certdump

Dump a PEM file containing certificates.

It takes a number of files on the command line which should contain
at least one certificate, and dumps the certificates found in those
files. If the -l flag is given, it is assumed the file is a bundle and
only the leaf certificate will be shown.

Certificates may also be passed on standard input; no arguments, or a
single "-" argument, inform certdump that it should read certificates
from standard input. This allows chaining, à la

	cfssl bundle -domain example.net | jq .bundle | certdump

Example (kyleisom.pem and tyrfingr.pem are the bundled certificates
for two of my sites):

$ certdump *.pem
--kyleisom.pem ---
CERTIFICATE
Subject: /*.kyleisom.net/OU=Domain Control Validated/OU=PositiveSSL Wildcard
Issuer: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
	Signature algorithm: RSA / SHA256
Details:
	Public key: RSA-2048
	Serial number: 140424811868659069090147614569911695367
	AKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
	SKI: 64:07:29:EA:3A:FE:2C:00:48:62:FB:22:E4:E9:72:7E:2F:0F:C3:2D
	Valid from: 2014-11-16T00:00:00+0000
	     until: 2015-11-16T23:59:59+0000
	Key usages: key encipherment, digital signature
	Extended usages: server auth, client auth
	Basic constraints: valid
	SANs: *.kyleisom.net, kyleisom.net
CERTIFICATE
Subject: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
Issuer: /COMODO RSA Certification Authority/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
	Signature algorithm: RSA / SHA384
Details:
	Public key: RSA-2048
	Serial number: 57397899145990363081023081275480378375
	AKI: BB:AF:7E:02:3D:FA:A6:F1:3C:84:8E:AD:EE:38:98:EC:D9:32:32:D4
	SKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
	Valid from: 2014-02-12T00:00:00+0000
	     until: 2029-02-11T23:59:59+0000
	Key usages: cert sign, crl sign, digital signature
	Extended usages: server auth, client auth
	Basic constraints: valid, is a CA certificate, max path length 0
	SANs:
---tyrfingr.pem ---
CERTIFICATE
Subject: /*.tyrfingr.is/OU=Domain Control Validated/OU=PositiveSSL Wildcard
Issuer: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
        Signature algorithm: RSA / SHA256
Details:
        Public key: RSA-2048
        Serial number: 129805972439942088783496286074667556011
        AKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
        SKI: C6:25:79:D7:A7:9A:85:BE:7F:DE:3B:3D:7A:B7:2E:96:DE:46:05:D7
        Valid from: 2014-10-03T00:00:00+0000
             until: 2015-10-03T23:59:59+0000
        Key usages: key encipherment, digital signature
        Extended usages: server auth, client auth
        Basic constraints: valid
        SANs: *.tyrfingr.is, tyrfingr.is
CERTIFICATE
Subject: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
Issuer: /COMODO RSA Certification Authority/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
        Signature algorithm: RSA / SHA384
Details:
        Public key: RSA-2048
        Serial number: 57397899145990363081023081275480378375
        AKI: BB:AF:7E:02:3D:FA:A6:F1:3C:84:8E:AD:EE:38:98:EC:D9:32:32:D4
        SKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
        Valid from: 2014-02-12T00:00:00+0000
             until: 2029-02-11T23:59:59+0000
        Key usages: cert sign, digital signature, crl sign
        Extended usages: server auth, client auth
        Basic constraints: valid, is a CA certificate, max path length 0
        SANs:
CERTIFICATE
Subject: /COMODO RSA Certification Authority/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
Issuer: /AddTrust External CA Root/C=SE/O=AddTrust AB/OU=AddTrust External TTP
    Network
        Signature algorithm: RSA / SHA384
Details:
        Public key: RSA-4096
        Serial number: 52374340215108295845375962883522092578
        AKI: AD:BD:98:7A:34:B4:26:F7:FA:C4:26:54:EF:03:BD:E0:24:CB:54:1A
        SKI: BB:AF:7E:02:3D:FA:A6:F1:3C:84:8E:AD:EE:38:98:EC:D9:32:32:D4
        Valid from: 2000-05-30T10:48:38+0000
             until: 2020-05-30T10:48:38+0000
        Key usages: digital signature, crl sign, cert sign
        Basic constraints: valid, is a CA certificate
        SANs:

$ certdump *.pem
--kyleisom.pem ---
CERTIFICATE
Subject: /*.kyleisom.net/OU=Domain Control Validated/OU=PositiveSSL Wildcard
Issuer: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
	Signature algorithm: RSA / SHA256
Details:
	Public key: RSA-2048
	Serial number: 140424811868659069090147614569911695367
	AKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
	SKI: 64:07:29:EA:3A:FE:2C:00:48:62:FB:22:E4:E9:72:7E:2F:0F:C3:2D
	Valid from: 2014-11-16T00:00:00+0000
	     until: 2015-11-16T23:59:59+0000
	Key usages: digital signature, key encipherment
	Extended usages: server auth, client auth
	Basic constraints: valid
	SANs: *.kyleisom.net, kyleisom.net
--tyrfingr.pem ---
CERTIFICATE
Subject: /*.tyrfingr.is/OU=Domain Control Validated/OU=PositiveSSL Wildcard
Issuer: /COMODO RSA Domain Validation Secure Server CA/C=GB/O=COMODO CA
    Limited/L=Salford/ST=Greater Manchester
	Signature algorithm: RSA / SHA256
Details:
	Public key: RSA-2048
	Serial number: 129805972439942088783496286074667556011
	AKI: 90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7
	SKI: C6:25:79:D7:A7:9A:85:BE:7F:DE:3B:3D:7A:B7:2E:96:DE:46:05:D7
	Valid from: 2014-10-03T00:00:00+0000
	     until: 2015-10-03T23:59:59+0000
	Key usages: digital signature, key encipherment
	Extended usages: server auth, client auth
	Basic constraints: valid
	SANs: *.tyrfingr.is, tyrfingr.is

This same result could be had with

$ cfssl bundle -domain kyleisom.net | jq .bundle | certdump

