crypto: fix handling of iv generator hash defaults

When opening an existing LUKS volume, if the iv generator is
essiv, then the iv hash algorithm is mandatory to provide. We
must report an error if it is omitted in the cipher mode spec,
not silently default to hash 0 (md5).  If the iv generator is
not essiv, then we explicitly ignore any iv hash algorithm,
rather than report an error, for compatibility with dm-crypt.

When creating a new LUKS volume, if the iv generator is essiv
and no iv hsah algorithm is provided, we should default to
using the sha256 hash.

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

3 files changed, 273 insertions, 0 deletions

diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 63649f1091..fcf3b040e4 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -776,6 +776,11 @@ qcrypto_block_luks_open(QCryptoBlock *block,
     }
 
     if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) {
+        if (!ivhash_name) {
+            ret = -EINVAL;
+            error_setg(errp, "Missing IV generator hash specification");
+            goto fail;
+        }
         ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg,
                                                       ivhash,
                                                       &local_err);
@@ -785,6 +790,13 @@ qcrypto_block_luks_open(QCryptoBlock *block,
             goto fail;
         }
     } else {
+        /* Note we parsed the ivhash_name earlier in the cipher_mode
+         * spec string even with plain/plain64 ivgens, but we
+         * will ignore it, since it is irrelevant for these ivgens.
+         * This is for compat with dm-crypt which will silently
+         * ignore hash names with these ivgens rather than report
+         * an error about the invalid usage
+         */
         ivcipheralg = cipheralg;
     }
 
@@ -904,6 +916,15 @@ qcrypto_block_luks_create(QCryptoBlock *block,
     if (!luks_opts.has_hash_alg) {
         luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256;
     }
+    if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
+        if (!luks_opts.has_ivgen_hash_alg) {
+            luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256;
+            luks_opts.has_ivgen_hash_alg = true;
+        }
+    }
+    /* Note we're allowing ivgen_hash_alg to be set even for
+     * non-essiv iv generators that don't need a hash. It will
+     * be silently ignored, for compatibility with dm-crypt */
 
     if (!options->u.luks.key_secret) {
         error_setg(errp, "Parameter 'key-secret' is required for cipher");
diff --git a/tests/qemu-iotests/149 b/tests/qemu-iotests/149
index 52e23d2946..84072513db 100755
--- a/tests/qemu-iotests/149
+++ b/tests/qemu-iotests/149
@@ -153,6 +153,8 @@ def cryptsetup_format(config):
     cipher = config.cipher + "-" + config.mode + "-" + config.ivgen
     if config.ivgen_hash is not None:
         cipher = cipher + ":" + config.ivgen_hash
+    elif config.ivgen == "essiv":
+        cipher = cipher + ":" + "sha256"
     args.extend(["--cipher", cipher])
     if config.mode == "xts":
         args.extend(["--key-size", str(config.keylen * 2)])
@@ -479,6 +481,16 @@ configs = [
                    "6": "slot6",
                    "7": "slot7",
                }),
+
+    # Check handling of default hash alg (sha256) with essiv
+    LUKSConfig("aes-256-cbc-essiv-auto-sha1",
+               "aes", 256, "cbc", "essiv", None, "sha1"),
+
+    # Check that a useless hash provided for 'plain64' iv gen
+    # is ignored and no error raised
+    LUKSConfig("aes-256-cbc-plain64-sha256-sha1",
+               "aes", 256, "cbc", "plain64", "sha256", "sha1"),
+
 ]
 
 blacklist = [
diff --git a/tests/qemu-iotests/149.out b/tests/qemu-iotests/149.out
index 287f013012..90b5b55efb 100644
--- a/tests/qemu-iotests/149.out
+++ b/tests/qemu-iotests/149.out
@@ -1878,3 +1878,243 @@ sudo cryptsetup -q -v luksClose qiotest-145-aes-256-xts-plain-sha1-pwallslots
 # Delete image
 unlink TEST_DIR/luks-aes-256-xts-plain-sha1-pwallslots.img
 
+# ================= dm-crypt aes-256-cbc-essiv-auto-sha1 =================
+# Create image
+truncate TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img --size 4194304MB
+# Format image
+sudo cryptsetup -q -v luksFormat --cipher aes-cbc-essiv:sha256 --key-size 256 --hash sha1 --key-slot 0 --key-file - TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Write test pattern 0xa7
+qemu-io -c write -P 0xa7 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x13
+qemu-io -c write -P 0x13 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Read test pattern 0xa7
+qemu-io -c read -P 0xa7 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x13
+qemu-io -c read -P 0x13 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x91
+qemu-io -c write -P 0x91 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x5e
+qemu-io -c write -P 0x5e 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Read test pattern 0x91
+qemu-io -c read -P 0x91 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x5e
+qemu-io -c read -P 0x5e 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Delete image
+unlink TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+
+# ================= qemu-img aes-256-cbc-essiv-auto-sha1 =================
+# Create image
+qemu-img create -f luks --object secret,id=sec0,data=MTIzNDU2,format=base64 -o key-secret=sec0,cipher-alg=aes-256,cipher-mode=cbc,ivgen-alg=essiv,hash-alg=sha1 TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img 4194304M
+Formatting 'TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img', fmt=luks size=4398046511104 key-secret=sec0 cipher-alg=aes-256 cipher-mode=cbc ivgen-alg=essiv hash-alg=sha1
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Write test pattern 0xa7
+qemu-io -c write -P 0xa7 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x13
+qemu-io -c write -P 0x13 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Read test pattern 0xa7
+qemu-io -c read -P 0xa7 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x13
+qemu-io -c read -P 0x13 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x91
+qemu-io -c write -P 0x91 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x5e
+qemu-io -c write -P 0x5e 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Read test pattern 0x91
+qemu-io -c read -P 0x91 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x5e
+qemu-io -c read -P 0x5e 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-essiv-auto-sha1
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-essiv-auto-sha1
+# Delete image
+unlink TEST_DIR/luks-aes-256-cbc-essiv-auto-sha1.img
+
+# ================= dm-crypt aes-256-cbc-plain64-sha256-sha1 =================
+# Create image
+truncate TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img --size 4194304MB
+# Format image
+sudo cryptsetup -q -v luksFormat --cipher aes-cbc-plain64:sha256 --key-size 256 --hash sha1 --key-slot 0 --key-file - TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Write test pattern 0xa7
+qemu-io -c write -P 0xa7 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x13
+qemu-io -c write -P 0x13 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Read test pattern 0xa7
+qemu-io -c read -P 0xa7 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x13
+qemu-io -c read -P 0x13 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x91
+qemu-io -c write -P 0x91 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x5e
+qemu-io -c write -P 0x5e 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Read test pattern 0x91
+qemu-io -c read -P 0x91 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x5e
+qemu-io -c read -P 0x5e 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Delete image
+unlink TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+
+# ================= qemu-img aes-256-cbc-plain64-sha256-sha1 =================
+# Create image
+qemu-img create -f luks --object secret,id=sec0,data=MTIzNDU2,format=base64 -o key-secret=sec0,cipher-alg=aes-256,cipher-mode=cbc,ivgen-alg=plain64,hash-alg=sha1,ivgen-hash-alg=sha256 TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img 4194304M
+Formatting 'TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img', fmt=luks size=4398046511104 key-secret=sec0 cipher-alg=aes-256 cipher-mode=cbc ivgen-alg=plain64 ivgen-hash-alg=sha256 hash-alg=sha1
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Write test pattern 0xa7
+qemu-io -c write -P 0xa7 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x13
+qemu-io -c write -P 0x13 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Read test pattern 0xa7
+qemu-io -c read -P 0xa7 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x13
+qemu-io -c read -P 0x13 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x91
+qemu-io -c write -P 0x91 100M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+wrote 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Write test pattern 0x5e
+qemu-io -c write -P 0x5e 3145728M 10M --object secret,id=sec0,data=MTIzNDU2,format=base64 --image-opts driver=luks,key-secret=sec0,file.filename=TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+wrote 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Open dev
+sudo cryptsetup -q -v luksOpen TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Set dev owner
+sudo chown UID:GID /dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Read test pattern 0x91
+qemu-io -c read -P 0x91 100M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+read 10485760/10485760 bytes at offset 104857600
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Read test pattern 0x5e
+qemu-io -c read -P 0x5e 3145728M 10M --image-opts driver=file,filename=/dev/mapper/qiotest-145-aes-256-cbc-plain64-sha256-sha1
+read 10485760/10485760 bytes at offset 3298534883328
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+# Close dev
+sudo cryptsetup -q -v luksClose qiotest-145-aes-256-cbc-plain64-sha256-sha1
+# Delete image
+unlink TEST_DIR/luks-aes-256-cbc-plain64-sha256-sha1.img
+