Function mbedtls_x509_csr_parse 

pub unsafe extern "C" fn mbedtls_x509_csr_parse(
    csr: *mut mbedtls_x509_csr,
    buf: *const c_uchar,
    buflen: usize,
) -> c_int

\brief Load a Certificate Signing Request (CSR), DER or PEM format

\note See notes for \c mbedtls_x509_csr_parse_der()

\note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto subsystem must have been initialized by calling psa_crypto_init() before calling this function.

\param csr CSR context to fill \param buf buffer holding the CRL data \param buflen size of the buffer (including the terminating null byte for PEM data)

\return 0 if successful, or a specific X509 or PEM error code