🔐 How to Use SHA1 on macOS

🔎 What is a SHA1 Checksum?

SHA1 (Secure Hash Algorithm 1) is a cryptographic hash function that generates a unique string for a file. Use it to:

• ✅ Verify file integrity (detect tampering).
• 🔒 Authenticate downloads by matching checksums.

✍️ Generate a SHA1 Checksum

1️⃣ Open Terminal

• Search for Terminal with Cmd + Space (Spotlight).

2️⃣ Navigate to the File

• Use the cd command to locate your file:

  cd /path/to/your/file

3️⃣ Run the Checksum Command

• Replace yourfile with the file name:

  shasum -a 1 yourfile

• Example output:

  da39a3ee5e6b4b0d3255bfef95601890afd80709  yourfile

4️⃣ Compare Values

• Match the checksum from the output with the source-provided value.

🌐 Use SHA1 with curl

1️⃣ Download the File

• Use curl with the file URL:

  curl -O https://example.com/myfile.pkg

2️⃣ Generate the Checksum

• Run the SHA1 command:

  shasum -a 1 myfile.pkg

3️⃣ Verify Integrity

• Compare the generated checksum with the one provided by the source.

🚀 Example Workflow

1. Download the file:

   curl -O https://example.com/software.pkg

2. Generate SHA1 checksum:

   shasum -a 1 software.pkg

3. Compare checksum:
   • Provided: abc123...
   • Output:

     abc123...  software.pkg

   • ✅ Match means the file is secure.

💡 Need More Help?

• macOS Terminal Guide
• Understanding SHA1