OSX/libsecurity_asn1/lib/SecNssCoder.h

   1 /*
   2  * Copyright (c) 2003-2006,2008,2010-2012 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  *
  23  * SecNssCoder.h: simple C++ wrapper for PLArenaPool and the
  24  * high-level ANS1 encode/decode routines.
  25  */
  26 #ifndef _SEC_NSS_CODER_H_
  27 #define _SEC_NSS_CODER_H_
  28
  29 #include <security_asn1/plarenas.h>
  30 #include <security_asn1/prerror.h>
  31 #include <Security/secasn1t.h>
  32 #include <security_asn1/seccomon.h>
  33 #include <security_utilities/alloc.h>
  34 #include <security_cdsa_utilities/cssmdata.h>
  35
  36 /*
  37  * Default chunk size for new arena pool.
  38  * FIXME: analyze & measure different defaults here. I'm pretty sure
  39  * that only performance - not correct behavior - is affected by
  40  * an arena pool's chunk size.
  41  */
  42 #define SNC_CHUNKSIZE_DEF               1024
  43
  44 class SecNssCoder
  45 {
  46 public:
  47         SecNssCoder(
  48                 PRUint32 chunkSize = SNC_CHUNKSIZE_DEF);
  49         ~SecNssCoder();
  50
  51         /*
  52          * BER decode an untyped item per the specified
  53          * template array. The result is allocated
  54          * by this object's PLArenaPool and is freed when
  55          * this object is deleted.
  56          *
  57          * The dest pointer is a template-specific struct allocated
  58          * by the caller and must be zeroed by the caller.
  59          *
  60          * This does not throw any exceptions; error status
  61          * (obtained from PR_GetError() is returned.
  62          */
  63         PRErrorCode     decode(
  64                 const void                              *src,           // BER-encoded source
  65                 size_t                          len,
  66                 const SecAsn1Template   *templ,
  67                 void                                    *dest);
  68
  69         /* convenience routine, decode from an SECItem */
  70         PRErrorCode     decodeItem(
  71                 const SECItem                   &item,          // BER-encoded source
  72                 const SecAsn1Template   *templ,
  73                 void                                    *dest)
  74                 {
  75                         return decode(item.Data, item.Length, templ, dest);
  76                 }
  77
  78
  79         /*
  80          * BER-encode. This object's arena pool retains a copy of
  81          * the encoded data.
  82          *
  83          * The src pointer is a template-specific struct.
  84          *
  85          * This does not throw any exceptions; error status
  86          * (obtained from PR_GetError() is returned.
  87          */
  88         PRErrorCode encodeItem(
  89                 const void                              *src,
  90                 const SecAsn1Template   *templ,
  91                 SECItem                                 &dest);
  92
  93         /*
  94          * Some alloc-related methods which come in handy when using
  95          * this class. All memory is allocated using this object's
  96          * arena pool. Caller never has to free it. Used for
  97          * temp allocs of memory which only needs a scope which is the
  98          * same as this object.
  99          *
 100          * These throw a CssmError in the highly unlikely event of
 101          * a malloc failure.
 102          */
 103         void *malloc(
 104                 size_t                                  len);
 105
 106         /* allocate space for num copies of specified type */
 107         template <class T> T *mallocn(unsigned num = 1)
 108                 { return reinterpret_cast<T *>(malloc_T(sizeof(T),num)); }
 109
 110         /* malloc item.Data, set item.Length */
 111         void allocItem(
 112                 SECItem                                 &item,
 113                 size_t                                  len);
 114
 115         /* malloc and copy, various forms */
 116         void allocCopyItem(
 117                 const void                              *src,
 118                 size_t                                  len,
 119                 SECItem                                 &dest);
 120
 121         void allocCopyItem(
 122                 const SECItem                   &src,
 123                 SECItem                                 &dest)
 124                         { allocCopyItem(src.Data, src.Length, dest); }
 125
 126         void allocCopyItem(
 127                 const CssmData                  &src,
 128                 SECItem                                 &dest)
 129                         { allocCopyItem(src.data(), src.length(), dest); }
 130
 131         PLArenaPool     *pool() const { return mPool;}
 132
 133 private:
 134         PLArenaPool             *mPool;
 135
 136     void *malloc_T(size_t unit_bytesize,
 137                    size_t num_units);
 138 };
 139
 140 /*
 141  * Stateless function to BER-encode directly into a Allocator's
 142  * space. The only persistent allocated memory is allocated by
 143  * the Allocator.
 144  *
 145  * The src pointer is a template-specific struct.
 146  *
 147  * This does not throw any exceptions; error status
 148  * (obtained from PR_GetError() is returned.
 149  */
 150 PRErrorCode SecNssEncodeItem(
 151         const void                              *src,
 152         const SecAsn1Template   *templ,
 153         Allocator                       &alloc,
 154         SECItem                                 &dest);
 155
 156 /*
 157  * Same thing, using a CssmOwnedData.
 158  */
 159 PRErrorCode SecNssEncodeItemOdata(
 160         const void                              *src,
 161         const SecAsn1Template   *templ,
 162         CssmOwnedData                   &odata);
 163
 164 #endif  /* _SEC_NSS_CODER_H_ */