scsi: target: iscsi: Use bin2hex instead of a re-implementation

BugLink: https://bugs.launchpad.net/bugs/1798770

commit 8c39e269 upstream.
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[plr.vincent@gmail.com: hunk context change for 4.4 and 4.9, no code change]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/target/iscsi/iscsi_target_auth.c

@@ -26,15 +26,6 @@
 #include "iscsi_target_nego.h"
 #include "iscsi_target_auth.h"
 
-static void chap_binaryhex_to_asciihex(char *dst, char *src, int src_len)
-{
-	int i;
-
-	for (i = 0; i < src_len; i++) {
-		sprintf(&dst[i*2], "%02x", (int) src[i] & 0xff);
-	}
-}
-
 static void chap_gen_challenge(
 	struct iscsi_conn *conn,
 	int caller,
@@ -47,7 +38,7 @@ static void chap_gen_challenge(
 	memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1);
 
 	get_random_bytes(chap->challenge, CHAP_CHALLENGE_LENGTH);
-	chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge,
+	bin2hex(challenge_asciihex, chap->challenge,
 				CHAP_CHALLENGE_LENGTH);
 	/*
 	 * Set CHAP_C, and copy the generated challenge into c_str.
@@ -287,7 +278,7 @@ static int chap_server_compute_md5(
 	}
 	crypto_free_hash(tfm);
 
-	chap_binaryhex_to_asciihex(response, server_digest, MD5_SIGNATURE_SIZE);
+	bin2hex(response, server_digest, MD5_SIGNATURE_SIZE);
 	pr_debug("[server] MD5 Server Digest: %s\n", response);
 
 	if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) {
@@ -431,7 +422,7 @@ static int chap_server_compute_md5(
 	/*
 	 * Convert response from binary hex to ascii hext.
 	 */
-	chap_binaryhex_to_asciihex(response, digest, MD5_SIGNATURE_SIZE);
+	bin2hex(response, digest, MD5_SIGNATURE_SIZE);
 	*nr_out_len += sprintf(nr_out_ptr + *nr_out_len, "CHAP_R=0x%s",
 			response);
 	*nr_out_len += 1;