ssl certificates and operations

SSLCertificates&OperationsNisheedMeethal

7Nov’16

Chapters

• PurposeofSSLcertificates• Request,sign,installandverify

• CASignedvs.Selfsigned

• SSLCertificatetypes• DV(basic),OV(enhanced)&EV(complete)

• OpenSSL• CertificateStructure• Chainoftrust• TrustStores• Certificatepinning• Freecertificates

PurposeofSSLcertificates• Server[/Client]authenticationforsource[/dest]validationandtrust.

• Securedatatransferusingencryption

SSLCommunicationProcess1. Serverauthentication(Handshake)2. KeyExchange3. Encrypteddatatransfer(Record)

Highest SSL Version, Ciphers Supported, Data Compression Methods, Session Id = 0, Random Data

Selected SSL Version, Selected Cipher,Selected Data Compression Method, Assigned Session Id, Random Data, Server Certificate

(Client Certificate Request)Server Hello Done

Indicates that further communication to server will be encrypted

Digest of all SSL handshake commands for integrity check

Indicates that further communication to client will be encrypted

Digest of all SSL handshake commands for integrity check

Request,sign,installandverify

3.GetitsignedbyCA,saymysite.crt

Certverificationbybrowser

▶ openssl genrsa -out mysite.key 4096▶ openssl req -new -key mysite.key -out mysite.csr

2.Sendmysite.csr totheCAofyourchoice.

1.Generatetheprivatekeyandcertificatesigningrequestforyoursite.

4.Installthecertificate

▶ openssl req -x509 -newkey rsa:4096 -keyout mysite.key -out mysite.crt -days 365

CASigned

SelfSigned

1.Generatetheprivatekeyandselfsigned certificatefor365days.

2.Installthecertificate

SSLCertificatetypes(DV,OV,EV)

• DV– DomainValidated(Basic)• Smallormedium levelwebsiteownerswhoonlywishtoencrypttheirdomaincanissueDVSSLcertificate.(https://www.ycombinator.com/,https://www.nisheed.com)

• Features• Greenpadlock• Lowerprice• Quickissuancewithinminutes• Nopaperworkordocumentationrequiredforvalidation.Validatedagainestthe

domain. Itdoesnotguaranteetheidentityofthewebsite'sownernortheactualexistenceoftheorganization

• 99.9%mobileandwebbrowsercompatibility• ComesupwithWildcardandMultiDomainfeatures• Reissueasmanytimesasneededduringthevalidityperiod

• Validationprocess(email,file,registrar)• https://aboutssl.org/domain-validated-ssl-validation-process

SSLCertificatetypes(DV,OV,EV)

• OV– OrganizationValidated(Enhanced)• Businessidentityleveltrust.Organizationnameprinted inthecertificate.

(https://www.intuit.com/,https://www.icicbank.com,https://www.reddit.com/ )

• Features• Greenpadlock• 1-3daysforissuance• MoretrustedthanDV• Organizationnameisvalidatedandpartofthecertificate.(IssuetoOrganizationand

Subjectarefilledup)

• https://aboutssl.org/document-require-for-ov-ssl-code-signing-certificate

SSLCertificatetypes(DV,OV,EV)

• EV– ExtendedValidated(Complete)• Fortrustedandhighsecuritysites(https://www.godaddy.com,https://www.actalis.it/,

https://www.geotrust.com/,https://www.online.citibank.co.in/ )• Features

• GreenAddress Bar+OrganizationName+TrustSeal

• Upto10business daysforissuance&VeryStrictValidation Process• OVbydefault+High256-bitencryptionwith2048-bitKeyLength• MultidomainwithSANonly.

• https://aboutssl.org/document-require-for-ev-ssl-certificate

OpenSSLReadcert(online)openssl s_client -connect www.google.com:443 < /dev/null 2>/dev/nullopenssl s_client -showcerts -connect www.google.com:443 < /dev/null 2>/dev/null

Readthecert- x509decoded (online)openssl s_client -connect qbo.intuit.com:443 < /dev/null 2>/dev/null | openssl x509 -in /dev/stdin –text

Checkexpiry[startdate,fingerpring,…]openssl s_client -connect qbo.intuit.com:443 < /dev/null 2>/dev/null | openssl x509 -in /dev/stdin -noout –enddate [-startdate –fingerprint -sha1, …]

Verifythekeyandcert(offline)openssl rsa -in admin.prod-lvdc.qbo.ie.intuit.com.key -noout -modulus | openssl shasumopenssl x509 -in admin.prod-lvdc.qbo.ie.intuit.com.crt -noout -modulus | openssl shasum

PublickeyextractionfromPrivatekeyopenssl rsa -in mysite.key -pubout > mysite.pub.key openssl req -noout -in mysite.csr –pubkey > mysite.pub.key

Removepassphrasefromprivaekeyopenssl rsa -in mysite.key -out nopassphrase_mysite.key

CertificateStructure

x509- PKIX(PublicKeyInfrastructure) certificate- rfc6818

Encoding

DER=>BinaryDERencoded certs.(appearas.cer/.crtfiles)

PEM=>ASCII(Base64)armoreddataprefixedwitha“—– BEGIN…”line.(appearsas.cer/.crt/.pemfiles)

Fileextensions

.crt=>*nixconventionofbinaryDERorBase64PEM

.cer=>MicrosoftcoventionofbinaryDERorBase64PEM

.key=>public/private PKCS#8 keys.DERorPEM.

#Viewcertcontent▶ openssl x509 -in ServerCertificate.pem -text -noout▶ openssl x509 -in ServerCertificate.der -inform der -text -noout

#Encodingconversion▶ openssl x509 -in ServerCertificate.cer -outform der -out ServerCertificate.der▶ openssl x509 -in ServerCertificate.der -inform der -outform pem -out ServerCertificate.pem

CertificateStructure▶ openssl s_client-connectqbo.intuit.com:443</dev/null 2>/dev/null |openssl x509-in/dev/stdin –text

▶ openssl s_client–connectgoogle.com:443 -showcerts</dev/null2>/dev/null

Google.com(EE/Leaf)

GIA(ICA)

Geotrust(ICA)

Equifax(rootCA)

ChainofTrust

TrustStores

• Application truststores• Browser

• Public keysofallmajorCAscomewithrelease• Java (tomcat,coldfusionetc.)

• Mostlytherebutlessfrequently updated.• Youneedtotakecareifcustomized.

▶ /usr/local/java/jre/bin/keytool -import -v -alias SHA2_Standard_Inter_Symantec_Class_3_Standard_SSL_CA_G4 -file /$path/SHA2_Standard_Inter_Symantec_Class_3_Standard_SSL_CA_G4.cer -keystore /application/conf/jssecacerts -storepass changeit –noprompt

▶ /usr/local/java/jre/bin/keytool -list -v -keystore /application/conf/jssecacerts -storepass changeit –noprompt

▶ /usr/cfusion8/runtime/jre/bin/keytool -import -v -alias SHA2_EV_Inter_Symantec_Class_3_EV_SSL_CA_G3 -file /root/SHA2_EV_Inter_Symantec_Class_3_EV_SSL_CA_G3.cer -keystore /usr/cfusion8/runtime/jre/lib/security/cacerts -storepass changeit

▶ /usr/cfusion8/runtime/jre/bin/keytool -list -v -keystore /usr/cfusion8/runtime/jre/lib/security/cacerts -storepass changeit

Whenshouldyouupdatetheapplicationtruststore?

CertificatepinningHTTPPublicKeyPinning,orHPKP (rfc7469).

ThisstandardallowswebsitestosendanHTTPheaderinstructingthebrowsertoremember(or"pin")partsofitsSSLcertificatechain.Thebrowserwillthenrefusesubsequent connectionsthatdon'tmatchthepinsthatithaspreviouslyreceived.Here'sanexampleofanHPKPheader:

Public-Key-Pins: pin-sha256="d6qzRu9zOECb90Uez27xWltNsj0e1Md7GkYYkVoZWmM="; pin-sha256="LPJNul+wow4m6DsqxbninhsWHlwfp0JecwQzYpOLmCQ="; max-age=259200

Public-Key-Pins-Report-Only: max-age=2592000; pin-sha256="E9CZ9INDbd+2eRQozYqqbQ2yXLVKB9+xcprMF+44U1g="; pin-sha256="LPJNul+wow4m6DsqxbninhsWHlwfp0JecwQzYpOLmCQ=";

report-uri="https://example.net/pkp-report"

#Generateprivatekeyandcsr.▶ openssl genrsa -out mysite.key 4096▶ openssl req -new -key mysite.key -out mysite.csr

#GetthecrtfromCA▶ openssl x509 -noout -in mysite.crt -pubkey | openssl asn1parse -noout -inform pem -out mysite.pub.key▶ openssl dgst -sha256 -binary mysite.pub.key | openssl enc -base64

#Formtheheaderandaddtowebserver(eg:- apache).Header add Public-Key-Pins "max-age=500; includeSubDomains;

pin-sha256=\"wBVXRiGdJMKG7vQhr9tZ9br9Md4l7cO69LF2a88Au/o=\";

Free&Opencertificates

• Let’sEncrypt• https://letsencrypt.org/getting-started/

Usefulresources:

https://www.ssllabs.com/ssltest/https://aboutssl.org/ssl-tools/ssl-checker.phphttps://tools.ietf.org/html/rfc6818https://certbot.eff.org/