(PHP 4 >= 4.2.0, PHP 5)
openssl_csr_export — Exports a CSR as a string
openssl_csr_export() takes the Certificate Signing Request represented by csr and stores it as ascii-armoured text into out, which is passed by reference.
The optional parameter notext affects the verbosity of the output; if it is FALSE, then additional human-readable information is included in the output. The default value of notext is TRUE.
成功时返回 TRUE， 或者在失败时返回 FALSE.