thodg/libgit2

diff --git a/fuzzers/packfile_fuzzer.c b/fuzzers/packfile_fuzzer.c
index 6002fa1..23ecaf8 100644
--- a/fuzzers/packfile_fuzzer.c
+++ b/fuzzers/packfile_fuzzer.c
@@ -94,7 +94,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 			fprintf(stderr, "Failed to compute the SHA1 hash\n");
 			abort();
 		}
-		if (git_indexer_append(indexer, &oid, sizeof(oid), &stats) < 0) {
+		if (git_indexer_append(indexer, &oid.id, GIT_OID_RAWSZ, &stats) < 0) {
 			goto cleanup;
 		}
 	}
diff --git a/src/libgit2/commit_graph.c b/src/libgit2/commit_graph.c
index 70e866b..10947ac 100644
--- a/src/libgit2/commit_graph.c
+++ b/src/libgit2/commit_graph.c
@@ -138,7 +138,7 @@ static int commit_graph_parse_oid_lookup(
 		struct git_commit_graph_chunk *chunk_oid_lookup)
 {
 	uint32_t i;
-	git_oid *oid, *prev_oid, zero_oid = {{0}};
+	unsigned char *oid, *prev_oid, zero_oid[GIT_OID_RAWSZ] = {0};
 
 	if (chunk_oid_lookup->offset == 0)
 		return commit_graph_error("missing OID Lookup chunk");
@@ -147,10 +147,10 @@ static int commit_graph_parse_oid_lookup(
 	if (chunk_oid_lookup->length != file->num_commits * GIT_OID_RAWSZ)
 		return commit_graph_error("OID Lookup chunk has wrong length");
 
-	file->oid_lookup = oid = (git_oid *)(data + chunk_oid_lookup->offset);
-	prev_oid = &zero_oid;
-	for (i = 0; i < file->num_commits; ++i, ++oid) {
-		if (git_oid_cmp(prev_oid, oid) >= 0)
+	file->oid_lookup = oid = (unsigned char *)(data + chunk_oid_lookup->offset);
+	prev_oid = zero_oid;
+	for (i = 0; i < file->num_commits; ++i, oid += GIT_OID_RAWSZ) {
+		if (git_oid_raw_cmp(prev_oid, oid) >= 0)
 			return commit_graph_error("OID Lookup index is non-monotonic");
 		prev_oid = oid;
 	}
@@ -437,7 +437,7 @@ static int git_commit_graph_entry_get_byindex(
 	}
 
 	commit_data = file->commit_data + pos * (GIT_OID_RAWSZ + 4 * sizeof(uint32_t));
-	git_oid_cpy(&e->tree_oid, (const git_oid *)commit_data);
+	git_oid_fromraw(&e->tree_oid, commit_data);
 	e->parent_indices[0] = ntohl(*((uint32_t *)(commit_data + GIT_OID_RAWSZ)));
 	e->parent_indices[1] = ntohl(
 			*((uint32_t *)(commit_data + GIT_OID_RAWSZ + sizeof(uint32_t))));
@@ -470,7 +470,8 @@ static int git_commit_graph_entry_get_byindex(
 			e->parent_count++;
 		}
 	}
-	git_oid_cpy(&e->sha1, &file->oid_lookup[pos]);
+
+	git_oid_fromraw(&e->sha1, &file->oid_lookup[pos * GIT_OID_RAWSZ]);
 	return 0;
 }
 
@@ -514,7 +515,7 @@ int git_commit_graph_entry_find(
 {
 	int pos, found = 0;
 	uint32_t hi, lo;
-	const git_oid *current = NULL;
+	const unsigned char *current = NULL;
 
 	GIT_ASSERT_ARG(e);
 	GIT_ASSERT_ARG(file);
@@ -528,26 +529,25 @@ int git_commit_graph_entry_find(
 	if (pos >= 0) {
 		/* An object matching exactly the oid was found */
 		found = 1;
-		current = file->oid_lookup + pos;
+		current = file->oid_lookup + (pos * GIT_OID_RAWSZ);
 	} else {
 		/* No object was found */
 		/* pos refers to the object with the "closest" oid to short_oid */
 		pos = -1 - pos;
 		if (pos < (int)file->num_commits) {
-			current = file->oid_lookup + pos;
+			current = file->oid_lookup + (pos * GIT_OID_RAWSZ);
 
-			if (!git_oid_ncmp(short_oid, current, len))
+			if (!git_oid_raw_ncmp(short_oid->id, current, len))
 				found = 1;
 		}
 	}
 
 	if (found && len != GIT_OID_HEXSZ && pos + 1 < (int)file->num_commits) {
 		/* Check for ambiguousity */
-		const git_oid *next = current + 1;
+		const unsigned char *next = current + GIT_OID_RAWSZ;
 
-		if (!git_oid_ncmp(short_oid, next, len)) {
+		if (!git_oid_raw_ncmp(short_oid->id, next, len))
 			found = 2;
-		}
 	}
 
 	if (!found)
@@ -1019,7 +1019,9 @@ static int commit_graph_write(
 	/* Fill the OID Lookup table. */
 	git_vector_foreach (&w->commits, i, packed_commit) {
 		error = git_str_put(&oid_lookup,
-			(const char *)&packed_commit->sha1, sizeof(git_oid));
+			(const char *)&packed_commit->sha1.id,
+			GIT_OID_RAWSZ);
+
 		if (error < 0)
 			goto cleanup;
 	}
@@ -1034,8 +1036,9 @@ static int commit_graph_write(
 		unsigned int parentcount = (unsigned int)git_array_size(packed_commit->parents);
 
 		error = git_str_put(&commit_data,
-				(const char *)&packed_commit->tree_oid,
-				sizeof(git_oid));
+			(const char *)&packed_commit->tree_oid.id,
+			GIT_OID_RAWSZ);
+
 		if (error < 0)
 			goto cleanup;
 
diff --git a/src/libgit2/commit_graph.h b/src/libgit2/commit_graph.h
index 45e125b..b78ab81 100644
--- a/src/libgit2/commit_graph.h
+++ b/src/libgit2/commit_graph.h
@@ -36,7 +36,7 @@ typedef struct git_commit_graph_file {
 	uint32_t num_commits;
 
 	/* The OID Lookup table. */
-	git_oid *oid_lookup;
+	unsigned char *oid_lookup;
 
 	/*
 	 * The Commit Data table. Each entry contains the OID of the commit followed
diff --git a/src/libgit2/index.c b/src/libgit2/index.c
index aa97c64..f44c507 100644
--- a/src/libgit2/index.c
+++ b/src/libgit2/index.c
@@ -74,7 +74,7 @@ struct entry_short {
 	uint32_t uid;
 	uint32_t gid;
 	uint32_t file_size;
-	git_oid oid;
+	unsigned char oid[GIT_OID_RAWSZ];
 	uint16_t flags;
 	char path[1]; /* arbitrary length */
 };
@@ -88,7 +88,7 @@ struct entry_long {
 	uint32_t uid;
 	uint32_t gid;
 	uint32_t file_size;
-	git_oid oid;
+	unsigned char oid[GIT_OID_RAWSZ];
 	uint16_t flags;
 	uint16_t flags_extended;
 	char path[1]; /* arbitrary length */
@@ -2480,9 +2480,11 @@ static int read_entry(
 	entry.uid = ntohl(source.uid);
 	entry.gid = ntohl(source.gid);
 	entry.file_size = ntohl(source.file_size);
-	git_oid_cpy(&entry.id, &source.oid);
 	entry.flags = ntohs(source.flags);
 
+	if (git_oid_fromraw(&entry.id, source.oid) < 0)
+		return -1;
+
 	if (entry.flags & GIT_INDEX_ENTRY_EXTENDED) {
 		uint16_t flags_raw;
 		size_t flags_offset;
@@ -2803,9 +2805,7 @@ static int write_disk_entry(git_filebuf *file, git_index_entry *entry, const cha
 	ondisk.uid = htonl(entry->uid);
 	ondisk.gid = htonl(entry->gid);
 	ondisk.file_size = htonl((uint32_t)entry->file_size);
-
-	git_oid_cpy(&ondisk.oid, &entry->id);
-
+	git_oid_raw_cpy(ondisk.oid, entry->id.id);
 	ondisk.flags = htons(entry->flags);
 
 	if (entry->flags & GIT_INDEX_ENTRY_EXTENDED) {
diff --git a/src/libgit2/indexer.c b/src/libgit2/indexer.c
index f9a32e7..afb9ce8 100644
--- a/src/libgit2/indexer.c
+++ b/src/libgit2/indexer.c
@@ -385,7 +385,7 @@ static int check_object_connectivity(git_indexer *idx, const git_rawobj *obj)
 			size_t i;
 
 			git_array_foreach(tree->entries, i, entry)
-				if (add_expected_oid(idx, entry->oid) < 0)
+				if (add_expected_oid(idx, &entry->oid) < 0)
 					goto out;
 
 			break;
@@ -1269,7 +1269,7 @@ int git_indexer_commit(git_indexer *idx, git_indexer_progress *stats)
 
 	/* Write out the object names (SHA-1 hashes) */
 	git_vector_foreach(&idx->objects, i, entry) {
-		git_filebuf_write(&index_file, &entry->oid, sizeof(git_oid));
+		git_filebuf_write(&index_file, &entry->oid.id, GIT_OID_RAWSZ);
 	}
 
 	/* Write out the CRC32 values */
diff --git a/src/libgit2/iterator.c b/src/libgit2/iterator.c
index 15bb63d..bc6f766 100644
--- a/src/libgit2/iterator.c
+++ b/src/libgit2/iterator.c
@@ -613,7 +613,7 @@ GIT_INLINE(int) tree_iterator_frame_push_neighbors(
 			break;
 
 		if ((error = git_tree_lookup(&tree,
-			iter->base.repo, entry->tree_entry->oid)) < 0)
+			iter->base.repo, &entry->tree_entry->oid)) < 0)
 			break;
 
 		if (git_vector_insert(&parent_frame->similar_trees, tree) < 0)
@@ -659,7 +659,7 @@ GIT_INLINE(int) tree_iterator_frame_push(
 	int error;
 
 	if ((error = git_tree_lookup(&tree,
-			iter->base.repo, entry->tree_entry->oid)) < 0 ||
+			iter->base.repo, &entry->tree_entry->oid)) < 0 ||
 		(error = tree_iterator_frame_init(iter, tree, entry)) < 0)
 		goto done;
 
@@ -740,7 +740,7 @@ static void tree_iterator_set_current(
 
 	iter->entry.mode = tree_entry->attr;
 	iter->entry.path = iter->entry_path.ptr;
-	git_oid_cpy(&iter->entry.id, tree_entry->oid);
+	git_oid_cpy(&iter->entry.id, &tree_entry->oid);
 }
 
 static int tree_iterator_advance(const git_index_entry **out, git_iterator *i)
diff --git a/src/libgit2/midx.c b/src/libgit2/midx.c
index 0092601..d4e53c4 100644
--- a/src/libgit2/midx.c
+++ b/src/libgit2/midx.c
@@ -115,7 +115,7 @@ static int midx_parse_oid_lookup(
 		struct git_midx_chunk *chunk_oid_lookup)
 {
 	uint32_t i;
-	git_oid *oid, *prev_oid, zero_oid = {{0}};
+	unsigned char *oid, *prev_oid, zero_oid[GIT_OID_RAWSZ] = {0};
 
 	if (chunk_oid_lookup->offset == 0)
 		return midx_error("missing OID Lookup chunk");
@@ -124,10 +124,10 @@ static int midx_parse_oid_lookup(
 	if (chunk_oid_lookup->length != idx->num_objects * GIT_OID_RAWSZ)
 		return midx_error("OID Lookup chunk has wrong length");
 
-	idx->oid_lookup = oid = (git_oid *)(data + chunk_oid_lookup->offset);
-	prev_oid = &zero_oid;
-	for (i = 0; i < idx->num_objects; ++i, ++oid) {
-		if (git_oid_cmp(prev_oid, oid) >= 0)
+	idx->oid_lookup = oid = (unsigned char *)(data + chunk_oid_lookup->offset);
+	prev_oid = zero_oid;
+	for (i = 0; i < idx->num_objects; ++i, oid += GIT_OID_RAWSZ) {
+		if (git_oid_raw_cmp(prev_oid, oid) >= 0)
 			return midx_error("OID Lookup index is non-monotonic");
 		prev_oid = oid;
 	}
@@ -389,7 +389,7 @@ int git_midx_entry_find(
 	int pos, found = 0;
 	size_t pack_index;
 	uint32_t hi, lo;
-	const git_oid *current = NULL;
+	unsigned char *current = NULL;
 	const unsigned char *object_offset;
 	off64_t offset;
 
@@ -403,26 +403,25 @@ int git_midx_entry_find(
 	if (pos >= 0) {
 		/* An object matching exactly the oid was found */
 		found = 1;
-		current = idx->oid_lookup + pos;
+		current = idx->oid_lookup + (pos * GIT_OID_RAWSZ);
 	} else {
 		/* No object was found */
 		/* pos refers to the object with the "closest" oid to short_oid */
 		pos = -1 - pos;
 		if (pos < (int)idx->num_objects) {
-			current = idx->oid_lookup + pos;
+			current = idx->oid_lookup + (pos * GIT_OID_RAWSZ);
 
-			if (!git_oid_ncmp(short_oid, current, len))
+			if (!git_oid_raw_ncmp(short_oid->id, current, len))
 				found = 1;
 		}
 	}
 
 	if (found && len != GIT_OID_HEXSZ && pos + 1 < (int)idx->num_objects) {
 		/* Check for ambiguousity */
-		const git_oid *next = current + 1;
+		const unsigned char *next = current + GIT_OID_RAWSZ;
 
-		if (!git_oid_ncmp(short_oid, next, len)) {
+		if (!git_oid_raw_ncmp(short_oid->id, next, len))
 			found = 2;
-		}
 	}
 
 	if (!found)
@@ -450,7 +449,7 @@ int git_midx_entry_find(
 		return midx_error("invalid index into the packfile names table");
 	e->pack_index = pack_index;
 	e->offset = offset;
-	git_oid_cpy(&e->sha1, current);
+	git_oid_fromraw(&e->sha1, current);
 	return 0;
 }
 
@@ -459,13 +458,17 @@ int git_midx_foreach_entry(
 		git_odb_foreach_cb cb,
 		void *data)
 {
+	git_oid oid;
 	size_t i;
 	int error;
 
 	GIT_ASSERT_ARG(idx);
 
 	for (i = 0; i < idx->num_objects; ++i) {
-		if ((error = cb(&idx->oid_lookup[i], data)) != 0)
+		if ((error = git_oid_fromraw(&oid, &idx->oid_lookup[i * GIT_OID_RAWSZ])) < 0)
+			return error;
+
+		if ((error = cb(&oid, data)) != 0)
 			return git_error_set_after_callback(error);
 	}
 
@@ -751,7 +754,7 @@ static int midx_write(
 
 	/* Fill the OID Lookup table. */
 	git_vector_foreach (&object_entries, i, entry) {
-		error = git_str_put(&oid_lookup, (const char *)&entry->sha1, sizeof(entry->sha1));
+		error = git_str_put(&oid_lookup, (char *)&entry->sha1.id, GIT_OID_RAWSZ);
 		if (error < 0)
 			goto cleanup;
 	}
diff --git a/src/libgit2/midx.h b/src/libgit2/midx.h
index 7dd851b..bcb0d9a 100644
--- a/src/libgit2/midx.h
+++ b/src/libgit2/midx.h
@@ -17,6 +17,7 @@
 #include "map.h"
 #include "mwindow.h"
 #include "odb.h"
+#include "oid.h"
 
 /*
  * A multi-pack-index file.
@@ -40,7 +41,7 @@ typedef struct git_midx_file {
 	uint32_t num_objects;
 
 	/* The OID Lookup table. */
-	git_oid *oid_lookup;
+	unsigned char *oid_lookup;
 
 	/* The Object Offsets table. Each entry has two 4-byte fields with the pack index and the offset. */
 	const unsigned char *object_offsets;
diff --git a/src/libgit2/oid.c b/src/libgit2/oid.c
index 19061e8..fb92174 100644
--- a/src/libgit2/oid.c
+++ b/src/libgit2/oid.c
@@ -187,8 +187,7 @@ int git_oid_fromraw(git_oid *out, const unsigned char *raw)
 
 int git_oid_cpy(git_oid *out, const git_oid *src)
 {
-	memcpy(out->id, src->id, sizeof(out->id));
-	return 0;
+	return git_oid_raw_cpy(out->id, src->id);
 }
 
 int git_oid_cmp(const git_oid *a, const git_oid *b)
@@ -203,25 +202,7 @@ int git_oid_equal(const git_oid *a, const git_oid *b)
 
 int git_oid_ncmp(const git_oid *oid_a, const git_oid *oid_b, size_t len)
 {
-	const unsigned char *a = oid_a->id;
-	const unsigned char *b = oid_b->id;
-
-	if (len > GIT_OID_HEXSZ)
-		len = GIT_OID_HEXSZ;
-
-	while (len > 1) {
-		if (*a != *b)
-			return 1;
-		a++;
-		b++;
-		len -= 2;
-	};
-
-	if (len)
-		if ((*a ^ *b) & 0xf0)
-			return 1;
-
-	return 0;
+	return git_oid_raw_ncmp(oid_a->id, oid_b->id, len);
 }
 
 int git_oid_strcmp(const git_oid *oid_a, const char *str)
diff --git a/src/libgit2/oid.h b/src/libgit2/oid.h
index 5baec33..abae9a4 100644
--- a/src/libgit2/oid.h
+++ b/src/libgit2/oid.h
@@ -25,11 +25,44 @@ extern const git_oid git_oid__empty_tree_sha1;
  */
 char *git_oid_allocfmt(const git_oid *id);
 
-GIT_INLINE(int) git_oid__hashcmp(const unsigned char *sha1, const unsigned char *sha2)
+GIT_INLINE(int) git_oid_raw_ncmp(
+	const unsigned char *sha1,
+	const unsigned char *sha2,
+	size_t len)
+{
+	if (len > GIT_OID_HEXSZ)
+		len = GIT_OID_HEXSZ;
+
+	while (len > 1) {
+		if (*sha1 != *sha2)
+			return 1;
+		sha1++;
+		sha2++;
+		len -= 2;
+	};
+
+	if (len)
+		if ((*sha1 ^ *sha2) & 0xf0)
+			return 1;
+
+	return 0;
+}
+
+GIT_INLINE(int) git_oid_raw_cmp(
+	const unsigned char *sha1,
+	const unsigned char *sha2)
 {
 	return memcmp(sha1, sha2, GIT_OID_RAWSZ);
 }
 
+GIT_INLINE(int) git_oid_raw_cpy(
+	unsigned char *dst,
+	const unsigned char *src)
+{
+	memcpy(dst, src, GIT_OID_RAWSZ);
+	return 0;
+}
+
 /*
  * Compare two oid structures.
  *
@@ -39,7 +72,7 @@ GIT_INLINE(int) git_oid__hashcmp(const unsigned char *sha1, const unsigned char 
  */
 GIT_INLINE(int) git_oid__cmp(const git_oid *a, const git_oid *b)
 {
-	return git_oid__hashcmp(a->id, b->id);
+	return git_oid_raw_cmp(a->id, b->id);
 }
 
 GIT_INLINE(void) git_oid__cpy_prefix(
diff --git a/src/libgit2/oidmap.c b/src/libgit2/oidmap.c
index 0ae8bf3..eaf9fa0 100644
--- a/src/libgit2/oidmap.c
+++ b/src/libgit2/oidmap.c
@@ -19,7 +19,7 @@ __KHASH_TYPE(oid, const git_oid *, void *)
 GIT_INLINE(khint_t) git_oidmap_hash(const git_oid *oid)
 {
 	khint_t h;
-	memcpy(&h, oid, sizeof(khint_t));
+	memcpy(&h, oid->id, sizeof(khint_t));
 	return h;
 }
 
diff --git a/src/libgit2/pack.c b/src/libgit2/pack.c
index 5c0cba7..16fe378 100644
--- a/src/libgit2/pack.c
+++ b/src/libgit2/pack.c
@@ -1001,13 +1001,14 @@ int get_delta_base(
 		base_offset = delta_obj_offset - unsigned_base_offset;
 		*curpos += used;
 	} else if (type == GIT_OBJECT_REF_DELTA) {
+		git_oid base_oid;
+		git_oid_fromraw(&base_oid, base_info);
+
 		/* If we have the cooperative cache, search in it first */
 		if (p->has_cache) {
 			struct git_pack_entry *entry;
-			git_oid oid;
 
-			git_oid_fromraw(&oid, base_info);
-			if ((entry = git_oidmap_get(p->idx_cache, &oid)) != NULL) {
+			if ((entry = git_oidmap_get(p->idx_cache, &base_oid)) != NULL) {
 				if (entry->offset == 0)
 					return packfile_error("delta offset is zero");
 
@@ -1024,7 +1025,7 @@ int get_delta_base(
 		}
 
 		/* The base entry _must_ be in the same pack */
-		if (pack_entry_find_offset(&base_offset, &unused, p, (git_oid *)base_info, GIT_OID_HEXSZ) < 0)
+		if (pack_entry_find_offset(&base_offset, &unused, p, &base_oid, GIT_OID_HEXSZ) < 0)
 			return packfile_error("base entry delta is not in the same pack");
 		*curpos += 20;
 	} else
@@ -1082,7 +1083,7 @@ static int packfile_open_locked(struct git_pack_file *p)
 {
 	struct stat st;
 	struct git_pack_header hdr;
-	git_oid sha1;
+	unsigned char sha1[GIT_OID_RAWSZ];
 	unsigned char *idx_sha1;
 
 	if (pack_index_open_locked(p) < 0)
@@ -1130,12 +1131,12 @@ static int packfile_open_locked(struct git_pack_file *p)
 
 	/* Verify the pack matches its index. */
 	if (p->num_objects != ntohl(hdr.hdr_entries) ||
-		p_pread(p->mwf.fd, sha1.id, GIT_OID_RAWSZ, p->mwf.size - GIT_OID_RAWSZ) < 0)
+	    p_pread(p->mwf.fd, sha1, GIT_OID_RAWSZ, p->mwf.size - GIT_OID_RAWSZ) < 0)
 		goto cleanup;
 
 	idx_sha1 = ((unsigned char *)p->index_map.data) + p->index_map.len - 40;
 
-	if (git_oid__cmp(&sha1, (git_oid *)idx_sha1) != 0)
+	if (git_oid_raw_cmp(sha1, idx_sha1) != 0)
 		goto cleanup;
 
 	if (git_mwindow_file_register(&p->mwf) < 0)
@@ -1340,10 +1341,14 @@ int git_pack_foreach_entry(
 		}
 
 		git_vector_free(&offsets);
-		p->oids = (git_oid **)git_vector_detach(NULL, NULL, &oids);
+		p->oids = (unsigned char **)git_vector_detach(NULL, NULL, &oids);
 	}
 
-	/* We need to copy the OIDs to another array before we relinquish the lock to avoid races. */
+	/*
+	 * We need to copy the OIDs to another array before we
+	 * relinquish the lock to avoid races.  We can also take
+	 * this opportunity to put them into normal form.
+	 */
 	git_array_init_to_size(oids, p->num_objects);
 	if (!oids.ptr) {
 		git_mutex_unlock(&p->lock);
@@ -1357,7 +1362,7 @@ int git_pack_foreach_entry(
 			git_array_clear(oids);
 			GIT_ERROR_CHECK_ALLOC(oid);
 		}
-		git_oid_cpy(oid, p->oids[i]);
+		git_oid_fromraw(oid, p->oids[i]);
 	}
 
 	git_mutex_unlock(&p->lock);
@@ -1380,7 +1385,7 @@ int git_pack_foreach_entry_offset(
 {
 	const unsigned char *index;
 	off64_t current_offset;
-	const git_oid *current_oid;
+	git_oid current_oid;
 	uint32_t i;
 	int error = 0;
 
@@ -1422,8 +1427,9 @@ int git_pack_foreach_entry_offset(
 				current_offset = (((off64_t)ntohl(*((uint32_t *)(large_offset_ptr + 0)))) << 32) |
 						ntohl(*((uint32_t *)(large_offset_ptr + 4)));
 			}
-			current_oid = (const git_oid *)(index + 20 * i);
-			if ((error = cb(current_oid, current_offset, data)) != 0) {
+
+			git_oid_fromraw(&current_oid, (index + 20 * i));
+			if ((error = cb(&current_oid, current_offset, data)) != 0) {
 				error = git_error_set_after_callback(error);
 				goto cleanup;
 			}
@@ -1431,8 +1437,8 @@ int git_pack_foreach_entry_offset(
 	} else {
 		for (i = 0; i < p->num_objects; i++) {
 			current_offset = ntohl(*(const uint32_t *)(index + 24 * i));
-			current_oid = (const git_oid *)(index + 24 * i + 4);
-			if ((error = cb(current_oid, current_offset, data)) != 0) {
+			git_oid_fromraw(&current_oid, (index + 24 * i + 4));
+			if ((error = cb(&current_oid, current_offset, data)) != 0) {
 				error = git_error_set_after_callback(error);
 				goto cleanup;
 			}
@@ -1451,7 +1457,7 @@ int git_pack__lookup_sha1(const void *oid_lookup_table, size_t stride, unsigned 
 
 	while (lo < hi) {
 		unsigned mi = (lo + hi) / 2;
-		int cmp = git_oid__hashcmp(base + mi * stride, oid_prefix);
+		int cmp = git_oid_raw_cmp(base + mi * stride, oid_prefix);
 
 		if (!cmp)
 			return mi;
@@ -1530,7 +1536,7 @@ static int pack_entry_find_offset(
 		if (pos < (int)p->num_objects) {
 			current = index + pos * stride;
 
-			if (!git_oid_ncmp(short_oid, (const git_oid *)current, len))
+			if (!git_oid_raw_ncmp(short_oid->id, current, len))
 				found = 1;
 		}
 	}
@@ -1539,7 +1545,7 @@ static int pack_entry_find_offset(
 		/* Check for ambiguousity */
 		const unsigned char *next = current + stride;
 
-		if (!git_oid_ncmp(short_oid, (const git_oid *)next, len)) {
+		if (!git_oid_raw_ncmp(short_oid->id, next, len)) {
 			found = 2;
 		}
 	}
diff --git a/src/libgit2/pack.h b/src/libgit2/pack.h
index bf279c6..f87249b 100644
--- a/src/libgit2/pack.h
+++ b/src/libgit2/pack.h
@@ -19,6 +19,7 @@
 #include "offmap.h"
 #include "oidmap.h"
 #include "zstream.h"
+#include "oid.h"
 
 /**
  * Function type for callbacks from git_pack_foreach_entry_offset.
@@ -104,7 +105,7 @@ struct git_pack_file {
 	git_time_t mtime;
 	unsigned pack_local:1, pack_keep:1, has_cache:1;
 	git_oidmap *idx_cache;
-	git_oid **oids;
+	unsigned char **oids;
 
 	git_pack_cache bases; /* delta base cache */
 
diff --git a/src/libgit2/remote.c b/src/libgit2/remote.c
index 1a79faa..3d05937 100644
--- a/src/libgit2/remote.c
+++ b/src/libgit2/remote.c
@@ -1830,7 +1830,7 @@ static int update_one_tip(
 	}
 
 	if (error == GIT_ENOTFOUND) {
-		memset(&old, 0, GIT_OID_RAWSZ);
+		memset(&old, 0, sizeof(git_oid));
 		error = 0;
 
 		if (autotag && (error = git_vector_insert(update_heads, head)) < 0)
diff --git a/src/libgit2/tree-cache.c b/src/libgit2/tree-cache.c
index 0977c92..cd69e7b 100644
--- a/src/libgit2/tree-cache.c
+++ b/src/libgit2/tree-cache.c
@@ -263,7 +263,7 @@ static void write_tree(git_str *out, git_tree_cache *tree)
 	git_str_printf(out, "%s%c%"PRIdZ" %"PRIuZ"\n", tree->name, 0, tree->entry_count, tree->children_count);
 
 	if (tree->entry_count != -1)
-		git_str_put(out, (const char *) &tree->oid, GIT_OID_RAWSZ);
+		git_str_put(out, (char *)&tree->oid.id, GIT_OID_RAWSZ);
 
 	for (i = 0; i < tree->children_count; i++)
 		write_tree(out, tree->children[i]);
diff --git a/src/libgit2/tree.c b/src/libgit2/tree.c
index a1545dc..a5371fd 100644
--- a/src/libgit2/tree.c
+++ b/src/libgit2/tree.c
@@ -82,6 +82,7 @@ int git_tree_entry_cmp(const git_tree_entry *e1, const git_tree_entry *e2)
 static git_tree_entry *alloc_entry(const char *filename, size_t filename_len, const git_oid *id)
 {
 	git_tree_entry *entry = NULL;
+	char *filename_ptr;
 	size_t tree_len;
 
 	TREE_ENTRY_CHECK_NAMELEN(filename_len);
@@ -95,21 +96,13 @@ static git_tree_entry *alloc_entry(const char *filename, size_t filename_len, co
 	if (!entry)
 		return NULL;
 
-	{
-		char *filename_ptr;
-		void *id_ptr;
-
-		filename_ptr = ((char *) entry) + sizeof(git_tree_entry);
-		memcpy(filename_ptr, filename, filename_len);
-		entry->filename = filename_ptr;
-
-		id_ptr = filename_ptr + filename_len + 1;
-		git_oid_cpy(id_ptr, id);
-		entry->oid = id_ptr;
-	}
-
+	filename_ptr = ((char *) entry) + sizeof(git_tree_entry);
+	memcpy(filename_ptr, filename, filename_len);
+	entry->filename = filename_ptr;
 	entry->filename_len = (uint16_t)filename_len;
 
+	git_oid_cpy(&entry->oid, id);
+
 	return entry;
 }
 
@@ -231,7 +224,7 @@ int git_tree_entry_dup(git_tree_entry **dest, const git_tree_entry *source)
 
 	GIT_ASSERT_ARG(source);
 
-	cpy = alloc_entry(source->filename, source->filename_len, source->oid);
+	cpy = alloc_entry(source->filename, source->filename_len, &source->oid);
 	if (cpy == NULL)
 		return -1;
 
@@ -269,7 +262,7 @@ const char *git_tree_entry_name(const git_tree_entry *entry)
 const git_oid *git_tree_entry_id(const git_tree_entry *entry)
 {
 	GIT_ASSERT_ARG_WITH_RETVAL(entry, NULL);
-	return entry->oid;
+	return &entry->oid;
 }
 
 git_object_t git_tree_entry_type(const git_tree_entry *entry)
@@ -292,7 +285,7 @@ int git_tree_entry_to_object(
 	GIT_ASSERT_ARG(entry);
 	GIT_ASSERT_ARG(object_out);
 
-	return git_object_lookup(object_out, repo, entry->oid, GIT_OBJECT_ANY);
+	return git_object_lookup(object_out, repo, &entry->oid, GIT_OBJECT_ANY);
 }
 
 static const git_tree_entry *entry_fromname(
@@ -331,7 +324,7 @@ const git_tree_entry *git_tree_entry_byid(
 	GIT_ASSERT_ARG_WITH_RETVAL(tree, NULL);
 
 	git_array_foreach(tree->entries, i, e) {
-		if (memcmp(&e->oid->id, &id->id, sizeof(id->id)) == 0)
+		if (git_oid_equal(&e->oid, id))
 			return e;
 	}
 
@@ -432,7 +425,7 @@ int git_tree__parse_raw(void *_tree, const char *data, size_t size)
 			entry->attr = attr;
 			entry->filename_len = (uint16_t)filename_len;
 			entry->filename = buffer;
-			entry->oid = (git_oid *) ((char *) buffer + filename_len + 1);
+			git_oid_fromraw(&entry->oid, ((unsigned char *) buffer + filename_len + 1));
 		}
 
 		buffer += filename_len + 1;
@@ -536,7 +529,7 @@ static int git_treebuilder__write_with_buffer(
 
 		git_str_printf(buf, "%o ", entry->attr);
 		git_str_put(buf, entry->filename, entry->filename_len + 1);
-		git_str_put(buf, (char *)entry->oid->id, GIT_OID_RAWSZ);
+		git_str_put(buf, (char *)entry->oid.id, GIT_OID_RAWSZ);
 
 		if (git_str_oom(buf)) {
 			error = -1;
@@ -765,7 +758,7 @@ int git_treebuilder_new(
 		git_array_foreach(source->entries, i, entry_src) {
 			if (append_entry(
 				bld, entry_src->filename,
-				entry_src->oid,
+				&entry_src->oid,
 				entry_src->attr,
 				false) < 0)
 				goto on_error;
@@ -798,7 +791,7 @@ int git_treebuilder_insert(
 		return error;
 
 	if ((entry = git_strmap_get(bld->map, filename)) != NULL) {
-		git_oid_cpy((git_oid *) entry->oid, id);
+		git_oid_cpy(&entry->oid, id);
 	} else {
 		entry = alloc_entry(filename, strlen(filename), id);
 		GIT_ERROR_CHECK_ALLOC(entry);
@@ -954,7 +947,7 @@ int git_tree_entry_bypath(
 		return git_tree_entry_dup(entry_out, entry);
 	}
 
-	if (git_tree_lookup(&subtree, root->object.repo, entry->oid) < 0)
+	if (git_tree_lookup(&subtree, root->object.repo, &entry->oid) < 0)
 		return -1;
 
 	error = git_tree_entry_bypath(
@@ -995,7 +988,7 @@ static int tree_walk(
 			git_tree *subtree;
 			size_t path_len = git_str_len(path);
 
-			error = git_tree_lookup(&subtree, tree->object.repo, entry->oid);
+			error = git_tree_lookup(&subtree, tree->object.repo, &entry->oid);
 			if (error < 0)
 				break;
 
diff --git a/src/libgit2/tree.h b/src/libgit2/tree.h
index 6bd9ed6..0dd963f 100644
--- a/src/libgit2/tree.h
+++ b/src/libgit2/tree.h
@@ -19,7 +19,7 @@
 struct git_tree_entry {
 	uint16_t attr;
 	uint16_t filename_len;
-	const git_oid *oid;
+	git_oid oid;
 	const char *filename;
 };
 
diff --git a/tests/libgit2/iterator/tree.c b/tests/libgit2/iterator/tree.c
index 4145c8d..06a920a 100644
--- a/tests/libgit2/iterator/tree.c
+++ b/tests/libgit2/iterator/tree.c
@@ -268,7 +268,7 @@ static void check_tree_entry(
 
 	cl_git_pass(git_iterator_current_tree_entry(&te, i));
 	cl_assert(te);
-	cl_assert(git_oid_streq(te->oid, oid) == 0);
+	cl_assert(git_oid_streq(&te->oid, oid) == 0);
 
 	cl_git_pass(git_iterator_current(&ie, i));
 
diff --git a/tests/libgit2/object/raw/hash.c b/tests/libgit2/object/raw/hash.c
index 5a3e818..8f22fe0 100644
--- a/tests/libgit2/object/raw/hash.c
+++ b/tests/libgit2/object/raw/hash.c
@@ -24,20 +24,23 @@ static char *bye_text = "bye world\n";
 void test_object_raw_hash__hash_by_blocks(void)
 {
 	git_hash_ctx ctx;
+	unsigned char hash[GIT_HASH_SHA1_SIZE];
 	git_oid id1, id2;
 
 	cl_git_pass(git_hash_ctx_init(&ctx, GIT_HASH_ALGORITHM_SHA1));
 
 	/* should already be init'd */
 	cl_git_pass(git_hash_update(&ctx, hello_text, strlen(hello_text)));
-	cl_git_pass(git_hash_final(id2.id, &ctx));
+	cl_git_pass(git_hash_final(hash, &ctx));
+	cl_git_pass(git_oid_fromraw(&id2, hash));
 	cl_git_pass(git_oid_fromstr(&id1, hello_id));
 	cl_assert(git_oid_cmp(&id1, &id2) == 0);
 
 	/* reinit should permit reuse */
 	cl_git_pass(git_hash_init(&ctx));
 	cl_git_pass(git_hash_update(&ctx, bye_text, strlen(bye_text)));
-	cl_git_pass(git_hash_final(id2.id, &ctx));
+	cl_git_pass(git_hash_final(hash, &ctx));
+	cl_git_pass(git_oid_fromraw(&id2, hash));
 	cl_git_pass(git_oid_fromstr(&id1, bye_id));
 	cl_assert(git_oid_cmp(&id1, &id2) == 0);
 
@@ -47,9 +50,11 @@ void test_object_raw_hash__hash_by_blocks(void)
 void test_object_raw_hash__hash_buffer_in_single_call(void)
 {
 	git_oid id1, id2;
+	unsigned char hash[GIT_HASH_SHA1_SIZE];
 
 	cl_git_pass(git_oid_fromstr(&id1, hello_id));
-	git_hash_buf(id2.id, hello_text, strlen(hello_text), GIT_HASH_ALGORITHM_SHA1);
+	cl_git_pass(git_hash_buf(hash, hello_text, strlen(hello_text), GIT_HASH_ALGORITHM_SHA1));
+	cl_git_pass(git_oid_fromraw(&id2, hash));
 	cl_assert(git_oid_cmp(&id1, &id2) == 0);
 }
 
diff --git a/tests/libgit2/object/raw/short.c b/tests/libgit2/object/raw/short.c
index e8d2cf5..cc2b5f6 100644
--- a/tests/libgit2/object/raw/short.c
+++ b/tests/libgit2/object/raw/short.c
@@ -28,12 +28,15 @@ static int insert_sequential_oids(
 	int i, min_len = 0;
 	char numbuf[16];
 	git_oid oid;
+	unsigned char hashbuf[GIT_HASH_SHA1_SIZE];
 	char **oids = git__calloc(n, sizeof(char *));
 	cl_assert(oids != NULL);
 
 	for (i = 0; i < n; ++i) {
 		p_snprintf(numbuf, sizeof(numbuf), "%u", (unsigned int)i);
-		git_hash_buf(oid.id, numbuf, strlen(numbuf), GIT_HASH_ALGORITHM_SHA1);
+		git_hash_buf(hashbuf, numbuf, strlen(numbuf), GIT_HASH_ALGORITHM_SHA1);
+
+		git_oid_fromraw(&oid, hashbuf);
 
 		oids[i] = git__malloc(GIT_OID_HEXSZ + 1);
 		cl_assert(oids[i]);
diff --git a/tests/libgit2/object/tree/parse.c b/tests/libgit2/object/tree/parse.c
index 9d76a74..4e871dc 100644
--- a/tests/libgit2/object/tree/parse.c
+++ b/tests/libgit2/object/tree/parse.c
@@ -40,7 +40,7 @@ static void assert_tree_parses(const char *data, size_t datalen,
 		cl_assert(entry = git_tree_entry_byname(tree, expected->filename));
 		cl_assert_equal_s(expected->filename, entry->filename);
 		cl_assert_equal_i(expected->attr, entry->attr);
-		cl_assert_equal_oid(&oid, entry->oid);
+		cl_assert_equal_oid(&oid, &entry->oid);
 	}
 
 	git_object_free(&tree->object);
diff --git a/tests/libgit2/pack/packbuilder.c b/tests/libgit2/pack/packbuilder.c
index f235798..0889f46 100644
--- a/tests/libgit2/pack/packbuilder.c
+++ b/tests/libgit2/pack/packbuilder.c
@@ -68,7 +68,7 @@ static void seed_packbuilder(void)
 	cl_git_pass(git_revwalk_push_ref(_revwalker, "HEAD"));
 
 	while (git_revwalk_next(&oid, _revwalker) == 0) {
-		o = git__malloc(GIT_OID_RAWSZ);
+		o = git__malloc(sizeof(git_oid));
 		cl_assert(o != NULL);
 		git_oid_cpy(o, &oid);
 		cl_git_pass(git_vector_insert(&_commits, o));