libsecurity_keychain/libDER/libDER/DER_Encode.h

   1 /* Copyright (c) 2005-2007 Apple Inc. All Rights Reserved. */
   2
   3 /*
   4  * DER_Encode.h - DER encoding routines
   5  *
   6  * Created Dec. 2 2005 by dmitch
   7  */
   8
   9 #ifndef _DER_ENCCODE_H_
  10 #define _DER_ENCODE_H_
  11
  12 #ifdef __cplusplus
  13 extern "C" {
  14 #endif
  15
  16 #include <libDER/libDER.h>
  17
  18 /*
  19  * Max size of an encoded item given its length.
  20  * This includes a possible leading zero prepended to a signed integer
  21  * (see DER_ENC_SIGNED_INT below).
  22  */
  23 #define DER_MAX_ENCODED_SIZE(len)                                       \
  24         ( 1 +                   /* tag */                                               \
  25           5 +                   /* max length */                                \
  26           1 +                   /* possible prepended zero */   \
  27           len)
  28
  29 /* calculate size of encoded length */
  30 DERSize DERLengthOfLength(
  31         DERSize length);
  32
  33 /* encode length */
  34 DERReturn DEREncodeLength(
  35         DERSize length,
  36         DERByte *buf,           /* encoded length goes here */
  37         DERSize *inOutLen);     /* IN/OUT */
  38
  39 /* calculate size of encoded length */
  40 DERSize DERLengthOfItem(
  41         DERTag tag,
  42         DERSize length);
  43
  44 /* encode item */
  45 DERReturn DEREncodeItem(
  46         DERTag tag,
  47         DERSize length,
  48     const DERByte *src,
  49         DERByte *derOut,        /* encoded item goes here */
  50         DERSize *inOutLen);     /* IN/OUT */
  51
  52 /*
  53  * Per-item encode options.
  54  */
  55
  56 /* explicit default, no options */
  57 #define DER_ENC_NO_OPTS                 0x0000
  58
  59 /* signed integer check: if incoming m.s. bit is 1, prepend a zero */
  60 #define DER_ENC_SIGNED_INT              0x0100
  61
  62 /* DERItem contains fully encoded item - copy, don't encode */
  63 #define DER_ENC_WRITE_DER               0x0200
  64
  65
  66 /*
  67  * High-level sequence or set encode support.
  68  *
  69  * The outgoing sequence is expressed as an array of DERItemSpecs, each
  70  * of which corresponds to one item in the encoded sequence.
  71  *
  72  * Normally the tag of the encoded item comes from the associated
  73  * DERItemSpec, and the content comes from the DERItem whose address is
  74  * the src arg plus the offset value in the associated DERItemSpec.
  75  *
  76  * If the DER_ENC_WRITE_DER option is true for a given DERItemSpec then
  77  * no per-item encoding is done; the DER - with tag, length, and content -
  78  * is taken en masse from the associated DERItem.
  79  */
  80 DERReturn DEREncodeSequence(
  81         DERTag                          topTag,         /* ASN1_CONSTR_SEQUENCE, ASN1_CONSTR_SET */
  82         const void                      *src,           /* generally a ptr to a struct full of
  83                                                                          *    DERItems */
  84         DERShort                        numItems,       /* size of itemSpecs[] */
  85         const DERItemSpec       *itemSpecs,
  86         DERByte                         *derOut,        /* encoded data written here */
  87         DERSize                         *inOutLen);     /* IN/OUT */
  88
  89 /* precalculate the length of an encoded sequence. */
  90 DERSize DERLengthOfEncodedSequence(
  91         DERTag                          topTag,         /* ASN1_CONSTR_SEQUENCE, ASN1_CONSTR_SET */
  92         const void                      *src,           /* generally a ptr to a struct full of
  93                                                                          *    DERItems */
  94         DERShort                        numItems,       /* size of itemSpecs[] */
  95         const DERItemSpec       *itemSpecs);
  96
  97
  98 #ifdef __cplusplus
  99 }
 100 #endif
 101
 102 #endif  /* _DER_DECODE_H_ */
 103