阶段 B 步骤 6：.stb 写侧新格式（头 104 + 型号标识 + SHA-256 文件尾）。
- Stb：kHeaderSize 104、kSha256Size 32；SHA-256 实现（FIPS 180-4，含标准测试向量验证）； fill_model_id（name+version 拼 32 字节补 '\0'）；StbView 解析新格式 + model_id()/model_matches()/sha_ok()（数据段不含尾、缺尾报错） - Codegen：assemble_image 写型号标识（偏移 72）+ 文件尾 SHA-256 - main.cpp：--disasm 显示 model/sha；写后自检（ok+sha+型号匹配，失败报错） - 测试：machine_test +SHA-256 已知向量（空串/abc）与型号标识断言（53 断言）； codegen_test data_len 断言 +32（SHA 尾）；ctest 12/12 - 验证：line1 288 字节 model=STATOR1 sha=ok；篡改一字节 sha=BAD
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@@ -44,8 +44,129 @@ namespace {
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return v;
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}
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// ---- SHA-256（FIPS 180-4）----
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const uint32_t kShaK[64] = {
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0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
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0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
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0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
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0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
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0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
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0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
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0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
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0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
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0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
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0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
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0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
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};
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inline uint32_t rotr(uint32_t x, uint32_t n) { return (x >> n) | (x << (32 - n)); }
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struct Sha256 {
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uint32_t h[8] = {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
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0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
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uint64_t total = 0;
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uint8_t block[64];
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size_t block_len = 0;
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void update(const uint8_t* data, size_t len) {
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total += len;
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while (len > 0) {
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const size_t take = (block_len < 64) ? (64 - block_len) : 0;
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const size_t n = len < take ? len : take;
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if (n > 0) {
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for (size_t i = 0; i < n; ++i) {
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block[block_len + i] = data[i];
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}
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block_len += n;
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data += n;
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len -= n;
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if (block_len == 64) {
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process();
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block_len = 0;
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}
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} else {
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break;
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}
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}
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}
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void process() {
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uint32_t w[64];
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for (int i = 0; i < 16; ++i) {
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w[i] = get_be32(block + i * 4);
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}
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for (int i = 16; i < 64; ++i) {
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const uint32_t s0 = rotr(w[i - 15], 7) ^ rotr(w[i - 15], 18) ^ (w[i - 15] >> 3);
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const uint32_t s1 = rotr(w[i - 2], 17) ^ rotr(w[i - 2], 19) ^ (w[i - 2] >> 10);
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w[i] = w[i - 16] + s0 + w[i - 7] + s1;
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}
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uint32_t a = h[0], b = h[1], c = h[2], d = h[3];
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uint32_t e = h[4], f = h[5], g = h[6], hh = h[7];
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for (int i = 0; i < 64; ++i) {
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const uint32_t s1 = rotr(e, 6) ^ rotr(e, 11) ^ rotr(e, 25);
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const uint32_t ch = (e & f) ^ (~e & g);
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const uint32_t t1 = hh + s1 + ch + kShaK[i] + w[i];
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const uint32_t s0 = rotr(a, 2) ^ rotr(a, 13) ^ rotr(a, 22);
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const uint32_t maj = (a & b) ^ (a & c) ^ (b & c);
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const uint32_t t2 = s0 + maj;
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hh = g;
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g = f;
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f = e;
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e = d + t1;
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d = c;
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c = b;
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b = a;
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a = t1 + t2;
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}
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h[0] += a; h[1] += b; h[2] += c; h[3] += d;
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h[4] += e; h[5] += f; h[6] += g; h[7] += hh;
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}
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void final(uint8_t out[32]) {
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const uint64_t bitlen = total * 8;
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const uint8_t pad = 0x80;
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update(&pad, 1);
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const uint8_t zeros[64] = {0};
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// 补零到 block_len == 56（跨块时先补满当前块再补）
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while (block_len != 56) {
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const size_t n = (block_len < 56) ? (56 - block_len) : (64 - block_len);
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update(zeros, n);
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}
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// 64 位大端比特长度
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for (int i = 0; i < 8; ++i) {
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const uint8_t b2[1] = {static_cast<uint8_t>((bitlen >> (56 - 8 * i)) & 0xFF)};
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update(b2, 1);
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}
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for (int i = 0; i < 8; ++i) {
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out[i * 4 + 0] = static_cast<uint8_t>((h[i] >> 24) & 0xFF);
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out[i * 4 + 1] = static_cast<uint8_t>((h[i] >> 16) & 0xFF);
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out[i * 4 + 2] = static_cast<uint8_t>((h[i] >> 8) & 0xFF);
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out[i * 4 + 3] = static_cast<uint8_t>(h[i] & 0xFF);
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}
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}
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static uint32_t get_be32(const uint8_t* p) {
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return (static_cast<uint32_t>(p[0]) << 24) | (static_cast<uint32_t>(p[1]) << 16) |
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(static_cast<uint32_t>(p[2]) << 8) | static_cast<uint32_t>(p[3]);
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}
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};
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} // namespace
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void sha256(const uint8_t* data, size_t len, uint8_t out[kSha256Size]) {
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Sha256 s;
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s.update(data, len);
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s.final(out);
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}
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void fill_model_id(const std::string& name, uint32_t version, char out[kModelIdSize]) {
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const std::string id = name + std::to_string(version);
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for (size_t i = 0; i < kModelIdSize; ++i) {
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out[i] = i < id.size() ? id[i] : '\0';
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}
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}
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StbView StbView::from(const uint8_t* buf, size_t len) {
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StbView v;
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v.buf_ = buf;
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@@ -77,11 +198,15 @@ StbView StbView::from(const uint8_t* buf, size_t len) {
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v.offset_fb_ = get_le32(buf + 64);
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v.offset_data_ = get_le32(buf + 68);
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// 段校验
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// 段校验（12.13：文件尾 SHA-256[32] 在数据段之后）
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if (len < static_cast<size_t>(v.offset_data_) + kSha256Size) {
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v.err_ = "missing sha256 tail";
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return v;
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}
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const uint64_t offs[5] = {get_le32(buf + 52), get_le32(buf + 56), v.offset_code_,
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v.offset_fb_, v.offset_data_};
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for (int i = 0; i < 5; ++i) {
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if (offs[i] < kHeaderSize || offs[i] > len) {
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if (offs[i] < kHeaderSize || offs[i] > len - kSha256Size) {
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v.err_ = "segment offset out of range";
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return v;
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}
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@@ -154,7 +279,35 @@ const uint8_t* StbView::data_bytes() const {
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}
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size_t StbView::data_len() const {
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return ok_ ? len_ - offset_data_ : 0;
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return ok_ ? (len_ - kSha256Size) - offset_data_ : 0;
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}
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std::string StbView::model_id() const {
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if (!ok_) {
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return "";
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}
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std::string s(reinterpret_cast<const char*>(buf_ + 72), kModelIdSize);
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const size_t z = s.find('\0');
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if (z != std::string::npos) {
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s.resize(z);
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}
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return s;
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}
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bool StbView::model_matches(const std::string& name, uint32_t version) const {
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char want[kModelIdSize];
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fill_model_id(name, version, want);
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return std::memcmp(buf_ + 72, want, kModelIdSize) == 0;
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}
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bool StbView::sha_ok() const {
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if (!ok_) {
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return false;
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}
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const size_t content_len = len_ - kSha256Size;
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uint8_t digest[kSha256Size];
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sha256(buf_, content_len, digest);
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return std::memcmp(buf_ + content_len, digest, kSha256Size) == 0;
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}
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bool read_stb_file(const char* path, std::vector<uint8_t>* out, std::string* err) {
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