On Thu, Jun 03, 2010, Mounir IDRASSI wrote: > Hi, > > One simple and efficient method to distinguish between PEM and DER encoding > for a CRL or a certificate is to read the first byte : if it's equal to > 0x30 then this DER (this is the start of an ASN.1 Sequence) , otherwise it > is PEM encoded. > This works ONLY if you are sure that the given file is either PEM or DER > encoded and that the encoded object is an ASN.1 Sequence. >
Since the 0x30 byte correspond to the ASCII character '0' there is a slight chance this will fail if the file is PEM format and contains text before the PEM headers. This can be further reduced by checking the length field following the SEQUENCE tag. Steve. -- Dr Stephen N. Henson. OpenSSL project core developer. Commercial tech support now available see: http://www.openssl.org ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
