Bug 26904: OPAC password recovery allows regexp in email

When using OPAC password recovery form, opac/opac-password-recovery.pl :
if one provides correct login and an email, there is a check that this email is one of patron's.

This check uses RegExp with case insensitive :
  if ( $email && !( any { /^$email$/i } @emails ) )

This is a security issue since one can simply enter '.*'.
Severity is normal because the login must be a correct.

I propose to use simple string compare with lowercase to be case insensitive.

Test plan :
1) Don't apply patch
2) Enable system preference 'OpacResetPassword'
3) Go to 'OPAC > Log in to your account > Forgot your password?'
4) Enter an existing userid or cardnumber and '.*' in 'Email'
5) The password recovery is created ! (check table 'borrower_password_recovery')
6) Apply patch
7) Enter an existing userid or cardnumber and '.*' in 'Email'
8) You get the message 'No account was found with the provided information.'
9) Enter an existing userid or cardnumber and in 'Email' the corresponding email but with different case
10) The password recovery is created (check table 'borrower_password_recovery')

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>

Backport to 19.05.x:
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>

opac/opac-password-recovery.pl

@@ -85,7 +85,7 @@ if ( $query->param('sendEmail') || $query->param('resendEmail') ) {
             $firstNonEmptyEmail = $emails[0] if @emails;
 
             # Is the given email one of the borrower's ?
-            if ( $email && !( any { /^$email$/i } @emails ) ) {
+            if ( $email && !( any { lc($_) eq lc($email) } @emails ) ) {
                 $hasError    = 1;
                 $errNoBorrowerFound = 1;
             }