AgentSkillsCN

image-verification

使用 Magic Bytes 校验图像文件签名，并计算 SHA-256 加密哈希值。

SKILL.md
--- frontmatter
name: image-verification
description: Validates image file signatures using Magic Bytes and calculates SHA-256 cryptographic hash
license: MIT
compatibility: opencode
metadata:
  audience: developers
  workflow: clinical-pipeline

What I do

I verify image authenticity before processing. I check file signatures (Magic Bytes) to confirm the file is a valid image type and calculate a SHA-256 hash for audit trails and duplicate detection.

When to use me

Use this when:

  • •An image is uploaded and needs validation
  • •You need to ensure the file is actually an image (not malicious content)
  • •You need a cryptographic hash for the image (audit/duplicate check)

Key Concepts

  • •Magic Bytes: File signature bytes that identify the format (e.g., FF D8 FF for JPEG)
  • •SHA-256 Hash: 256-bit cryptographic hash for integrity and identification
  • •Crypto Subtle: Browser Web Crypto API for cryptographic operations

Source Files

  • •services/crypto.ts: Cryptographic operations
  • •services/vision.ts: Image validation helpers

Code Patterns

  • •Use crypto.subtle.digest('SHA-256', ...) for hashing
  • •Check first bytes of ArrayBuffer for magic bytes
  • •Reject invalid files immediately with clear error messages

Operational Constraints

  • •Must reject non-image files before any processing
  • •Hash is used for deduplication and audit trail
  • •Always log verification results for traceability