how to begin with SASL&PAM developing?where is the doc sources?

[frederick van targero]

i met one case, my postfix.smtp.auth can not work with pam (which invoke by sasl), until i allow the sasl access /etc/shadow.
it is means, the clause in /usr/lib/sasl/smptd.conf:
must be
pwcheck_method:shadow,
can not be pwcheck_method:pam;

as well as what my have set in /etc/pam.d/smtp give no use in thus process.

for i need to make it work with my own ERPs staffs other than independent DBD/MYSQLs, i found i have to analysis the sasl and pam, but how to begin, i found little doc and source about it .

thanks for your tips.
frederick