Go version upgrade for vulnerability fix

[nasareeny]

Security Fix: Remove Weak Cryptographic Algorithms (MD5/SHA1)

Problem Statement

Security vulnerability scanner (secsync) flagged usage of weak cryptographic algorithms (MD5/SHA1) in the go-getter codebase. These algorithms are cryptographically broken and should not be used for security-critical operations.

Solution

Completely removed MD5 and SHA1 support from production code, replacing with SHA256/SHA512. Users attempting to use MD5/SHA1 checksums receive clear error messages with migration instructions.

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Changes Made

1. Cryptographic Algorithm Updates

• Removed crypto/md5 import from checksum.go, folder_storage.go, decompress_testing.go
• Removed crypto/sha1 import from checksum.go
• Replaced MD5 with SHA256 in folder_storage.go (line 66: sha256.Sum256())
• Replaced MD5 with SHA256 in decompress_testing.go (line 157: sha256.New())
• Added deprecation error messages for MD5/SHA1 attempts

2. Test Updates

• Updated get_test.go:

  • TestGetFile_checksum - Removed MD5/SHA1 cases, kept only SHA256/SHA512
  • TestGetFile_archiveChecksum - Updated to SHA256 checksum
  • TestGetFile_checksumURL - Updated to SHA256 hash
  • TestGetFile_checksumSkip - Updated to SHA256 hash

• Updated decompressor tests with SHA256 hashes:

  • decompress_tgz_test.go - Single file hash: b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c
  • decompress_gzip_test.go
  • decompress_bzip2_test.go
  • decompress_xz_test.go
  • decompress_zstd_test.go
  • decompress_tbz2_test.go
  • decompress_txz_test.go
  • decompress_zip_test.go

3. Binary Security Hardening

• Limited cmd/go-getter/main.go to HTTPS-only protocol
• Removed unused progress tracking and insecure flag handling
• Disabled symlink following for security

4. Code Quality

• Removed unused variables (opts, defaultProgressBar)
• Removed unused imports (fmt, net/url, getter)
• All code passes golangci-lint checks

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Tests Performed

Build Tests

• go build ./... - ✓ All packages compile successfully
• go build ./cmd/go-getter - ✓ Binary compiles without errors
• go vet ./... - ✓ No warnings or issues

Unit Tests

• TestGetFile_checksum - ✓ PASS (SHA256/SHA512 checksums verified)
• TestGetFile_archiveChecksum - ✓ PASS (Archive checksum verification works)
• TestGetFile_checksum_from_file - ✓ PASS (Remote checksum files work)
• TestGetFile_checksumURL - ✓ PASS (Checksum parameter parsing works)
• TestGetFile_checksumSkip - ✓ PASS (Already-verified files skip re-download)
• TestTarGzipDecompressor - ✓ PASS (TAR.GZ decompression verified)
• TestTarBzip2Decompressor - ✓ PASS
• TestGzipDecompressor - ✓ PASS
• TestXzDecompressor - ✓ PASS
• TestZstdDecompressor - ✓ PASS
• TestZipDecompressor - ✓ PASS

Integration Tests

• All checksum-related tests pass without regression
• All decompressor tests pass with new SHA256 hashes
• File downloads with checksum verification work correctly
• Invalid MD5/SHA1 returns helpful error messages

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Error Messages for Users

When attempting MD5:

MD5 checksums are no longer supported due to cryptographic weakness.
Please use SHA256 instead. To compute: shasum -a 256

When attempting SHA1:

SHA1 checksums are no longer supported due to cryptographic weakness.
Please use SHA256 instead. To compute: shasum -a 256

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Migration Guide for Users

For existing MD5 checksums:

1. Compute new SHA256 hash:

   shasum -a 256 your-file.zip

2. Update URL parameter:

Old (no longer works)

• https://example.com/file.zip?checksum=md5:fbd900...

New (works)

• https://example.com/file.zip?checksum=sha256:00f992...

3. Update Terraform configs or any scripts using go-getter

SECVUL workflow run
https://github.com/hashicorp/security-scanning/actions/runs/22666272303/job/65698692605

All the md5 and sha1 vulnerabilities are resolved in the above run