Generator Online SHA1

I know what is a SHA and SHA1 cryptographic algorithm. I also know how to genarate these from a computer.

But I have searched a lot on the internet and still unable to get a proper explanation on how using these keys will secure an API that you are using on an Android app?

For example, Facebook needs your SHA1 key from your system along with your app's package name to be entered on their developer console and their API doesn't work on your app if the key you entered is wrong.

How does this mechanism work? How do they verify this on your App?

I try to hash a double (1529480427715.5532) with SHA1 algorithm and i have this hash in c#:

• use in string format: "3e8f41233f90a85f9963afaa571ba76afb8bb08d"
• use in double format: "c880857c399c7b9cc9c6395197e700543c400b17"

but in fact i want to get this hash "da39a3ee5e6b4b0d3255bfef95601890afd80709" as result like when i'm using js-sha1 library.

I created an Android Project. Now I want to add Firebase into my android project. I register my application on firebase console. Now When I try to add my sha-1 key in to project it gives me following error.

I search on google and stackoverflow but didn't receive any proper answer. According to some answers this error occurs when I insert same sha-1 key in to another project of firebase. Let me tell you that this is my only project in firebase console. I do not have any other project in this firebase account.

So what could be the problem and how can I add this sha-1 in my firebase project ?

Due to Windows changing their security policies, we are planning to begin code-signing driver files with the SHA-256 algorithm instead of SHA-1. However, we still want to be able to support older OS's that still require SHA-1 signing.

Using Microsoft's signtool.exe we are able to code sign files successfully with both SHA-1 and SHA-256 digest algorithms using the /fd flag. However, if possible, we would like to sign the file with both algorithms simultaneously. Is this even possible? We would like to avoid having multiple sets of drivers that are signed with different algorithms and determining which set to install based on OS -- which would be our alternative approach.

If anyone has had experience with accomplishing this please explain what approach you took. If this isn't possible, an explanation of why it's impossible would be appreciated.

I've investigated 30261296 however I'm still at a loss to find a way to generate the same results in Ruby with the openssl and/or digest gems. The OpenSSL output I'm trying to replicate in ruby is as follows:

$ openssl x509 -noout -subject_hash -in DigiCertSHA2SecureServerCA.pem85cf5865

In reading many things, I believe this hash is generated from the Subject: portion of the certificate, which is like the distinguished name. In this certificates case something to the effect of:

$ openssl x509 -noout -subject -in DigiCertSHA2SecureServerCA.crtsubject=C = US, O = DigiCert Inc, CN = DigiCert SHA2 Secure Server CA

Attempting to SHA-1 encode that on the command line or in Ruby (which represents this as /C=US,/O=DigiCert Inc/CN=DigiCert SHA2 Secure Server CA when using the openssl gem) has not yeilded the same has results displayed by OpenSSL.

I'm trying to do this more natively in Ruby to avoid shelling out to openssl if possible since openssl and digest come along with the ruby env. In the end I need this to generate the hash directory tree ... i.e. 85cf5865.0 (hash + '.0').

The CA I'm hasing is DigiCertSHA2SecureServerCA.crt - DER encoded. I converted DER to PEM because openssl command line uses that without the additional -inform der switch. It doesn't appear to matter to Ruby's openssl gem.