How to find signature of apk file?

Question

What's the easiest way to find signature of an apk file? Please note that I'm not asking about code. I just want to find it from my pc. Signature like this one 975yYkKAQF+KST7g3ASHvHkYopq=

Answer 1

$ $ANDROID_SDK/build-tools/$BUILD_TOOLS_VERSION/apksigner verify --print-certs -v $APK_FILE

Example:

$ /Users/hborders/android/build-tools/29.0.2/apksigner verify --print-certs -v ~/Desktop/my-apk.apk

Verifies
Verified using v1 scheme (JAR signing): true
Verified using v2 scheme (APK Signature Scheme v2): true
Verified using v3 scheme (APK Signature Scheme v3): false
Number of signers: 1
Signer #1 certificate DN: CN=Bob Smith, OU=Acme, O=Acme, L=San Francisco, ST=California, C=US
Signer #1 certificate SHA-256 digest: f1f2f3f3f21f26a67s76a6a76a76a76a76a67c78c8c78c709c90c90c09932451
Signer #1 certificate SHA-1 digest: 839103847abdefcbade123713957358920
Signer #1 certificate MD5 digest: 182831983712923f2e2e2f2a2c2fbc25
Signer #1 key algorithm: RSA
Signer #1 key size (bits): 1024
Signer #1 public key SHA-256 digest: 8acaca8cabcaabdadc8cc99cc695ace47aec4c747c746c476cae4657c47c4765
Signer #1 public key SHA-1 digest: b11bca4123bea24befbe5b8be9768ef078

apksigner is part of the Android SDK in the build-tools directory. It's the tool print-apk-signature uses.

Answer 2

Signature[] sigs = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
for (Signature sig : sigs)
{
    Trace.i("MyApp", "Signature hashcode : " + sig.hashCode());
}

http://developer.android.com/reference/android/content/pm/PackageManager.html

this might help

First, unzip the APK and extract the file /META-INF/ANDROID_.RSA (this file may also be CERT.RSA, but there should only be one .RSA file).

Then issue this command:

keytool -printcert -file ANDROID_.RSA You will get certificate fingerprints like this:

 MD5:  B3:4F:BE:07:AA:78:24:DC:CA:92:36:FF:AE:8C:17:DB
 SHA1: 16:59:E7:E3:0C:AA:7A:0D:F2:0D:05:20:12:A8:85:0B:32:C5:4F:68
 Signature algorithm name: SHA1withRSA

Then use the keytool again to print out all the aliases of your signing keystore:

keytool -list -keystore my-signing-key.keystore You will get a list of aliases and their certificate fingerprint:

android_key, Jan 23, 2010, PrivateKeyEntry, Certificate fingerprint (MD5): B3:4F:BE:07:AA:78:24:DC:CA:92:36:FF:AE:8C:17:DB Voila! we can now determined the apk has been signed with this keystore, and with the alias 'android_key'.

Keytool is part of Java, so make sure your PATH has Java installation dir in it.

How do I find out which keystore was used to sign an app?