projects / apple / security.git / blame
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1 | (RCS control information is at the end of this file.) |
| 2 | ||
| 3 | ||
| 4 | C ANY example README | |
| 5 | ------------------ | |
| 6 | ||
| 7 | This example shows how the snacc compiler handles the ANY DEFINED BY | |
| 8 | type in C. ANY types (not ANY DEFINED BY) require the modifications | |
| 9 | to the generated code. Type "make" to build this example. | |
| 10 | ||
| 11 | This directory should have the following files in it: | |
| 12 | ||
| 13 | README | |
| 14 | genber.c | |
| 15 | example.c | |
| 16 | makefile | |
| 17 | ||
| 18 | There are 3 programs generated by the makefile: | |
| 19 | ||
| 20 | genber - builds a BER value of the AnyTestType and writes it | |
| 21 | to a file called "att.ber" | |
| 22 | ||
| 23 | def - takes file name of an AnyTestType value. Decodes the | |
| 24 | file and re-encodes it to stdout. Uses definite | |
| 25 | lengths for constructed values. | |
| 26 | ||
| 27 | indef - takes file name of an AnyTestType value. Decodes the | |
| 28 | file and re-encodes it to stdout. Uses indefinite | |
| 29 | lengths for constructed values. | |
| 30 | ||
| 31 | ||
| 32 | These files use the code generated by snacc from the | |
| 33 | snacc/asn1specs/any.asn1 file. (see the makefile) | |
| 34 | ||
| 35 | Look at genber.c to see how values can be built and printed. | |
| 36 | ||
| 37 | Look at the generated code in any_test.c and any_test.h to see how the | |
| 38 | any hash table is built. | |
| 39 | ||
| 40 | ||
| 41 | try the following commands in your c-shell: | |
| 42 | ||
| 43 | %1 genber # generate the att.ber file | |
| 44 | %2 indef att.ber > tmp.ber # decode att.ber an re-encode into tmp.ber | |
| 45 | %3 def tmp.ber > tmp2.ber # decode tmp.ber an re-encode into tmp2.ber | |
| 46 | %4 diff att.ber tmp2.ber # compare .ber files (should be the same) | |
| 47 | ||
| 48 | When you are finished with the example type "make clean" to remove | |
| 49 | the binaries and generated code. | |
| 50 | ||
| 51 | ||
| 52 | ||
| 53 | Things To Note | |
| 54 | -------------- | |
| 55 | ||
| 56 | Snacc ASN.1 comment commands | |
| 57 | ||
| 58 | In the snacc/asn1specs/any.asn1 file, the AnyTestType has a special | |
| 59 | "--snacc" ASN.1 comment after ::= to give snacc some extra information | |
| 60 | about the AnyTestType. | |
| 61 | ||
| 62 | AnyTestType ::= --snacc isPdu:"TRUE" -- SEQUENCE { ... etc. ... } | |
| 63 | ||
| 64 | The "isPdu" flag tells snacc that the AnyTestType is a PDU type that | |
| 65 | you will be calling the encoding and decoding routines directly | |
| 66 | from your code. This causes snacc to generate the "BEncAnyTestType" | |
| 67 | and "BDecAnyTestType" routines in addition to the standard | |
| 68 | "BEncAnyTestTypeContent" and "BDecAnyTestTypeContent". | |
| 69 | ||
| 70 | The Content encoding and decoding routines only deal with the content | |
| 71 | of the type, ignoring all of the tag and length pairs on the given | |
| 72 | type (in this case the UNIVERSAL (CONSTRUCTED) 16 tag and the length | |
| 73 | for the SEQUENCE). The "BEncAnyTestType" and "BDecAnyTestType" | |
| 74 | routines do encode the SEQUENCE tag and its length. This design is | |
| 75 | motivated by IMPLICIT tagging. | |
| 76 | ||
| 77 | The compiler generated routines generally only call the content | |
| 78 | oriented routines except in the case of ANY and ANY DEFINED BY types. | |
| 79 | For ANY and ANY DEFINED BY types the PDU form of the rouine is called | |
| 80 | since the tags are not known by the containing type. | |
| 81 | ||
| 82 | ||
| 83 | SNMP OBJECT-TYPE Macro | |
| 84 | ||
| 85 | The SNMP OBJECT-TYPE macro is used to define the id to type mapping | |
| 86 | for ANY DEFINED BY types. The macro has been modified to accept both | |
| 87 | INTEGERs and OBJECT IDENTIFIERs as values (see | |
| 88 | snacc/asn1specs/any.asn1). This macro can be used with other | |
| 89 | protocols to define the id to type mapping. | |
| 90 | ||
| 91 | Two hash tables are used to hold the id to type mappings. One for | |
| 92 | INTEGER to type mappings and the other for OBJECT IDENTIFIER to type | |
| 93 | mappings. You must explicitly initialize the hash tables by calling | |
| 94 | generated init routines once at the beginning of your program. Each | |
| 95 | module that has OBJECT-TYPE macros in it will generate an | |
| 96 | "InitAny<module name>" routine. You must call every init routine to | |
| 97 | add all the mappings to the hash table(s). | |
| 98 | ||
| 99 | #------------------------------------------------------------------------------- | |
| 100 | # $Header: /cvs/Darwin/Security/SecuritySNACCRuntime/c-examples/any/README,v 1.1.1.1 2001/05/18 23:14:07 mb Exp $ | |
| 101 | # $Log: README,v $ | |
| 102 | # Revision 1.1.1.1 2001/05/18 23:14:07 mb | |
| 103 | # Move from private repository to open source repository | |
| 104 | # | |
| 105 | # Revision 1.1.1.1 1999/03/16 18:06:08 aram | |
| 106 | # Originals from SMIME Free Library. | |
| 107 | # | |
| 108 | # Revision 1.2 1997/02/16 20:26:14 rj | |
| 109 | # check-in of a few cosmetic changes | |
| 110 | # | |
| 111 | # Revision 1.1 1994/08/31 08:46:17 rj | |
| 112 | # first check-in. for a list of changes to the snacc-1.1 distribution please refer to the ChangeLog. | |
| 113 | # |