How to download all advertised SSL certificates for a domain via openssl binary?
question
Lets say I want to download each ssl certificate for a specific website so I can do certificate pinning later.
How can I query a web server using openssl to download all available certificates without knowing any of its properties?
example
The domain api.cyberghostvpn.com has a certificate with the following signatures:
- ECDSA + SHA256
- RSA + SHA256
- RSA + SHA1
To download these files, you can use the following command:
回声 \
openssl s_client -connect api.cyberghostvpn.com:443 2> / dev / null -sigalgs'ECDSA + SHA256'2> / dev / null | \\ openssl x509 -outform DER> api_ECDSA + SHA256.crt
echo | \回声| \
openssl s_client -connect api.cyberghostvpn.com:443 2> / dev / null -sigalgs'RSA + SHA256'2> / dev / null | \ openssl x509 -outform DER> api_RSA + SHA256.crt
echo | \
openssl s_client -connect api.cyberghostvpn.com:443 2> / dev / null -sigalgs'RSA + SHA1'2> / dev / null | \ openssl x509 -outform DER> api_RSA + SHA1.crt
Supplies
@Seth：
You don't need to be a domain owner to be interested in a website's public ssl certificate.
In my case, I'm interested in these certificates as I now use their thumbprints in a custom TrustManager (Java) I write to make sure I get the correct certificate. I'm using this in a custom okHTTP client so I can connect directly to the api server (knowing the IP) without a DNS lookup (may be blocked in some countries...).Cloudflare does not allow these certificates to be downloaded in its web interface.
@Alex：
First step - these commands are actually executed one after the other (superuser is removing my line... sorry) - Answer:
Your command just prints out the certificate chain for that valid ssl connection.
The chain starts with the root authority and ends with the server certificate.
On the server, multiple ssl certificates are installed to enhance client compatibility (so newer clients can make more secure connections). Each command I specified above downloads a different server certificate depending on the cipher suite + hashing algorithm I allow for '-sigalgs'.
second comment
Do not you trust me? Look at the output!
- serial number:
- 96：4f：da：8c：12：ff：3f：c0：9b：65：71：33：31：f6：fc：7e
- 1f：78：84：e8：e5：e8：72：7b：43：36：12：7f：15：32：14：46
- is: b3:dc:01:de:39:74:99:7b:99:a1:db:97:d4:34:46
- Signature Algorithm:
- sha256WithRSAEncryption
- sha1WithRSAEncryption
- ecdsa with SHA256
- User Alternative Name
- DNS：ssl366066.cloudflaressl.com
- DNS：*。cyberghostvpn.com
- DNS：cyberghostvpn.com
First certificate:
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
96:4f:da:8c:12:ff:3f:c0:9b:65:71:33:31:f6:fc:7e
Signature Algorithm: sha256WithRSAEncryption
Issuer: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA 2
Validity
Not Before: Mar 3 00:00:00 2018 GMT
Not After : Sep 9 23:59:59 2018 GMT
Subject: OU=Domain Control Validated, OU=PositiveSSL Multi-Domain, CN=ssl366066.cloudflaressl.com
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:cd:47:a0:24:81:11:b2:8a:6d:e5:91:02:f0:0e:
d6:46:92:5f:28:4b:0c:9e:66:f8:e9:1d:d4:1f:4f:
64:70:4a:5d:e9:a2:a6:cc:71:dc:76:15:f3:8a:6c:
59:e1:9c:5c:38:46:de:53:9b:c3:2d:87:c0:49:1b:
a2:68:1a:fb:ba:f7:5b:ec:b4:f9:92:85:1e:72:12:
78:94:47:ac:b9:3d:a3:cf:03:ed:18:e0:d0:8e:1f:
6b:59:49:f4:76:57:19:18:74:38:e1:77:45:74:7f:
ce:c4:59:77:4a:25:7b:88:58:9d:9f:ac:8c:4a:b6:
8c:cc:46:9b:9e:33:6d:52:26:6a:e3:b3:5d:6d:4a:
0a:e9:a0:4f:a8:3b:c4:cd:5f:1c:f9:50:7a:0d:da:
f1:ca:61:50:c2:56:52:ba:33:80:05:24:9a:58:49:
ff:90:36:de:06:24:32:29:47:2b:7d:ec:a5:ab:f7:
a6:fd:cf:04:46:02:b4:6b:d2:39:ee:f1:66:d5:e2:
23:1b:46:b8:d0:6d:e4:d1:1f:5d:26:e4:5e:44:6b:
b2:7b:bc:81:17:56:51:92:ec:61:95:bf:9a:56:8f:
5d:3d:66:e5:74:1a:a5:42:a6:ca:6d:4f:49:44:19:
5f:b8:e5:64:8a:24:31:80:32:bf:c7:7e:09:0a:7e:
19:ed
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Authority Key Identifier:
keyid:D4:B0:F4:FD:4F:9C:42:A4:6C:DC:3D:2E:EE:5B:41:18:C9:AD:03:F6
X509v3 Subject Key Identifier:
5C:DD:94:66:77:CE:58:18:D8:64:2B:82:2E:3F:7F:F2:95:03:6B:84
X509v3 Key Usage: critical
Digital Signature, Key Encipherment
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Extended Key Usage:
TLS Web Server Authentication, TLS Web Client Authentication
X509v3 Certificate Policies:
Policy: 1.3.6.1.4.1.6449.1.2.2.7
CPS: https://secure.comodo.com/CPS
Policy: 2.23.140.1.2.1
X509v3 CRL Distribution Points:
Full Name:
URI:http://crl.comodoca4.com/COMODORSADomainValidationSecureServerCA2.crl
Authority Information Access:
CA Issuers - URI:http://crt.comodoca4.com/COMODORSADomainValidationSecureServerCA2.crt
OCSP - URI:http://ocsp.comodoca4.com
X509v3 Subject Alternative Name:
DNS:ssl366066.cloudflaressl.com, DNS:*.cyberghostvpn.com, DNS:cyberghostvpn.com
Signature Algorithm: sha256WithRSAEncryption
3f:a2:7c:83:b5:e4:22:33:a1:c0:07:a3:7e:d0:8b:06:2f:d3:
6e:d6:c2:2f:a5:66:49:0c:bb:39:dc:1c:be:0e:a3:ba:44:e9:
3d:99:34:e7:3b:9d:4f:60:35:d1:52:fc:63:7d:a8:08:9e:52:
24:36:8e:d0:89:4d:44:4e:d4:7c:9d:fd:87:dd:b6:7c:51:26:
90:25:89:eb:88:0a:d5:37:18:bb:14:8b:d5:f6:2a:f0:f3:fc:
31:04:db:d9:90:00:cc:e4:92:f6:cb:6c:fd:2e:af:ce:a0:fe:
c6:54:58:fd:fc:43:bb:48:be:03:15:c0:95:54:1f:4f:8e:34:
c1:b1:06:46:1d:69:3e:ca:8c:8b:91:07:4d:64:d2:46:48:9d:
2e:9e:3f:da:f5:73:7b:2c:07:f3:89:89:e0:93:78:9f:b4:be:
3d:d6:b7:3a:ba:20:a7:1f:3b:f0:8e:5b:d1:ea:07:8b:9c:a6:
3d:16:56:a2:2e:c9:f7:81:9c:af:c5:65:00:0a:eb:49:c9:23:
a0:70:8d:3d:4a:50:73:64:d8:49:f0:5f:b2:c9:bc:99:78:6f:
53:73:83:74:ac:00:c4:3e:cf:d6:5a:2d:57:5e:3d:60:b3:02:
bd:3d:66:89:c7:9c:e4:3e:89:5d:7c:14:a3:f5:3c:42:fd:a4:
0a:06:9b:fe
Second certificate
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
1f:78:84:e8:e5:e8:72:7b:43:36:12:7f:15:32:14:46
Signature Algorithm: sha1WithRSAEncryption
Issuer: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO Domain Validation Legacy Server CA 2
Validity
Not Before: Mar 2 00:00:00 2018 GMT
Not After : Sep 8 23:59:59 2018 GMT
Subject: OU=Domain Control Validated, OU=Legacy Multi-Domain SSL, CN=ssl366065.cloudflaressl.com
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:cb:9c:14:cd:c9:78:7e:0d:9a:1b:af:98:bd:6d:
21:c7:12:04:d4:97:fd:de:bc:ea:a9:fd:d4:2b:e7:
d0:98:b5:54:f2:2b:aa:6c:fb:60:86:9c:cf:ae:d4:
e3:fe:ad:b9:95:f0:ae:c5:9b:9f:f3:3a:51:93:55:
7a:e6:62:4e:47:5c:15:b8:f0:64:a3:07:6a:f1:32:
8b:7f:f8:d6:2b:ed:34:67:25:95:b0:f2:e8:ac:aa:
cf:e2:7c:a8:39:10:c5:c5:78:e8:69:f4:44:67:94:
7f:88:36:2d:0f:a5:c9:a1:4f:eb:04:7f:06:c3:c7:
c3:5a:8b:ea:65:e4:78:98:57:67:4e:98:7d:63:e1:
7f:4d:90:93:35:ac:57:a2:7a:82:36:c4:73:5c:c2:
a2:26:87:c6:2d:db:ec:9f:d8:89:84:a8:b9:c0:fe:
7b:e9:c7:11:61:f7:8c:48:2c:86:65:0a:08:8f:1f:
10:e0:3a:f4:2e:1d:f3:92:5e:4b:46:97:37:d9:6b:
dd:ca:ed:a4:7f:b5:8e:85:66:a0:b7:a7:e8:89:46:
cf:fd:78:f7:bc:dd:fc:29:d1:5f:1e:89:ba:2e:44:
f6:ba:36:32:4e:99:d7:53:13:a6:76:9a:4f:a0:15:
91:bd:83:08:20:7c:cc:be:9e:c9:ae:8d:c8:ad:ab:
cd:1d
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Authority Key Identifier:
keyid:99:8E:02:95:C5:1E:55:22:7B:87:70:8B:5E:1C:01:C2:76:C4:AE:E8
X509v3 Subject Key Identifier:
58:D9:A7:F4:57:FE:6E:E2:E9:D0:F0:80:E3:25:07:6B:B3:20:17:AC
X509v3 Key Usage: critical
Digital Signature, Key Encipherment
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Extended Key Usage:
TLS Web Server Authentication, TLS Web Client Authentication
X509v3 Certificate Policies:
Policy: 1.3.6.1.4.1.6449.1.2.2.7
CPS: https://secure.comodo.com/CPS
X509v3 CRL Distribution Points:
Full Name:
URI:http://crl.comodoca4.com/COMODODomainValidationLegacyServerCA2.crl
Authority Information Access:
CA Issuers - URI:http://crt.comodoca4.com/COMODODomainValidationLegacyServerCA2.crt
OCSP - URI:http://ocsp.comodoca4.com
X509v3 Subject Alternative Name:
DNS:ssl366065.cloudflaressl.com, DNS:*.cyberghostvpn.com, DNS:cyberghostvpn.com
Signature Algorithm: sha1WithRSAEncryption
07:1b:13:eb:96:01:9f:da:7d:80:5f:72:92:c0:bd:6b:86:ea:
b5:5b:e6:35:6b:c7:dc:a1:1b:65:62:69:3f:bd:45:af:8e:ca:
95:76:c9:69:97:8d:2f:b2:36:96:e9:41:ab:fe:7a:36:fb:ce:
e9:f5:5d:fb:01:40:7e:6f:d9:e7:24:ac:a2:99:b3:2c:3b:dc:
4c:cc:69:90:ed:6e:da:0c:a0:86:95:dd:69:65:a4:de:41:51:
85:2e:1c:3c:56:00:ae:d6:4d:bb:e7:e8:8c:94:f9:fe:cc:0c:
c2:41:62:5d:64:b4:0e:53:67:56:c1:db:87:75:5a:e9:6c:01:
be:45:aa:92:fa:e8:4f:7a:a1:44:f9:00:48:a7:55:ee:d6:9b:
1f:9e:70:e0:fa:c5:7e:cd:9b:d8:c8:a1:e8:bb:4d:7f:31:ef:
9a:cf:27:ff:39:f7:ce:80:9d:11:cc:d1:29:69:de:ad:04:51:
cd:b1:8e:af:63:00:d4:08:e7:90:5c:f1:82:8e:8f:0d:0d:8c:
42:1e:17:ce:6a:20:00:77:04:cc:c2:e3:11:af:78:3b:3c:0b:
d2:4e:1d:5a:ec:58:77:09:15:bc:f0:0e:cf:fa:ea:51:1c:19:
a3:5f:69:cb:f4:8a:83:f7:2c:de:a1:5f:2e:fe:47:06:e0:87:
8e:3b:12:52
The third certificate:
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
be:b3:dc:01:de:39:74:99:7b:99:a1:db:97:d4:34:46
Signature Algorithm: ecdsa-with-SHA256
Issuer: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO ECC Domain Validation Secure Server CA 2
Validity
Not Before: Mar 2 00:00:00 2018 GMT
Not After : Sep 8 23:59:59 2018 GMT
Subject: OU=Domain Control Validated, OU=PositiveSSL Multi-Domain, CN=ssl366067.cloudflaressl.com
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:92:0b:93:8a:65:ce:02:eb:f9:81:be:cf:54:19:
eb:5b:b4:ce:61:1b:32:25:b0:ca:da:e1:1a:b9:59:
98:cd:d0:0a:81:0d:4a:99:1b:e8:f5:fd:e1:1f:7b:
07:36:a9:85:4f:17:54:f3:71:1a:ee:1b:ad:af:98:
7c:55:97:7a:7b
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Authority Key Identifier:
keyid:40:09:61:67:F0:BC:83:71:4F:DE:12:08:2C:6F:D4:D4:2B:76:3D:96
X509v3 Subject Key Identifier:
C6:2E:B1:E7:71:C3:3E:B8:B6:B5:2F:34:8A:5A:06:ED:EB:15:A1:60
X509v3 Key Usage: critical
Digital Signature
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Extended Key Usage:
TLS Web Server Authentication, TLS Web Client Authentication
X509v3 Certificate Policies:
Policy: 1.3.6.1.4.1.6449.1.2.2.7
CPS: https://secure.comodo.com/CPS
Policy: 2.23.140.1.2.1
X509v3 CRL Distribution Points:
Full Name:
URI:http://crl.comodoca4.com/COMODOECCDomainValidationSecureServerCA2.crl
Authority Information Access:
CA Issuers - URI:http://crt.comodoca4.com/COMODOECCDomainValidationSecureServerCA2.crt
OCSP - URI:http://ocsp.comodoca4.com
X509v3 Subject Alternative Name:
DNS:ssl366067.cloudflaressl.com, DNS:*.cyberghostvpn.com, DNS:cyberghostvpn.com
Signature Algorithm: ecdsa-with-SHA256
30:46:02:21:00:bf:a3:b1:95:e2:2f:42:5f:8c:e3:f5:24:5f:
7b:cb:6b:22:bc:98:47:3e:31:6c:25:9d:fc:15:36:9a:26:45:
b9:02:21:00:82:32:aa:6e:e3:6f:5f:41:b9:91:e1:bd:0e:39:
e4:2c:35:60:ce:8a:72:db:6e:48:63:e7:6b:44:5a:f3:4c:5e
If you don't have access to the server, the only way to find out what signature algorithms the server will support is to try each in turn, which is similar to what you've done, but covers all possibilities. A simple script will do that for you. Assuming you have access to a Unix-like shell:
for sign in RSA DSA ECDSA; do
for digest in MD5 SHA1 SHA224 SHA256 SHA384 SHA512; do
sigalgs="${sign}+${digest}"
echo "Trying $sigalgs"
echo | openssl s_client -connect api.cyberghostvpn.com:443 -sigalgs "$sigalgs" 2> /dev/null > "${sigalgs}.cer"
if [ $? != 0 ]; then rm "${sigalgs}.cer"; fi
done
done
Strangely, not all servers follow the SignatureAlgorithm extension in the ClientHello message. www.google.comReturned for all RSA requests sha256withRSAEncryption, and failed for DSA and ECDSA.