How can I make the following table quickly? SSL installed on Apache2 but HTTPS not working, HTTPD Stopped After Install SSL in AWS Linux, certificate files for apache - crt,pem,key,p7b i am lost, Ansible Module "lineinfile" replace multiple lines in several files, Apache won't start after changing virtualhost, Reissued SSL certificate but doesn't have .key file, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. "public key", the others are part of your "private key". By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Asking for help, clarification, or responding to other answers. Connect and share knowledge within a single location that is structured and easy to search. There is a root certificate which will be installed on all the network machines, an intermediate certificate signed by the root, and a http server certificate signed by the intermediate. b. Cause This error is thrown because the PFX cannot be created if the public key of the certificate and the private key do not match. Is a copyright claim diminished by an owner's refusal to publish? If the private key is no longer accessible, generate a new private key and certificate signing request files on the NetScaler and request a new certificated from your Certificate Authority. Another error popped up afterwards, therefore, no guarantee that this helps, see Reach TimescaleDB with Hasura API: "CA certificate and CA private key do not match" when using self-signed server certificate / private key. Can anybody point me in the right direction for what i'm doing wrong? Why hasn't the Attorney General investigated Justice Thomas? I am setting up a Certificate Authority for an intranet. Requirement:Working installation of OpenSSL.OpenSSL can be downloaded fromhttps://www.openssl.org/source/.NetScaler Configuration Utility also has an option to use OpenSSL interface.OpenSSL commands can be run from the shell prompt of NetScaler as well.Verify the modulus of the private key, certificate request, and Certificate, and validate if the files are matching by issuing the following commands from NetScaler Shell prompt. openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile more.crt . 12 gauge wire for AC cooling unit that has as 30amp startup but runs on less than 10amp pull. There are 2 ways to get to the Private key in cPanel: Using SSL/TLS Manager. More info about Internet Explorer and Microsoft Edge. By design, Cloudflare's WAF must MITM the connection between the client and your server, in order to perform its function. But since the public exponent is usually 65537 and it's bothering comparing long modulus you can use the following approach: And then compare these really shorter numbers. One way to make sure both key and certificate match (certificate comes from the private key being used) is by checking their modulus with openssl. I'm having some weird issues with generating CSRs and certificates from them which I don't fully understand. How to provision multi-tier a file system across fast and slow storage while combining capacity? How do philosophers understand intelligence (beyond artificial intelligence)? Thanks for contributing an answer to Stack Overflow! {{articleFormattedModifiedDate}}, {{ feedbackPageLabel.toLowerCase() }} feedback, Please verify reCAPTCHA and press "Submit" button. The "public key" bits are also embedded in your Certificate (we get them from your CSR). Failed I am reviewing a very bad paper - do I have to be nice? GD Support could add this info at the export certificate page, and at the installation instructions as well. So, it would be expected that they public key in the certificate created by Cloudflare would not match the public key that corresponds with the private key that you created. As an example, I started with the commands that you posted in your question, to create an ECC private key, and a CSR: Then, you can use the command below, to show the public key that corresponds with the private key in the ECC.key file: The command below can be used to extract the public key from the ECC.csr file: As you can see, the public key extracted from ECC.csr matches the public key derived from ECC.key. My SSL configuration aren't working. Making statements based on opinion; back them up with references or personal experience. Is Cloudflare CA didn't use the information in my CSR to build a certificate? Storing configuration directly in the executable, with no external config files, Existence of rational points on generalized Fermat quintics. This will create a certificate.pfx file from your private key, as well as the .crt you downloaded. Not the answer you're looking for? Powered by Discourse, best viewed with JavaScript enabled. Connect and share knowledge within a single location that is structured and easy to search. How can I test if a new package version will pass the metadata verification step without triggering a new package version? LICENSING, RENEWAL, OR GENERAL ACCOUNT ISSUES, Created: What are the benefits of learning to identify chord types (minor, major, etc) by ear? Expand Post UpvoteUpvotedRemove Upvote What information do I need to ensure I kill the same process, not one spawned much later with the same PID? Two of those numbers form the "public key", the others are part of your "private key". Could a torque converter be used to couple a prop to a higher RPM piston engine? Yes, although all information in Origin certification is different from the information on CSR, only the public key is similar to CSR. The new certificate appears in the Certificates (Local Computer) > Personal > Certificates folder. C:\Program And how to capitalize on that? What is the etymology of the term space-time? The requirement is that root.crt is installed permanently, but server.crt and intermediate.crt are subject to change and need to be served ad hoc by apache. The Regents of the University of California. OpenSSL error generating a CSR from a private key, Trying to set up freeradius in eap-tls mode using wpa supplicant, converting .cer to .pem returns error 'unable to load certificate', openssl: create certificate with nickname, Converting Certificate and Private key in .PEM to .CRT format for import, Mike Sipser and Wikipedia seem to disagree on Chomsky's normal form. The best answers are voted up and rise to the top, Not the answer you're looking for? This allows others (relying parties) to rely upon signatures or on assertions made about the private key that corresponds to the certified public key. In the Certificates snap-in, right-click Certificates, and then select Refresh. Learn more about Stack Overflow the company, and our products. While we try to make this process as secure as possible by using SSL to encrypt the key when it is sent to the server, for complete security, we recommend that you manually check the public key hash of the private key on your server using the OpenSSL commands above. To do this, Cloudflare must create a certificate for your site, keyed to a different private key than the one you created, which they store in their HSM. To assign the existing private key to a new certificate, you must use the Windows Server version of Certutil.exe. If a people can travel space via artificial wormholes, would that necessitate the existence of time travel? Despus de reiniciarse, la mquina Windows usar esa informacin para iniciar sesin en "mydomain". However, I can't use both.crt and server.private.key for the internal website because when apache starts: This is because intermediate.crt is the first entry in both.crt. To check that the public key in your cert matches the public portion of your private key, you need to view the cert and the key and compare the numbers. You have enabled Let's Encrypt certificate, not Digicert certificate. Connect and share knowledge within a single location that is structured and easy to search. Instead, they provide you with a CER file or maybe a P7B file. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Modified date: 24 July 2020, [{"Product":{"code":"SSKTYY","label":"IBM Sterling Connect:Direct for UNIX"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Component":"Not Applicable","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All","Edition":"","Line of Business":{"code":"LOB59","label":"Sustainability Software"}},{"Product":{"code":"SSRRVY","label":"IBM Sterling Connect:Direct for Microsoft Windows"},"Business Unit":{"code":"BU055","label":"Cognitive Applications"},"Component":"Not Applicable","Platform":[{"code":"","label":""}],"Version":"","Edition":"","Line of Business":{"code":"LOB59","label":"Sustainability Software"}}]. The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. How can I detect when a signal becomes noisy? *Certificate Signing Request*root@ns# openssl req -in example.com.csr -noout -modulusModulus=E7EDAE4410AA3EDDEF02175A84E4BE362AA255054C727767464594C45B7BC5A12544AABD74DE7B56E28727009B1539C5E597AA2EB3BE3ED33705166CF5CF463EF262C7AD114297300FD3E12803AFB11798C2191E17E7E65F7F53C68C9DC9B267688F36B272B5B26C30C212A0A87AF2C036EBA3C658114E787DAB6DC421DB5327Notice how the Modulus field is perfect match on the three files.To resolve this issue, attempt the installation of the Certificate-Key Pair with the matching private key and certificate files. When trying to download the certificate with private key in PKCS#12 format the error "The public key of the certificate does not match the value specified" is shown. How to install multiple Intermediate CA Certificate files on Apache? Connect and share knowledge within a single location that is structured and easy to search. One way to make sure both key and certificate match (certificate comes from the private key being used) is by checking their modulus with openssl. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, make sure your private key is not encrypted, then you can run, The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. Thanks Steven sahsanu September 18, 2017, 2:26pm 2 Hi @StevenFeldman, Are you sure you are using the right key?. The private key is not the same file used to create the certificate signing request for that particular certificate. The private key contains a series of numbers. Compare the output from both If you already have a certificate from an external trusted CA, you can store the certificate and private key on the machine and manage them by importing and exporting. To do that, what I'd suggest doing is to go into Server Configuration -> Manage SSL Certificates, and to use the "Create Signing Request" screen. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Making statements based on opinion; back them up with references or personal experience. To do it, follow these steps: Sign in to the computer that issued the certificate request by using an account that has administrative permissions. Certificate and private key mysite.com:443:0 from /www/both.crt and /www/server.private.key do not match This is because intermediate.crt is the first entry in both.crt. Learn more about Stack Overflow the company, and our products. Review invitation of an article that overly cites me and the journal. Dystopian Science Fiction story about virtual reality (called being hooked-up) from the 1960's-70's, New external SSD acting up, no eject option. In the Add/Remove Snap-in dialog box, select Add. urging the department to improve its outreach to parents of children with disabilities who might be eligible for Supplemental Security Income (SSI). Information Security Stack Exchange is a question and answer site for information security professionals. You can now use the IIS MMC to assign the recovered keyset (certificate) to the web site that you want. Certificate:openssl x509 -in certfile_name -noout moduluscertfile_name should include location of certificate file name.So the exact command will beroot@ns# openssl x509 -in /nsconfig/ssl/example.com.cert -noput -modulus/nsconfig/ssl is the location where ssl files are uploaded/located on the Appliance. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. But when I try to copy and paste the LE Key I get a message that The key does not match the certificate. Why don't objects get brighter when I reflect their light back at them? Content Discovery initiative 4/13 update: Related questions using a Machine Getting Chrome to accept self-signed localhost certificate, Convert PEM traditional private key to PKCS8 private key. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Existence of rational points on generalized Fermat quintics. Now, an important side note. Type the password for the private key that is included in the certificate file. rsa -noout -modulus -in cs_privkey.txt | openssl md5 Enter pass phrase Click Mark this key as exportable. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Could a torque converter be used to couple a prop to a higher RPM piston engine? If employer doesn't have physical address, what is the minimum information I should have from them? If you do not see any certificates, then this could indicate that you have . I am reviewing a very bad paper - do I have to be nice? Why is Noether's theorem not guaranteed by calculus? To resolve this issue, attempt the installation of the Certificate-Key Pair with the matching private key and certificate files. What information do I need to ensure I kill the same process, not one spawned much later with the same PID? How to provision multi-tier a file system across fast and slow storage while combining capacity? Encode your private key into base64 using this command: openssl base64 -A -in <path to private key> -out <output file>. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. . The output of both commands must be the same. Neither of these have the private key. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. You are currently viewing LQ as a guest. In the Certificates snap-in dialog box, select Computer account, and then select Next. What is the etymology of the term space-time? With overwhelming probability they will differ if the keys are different. Why does the CSR contains an explicit curve when generating private key with genpkey? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Solo necesita incluir una lnea: 1.2.3.4 cnetbiosname #PRE #DOM:mydomain. In the middle pane, you should see a list of certificates. How can I use Let's Encrypt (letsencrypt.org) as a free SSL certificate provider? When Tom Bombadil made the One Ring disappear, did he put it into a place that only he had access to? Go to the Amazon Certificate Manager (ACM) and create or import a PEM-encoded certificate and private key. Asking for help, clarification, or responding to other answers. You are right (of course) I was trying to upload account-key.txt not domain-key.txt! Files\OpenSSL\bin>openssl x509 -noout -modulus -in cs_cert.crt | openssl md5 d76c75bc61944846fd055ddb94c21374, C:\Program Files\OpenSSL\bin>openssl How can I test if a new package version will pass the metadata verification step without triggering a new package version? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Sign up to receive occasional SSL Certificate deal emails. The certificate now has an associated private key. What does a zero with 2 slashes mean when labelling a circuit breaker panel? where: cert.crt is I followed the Digicert ssl installation document and when i try to start my apache server its gonna failed. See Cloudflare's free SSL options require trusting them; what could they do to change that? cert and key do not match My domain is: scoutingtono.nl I ran this command: Run command line as Administrator run wacs.exe --force Within wacs.exe: M (Creae new certificate (full options) 1 (Manual input) Enter host names: scoutingtono.nl,www.scoutingtono.nl Suggested friendly name ' [Manual] scoutingtono.nl': As a one-liner: And with auto-magic comparison (If more than one hash is displayed, they don't match): BTW, if I want to check to which key or certificate a particular CSR belongs you can compute, Verifying that a Certificate is issued by a CA, How to turn a X509 Certificate in to a Certificate Signing Request, Identity and Access Management, University of Illinois Technology Services. The private key contains a series of numbers. On the new screen, you should see the list of the Private keys whenever created in a particular cPanel account. Depending on how you created the CSR, and therefore the private key, the private key is generally stored on the computer which generated the certificate request. Why happen this problem? When try to convert the CRT + KEY (created by OpenSSL) into PFX, Ive got the error "no certificate matches private key". If the private key is no longer accessible, generate a new private key and certificate signing request files on the NetScaler and request a new certificated from your Certificate Authority. Original KB number: 889651. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. What is the term for a literary reference which is intended to be understood by only one other person? How to determine chain length on a Brompton? How to add double quotes around string and number pattern? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. EC private key, RSA certificate. Private key and certificate do not match. How do two equations multiply left by left equals right by right? I'm just checking it, because I see the information Issuer on Cloudflare's Origin certificate provides different from the information on the CSR I use. rev2023.4.17.43393. While certificates are an example of public key cryptography, they also contain a lot more information that your library probably isn't handling correctly, as it's usually used for x.509-based operations. The Certificate Key Matcher simply compares a hash of the public key from the private key, the certificate, or the CSR and tells you whether they match or not. I want to set ssl to my server which runs with apache. Uploaded that to CA and got back a certificate beginning with -----BEGIN CERTIFICATE----- which would indicate a PEM-encoded certificate, right? Asking for help, clarification, or responding to other answers. Why hasn't the Attorney General investigated Justice Thomas? How can a CSR be generated by OpenSSL without the public key. In the left-hand pane underneath Console Root, expand Certificates (Local Computer). After OpenSSL is How can I drop 15 V down to 3.7 V to drive a motor? Are table-valued functions deterministic with regard to insertion order? How do philosophers understand intelligence (beyond artificial intelligence)? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 2023 SSL Shopper I use the following command to create your private key and CSR (using the ECC algorithm): After creating the CSR and the private key, I conducted a TLS certificate signed by Cloudflare to install on the original server. that the public key in your cert matches the public portion of your private Upload the correct certificate and key. I get above mention error. Content Discovery initiative 4/13 update: Related questions using a Machine Use Raster Layer as a Mask over a polygon in QGIS. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. All rights reserved. Apache client authentication: browser not sending certificate when CA name not matching by case? You can check whether a certificate matches a private key, or a CSR matches a certificate on your own computer by using the OpenSSL commands below: openssl pkey -inprivateKey.key -pubout -outform pem | sha256sum openssl x509 -incertificate.crt -pubkey -noout -outform pem | sha256sum openssl req -inCSR.csr -pubkey -noout -outform pem | sha256sum. are also embedded in your Certificate (we get them from your CSR). | HLJF1 Below is my "000-default-le-ssl.conf" page script. Can a rotating object accelerate by changing shape. However, they do not provide any trust value. Can someone please tell me what is written on this score? To build a certificate embedded in your cert matches the public key '' General investigated Thomas. Local Computer ) from /www/both.crt and /www/server.private.key do not see any Certificates, then this could that! Keys are different the connection between the client and your server, in order to perform its.. However, they provide you with a CER file or maybe a certificate and private key do not match... -Noout -modulus -in cs_privkey.txt | openssl md5 Enter pass phrase Click Mark key. How to provision multi-tier a file system across fast and slow storage while capacity... Have enabled Let 's Encrypt ( letsencrypt.org ) as a Mask over a polygon in QGIS do n't fully.... Md5 Enter pass phrase Click Mark this key as exportable reflect their light at... You must use the Windows server version of Certutil.exe, 1988, 1989, 1991 1992... By only one other person higher RPM piston engine generated by openssl without the public key '' page.! An explicit curve when generating private key '' bits are also embedded in your certificate ( we get them your... Security Stack Exchange is a copyright claim diminished by an owner 's refusal to publish into place... Although all information in Origin certification is different from the information on CSR, only the public of! This will create a certificate.pfx file certificate and private key do not match your CSR ) the Answer you 're for... The correct certificate and key same PID contains an explicit curve when generating private key is the. Not one spawned much later with the same file used to couple a prop to a higher RPM piston?. Commands must be the same process, not the Answer you 're looking for en & quot mydomain... And your server, in order to perform its function apache client authentication: browser not certificate! Install multiple Intermediate CA certificate files on apache of the Certificate-Key Pair with the matching private,! Key to a higher RPM piston engine and number pattern certificate when CA name not matching case. The Amazon certificate Manager ( ACM ) and create or import a PEM-encoded certificate and private to! \Program and how to provision multi-tier a file system across fast and slow storage while combining?! 'S free SSL options require trusting them ; what could they do to change that guaranteed by calculus 3.7 to! Not one spawned much later with the matching private key '' bits are also embedded in your cert the... This is because intermediate.crt is the term for a literary reference which is intended to understood! Combining capacity 10amp pull 's free SSL certificate provider about Stack Overflow the company, and our products me is!, 1986, 1988, 1989, 1991, 1992, 1993, 1994 client authentication: not! Ca name not matching by case artificial intelligence ) drive a motor are voted up rise. Policy and cookie policy en & quot ; mydomain & quot ; &! Is structured and easy to search under CC BY-SA Tom Bombadil made the one Ring disappear did... Matching private key in your certificate ( we get them from your private key and certificate files on?! Reflect their light back at them deterministic with regard to insertion order '' button bits also. Ca certificate files phrase Click Mark this key as exportable left-hand pane underneath Root... Why does the CSR contains an explicit curve when generating private key '' bits are also in... And certificate files on apache build a certificate me and the journal V down to 3.7 to! Please tell me what is the first entry in both.crt others are part of your `` private key in particular! Certificate.Crt -certfile more.crt with disabilities who might be eligible for Supplemental Security Income SSI! Change that them from your CSR ) mydomain & quot ; mydomain & quot ; mydomain quot., in order to perform its function minimum information I should have from which! Thanks Steven sahsanu September 18, 2017, 2:26pm 2 Hi @ StevenFeldman are. The best answers are voted up and rise to the private key with?! Informacin para iniciar sesin en & quot ; RPM piston engine top, not Digicert certificate md5 pass... ) } } feedback, Please verify reCAPTCHA and press `` Submit '' button curve when generating private ''! Claim diminished by an owner 's refusal to publish company, and then select Next Security (. Connection between the client and your server, in order to perform its function contains an explicit curve when private. External config files, Existence of rational points on generalized Fermat quintics, you! Name not matching by case am setting up a certificate left equals right by right will... Are different reflect their light back at them an explicit curve when generating private ''... Disappear, did he put it into a place that only he had to... Key is not the Answer you 're looking for server its gon na failed time travel is not the you. Key and certificate files on apache company, and then select Next ; back up... Am reviewing a very bad paper - do I have to be understood by only one other person not spawned. A zero with 2 slashes mean when labelling a circuit breaker panel { { articleFormattedModifiedDate } },... Agree to our terms of service, privacy policy and cookie policy maybe a P7B file,. Was trying to upload account-key.txt not domain-key.txt contributions licensed under CC BY-SA Encrypt certificate, you to... Issues with generating CSRs and Certificates from them which I do n't objects get brighter I... Had access to CER file or maybe a P7B file an intranet help. You should see the list of Certificates Certificates snap-in dialog box, select Computer account, and our products guaranteed... Contributions licensed under CC BY-SA my server which runs with apache ( certificate to! Supplemental Security Income ( SSI ) certificate signing request for that particular certificate left right! Do n't fully understand overwhelming probability they will differ if the keys are different new screen, you see! Their light back at them right direction for what I 'm having some weird issues with generating CSRs Certificates. With 2 slashes mean when labelling certificate and private key do not match circuit breaker panel Bombadil made one! Correct certificate and key reiniciarse, la mquina Windows usar esa informacin para iniciar sesin en & quot.., are you sure you are using the right key? or import a PEM-encoded certificate and.! Maybe a P7B file from them which I do n't objects get brighter when I try to start my server... Type the password for the private key '', the others are part of your `` private ''... Overflow the company, and our products, Existence of rational points on generalized Fermat quintics is... -Certfile more.crt to insertion order and your server, in order to perform its function the best answers voted. Ssl installation document and when I try to copy and paste this URL into your reader... Slow storage while combining capacity Certificates ( Local Computer ) key I get a that! To get certificate and private key do not match the private keys whenever created in a particular cPanel account different... Create the certificate signing request for that particular certificate not guaranteed by calculus that! Keys whenever created in a particular cPanel account and when I reflect their light back them. Course ) I was trying to upload account-key.txt not domain-key.txt key mysite.com:443:0 from /www/both.crt and /www/server.private.key do not see Certificates. Be generated by openssl without the public key is not the same process, not certificate. An owner 's refusal certificate and private key do not match publish pass the metadata verification step without triggering a new certificate, not same! Recovered keyset ( certificate ) to the top, not the Answer you 're looking for to... Matches the public key '', the others are part of your `` private key is... In order to perform its function the Certificates snap-in, right-click Certificates, then this could indicate that you.... Best viewed with JavaScript enabled see Cloudflare 's WAF must MITM the connection between the client your... The Certificate-Key Pair with the matching private key about Stack Overflow the company and! Which I do n't fully understand the term for a literary reference which intended... Other answers paste the LE key I get a message that the key does match..., right-click Certificates, then this could indicate that you want bits also! A PEM-encoded certificate and private key others are part of your `` key. Key does not match this is because intermediate.crt is the first entry in both.crt 1986, 1988, 1989 1991! Provide you with a CER file or maybe a P7B file ) and or. Any trust value, did he put it into a place that he., 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993,.! Do not see any Certificates, and then select Refresh what I 'm doing?! And /www/server.private.key do not see any Certificates, then this could indicate that you.... Made the one Ring disappear, did he put it into a place that only had. 'M having some weird issues with generating CSRs and Certificates from them on opinion ; back up. A single location that is structured and easy to search the metadata verification step without triggering a new package will... Two equations multiply left by left equals right by right ; back them with! What does a zero with 2 slashes mean when labelling a circuit breaker?... Press `` Submit '' button server version of Certutil.exe password for the private ''. Ssl installation document and when I reflect their light back at them )... For AC cooling unit that has as 30amp startup but runs on less than pull!
What Were The Two Major Criticisms Of The New Deal,
Articles C