RFC7143 allows both Base64 and Hex encoding for CHAP binary entities
like Challenge and Response. Currently Linux iSCSI target supports only
Hex encoding. This patch adds a support of Base64 encoded CHAP Challenge
and CHAP Response that are required for CHAP tests in Windows HLK.
Signed-off-by: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_auth.c | 114 ++++++++++++++++++-----
drivers/target/iscsi/iscsi_target_nego.c | 3 +
drivers/target/iscsi/iscsi_target_nego.h | 1 +
3 files changed, 94 insertions(+), 24 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c
index 6e5611d8f51b..a5b72968f356 100644
--- a/drivers/target/iscsi/iscsi_target_auth.c
+++ b/drivers/target/iscsi/iscsi_target_auth.c
@@ -205,6 +205,38 @@ static struct iscsi_chap *chap_server_open(
return chap;
}
+static const char base64_lookup_table[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static int chap_base64_decode(u8 *dst, const char *src, size_t len)
+{
+ int i, bits = 0, ac = 0;
+ const char *p;
+ u8 *cp = dst;
+
+ for (i = 0; i < len; i++) {
+ if (src[i] == '=')
+ return cp - dst;
+
+ p = strchr(base64_lookup_table, src[i]);
+ if (p == NULL || src[i] == 0)
+ return -2;
+
+ ac <<= 6;
+ ac += (p - base64_lookup_table);
+ bits += 6;
+ if (bits >= 8) {
+ *cp++ = (ac >> (bits - 8)) & 0xff;
+ ac &= ~(BIT(16) - BIT(bits - 8));
+ bits -= 8;
+ }
+ }
+ if (ac)
+ return -1;
+
+ return cp - dst;
+}
+
static int chap_server_compute_hash(
struct iscsit_conn *conn,
struct iscsi_node_auth *auth,
@@ -295,16 +327,27 @@ static int chap_server_compute_hash(
pr_err("Could not find CHAP_R.\n");
goto out;
}
- if (type != HEX) {
- pr_err("Could not find CHAP_R.\n");
- goto out;
- }
- if (strlen(chap_r) != chap->digest_size * 2) {
- pr_err("Malformed CHAP_R\n");
- goto out;
- }
- if (hex2bin(client_digest, chap_r, chap->digest_size) < 0) {
- pr_err("Malformed CHAP_R\n");
+
+ switch (type) {
+ case HEX:
+ if (strlen(chap_r) != chap->digest_size * 2) {
+ pr_err("Malformed CHAP_R\n");
+ goto out;
+ }
+ if (hex2bin(client_digest, chap_r, chap->digest_size) < 0) {
+ pr_err("Malformed CHAP_R: invalid HEX\n");
+ goto out;
+ }
+ break;
+ case BASE64:
+ if (chap_base64_decode(client_digest, chap_r, strlen(chap_r)) !=
+ chap->digest_size) {
+ pr_err("Malformed CHAP_R: invalid BASE64\n");
+ goto out;
+ }
+ break;
+ default:
+ pr_err("Could not find CHAP_R\n");
goto out;
}
@@ -404,23 +447,46 @@ static int chap_server_compute_hash(
goto out;
}
- if (type != HEX) {
+ switch (type) {
+ case HEX:
+ initiatorchg_len = DIV_ROUND_UP(strlen(initiatorchg), 2);
+ if (!initiatorchg_len) {
+ pr_err("Unable to convert incoming challenge\n");
+ goto out;
+ }
+ if (initiatorchg_len > 1024) {
+ pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
+ goto out;
+ }
+
+ if (hex2bin(initiatorchg_binhex, initiatorchg,
+ initiatorchg_len) < 0) {
+ pr_err("Malformed CHAP_C: invalid HEX\n");
+ goto out;
+ }
+ break;
+ case BASE64:
+ initiatorchg_len = chap_base64_decode(initiatorchg_binhex,
+ initiatorchg,
+ strlen(initiatorchg));
+ if (initiatorchg_len < 0) {
+ pr_err("Malformed CHAP_C: invalid BASE64\n");
+ goto out;
+ }
+ if (!initiatorchg_len) {
+ pr_err("Unable to convert incoming challenge\n");
+ goto out;
+ }
+ if (initiatorchg_len > 1024) {
+ pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
+ goto out;
+ }
+ break;
+ default:
pr_err("Could not find CHAP_C.\n");
goto out;
}
- initiatorchg_len = DIV_ROUND_UP(strlen(initiatorchg), 2);
- if (!initiatorchg_len) {
- pr_err("Unable to convert incoming challenge\n");
- goto out;
- }
- if (initiatorchg_len > 1024) {
- pr_err("CHAP_C exceeds maximum binary size of 1024 bytes\n");
- goto out;
- }
- if (hex2bin(initiatorchg_binhex, initiatorchg, initiatorchg_len) < 0) {
- pr_err("Malformed CHAP_C\n");
- goto out;
- }
+
pr_debug("[server] Got CHAP_C=%s\n", initiatorchg);
/*
* During mutual authentication, the CHAP_C generated by the
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index fb93a1173954..767646438391 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -76,6 +76,9 @@ int extract_param(
if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
ptr += 2; /* skip 0x */
*type = HEX;
+ } else if (*ptr == '0' && (*(ptr+1) == 'b' || *(ptr+1) == 'B')) {
+ ptr += 2; /* skip 0b */
+ *type = BASE64;
} else
*type = DECIMAL;
diff --git a/drivers/target/iscsi/iscsi_target_nego.h b/drivers/target/iscsi/iscsi_target_nego.h
index ed30b9ee75e6..21d3cab90d08 100644
--- a/drivers/target/iscsi/iscsi_target_nego.h
+++ b/drivers/target/iscsi/iscsi_target_nego.h
@@ -4,6 +4,7 @@
#define DECIMAL 0
#define HEX 1
+#define BASE64 2
struct iscsit_conn;
struct iscsi_login;
--
2.25.1
