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-rw-r--r--src/librbd/crypto/CryptoInterface.h124
1 files changed, 124 insertions, 0 deletions
diff --git a/src/librbd/crypto/CryptoInterface.h b/src/librbd/crypto/CryptoInterface.h
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+++ b/src/librbd/crypto/CryptoInterface.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_CRYPTO_CRYPTO_INTERFACE_H
+#define CEPH_LIBRBD_CRYPTO_CRYPTO_INTERFACE_H
+
+#include "common/RefCountedObj.h"
+#include "include/buffer.h"
+#include "include/intarith.h"
+#include "librbd/io/Types.h"
+
+namespace librbd {
+namespace crypto {
+
+class CryptoInterface : public RefCountedObject {
+
+public:
+ virtual int encrypt(ceph::bufferlist* data, uint64_t image_offset) = 0;
+ virtual int decrypt(ceph::bufferlist* data, uint64_t image_offset) = 0;
+ virtual uint64_t get_block_size() const = 0;
+ virtual uint64_t get_data_offset() const = 0;
+ virtual const unsigned char* get_key() const = 0;
+ virtual int get_key_length() const = 0;
+
+ inline std::pair<uint64_t, uint64_t> get_pre_and_post_align(
+ uint64_t off, uint64_t len) {
+ if (len == 0) {
+ return std::make_pair(0, 0);
+ }
+ auto block_size = get_block_size();
+ return std::make_pair(p2phase(off, block_size),
+ p2nphase(off + len, block_size));
+ }
+
+ inline std::pair<uint64_t, uint64_t> align(uint64_t off, uint64_t len) {
+ auto aligns = get_pre_and_post_align(off, len);
+ return std::make_pair(off - aligns.first,
+ len + aligns.first + aligns.second);
+ }
+
+ inline bool is_aligned(uint64_t off, uint64_t len) {
+ auto aligns = get_pre_and_post_align(off, len);
+ return aligns.first == 0 && aligns.second == 0;
+ }
+
+ inline bool is_aligned(const io::ReadExtents& extents) {
+ for (const auto& extent: extents) {
+ if (!is_aligned(extent.offset, extent.length)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ inline void align_extents(const io::ReadExtents& extents,
+ io::ReadExtents* aligned_extents) {
+ for (const auto& extent: extents) {
+ auto aligned = align(extent.offset, extent.length);
+ aligned_extents->emplace_back(aligned.first, aligned.second);
+ }
+ }
+
+ inline int decrypt_aligned_extent(io::ReadExtent& extent,
+ uint64_t image_offset) {
+ if (extent.length == 0 || extent.bl.length() == 0) {
+ return 0;
+ }
+
+ if (extent.extent_map.empty()) {
+ extent.extent_map.emplace_back(extent.offset, extent.bl.length());
+ }
+
+ ceph::bufferlist result_bl;
+ io::Extents result_extent_map;
+
+ ceph::bufferlist curr_block_bl;
+ auto curr_offset = extent.offset;
+ auto curr_block_start_offset = curr_offset;
+ auto curr_block_end_offset = curr_offset;
+
+ // this will add a final loop iteration for decrypting the last extent
+ extent.extent_map.emplace_back(
+ extent.offset + extent.length + get_block_size(), 0);
+
+ for (auto [off, len]: extent.extent_map) {
+ auto [aligned_off, aligned_len] = align(off, len);
+ if (aligned_off > curr_block_end_offset) {
+ curr_block_bl.append_zero(curr_block_end_offset - curr_offset);
+ auto curr_block_length = curr_block_bl.length();
+ if (curr_block_length > 0) {
+ auto r = decrypt(
+ &curr_block_bl,
+ image_offset + curr_block_start_offset - extent.offset);
+ if (r != 0) {
+ return r;
+ }
+
+ curr_block_bl.splice(0, curr_block_length, &result_bl);
+ result_extent_map.emplace_back(
+ curr_block_start_offset, curr_block_length);
+ }
+
+ curr_block_start_offset = aligned_off;
+ curr_block_end_offset = aligned_off + aligned_len;
+ curr_offset = aligned_off;
+ }
+
+ curr_block_bl.append_zero(off - curr_offset);
+ extent.bl.splice(0, len, &curr_block_bl);
+ curr_offset = off + len;
+ curr_block_end_offset = aligned_off + aligned_len;
+ }
+
+ extent.bl = std::move(result_bl);
+ extent.extent_map = std::move(result_extent_map);
+
+ return 0;
+ }
+};
+
+} // namespace crypto
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_CRYPTO_CRYPTO_INTERFACE_H