Share a single buf_shift_right() implementation

Move the identical function used by both SAE and EAP-pwd to
src/utils/common.c to avoid duplicated implementation.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

src/common/sae.c

@@ -134,15 +134,6 @@ void sae_clear_data(struct sae_data *sae)
 }
 
 
-static void buf_shift_right(u8 *buf, size_t len, size_t bits)
-{
-	size_t i;
-	for (i = len - 1; i > 0; i--)
-		buf[i] = (buf[i - 1] << (8 - bits)) | (buf[i] >> bits);
-	buf[0] >>= bits;
-}
-
-
 static struct crypto_bignum * sae_get_rand(struct sae_data *sae)
 {
 	u8 val[SAE_MAX_PRIME_LEN];

src/eap_common/eap_pwd_common.c

@@ -119,15 +119,6 @@ EAP_PWD_group * get_eap_pwd_group(u16 num)
 }
 
 
-static void buf_shift_right(u8 *buf, size_t len, size_t bits)
-{
-	size_t i;
-	for (i = len - 1; i > 0; i--)
-		buf[i] = (buf[i - 1] << (8 - bits)) | (buf[i] >> bits);
-	buf[0] >>= bits;
-}
-
-
 /*
  * compute a "random" secret point on an elliptic curve based
  * on the password and identities.

src/utils/common.c

@@ -230,6 +230,16 @@ void inc_byte_array(u8 *counter, size_t len)
 }
 
 
+void buf_shift_right(u8 *buf, size_t len, size_t bits)
+{
+	size_t i;
+
+	for (i = len - 1; i > 0; i--)
+		buf[i] = (buf[i - 1] << (8 - bits)) | (buf[i] >> bits);
+	buf[0] >>= bits;
+}
+
+
 void wpa_get_ntp_timestamp(u8 *buf)
 {
 	struct os_time now;

src/utils/common.h

@@ -477,6 +477,7 @@ int hwaddr_aton2(const char *txt, u8 *addr);
 int hex2byte(const char *hex);
 int hexstr2bin(const char *hex, u8 *buf, size_t len);
 void inc_byte_array(u8 *counter, size_t len);
+void buf_shift_right(u8 *buf, size_t len, size_t bits);
 void wpa_get_ntp_timestamp(u8 *buf);
 int wpa_scnprintf(char *buf, size_t size, const char *fmt, ...);
 int wpa_snprintf_hex_sep(char *buf, size_t buf_size, const u8 *data, size_t len,