Smime class

class cryptosyspki.Smime

S/MIME entity utilities.

class Opts

Options for S/MIME methods.

ADDX = 1048576

Add an "x-" to the content subtype (for compatibility with legacy applications)

ENCODE_BASE64 = 65536

Encode output in base64

ENCODE_BINARY = 131072

Encode body in binary encoding

static extract(outputfile, inputfile, opts=0)

Extract the body from an S/MIME entity.

This is designed to extract the body from an S/MIME entity with a content type of application/pkcs7-mime with base64 or binary transfer encoding. In practice, it will extract the body from almost any type of S/MIME (or MIME) file, except one with quoted-printable transfer encoding.

Parameters:

  • outputfile (str) -- Name of output file to be created

  • inputfile (str) -- Name of input file containing S/MIME entity

  • opts (Smime.Opts) -- Options. By default, the output is encoded in binary. Use Opts.ENCODE_BASE64 to encode the output in base64.

Returns:

A positive number giving the size of the output file in bytes.

Return type:

int

static query(filename, query)

Query an S/MIME entity for selected information.

Parameters:

  • filename (str) -- Name of file containing S/MIME entity.

  • query (str) --

    Query string (case-insensitive). Valid queries are:

    • "content-type" -- Value of Content-Type, e.g. "application/pkcs7-mime".

    • "smime-type" -- Value of smime-type parameter of Content-Type, e.g. "enveloped-data".

    • "encoding" -- Value of Content-Transfer-Encoding, e.g. "base64".

    • "name" -- Value of name parameter of Content-Type, e.g. "smime.p7m".

    • "filename" -- Value of filename parameter of Content-Disposition, e.g. "smime.p7m".

Returns:

Result of query if found or an empty string if not found.

static wrap(outputfile, inputfile, opts=0)

Wrap a CMS object in an S/MIME entity.

Parameters:

  • outputfile (str) -- Output file to be created

  • inputfile (str) -- Input file containing CMS object. Expected to be a binary CMS object of type enveloped-data, signed-data or compressed-data; otherwise it is an error. The type of input file is detected automatically.

  • opts (Smime.Opts) -- Options.

Returns:

A positive number giving the size of the output file in bytes.

Return type:

int