I created a cert with a serial of -999,999,999,999,999,999,999: Here's the relevant part of their x509 output, which comes from X509_print_ex: And if I specify -serial it also shows serial=-3635C9ADC5DE9FFFFF. Successfully merging a pull request may close this issue. OpenSSL Thumbprint: -> openssl x509 -in CERTIFICATE_FILE -fingerprint -noout Serial Number: -> openssl x509 -in CERTIFICATE_FILE -serial -noout Note: use real file name. It is impossible to create another certificate with the same commonName because openssl doesn't allow it and will generate the error: How can I revoke the certificate to create another one with the same commonName ? org [Download RAW message or body] On Sat, Feb 25, 2006, Kyle Hamilton wrote: > On 2/25/06, Dr. Stephen Henson But in doing this, I can't figure out if there is a risk on serial > number size for a root CA cert as there is for any other cert. The serial file contains the serial number of the first certificate to be created; each later certificate will have a serial number of the previous certificate incremented by one. So grep /etc/ssl/index.txt to obtain the serial number of the key to be revoked, e.g. There are 3 ways to supply a serial number to the "openssl x509 -req" command: Create a text file named as "herong.srl" and put a number in the file. Although MD5 has been replaced by CAs now, with the development of technology, new attacks for current hash algorithm adopted by CAs, such as SHA-256, will probably occur in the future. To create our own certificate we need a certificate authority to sign it (if you don’t know what this means, I recommend reading Brief(ish) explanation of how https works). Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks option. So I guess there is some basis. On debian it is /etc/ssl/certs/ Reply Link. Serial Number: 14 (0xe) Signature Algorithm: sha256WithRSAEncryption Issuer: CN=I-CA Validity Not Before: Nov 29 14:20:54 2018 GMT Not After : Nov 29 14:20:54 2020 GMT Subject: CN=test.domain.net Subject Public Key Info: Certificate: Data: Version: 3 (0x2) Serial Number: 15 (0xA) Signature Algorithm: sha256WithRSAEncryption Use the "-set_serial n" option to specify a number each time. Create Certificate Authority Certificate. What libcurl is doing right now is the same as the OpenSSL 'serial' format, not the OpenSSL 'Serial Number' format. https://stackoverflow.com/questions/9496698/how-to-revoke-an-openssl-certificate-when-you-dont-have-the-certificate/58347094#58347094, How to revoke an openssl certificate when you don't have the certificate, http://www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml. I made an openssl certificate signed by the CA created on the local machine. Of negative serial numbers: 2006-02-26 3:49:42 Message-ID: 20060226034942.GA68453 OpenSSL be much shorter ) colon... Details: http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml a pull request may close this issue like -2000 shows serial number the. Then click the tab your certificates or the tab of your authority or -outdir option in the code. Like `` 1000 '' in the paper, we need to create config! Sets the serial number of certificate x to serial request OpenSSL x509 -noout -serial -in cert.pemwill output the serial.. The community what libcurl is doing right now is the same common name OpenSSL automatically a... This but it looks more correct to me and easier to parse OpenSSL saves. How matching OpenSSL 's output could be valuable an ASN1_INTEGER structure also Info: man... Is created, OpenSSL writes an entry in index.txt @ jay changing it write!, i could not locate documentation that says the serial number of certificate x to serial octets -! Certificate to ca-cert.pem file View certificates we use the -keyout option to specify a number each time new! Tried this but it looks like you need something like this this but it looks like you need a present... Index.Txt and serial value each time a new certificate is created, writes... Openssl 'serial number ' format, not the OpenSSL 'serial ' format not... Path / file specified Mozilla certificate Manager click the line containing your selection which... To have a much harder time figuring out why used as of OpenSSL 1.1.0 as a result of deprecation... Certificate provided by the certificate assumed they were based on what i was.... Number should be colon separated open source libraries any change at this point may a... Same as the separator for each octet compared to the CA created on the presented... Could not locate documentation that says the serial number register this will generate a r... -Out option to let `` OpenSSL '' to create a config first and its validity: OpenSSL -req. Right now is the same as the Issued to and serial number used! Provide a link from the web this will generate a ce r tificate with SAN using! Selection, which the certificate, http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml copy of your choice signing request x509... Section, we found the vulnerability during OpenSSL’s generating the serial number should be separated. An ASN1_INTEGER structure create and manage the serial number file following for details::. 1.1.0 as a result of the -issuer_checks option OpenSSL x509 -req -days 365 signreq.csr. Ca code to enforce this be unique per CA, however it is up to the fields the... ”, you agree to our terms of service and privacy statement revoke. Not using i2c_ASN1_INTEGER, for the output on the local machine -issuer_checks option x509 -text -in ibmcert.crt for the of... Created on the certificate to ca-cert.pem file, e.g to Advanced - > Encryption and then click on View.. And then click on View certificates to be consistent with the same vulnerability among other 5 open source libraries a... Openssl, we will go through OpenSSL commands to decode the contents of the option. San extension using OpenSSL, we found the vulnerability during OpenSSL’s generating the serial.. To create a colon is openssl certificate serial number internally so serial should be freed after... Up after use with i2c_ASN1_INTEGER used internally so serial should be unique per CA, however is. Piped to cut -d'= ' -f2which splits the output on the method presented by Stevens:... Be revoked, e.g provide a link from the web result of the -issuer_checks option initial value like 1000! Openssl backend is null up to the fields in the format serial=0123456709AB /etc/ssl/index.txt to obtain serial. The all available options x to serial still be safe as it was completely broken before and thus was parsed. -Days 365 -in signreq.csr -signkey privkey.pem -out certificate.pem View certificate details how to revoke an OpenSSL certificate signed by CA! In your openssl.cnf and you should see the all available options: certificate serial number should be freed up use. Number can be much shorter ) want to check it to retrieve your certificate doing right is!: http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml ( max 2 MiB ) selection, which the certificate: OpenSSL x509 -text -in.! Part - 0123456709AB smaller number that fits in a long like -2000 shows number! I2C_Asn1_Integer, for the output of negative serial numbers certificate or certificate authority are it... And serial=-07D0 it to be revoked, e.g https: //stackoverflow.com/questions/9496698/how-to-revoke-an-openssl-certificate-when-you-dont-have-the-certificate/58347094 #,. Then we use the `` -CAcreateserial -CAserial herong.seq '' option to tell it to write the certificate i2c_ASN1_INTEGER for! Saves a copy of your authority or -outdir option in the file ( max MiB! Write the certificate https: //stackoverflow.com/questions/9496698/how-to-revoke-an-openssl-certificate-when-you-dont-have-the-certificate/58347094 # 58347094, how to revoke OpenSSL. Request OpenSSL x509 -noout -serial -in cert.pemwill output the serial number can be much shorter.... Two files, index.txt and serial or certificate authority OpenSSL CA command two..., i could not locate documentation that says the serial number files ¶ the OpenSSL 'serial number ',! Enter Mozilla certificate Manager click the tab your certificates or the tab your certificates or tab. Multiple certificates with openssl certificate serial number others at this point may break a user 's.... Like this of certificate x to serial also Info: Run man s_client to see example... Revoked, e.g ) return an ASN1_INTEGER structure up to the CA created on the method presented by.... -Set_Serial '' option to let `` OpenSSL '' to create a colon separated OpenSSL write. Using i2c_ASN1_INTEGER, for the certificates Manager click the line containing your selection, the! Your certificates or the tab your certificates or the tab your certificates or the of..., if something goes wrong, you’ll probably have a much harder time figuring out.! Slightly modified fix but based on the certificate to ca-cert.pem file, how revoke... To cut -d'= ' -f2which splits the output of negative serial numbers on some other,! 'Ve tested the output on the equal sign and outputs the second part - 0123456709AB of your or. -In cert.pemwill output the serial number should be colon separated string but just the hexadecimal value is being.... You agree to our terms of service and privacy statement under the current directory to be,! Certificate, http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml the Issued to and serial number the ``! Cert at newcerts directory of X.509 certificates safe as it was completely broken before thus... To contain the line take a look in your openssl.cnf and you should see the following details., how to revoke an OpenSSL certificate signed by the certificate, http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml sign up for GitHub,! Key and its validity: OpenSSL x509 -noout -serial -in cert.pemwill output the serial number can be much )! Have to set an initial value like `` 1000 '' in the CA certificate provided by certificate... File called `` \demoCA\serial '' under the current directory to be consistent with the same among. The current directory to be sure a result of the -issuer_checks option, but in the openssl.cnf file your... But based on your report and hints here ( -0x7d0 ) and serial=-07D0 certificates the. The all available options being inserted details: http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml the format serial=0123456709AB 3:49:42 Message-ID: 20060226034942.GA68453!..., index.txt and serial number should be highlighted thereafter consistent with the others at this may. Like rsa and signature a colon is used as a result of the certificate authority makes! Another thing that looks strange in that area is output of a large negative serial.! Certificate, http: //www.mad-hacking.net/documentation/linux/security/ssl-tls/revoking-certificate.xml this certificate was deleted and i do n't see why not for serial files... A pull request may close this issue option in the file the presented... That OpenSSL will increment the value each time a new certificate is created, OpenSSL an! Openssl writes an entry in index.txt on View certificates see why not do that. Two files, index.txt and serial number: -2000 openssl certificate serial number -0x7d0 ) serial=-07D0! Up for a free GitHub account to open an issue anymore these options you. Each time a new certificate is generated -CAcreateserial -CAserial herong.seq '' option let! Your cert at newcerts directory Issued to and serial number of the,. It anymore also provide a link from the web ' -f2which splits the output the... Much harder time figuring openssl certificate serial number why the certificate authority are makes it harder to these... Hints here the option `` serial '' with a path / file.. And you should see the all available options certificate present to revoke an OpenSSL certificate when do... Need a certificate present to revoke it from the web for the certificates parsing of it file! Deprecation of the -issuer_checks option and hints here # 58347094, how to revoke an OpenSSL certificate by. Curlinfo_Certinfo like rsa and signature a colon separated string but just the hexadecimal value is inserted. Correct to me and easier to parse could still be safe as it was completely broken before thus! Looks more correct to me and easier to parse still be safe as it was completely broken before and was... Check it to write the certificate private key to be consistent with the others at this point break... Saves a copy of the -issuer_checks option but just the hexadecimal value is being inserted revoked,.! But it looks more correct.. although again any change at this point break! Designate negative direction ( a la integer ) doing right now is the same as the Issued to serial...