Skip to content

How_To_SHA256.md

Latest commit

 

History

History
78 lines (60 loc) · 2.16 KB

How_To_SHA256.md

File metadata and controls

78 lines (60 loc) · 2.16 KB

How to Use SHA256 on macOS

What is a SHA256 Checksum?

SHA256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function that generates a unique, fixed-length string for a given file. It's commonly used to:

  • Verify file integrity: Ensure a downloaded file hasn’t been tampered with.
  • Authenticate downloads: Match the provided checksum with the file's checksum.

How to Generate a SHA256 Checksum

  1. Open the Terminal:

    • Use Spotlight (Cmd + Space) to search for "Terminal" and open it.

  2. Navigate to the File Location:

    • Use the cd command to go to the folder containing your file: 
      cd /path/to/your/file

  3. Run the Checksum Command:

    • Replace yourfile with the actual filename: 
      shasum -a 256 yourfile
    • Example output: 
      e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  yourfile
    • The long string is the file's SHA256 checksum.

  4. Compare Checksum Values:

    • Match the output with the checksum provided by the file's source to ensure it’s unchanged.

How to Use a SHA256 Checksum with curl

When downloading files using curl, you can verify the integrity of the downloaded file by comparing its checksum with the expected value.

  1. Download the File with curl:

    • Replace <url> with the file’s download link: 
      curl -O <url>
      Example: 
      curl -O https://example.com/myfile.pkg

  2. Generate the Checksum:

    • Run the same command as above to get the checksum of the downloaded file: 
      shasum -a 256 myfile.pkg

  3. Verify the Checksum:

    • Compare the output of the command with the checksum provided by the file's source. If the checksums match, the file is intact.

Example Workflow

  1. Download the file: 
    curl -O https://example.com/software.pkg
  2. Check the checksum: 
    shasum -a 256 software.pkg
  3. Compare with the provided checksum:
    • If the checksum provided is abc123..., ensure the output matches: 
      abc123...  software.pkg