Viewing app certificate

To view the certificate that the app was signed with:

1. Extract the app from the Android device
2. Unzip the app
3. Browse to META-INF folder
4. look for a file end with .RSA
5. View cert information:
   1. keytool -printcert -file {FILENAME}.RSA

Example:

iot@mob ~/D/a/N/META-INF> ls *.RSA 
GOOGPLAY.RSA
iot@mob ~/D/a/N/META-INF> keytool -printcert -file GOOGPLAY.RSA 
Owner: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Issuer: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Serial number: bbf3305d0f4e1604c5e724bb88c0f191b1a0f1bf
Valid from: Wed Jun 20 05:27:54 PDT 2018 until: Sat Jun 20 05:27:54 PDT 2048
Certificate fingerprints:
	 SHA1: 37:A7:9C:75:22:7E:F5:C2:34:4D:7D:E5:4D:C8:85:8A:0B:60:CC:35
	 SHA256: 15:48:51:AC:CF:1E:FE:09:19:AB:B7:7D:B8:83:B0:BD:7F:69:38:F9:7A:7F:D2:85:9C:8B:C8:C4:7B:AC:95:59
Signature algorithm name: SHA256withRSA
Subject Public Key Algorithm: 4096-bit RSA key
Version: 3

Extensions: 

#1: ObjectId: 2.5.29.19 Criticality=false
BasicConstraints:[
  CA:true
  PathLen:2147483647
]