Passwords not working after migration from /etc/shadow to LDAP

I've migrated RHEL6 user accounts from traditional /etc/passwd, /etc/shadow, and /etc/group files to OpenLDAP. However, trying to log in as the migrated users does not work because of incorrect user password errors:

Example (removed) /etc/passwd line:

leopetr:x:1005:1005:Leo Petr:/mnt/home/leopetr:/bin/bash

Example (removed) /etc/shadow line:

leopetr:$6$+7sZw4ID$CyLfaFeo.aDn1Xd5.MCBWXDm131CIOPExg0hgUQb4sdInuXIf4IBU8LxJo7Hz144uIp3nYB6cmnIzLAyI6fzr.:16205:0:99999:7:::

(The hash corresponds to a randomly generated password for an unprivileged account.)

Example LDIF generated by OpenLDAP conversion tools:

dn: uid=leopetr,ou=People,dc=imdemocloud,dc=com
uid: leopetr
cn: Leo Petr
objectClass: account
objectClass: posixAccount
objectClass: top
objectClass: shadowAccount
userPassword: {crypt}$6$+7sZw4ID$CyLfaFeo.aDn1Xd5.MCBWXDm131CIOPExg0hgUQb4sdInuXIf4IBU8LxJo7Hz144uIp3nYB6cmnIzLAyI6fzr.
shadowLastChange: 16205
shadowMin: 0
shadowMax: 99999
shadowWarning: 7
loginShell: /bin/bash
uidNumber: 1005
gidNumber: 1005
homeDirectory: /mnt/home/leopetr
gecos: Leo Petr

I can su - to that user account as root, so the user record is accessible in LDAP. However, I can't log in as that user. Example:

$ su - leopetr
Password:
su: incorrect password

1. Why isn't the password working?

2. Is {crypt} the right prefix for a sha-512 password hash?

3. Is userPassword the right LDAP field for a password hash?

Edit: /etc/pam.d/su

#%PAM-1.0
auth        sufficient  pam_rootok.so
# Uncomment the following line to implicitly trust users in the "wheel" group.
#auth       sufficient  pam_wheel.so trust use_uid
# Uncomment the following line to require a user to be in the "wheel" group.
#auth       required    pam_wheel.so use_uid
auth        include     system-auth
account     sufficient  pam_succeed_if.so uid = 0 use_uid quiet
account     include     system-auth
password    include     system-auth
session     include     system-auth
session     optional    pam_xauth.so

/etc/pam.d/system-auth:

#%PAM-1.0
# This file is auto-generated.
# User changes will be destroyed the next time authconfig is run.
auth        required      pam_env.so
auth        sufficient    pam_fprintd.so
auth        sufficient    pam_unix.so nullok try_first_pass
auth        requisite     pam_succeed_if.so uid >= 500 quiet
auth        sufficient    pam_sss.so use_first_pass
auth        sufficient    pam_ldap.so use_first_pass
auth        required      pam_deny.so

account     required      pam_unix.so broken_shadow
account     sufficient    pam_localuser.so
account     sufficient    pam_succeed_if.so uid < 500 quiet
account     [default=bad success=ok user_unknown=ignore] pam_sss.so
account     [default=bad success=ok user_unknown=ignore] pam_ldap.so
account     required      pam_permit.so

password    requisite     pam_cracklib.so try_first_pass retry=3 minlen=8 dcredit=-1 ucredit=0 lcredit=-1 ocredit=0 type= reject_username
password    sufficient    pam_unix.so sha512 shadow nullok try_first_pass use_authtok
password    sufficient    pam_sss.so use_authtok
password    sufficient    pam_ldap.so use_authtok
password    required      pam_deny.so

session     optional      pam_keyinit.so revoke
session     required      pam_limits.so
session     optional      pam_mkhomedir.so umask=0077
session     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid
session     required      pam_unix.so
session     optional      pam_sss.so
session     optional      pam_ldap.so

/etc/sssd/sssd.conf:

[sssd]
config_file_version = 2
reconnection_retries = 3
sbus_timeout = 30
services = nss, pam
domains = LOCAL,LDAP

[nss]
filter_groups = root
filter_users = root
reconnection_retries = 3
entry_cache_timeout = 300
entry_cache_nowait_percentage = 75

[pam]
reconnection_retries = 3
offline_credentials_expiration = 2
offline_failed_login_attempts = 3
offline_failed_login_delay = 5

[domain/LDAP]
cache_credentials = true

id_provider = ldap
auth_provider = ldap

ldap_uri = ldaps://my_hostname.my_domain.com
ldap_search_base = dc=my_domain,dc=com
ldap_id_use_start_tls = true
ldap_tls_reqcert = never
ldap_tls_cacert = /etc/pki/tls/certs/ca-bundle.crt

/etc/nsswitch.conf:

#
# /etc/nsswitch.conf
#
# An example Name Service Switch config file. This file should be
# sorted with the most-used services at the beginning.
#
# The entry '[NOTFOUND=return]' means that the search for an
# entry should stop if the search in the previous entry turned
# up nothing. Note that if the search failed due to some other reason
# (like no NIS server responding) then the search continues with the
# next entry.
#
# Valid entries include:
#
#   nisplus         Use NIS+ (NIS version 3)
#   nis         Use NIS (NIS version 2), also called YP
#   dns         Use DNS (Domain Name Service)
#   files           Use the local files
#   db          Use the local database (.db) files
#   compat          Use NIS on compat mode
#   hesiod          Use Hesiod for user lookups
#   [NOTFOUND=return]   Stop searching if not found so far
#

# To use db, put the "db" in front of "files" for entries you want to be
# looked up first in the databases
#
# Example:
#passwd:    db files nisplus nis
#shadow:    db files nisplus nis
#group:     db files nisplus nis

passwd:     files sss ldap
shadow:     files sss ldap
group:      files sss ldap

#hosts:     db files nisplus nis dns
hosts:      files dns

# Example - obey only what nisplus tells us...
#services:   nisplus [NOTFOUND=return] files
#networks:   nisplus [NOTFOUND=return] files
#protocols:  nisplus [NOTFOUND=return] files
#rpc:        nisplus [NOTFOUND=return] files
#ethers:     nisplus [NOTFOUND=return] files
#netmasks:   nisplus [NOTFOUND=return] files

bootparams: nisplus [NOTFOUND=return] files

ethers:     files
netmasks:   files
networks:   files
protocols:  files
rpc:        files
services:   files sss

netgroup:   files sss ldap

publickey:  nisplus

automount:  files sss ldap
aliases:    files nisplus

Also, here are the authconfig commands I used:

authconfig --enablesssd --enablesssdauth --enablelocauthorize --enableldap --enableldapauth \
--ldapserver=ldaps://my_hostname.my_domain.com:636 --disableldaptls \
--ldapbasedn=dc=my_domain,dc=com \
--enablerfc2307bis --enablemkhomedir --enablecachecreds --update

authconfig --update --enablesssd --enablesssdauth

authconfig --enablesssd --update