[CRYPTO] cts: Add CTS mode required for Kerberos AES support

Implement CTS wrapper for CBC mode required for support of AES
encryption support for Kerberos (rfc3962).

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 11 insertions, 0 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 69f1be6816f7..e14ff1275018 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -213,6 +213,17 @@ config CRYPTO_CTR
           CTR: Counter mode
           This block cipher algorithm is required for IPSec.
 
+config CRYPTO_CTS
+        tristate "CTS support"
+        select CRYPTO_BLKCIPHER
+        help
+          CTS: Cipher Text Stealing
+          This is the Cipher Text Stealing mode as described by
+          Section 8 of rfc2040 and referenced by rfc3962.
+          (rfc3962 includes errata information in its Appendix A)
+          This mode is required for Kerberos gss mechanism support
+          for AES encryption.
+
 config CRYPTO_GCM
         tristate "GCM/GMAC support"
         select CRYPTO_CTR