SCTP: Fix build issues with SCTP AUTH.

SCTP-AUTH requires selection of CRYPTO, HMAC and SHA1 since
SHA1 is a MUST requirement for AUTH.  We also support SHA256,
but that's optional, so fix the code to treat it as such.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

3 files changed, 11 insertions, 6 deletions

diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index f30b537d6952..05f22a6afbcd 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -441,11 +441,14 @@ enum {
         SCTP_AUTH_HMAC_ID_RESERVED_0,
         SCTP_AUTH_HMAC_ID_SHA1,
         SCTP_AUTH_HMAC_ID_RESERVED_2,
-        SCTP_AUTH_HMAC_ID_SHA256
+#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
+        SCTP_AUTH_HMAC_ID_SHA256,
+#endif
+        __SCTP_AUTH_HMAC_MAX
 };
 
-#define SCTP_AUTH_HMAC_ID_MAX   SCTP_AUTH_HMAC_ID_SHA256
-#define SCTP_AUTH_NUM_HMACS (SCTP_AUTH_HMAC_ID_SHA256 + 1)
+#define SCTP_AUTH_HMAC_ID_MAX   __SCTP_AUTH_HMAC_MAX - 1
+#define SCTP_AUTH_NUM_HMACS     __SCTP_AUTH_HMAC_MAX
 #define SCTP_SHA1_SIG_SIZE 20
 #define SCTP_SHA256_SIG_SIZE 32
 
diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index 8210f549c492..5390bc792159 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -6,9 +6,9 @@ menuconfig IP_SCTP
         tristate "The SCTP Protocol (EXPERIMENTAL)"
         depends on INET && EXPERIMENTAL
         depends on IPV6 || IPV6=n
-        select CRYPTO if SCTP_HMAC_SHA1 || SCTP_HMAC_MD5
-        select CRYPTO_HMAC if SCTP_HMAC_SHA1 || SCTP_HMAC_MD5
-        select CRYPTO_SHA1 if SCTP_HMAC_SHA1
+        select CRYPTO
+        select CRYPTO_HMAC
+        select CRYPTO_SHA1
         select CRYPTO_MD5 if SCTP_HMAC_MD5
         ---help---
           Stream Control Transmission Protocol
diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index 6d89e35307aa..97e6ebd14500 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -54,11 +54,13 @@ static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
                 /* id 2 is reserved as well */
                 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
         },
+#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
         {
                 .hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
                 .hmac_name="hmac(sha256)",
                 .hmac_len = SCTP_SHA256_SIG_SIZE,
         }
+#endif
 };