5 files changed, 27 insertions, 2 deletions

diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 36bc856084..a9062bb0f2 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -846,8 +846,9 @@ qcrypto_block_luks_open(QCryptoBlock *block,
         }
     }
 
+    block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
     block->payload_offset = luks->header.payload_offset *
-        QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+        block->sector_size;
 
     luks->cipher_alg = cipheralg;
     luks->cipher_mode = ciphermode;
@@ -1240,8 +1241,9 @@ qcrypto_block_luks_create(QCryptoBlock *block,
                    QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
          QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 
+    block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
     block->payload_offset = luks->header.payload_offset *
-        QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+        block->sector_size;
 
     /* Reserve header space to match payload offset */
     initfunc(block, block->payload_offset, opaque, &local_err);
diff --git a/crypto/block-qcow.c b/crypto/block-qcow.c
index a456fe338b..4dd594a9ba 100644
--- a/crypto/block-qcow.c
+++ b/crypto/block-qcow.c
@@ -80,6 +80,7 @@ qcrypto_block_qcow_init(QCryptoBlock *block,
         goto fail;
     }
 
+    block->sector_size = QCRYPTO_BLOCK_QCOW_SECTOR_SIZE;
     block->payload_offset = 0;
 
     return 0;
diff --git a/crypto/block.c b/crypto/block.c
index c382393d9a..a7a9ad240e 100644
--- a/crypto/block.c
+++ b/crypto/block.c
@@ -170,6 +170,12 @@ uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block)
 }
 
 
+uint64_t qcrypto_block_get_sector_size(QCryptoBlock *block)
+{
+    return block->sector_size;
+}
+
+
 void qcrypto_block_free(QCryptoBlock *block)
 {
     if (!block) {
diff --git a/crypto/blockpriv.h b/crypto/blockpriv.h
index 0edb810e22..d227522d88 100644
--- a/crypto/blockpriv.h
+++ b/crypto/blockpriv.h
@@ -36,6 +36,7 @@ struct QCryptoBlock {
     QCryptoHashAlgorithm kdfhash;
     size_t niv;
     uint64_t payload_offset; /* In bytes */
+    uint64_t sector_size; /* In bytes */
 };
 
 struct QCryptoBlockDriver {
diff --git a/include/crypto/block.h b/include/crypto/block.h
index f0e543bee1..13232b2472 100644
--- a/include/crypto/block.h
+++ b/include/crypto/block.h
@@ -241,6 +241,21 @@ QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block);
 uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block);
 
 /**
+ * qcrypto_block_get_sector_size:
+ * @block: the block encryption object
+ *
+ * Get the size of sectors used for payload encryption. A new
+ * IV is used at the start of each sector. The encryption
+ * sector size is not required to match the sector size of the
+ * underlying storage. For example LUKS will always use a 512
+ * byte sector size, even if the volume is on a disk with 4k
+ * sectors.
+ *
+ * Returns: the sector in bytes
+ */
+uint64_t qcrypto_block_get_sector_size(QCryptoBlock *block);
+
+/**
  * qcrypto_block_free:
  * @block: the block encryption object
  *