[CRYPTO] seqiv: Add Sequence Number IV Generator

This generator generates an IV based on a sequence number by xoring it
with a salt.  This algorithm is mainly useful for CTR and similar modes.

This patch also sets it as the default IV generator for ctr.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 9 insertions, 0 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index c4b6c9125582..7ad9711eec98 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -32,6 +32,14 @@ config CRYPTO_BLKCIPHER
         tristate
         select CRYPTO_ALGAPI
 
+config CRYPTO_SEQIV
+        tristate "Sequence Number IV Generator"
+        select CRYPTO_BLKCIPHER
+        help
+          This IV generator generates an IV based on a sequence number by
+          xoring it with a salt.  This algorithm is mainly useful for CTR
+          and similar modes.
+
 config CRYPTO_HASH
         tristate
         select CRYPTO_ALGAPI
@@ -197,6 +205,7 @@ config CRYPTO_XTS
 config CRYPTO_CTR
         tristate "CTR support"
         select CRYPTO_BLKCIPHER
+        select CRYPTO_SEQIV
         select CRYPTO_MANAGER
         help
           CTR: Counter mode