Cross-component cryptographic message syntax message construction
Often, for reasons of wireless bandwidth conservation, incomplete messages are provided to wireless messaging devices. Employing cryptography, for confidentiality or authentication purposes, when including a received message that has been incompletely received can lead to lack of context on the receiver's end. By automatically obtaining the entirety of the message to be included, an outgoing message that includes the received message can be processed in a manner that securely and accurately represents the intended outgoing message. Alternatively, a server can assemble a composite message from a new message and an original message and, in cooperation with a wireless messaging device, construct a cryptographic message syntax message.
1. A method of processing an electronic message, said method comprising:
by a mobile wireless communication device:
detecting receipt of an instruction to transmit a composite message, where said composite message includes a new message and an original message and some parts of said original message are not downloaded to said mobile wireless communication device;
creating a cryptographic message syntax (CMS) message, said CMS message having a data structure wherein a first field is intentionally left empty;
transmitting, to a server associated with said mobile wireless communication device, said new message and an encryption request, said encryption request including said CMS message and an indication of said original message;
obtaining a composite message session key for use in carrying out said encryption request; and
transmitting, outside of said CMS message, said composite message session key to said server; and
by said server:
detecting receipt of said new message and said encryption request;
creating, responsive to said detecting, said composite message from said new message and said original message;
processing said composite message to obtain further data;
inserting said further data into said first field in said data structure in said CMS message; and
transmitting said CMS message;
thereby ensuring that said CMS message accurately corresponds to said composite message.
2. The method of claim 1 wherein said CMS message is a first CMS message and said method further comprises:
creating a second CMS message, said second CMS message having a data structure wherein a second field is intentionally left empty; and
wherein said encryption request includes said second CMS message.
3. The method of claim 2 wherein said first CMS message comprises Signed Data and said second CMS message comprises Enveloped Data.
4. The method of claim 1 wherein said data structure comprises a CMS Enveloped Data structure.
5. The method of claim 4 wherein said first field comprises an encryptedContent field.
6. The method of claim 1 wherein said data structure comprises a CMS Signed Data structure.
7. The method of claim 6 wherein said first field comprises an eContent field.
8. The method of claim 1 further comprising, at said server:
receiving cryptographic information; and
employing said cryptographic information to decrypt said original message.
9. The method of claim 1 wherein said encryption request further specifies signing of said composite message.
10. The method of claim 9 further comprising, responsive to said creating said composite message:
generating a hash of said composite message; and
transmitting said hash to an origin of said encryption request in conjunction with a hash signing request to sign said hash.
11. The method of claim 10 further comprising receiving a signature, where said signature comprises said hash signed at said origin of said encryption request.
12. The method of claim 11 wherein said further data comprises said signature.
13. The method of claim 12 wherein said first field is a signature field.
14. The method of claim 1 further comprising, at said server:
receiving cryptographic information;
wherein said processing said composite message to obtain further data includes employing said cryptographic information to encrypt said composite message, thereby forming an encrypted composite message.
15. The method of claim 14 wherein said further data comprises said encrypted composite message.
16. The method of claim 1 wherein said creating said composite message comprises including an attachment received in association with said new message.
17. The method of claim 1 wherein said creating said composite message comprises including an attachment received in association with said original message.
18. A system comprising:
a mobile wireless communication device comprising a hardware processor configured to:
detect receipt of an instruction to transmit a composite message, where said composite message includes a new message and an original message and some parts of said original message are not downloaded to said mobile wireless communication device;
create a cryptographic message syntax (CMS) message, said CMS message having a data structure wherein a first field is intentionally left empty;
transmit said new message to a server associated with said mobile wireless communication device;
transmit an encryption request to said server, said encryption request including said CMS message and specifying said original message;
obtain a composite message session key for use in carrying out said encryption request; and
transmit, outside of said CMS message, said composite message session key to said server;
said server configured to:
detect receipt of said new message and said encryption request;
create, responsive to said detecting, said composite message from said new message and said original message;
process said composite message to obtain further data;
insert said further data into said first field in said data structure in said CMS message; and
transmit said CMS message;
thereby ensuring that said CMS message accurately corresponds to said composite message.
19. A non-transitory computer-readable medium containing:
computer-executable instructions that, when performed by a processor in a mobile wireless communication device, cause said processor to:
detect receipt of an instruction to transmit a composite message, where said composite message includes a new message and an original message and some parts of said original message are not downloaded to said mobile wireless communication device;
create a cryptographic message syntax (CMS) message, said CMS message having a data structure wherein a first field is intentionally left empty;
transmit said new message to a server associated with said mobile wireless communication device;
transmit an encryption request to said server, said encryption request including said CMS message and specifying said original message;
obtaining a composite message session key for use in carrying out said encryption request; and
transmitting, outside of said CMS message, said composite message session key to said server; and
computer-executable instructions that, when performed by a processor in said server, cause said processor to:
detect receipt of said new message and said encryption request;
create, responsive to said detecting, said composite message from said new message and said original message;
process said composite message to obtain further data;
insert said further data into said first field in said data structure in said CMS message; and
transmit said CMS message;
thereby ensuring that said CMS message accurately corresponds to said composite message.