diff --git a/src/net/tcp/iscsi.c b/src/net/tcp/iscsi.c
index 8beeb87..fa1bb39 100644
--- a/src/net/tcp/iscsi.c
+++ b/src/net/tcp/iscsi.c
@@ -131,6 +131,14 @@ FEATURE ( FEATURE_PROTOCOL, "iSCSI", DHCP_EB_FEATURE_ISCSI, 1 );
    __einfo_error ( EINFO_EPROTO_INVALID_CHAP_RESPONSE )
 #define EINFO_EPROTO_INVALID_CHAP_RESPONSE \
    __einfo_uniqify ( EINFO_EPROTO, 0x04, "Invalid CHAP response" )
+#define EPROTO_INVALID_KEY_VALUE_PAIR \
+   __einfo_error ( EINFO_EPROTO_INVALID_KEY_VALUE_PAIR )
+#define EINFO_EPROTO_INVALID_KEY_VALUE_PAIR \
+   __einfo_uniqify ( EINFO_EPROTO, 0x05, "Invalid key/value pair" )
+#define EPROTO_VALUE_REJECTED \
+   __einfo_error ( EINFO_EPROTO_VALUE_REJECTED )
+#define EINFO_EPROTO_VALUE_REJECTED                    \
+   __einfo_uniqify ( EINFO_EPROTO, 0x06, "Parameter rejected" )

 static void iscsi_start_tx ( struct iscsi_session *iscsi );
 static void iscsi_start_login ( struct iscsi_session *iscsi );
@@ -1083,8 +1091,8 @@ static int iscsi_handle_chap_r_value ( struct iscsi_session *iscsi,
 struct iscsi_string_type {
    /** String key
     *
-    * This is the portion up to and including the "=" sign,
-    * e.g. "InitiatorName=", "CHAP_A=", etc.
+    * This is the portion preceding the "=" sign,
+    * e.g. "InitiatorName", "CHAP_A", etc.
     */
    const char *key;
    /** Handle iSCSI string value
@@ -1098,13 +1106,13 @@ struct iscsi_string_type {

 /** iSCSI text strings that we want to handle */
 static struct iscsi_string_type iscsi_string_types[] = {
-   { "TargetAddress=", iscsi_handle_targetaddress_value },
-   { "AuthMethod=", iscsi_handle_authmethod_value },
-   { "CHAP_A=", iscsi_handle_chap_a_value },
-   { "CHAP_I=", iscsi_handle_chap_i_value },
-   { "CHAP_C=", iscsi_handle_chap_c_value },
-   { "CHAP_N=", iscsi_handle_chap_n_value },
-   { "CHAP_R=", iscsi_handle_chap_r_value },
+   { "TargetAddress", iscsi_handle_targetaddress_value },
+   { "AuthMethod", iscsi_handle_authmethod_value },
+   { "CHAP_A", iscsi_handle_chap_a_value },
+   { "CHAP_I", iscsi_handle_chap_i_value },
+   { "CHAP_C", iscsi_handle_chap_c_value },
+   { "CHAP_N", iscsi_handle_chap_n_value },
+   { "CHAP_R", iscsi_handle_chap_r_value },
    { NULL, NULL }
 };

@@ -1118,16 +1126,35 @@ static struct iscsi_string_type iscsi_string_types[] = {
 static int iscsi_handle_string ( struct iscsi_session *iscsi,
                 const char *string ) {
    struct iscsi_string_type *type;
+   const char *separator;
+   const char *value;
    size_t key_len;
    int rc;

+   /* Find separator */
+   separator = strchr ( string, '=' );
+   if ( ! separator ) {
+       DBGC ( iscsi, "iSCSI %p malformed string %s\n",
+              iscsi, string );
+       return -EPROTO_INVALID_KEY_VALUE_PAIR;
+   }
+   key_len = ( separator - string );
+   value = ( separator + 1 );
+
+   /* Check for rejections.  Since we send only non-rejectable
+    * values, any rejection is a fatal protocol error.
+    */
+   if ( strcmp ( value, "Reject" ) == 0 ) {
+       DBGC ( iscsi, "iSCSI %p rejection: %s\n", iscsi, string );
+       return -EPROTO_VALUE_REJECTED;
+   }
+
+   /* Handle key/value pair */
    for ( type = iscsi_string_types ; type->key ; type++ ) {
-       key_len = strlen ( type->key );
        if ( strncmp ( string, type->key, key_len ) != 0 )
            continue;
        DBGC ( iscsi, "iSCSI %p handling %s\n", iscsi, string );
-       if ( ( rc = type->handle ( iscsi,
-                      ( string + key_len ) ) ) != 0 ) {
+       if ( ( rc = type->handle ( iscsi, value ) ) != 0 ) {
            DBGC ( iscsi, "iSCSI %p could not handle %s: %s\n",
                   iscsi, string, strerror ( rc ) );
            return rc;