[PATCH v2 07/17] crypto/cipher: Add GCM to QCryptoCipherMode

[Jamin Lin <jamin_lin@aspeedtech.com>]

Introduce the GCM cipher mode so authenticated encryption can be built
on top of the existing qcrypto_cipher API. GCM is an IV-based mode, so
register it in mode_need_iv. No backend advertises it yet, so it stays
unsupported until a backend and the AAD/tag helpers are added in the
following patches.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
---
 qapi/crypto.json | 4 +++-
 crypto/cipher.c  | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/qapi/crypto.json b/qapi/crypto.json
index 2b55befef9..6e3a98ff68 100644
--- a/qapi/crypto.json
+++ b/qapi/crypto.json
@@ -121,10 +121,12 @@
 #
 # @ctr: Counter (Since 2.8)
 #
+# @gcm: Galois/Counter Mode (Since 11.2)
+#
 # Since: 2.6
 ##
 { 'enum': 'QCryptoCipherMode',
-  'data': ['ecb', 'cbc', 'xts', 'ctr']}
+  'data': ['ecb', 'cbc', 'xts', 'ctr', 'gcm']}
 
 ##
 # @QCryptoIVGenAlgo:
diff --git a/crypto/cipher.c b/crypto/cipher.c
index 515165e0dc..52d071a90c 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -66,6 +66,7 @@ static const bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
     [QCRYPTO_CIPHER_MODE_CBC] = true,
     [QCRYPTO_CIPHER_MODE_XTS] = true,
     [QCRYPTO_CIPHER_MODE_CTR] = true,
+    [QCRYPTO_CIPHER_MODE_GCM] = true,
 };
 
 
-- 
2.43.0