diff --git a/lib/hdb/Makefile.am b/lib/hdb/Makefile.am
index ba28235b5..3c79219fd 100644
--- a/lib/hdb/Makefile.am
+++ b/lib/hdb/Makefile.am
@@ -29,6 +29,7 @@ gen_files_hdb = \
 	asn1_HDB_Ext_Lan_Manager_OWF.x \
 	asn1_HDB_Ext_Password.x \
 	asn1_HDB_Ext_Aliases.x \
+	asn1_HDB_Ext_KeySet.x \
 	asn1_HDB_extension.x \
 	asn1_HDB_extensions.x \
 	asn1_hdb_entry.x \
diff --git a/lib/hdb/common.c b/lib/hdb/common.c
index 2715adf63..90e600521 100644
--- a/lib/hdb/common.c
+++ b/lib/hdb/common.c
@@ -105,7 +105,6 @@ _hdb_fetch_kvno(krb5_context context, HDB *db, krb5_const_principal principal,
     krb5_principal enterprise_principal = NULL;
     krb5_data key, value;
     krb5_error_code ret;
-    int code;
 
     if (principal->name.name_type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
 	if (principal->name.name_string.len != 1) {
@@ -125,43 +124,72 @@ _hdb_fetch_kvno(krb5_context context, HDB *db, krb5_const_principal principal,
     hdb_principal2key(context, principal, &key);
     if (enterprise_principal)
 	krb5_free_principal(context, enterprise_principal);
-    code = db->hdb__get(context, db, key, &value);
+    ret = db->hdb__get(context, db, key, &value);
     krb5_data_free(&key);
-    if(code)
-	return code;
-    code = hdb_value2entry(context, &value, &entry->entry);
-    if (code == ASN1_BAD_ID && (flags & HDB_F_CANON) == 0) {
+    if(ret)
+	return ret;
+    ret = hdb_value2entry(context, &value, &entry->entry);
+    if (ret == ASN1_BAD_ID && (flags & HDB_F_CANON) == 0) {
 	krb5_data_free(&value);
 	return HDB_ERR_NOENTRY;
-    } else if (code == ASN1_BAD_ID) {
+    } else if (ret == ASN1_BAD_ID) {
 	hdb_entry_alias alias;
 
-	code = hdb_value2entry_alias(context, &value, &alias);
-	if (code) {
+	ret = hdb_value2entry_alias(context, &value, &alias);
+	if (ret) {
 	    krb5_data_free(&value);
-	    return code;
+	    return ret;
 	}
 	hdb_principal2key(context, alias.principal, &key);
 	krb5_data_free(&value);
 	free_hdb_entry_alias(&alias);
 
-	code = db->hdb__get(context, db, key, &value);
+	ret = db->hdb__get(context, db, key, &value);
 	krb5_data_free(&key);
-	if (code)
-	    return code;
-	code = hdb_value2entry(context, &value, &entry->entry);
-	if (code) {
+	if (ret)
+	    return ret;
+	ret = hdb_value2entry(context, &value, &entry->entry);
+	if (ret) {
 	    krb5_data_free(&value);
-	    return code;
+	    return ret;
 	}
     }
     krb5_data_free(&value);
     if (db->hdb_master_key_set && (flags & HDB_F_DECRYPT)) {
-	code = hdb_unseal_keys (context, db, &entry->entry);
-	if (code)
+	if ((flags & HDB_F_KVNO_SPECIFIED) == 0 &&
+	    (flags & HDB_F_CURRENT_KVNO) == 0) {
+
+	    /*
+	     * Decrypt all the old keys too, since we don't know which
+	     * the caller will need.
+	     */
+	    ret = hdb_unseal_keys_kvno(context, db, 0, &entry->entry);
+	    if (ret) {
+		hdb_free_entry(context, entry);
+		return ret;
+	    }
+	} else if ((flags & HDB_F_KVNO_SPECIFIED) != 0 &&
+	    kvno != entry->entry.kvno &&
+	    kvno < entry->entry.kvno &&
+	    kvno > 0) {
+
+	    /* Decrypt the keys we were asked for, if not the current ones */
+	    ret = hdb_unseal_keys_kvno(context, db, kvno, &entry->entry);
+	    if (ret) {
+		hdb_free_entry(context, entry);
+		return ret;
+	    }
+	}
+
+	/* Always decrypt the current keys too */
+	ret = hdb_unseal_keys(context, db, &entry->entry);
+	if (ret) {
 	    hdb_free_entry(context, entry);
+	    return ret;
+	}
     }
-    return code;
+
+    return ret;
 }
 
 static krb5_error_code
diff --git a/lib/hdb/hdb.asn1 b/lib/hdb/hdb.asn1
index a72851c9f..d24737fbf 100644
--- a/lib/hdb/hdb.asn1
+++ b/lib/hdb/hdb.asn1
@@ -87,6 +87,14 @@ HDB-Ext-Aliases ::= SEQUENCE {
 	aliases[1]		SEQUENCE OF Principal -- all names, inc primary
 }
 
+hdb_keyset ::= SEQUENCE {
+	kvno[0]		INTEGER (0..4294967295),
+	replace-time[1]	KerberosTime,	-- time this key was replaced
+	keys[2]		SEQUENCE OF Key
+}
+
+HDB-Ext-KeySet ::= SEQUENCE OF hdb_keyset
+
 
 HDB-extension ::= SEQUENCE {
         mandatory[0]    BOOLEAN,        -- kdc MUST understand this extension,
@@ -102,6 +110,7 @@ HDB-extension ::= SEQUENCE {
 		aliases[6]			HDB-Ext-Aliases,
 		last-pw-change[7]		KerberosTime,
 	        pkinit-cert[8]  		HDB-Ext-PKINIT-cert,
+	        hist-keys[9]			HDB-Ext-KeySet,
 		...
 	},
 	...
@@ -109,11 +118,6 @@ HDB-extension ::= SEQUENCE {
 
 HDB-extensions ::= SEQUENCE OF HDB-extension
 
-hdb_keyset ::= SEQUENCE {
-	kvno[1]		INTEGER (0..4294967295),
-	keys[0]		SEQUENCE OF Key
-}
-
 hdb_entry ::= SEQUENCE {
 	principal[0]	Principal  OPTIONAL, -- this is optional only 
 					     -- for compatibility with libkrb5
diff --git a/lib/hdb/hdb.c b/lib/hdb/hdb.c
index ca05cc4a1..aff576a30 100644
--- a/lib/hdb/hdb.c
+++ b/lib/hdb/hdb.c
@@ -168,13 +168,14 @@ hdb_unlock(int fd)
 void
 hdb_free_entry(krb5_context context, hdb_entry_ex *ent)
 {
-    size_t i;
+    Key *k;
+    int i;
 
     if (ent->free_entry)
 	(*ent->free_entry)(context, ent);
 
-    for(i = 0; i < ent->entry.keys.len; ++i) {
-	Key *k = &ent->entry.keys.val[i];
+    for(i = 0; i < ent->entry.keys.len; i++) {
+	k = &ent->entry.keys.val[i];
 
 	memset (k->key.keyvalue.data, 0, k->key.keyvalue.length);
     }
diff --git a/lib/hdb/hdb.h b/lib/hdb/hdb.h
index 469ec82ec..e82c5c51e 100644
--- a/lib/hdb/hdb.h
+++ b/lib/hdb/hdb.h
@@ -57,6 +57,7 @@ enum hdb_lockop{ HDB_RLOCK, HDB_WLOCK };
 #define HDB_F_CANON		32	/* want canonicalition */
 #define HDB_F_ADMIN_DATA	64	/* want data that kdc don't use  */
 #define HDB_F_KVNO_SPECIFIED	128	/* we want a particular KVNO */
+#define HDB_F_CURRENT_KVNO	256	/* we want the current KVNO */
 
 /* hdb_capability_flags */
 #define HDB_CAP_F_HANDLE_ENTERPRISE_PRINCIPAL 1
diff --git a/lib/hdb/keys.c b/lib/hdb/keys.c
index 3d0b9d7c1..9c0af5c47 100644
--- a/lib/hdb/keys.c
+++ b/lib/hdb/keys.c
@@ -39,7 +39,7 @@
  */
 
 void
-hdb_free_keys (krb5_context context, int len, Key *keys)
+hdb_free_keys(krb5_context context, int len, Key *keys)
 {
     int i;
 
@@ -56,6 +56,19 @@ hdb_free_keys (krb5_context context, int len, Key *keys)
     free (keys);
 }
 
+void
+hdb_free_keysets(krb5_context context, int len, hdb_keyset *keysets)
+{
+    int i;
+
+    for (i = 0; i < len; i++) {
+	hdb_free_keys(context, keysets[i].keys.len, keysets[i].keys.val);
+	keysets[i].keys.val = NULL;
+	keysets[i].keys.len = 0;
+    }
+    free (keysets);
+}
+
 /*
  * for each entry in `default_keys' try to parse it as a sequence
  * of etype:salttype:salt, syntax of this if something like:
@@ -196,6 +209,60 @@ parse_key_set(krb5_context context, const char *key,
     return 0;
 }
 
+
+krb5_error_code
+hdb_add_current_keys_to_history(krb5_context context, hdb_entry *entry)
+{
+    krb5_error_code ret;
+    HDB_extension *ext;
+    HDB_Ext_KeySet *hist_keys;
+    hdb_keyset *tmp_keysets;
+    int add = 0;
+
+    ext = hdb_find_extension(entry, choice_HDB_extension_data_hist_keys);
+    if (ext != NULL) {
+	hist_keys = &ext->data.u.hist_keys;
+	tmp_keysets = realloc(hist_keys->val,
+			      sizeof (*hist_keys->val) * (hist_keys->len + 1));
+	if (tmp_keysets == NULL)
+	    return ENOMEM;
+	hist_keys->val = tmp_keysets;
+	memmove(&hist_keys->val[1], hist_keys->val,
+		sizeof (*hist_keys->val) * hist_keys->len++);
+    } else {
+	add = 1;
+	ext = calloc(1, sizeof (*ext));
+	if (ext == NULL)
+	    return ENOMEM;
+	ext->data.element = choice_HDB_extension_data_hist_keys;
+	hist_keys = &ext->data.u.hist_keys;
+	hist_keys->val = calloc(1, sizeof (*hist_keys->val));
+	if (hist_keys->val == NULL) {
+	    free(hist_keys);
+	    return ENOMEM;
+	}
+	hist_keys->len = 1;
+    }
+
+    hist_keys->val[0].keys.val = entry->keys.val;
+    hist_keys->val[0].keys.len = entry->keys.len;
+    hist_keys->val[0].kvno = entry->kvno;
+    hist_keys->val[0].replace_time = time(NULL);
+
+    if (add) {
+	ret = hdb_replace_extension(context, entry, ext);
+	if (ret) {
+	    free_HDB_extension(ext);
+	    return ret;
+	}
+    }
+
+    /* hdb_replace_extension() copies ext, so we have to free it */
+    free_HDB_extension(ext);
+    return 0;
+}
+
+
 static krb5_error_code
 add_enctype_to_key_set(Key **key_set, size_t *nkeyset,
 		       krb5_enctype enctype, krb5_salt *salt)
diff --git a/lib/hdb/mkey.c b/lib/hdb/mkey.c
index 9a13d55a5..4ea7394f3 100644
--- a/lib/hdb/mkey.c
+++ b/lib/hdb/mkey.c
@@ -32,6 +32,7 @@
  */
 
 #include "hdb_locl.h"
+#include <assert.h>
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
@@ -479,6 +480,85 @@ hdb_unseal_keys(krb5_context context, HDB *db, hdb_entry *ent)
     return hdb_unseal_keys_mkey(context, ent, db->hdb_master_key);
 }
 
+krb5_error_code
+hdb_unseal_keys_kvno(krb5_context context, HDB *db, krb5_kvno kvno,
+		     hdb_entry *ent)
+{
+    krb5_error_code ret = KRB5KRB_AP_ERR_NOKEY;	/* XXX need a better code? */
+    HDB_extension *tmp;
+    HDB_Ext_KeySet *hist_keys;
+    hdb_keyset *tmp_keys;
+    Key *tmp_val;
+    unsigned int tmp_len;
+    krb5_kvno tmp_kvno;
+    int i, k;
+
+    assert(kvno == 0 || kvno < ent->kvno);
+
+    tmp = hdb_find_extension(ent, choice_HDB_extension_data_hist_keys);
+    if (tmp == NULL)
+	return ret;
+
+    tmp_len = ent->keys.len;
+    tmp_val = ent->keys.val;
+    tmp_kvno = ent->kvno;
+
+    hist_keys = &tmp->data.u.hist_keys;
+
+    for (i = hist_keys->len - 1; i >= 0; i++) {
+	if (kvno != 0 && hist_keys->val[i].kvno != kvno)
+	    continue;
+	for (k = 0; k < hist_keys->val[i].keys.len; k++) {
+	    ret = hdb_unseal_key_mkey(context,
+				      &hist_keys->val[i].keys.val[k],
+				      db->hdb_master_key);
+	    if (ret)
+		return (ret);
+	}
+
+	if (kvno == 0)
+	    continue;
+
+	/*
+	 * NOTE: What follows is a bit of an ugly hack.
+	 *
+	 * This is the keyset we're being asked for, so we add the
+	 * current keyset to the history, leave the one we were asked
+	 * for in the history, and pretend the one we were asked for is
+	 * also the current keyset.
+	 *
+	 * This is a bit of a defensive hack in case an entry fetched
+	 * this way ever gets modified then stored: if the keyset is not
+	 * changed we can detect this and put things back, else we won't
+	 * drop any keysets from history by accident.
+	 *
+	 * Note too that we only ever get called with a non-zero kvno
+	 * either in the KDC or in cases where we aren't changing the
+	 * HDB entry anyways, which is why this is just a defensive
+	 * hack.  We also don't fetch specific kvnos in the dump case,
+	 * so there's no danger that we'll dump this entry and load it
+	 * again, repeatedly causing the history to grow boundelessly.
+	 */
+	tmp_keys = realloc(hist_keys->val,
+		      sizeof (*hist_keys->val) * (hist_keys->len + 1));
+	if (tmp_keys == NULL)
+	    return ENOMEM;
+
+	memmove(&tmp_keys[1], tmp_keys,
+		sizeof (*hist_keys->val) * hist_keys->len++);
+	tmp_keys[0].keys.len = ent->keys.len;
+	tmp_keys[0].keys.val = ent->keys.val;
+	tmp_keys[0].kvno = ent->kvno;
+	tmp_keys[0].replace_time = time(NULL);
+	i++;
+	ent->keys.len = hist_keys->val[i].keys.len;
+	ent->keys.val = hist_keys->val[i].keys.val;
+	ent->kvno = kvno;
+    }
+
+    return (ret);
+}
+
 krb5_error_code
 hdb_unseal_key(krb5_context context, HDB *db, Key *k)
 {
diff --git a/lib/hdb/print.c b/lib/hdb/print.c
index 697d32d29..0ff767ec6 100644
--- a/lib/hdb/print.c
+++ b/lib/hdb/print.c
@@ -62,11 +62,12 @@ append_string(krb5_context context, krb5_storage *sp, const char *fmt, ...)
 {
     krb5_error_code ret;
     char *s;
+    int rc;
     va_list ap;
     va_start(ap, fmt);
-    vasprintf(&s, fmt, ap);
+    rc = vasprintf(&s, fmt, ap);
     va_end(ap);
-    if(s == NULL) {
+    if(rc < 0) {
 	krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
 	return ENOMEM;
     }
@@ -127,7 +128,7 @@ static krb5_error_code
 entry2string_int (krb5_context context, krb5_storage *sp, hdb_entry *ent)
 {
     char *p;
-    size_t i;
+    int i;
     krb5_error_code ret;
 
     /* --- principal */
@@ -234,7 +235,6 @@ entry2string_int (krb5_context context, krb5_storage *sp, hdb_entry *ent)
     } else
 	append_string(context, sp, "-");
 
-
     return 0;
 }
 
diff --git a/lib/hdb/test_hdbkeys.c b/lib/hdb/test_hdbkeys.c
index 1c3216d14..fd5dfcf81 100644
--- a/lib/hdb/test_hdbkeys.c
+++ b/lib/hdb/test_hdbkeys.c
@@ -88,6 +88,7 @@ main(int argc, char **argv)
     memset(&keyset, 0, sizeof(keyset));
 
     keyset.kvno = kvno_integer;
+    keyset.replace_time = time(NULL);
 
     ret = hdb_generate_key_set_password(context, principal, password_str,
 					&keyset.keys.val, &len);
diff --git a/lib/hdb/version-script.map b/lib/hdb/version-script.map
index 50a36cec0..bf0f35c81 100644
--- a/lib/hdb/version-script.map
+++ b/lib/hdb/version-script.map
@@ -4,6 +4,7 @@ HEIMDAL_HDB_1.0 {
 	global:
 		encode_hdb_keyset;
 		hdb_add_master_key;
+		hdb_add_current_keys_to_history;
 		hdb_check_db_format;
 		hdb_clear_extension;
 		hdb_clear_master_key;
diff --git a/lib/kadm5/chpass_s.c b/lib/kadm5/chpass_s.c
index d5407d154..8ffdefa47 100644
--- a/lib/kadm5/chpass_s.c
+++ b/lib/kadm5/chpass_s.c
@@ -58,6 +58,10 @@ change(void *server_handle,
     if(ret)
 	goto out;
 
+    ret = hdb_add_current_keys_to_history(context->context, &ent.entry);
+    if (ret)
+	goto out;
+
     if (context->db->hdb_capability_flags & HDB_CAP_F_HANDLE_PASSWORDS) {
 	ret = context->db->hdb_password(context->context, context->db,
 					&ent, password, cond);
@@ -170,6 +174,9 @@ kadm5_s_chpass_principal_with_key(void *server_handle,
 				      HDB_F_GET_ANY|HDB_F_ADMIN_DATA, &ent);
     if(ret == HDB_ERR_NOENTRY)
 	goto out;
+    ret = hdb_add_current_keys_to_history(context->context, &ent.entry);
+    if (ret)
+        goto out2;
     ret = _kadm5_set_keys2(context, &ent.entry, n_key_data, key_data);
     if(ret)
 	goto out2;
diff --git a/lib/kadm5/randkey_s.c b/lib/kadm5/randkey_s.c
index dcb179aac..adb3564be 100644
--- a/lib/kadm5/randkey_s.c
+++ b/lib/kadm5/randkey_s.c
@@ -59,6 +59,10 @@ kadm5_s_randkey_principal(void *server_handle,
     if(ret)
 	goto out;
 
+    ret = hdb_add_current_keys_to_history(context->context, &ent.entry);
+    if (ret)
+        goto out2;
+
     ret = _kadm5_set_keys_randomly (context,
 				    &ent.entry,
 				    new_keys,