github.com/JeffDeCola/my-go-tools/cryptography-tools/sha256-hash-file

sha256-hash-file TOOL

Get an sha256 hash (fingerprint) from an input file using the crypto/sha256 standard package. I also added a flag to read in your .ssh/id_rsa.pub key to get your ssh fingerprint.

tl;dr

# INSTALL VIA GO
go install sh256-hash-file.go

# GET SH256 FINGERPRINT ON FILE
sha256-hash-file testfile.txt

# GET SH256 FINGERPRINT ON KEY FILE
sha256-hash-file -ssh ~/.ssh/id_rsa.pub

Table of Contents

• OVERVIEW
• PREREQUISITES
• RUN
• TEST
• INSTALL
• USAGE
  • -h
  • -v
  • -ssh
  • -loglevel-string

Documentation and Reference

• crypto/sha256 standard package
• Refer to sha256-hash-from-file example in my-go-examples

OVERVIEW

In a nutshell, the guts of the code is,

plainTextBytes := []byte(plainText)

// HASH
sha256HashByte := sha256.Sum256(plainTextBytes)

// CONVERT TO STRING
sha256Hash := base64.RawStdEncoding.EncodeToString(sha256HashByte[:])

PREREQUISITES

You will need the following go packages,

go get -u -v github.com/sirupsen/logrus

RUN

To run.sh,

go run . testfile.txt
go run sha256-hash-file.go testfile.txt
go run sha256-hash-file.go testfile.txt -loglevel trace

If you run on testfile.txt your sha256 hash shall be,

r2pN5Sjq43jggvxvW34cT6s662//HfyemRss38ZA+vk

You may also use the -ssh flag to read in a public ssh key file,

go run . -ssh ~/.ssh/id_rsa.pub
go run sha256-hash-file.go -ssh ~/.ssh/id_rsa.pub
go run sha256-hash-file.go -ssh ~/.ssh/id_rsa.pub -loglevel trace

Its nice because you can check you have the right fingerprint at github.com/settings/keys.

You can also run the unix command to check your sha256,

 ssh-keygen -lf ~/.ssh/id_rsa.pub

TEST

To create _test files,

gotests -w -all sha256-hash-file.go

To unit-tests.sh,

go test -cover ./... | tee test/test_coverage.txt
cat test/test_coverage.txt

INSTALL

Will place an executable in your go bin,

go install sha256-hash-file.go

USAGE

sha256-hash-file {-h|-v|-ssh} [FILENAME] -loglevel [level]

-h

Help,

sha256-hash-file -h

-v

Version,

sha256-hash-file -v

-ssh

Check your public ssh file,

sha256-hash-file -ssh ~/.ssh/id_rsa.pub

-loglevel string

Can use trace, info or error,

sha256-hash-file -ssh ~/.ssh/id_rsa.pub -loglevel trace