问题
So reading this post: How can I calculate the SHA-256 hash of a string in Android?
and the docs: http://developer.android.com/reference/java/security/MessageDigest.html
I'm curious; which phones will support SHA-256? In the docs, the line about the 'NoSuchAlgorithmException' makes me think that some phones don't support all algorithms. Before I go implementing this for an app and expecting it to work the same on all phones I want to know if anyone knows anything about this...?
I find it strange that the MessageDigest class doesn't have some constants to pick the algorithm you want to use.
回答1:
All Android devices support SHA-256. The NoSuchAlgorithmException
indicates that a requested algorithm could not be found and is necessary because the method takes a String
argument for the algorithm name. If you passed in "foo-256", the method's only recourse is to throw a NoSuchAlgorithmException
because, for reasons beyond my understanding, there's no algorithm called "foo-256". Assuming you're passing in a name you're sure is an algorithm that Android can use, you'll never see that exception.
回答2:
Add NoSuchAlgorithmException as below:
public static String SHA256 (String text) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update(text.getBytes());
byte[] digest = md.digest();
return Base64.encodeToString(digest, Base64.DEFAULT);
}
回答3:
SHA-256withRSA is NOT supported in older android versions (verified the same in Android 4.0.3, 4.1.1). I have experienced this problem while using JSCEP. The digest algorithm returned by SCEP server is SHA-256. But SHA-256withRSA is not present in any default SecurityProviders in those android versions. Found a relevant link: Which versions of Android support which package signing algorithms?
This link shows that SHA-256withRSA was added later: https://android-review.googlesource.com/44360
回答4:
According to the Android Documentations for MessageDigest, SHA-256 is supported since API 1.
来源:https://stackoverflow.com/questions/10129311/does-every-android-phone-support-sha-256