From 15764b0b067b99d08b810303c4615fb8ee296887 Mon Sep 17 00:00:00 2001 From: "Jay Freeman (saurik)" Date: Fri, 6 Jan 2017 18:54:37 -0800 Subject: [PATCH] Avoid blowing up the stack hashing large binaries. --- ldid.cpp | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/ldid.cpp b/ldid.cpp index d7fdf7a..fa21a15 100644 --- a/ldid.cpp +++ b/ldid.cpp @@ -1381,6 +1381,11 @@ class NullBuffer : } }; +class Digest { + public: + uint8_t sha1_[LDID_SHA1_DIGEST_LENGTH]; +}; + class Hash { public: char sha1_[LDID_SHA1_DIGEST_LENGTH]; @@ -1652,14 +1657,14 @@ std::vector Sign(const void *idata, size_t isize, std::streambuf &output, if (!team.empty()) put(data, team.c_str(), team.size() + 1); - uint8_t storage[special + normal][LDID_SHA1_DIGEST_LENGTH]; - uint8_t (*hashes)[LDID_SHA1_DIGEST_LENGTH] = storage + special; + std::vector storage(special + normal); + auto *hashes(&storage[special]); - memset(storage, 0, sizeof(*storage) * special); + memset(storage.data(), 0, sizeof(Digest) * special); _foreach (blob, blobs) { auto local(reinterpret_cast(&blob.second[0])); - sha1((uint8_t *) (hashes - blob.first), local, Swap(local->length)); + sha1((hashes - blob.first)->sha1_, local, Swap(local->length)); } _foreach (slot, posts) { @@ -1669,11 +1674,11 @@ std::vector Sign(const void *idata, size_t isize, std::streambuf &output, if (normal != 1) for (size_t i = 0; i != normal - 1; ++i) - sha1(hashes[i], (PageSize_ * i < overlap.size() ? overlap.data() : top) + PageSize_ * i, PageSize_); + sha1(hashes[i].sha1_, (PageSize_ * i < overlap.size() ? overlap.data() : top) + PageSize_ * i, PageSize_); if (normal != 0) - sha1(hashes[normal - 1], top + PageSize_ * (normal - 1), ((limit - 1) % PageSize_) + 1); + sha1(hashes[normal - 1].sha1_, top + PageSize_ * (normal - 1), ((limit - 1) % PageSize_) + 1); - put(data, storage, sizeof(storage)); + put(data, storage.data(), sizeof(Digest) * storage.size()); const auto &save(insert(blobs, CSSLOT_CODEDIRECTORY, CSMAGIC_CODEDIRECTORY, data)); sha1(hash, save.data(), save.size()); -- 2.45.2