src/include/gpxe/cbc.h

   1 #ifndef _GPXE_CBC_H
   2 #define _GPXE_CBC_H
   3
   4 /** @file
   5  *
   6  * Cipher-block chaining
   7  *
   8  */
   9
  10 FILE_LICENCE ( GPL2_OR_LATER );
  11
  12 #include <gpxe/crypto.h>
  13
  14 /**
  15  * Set key
  16  *
  17  * @v ctx               Context
  18  * @v key               Key
  19  * @v keylen            Key length
  20  * @v raw_cipher        Underlying cipher algorithm
  21  * @v cbc_ctx           CBC context
  22  * @ret rc              Return status code
  23  */
  24 static inline int cbc_setkey ( void *ctx, const void *key, size_t keylen,
  25                                struct cipher_algorithm *raw_cipher,
  26                                void *cbc_ctx __unused ) {
  27
  28         return cipher_setkey ( raw_cipher, ctx, key, keylen );
  29 }
  30
  31 /**
  32  * Set initialisation vector
  33  *
  34  * @v ctx               Context
  35  * @v iv                Initialisation vector
  36  * @v raw_cipher        Underlying cipher algorithm
  37  * @v cbc_ctx           CBC context
  38  */
  39 static inline void cbc_setiv ( void *ctx __unused, const void *iv,
  40                                struct cipher_algorithm *raw_cipher,
  41                                void *cbc_ctx ) {
  42         memcpy ( cbc_ctx, iv, raw_cipher->blocksize );
  43 }
  44
  45 extern void cbc_encrypt ( void *ctx, const void *src, void *dst,
  46                           size_t len, struct cipher_algorithm *raw_cipher,
  47                           void *cbc_ctx );
  48 extern void cbc_decrypt ( void *ctx, const void *src, void *dst,
  49                           size_t len, struct cipher_algorithm *raw_cipher,
  50                           void *cbc_ctx );
  51
  52 /**
  53  * Create a cipher-block chaining mode of behaviour of an existing cipher
  54  *
  55  * @v _cbc_name         Name for the new CBC cipher
  56  * @v _cbc_cipher       New cipher algorithm
  57  * @v _raw_cipher       Underlying cipher algorithm
  58  * @v _raw_context      Context structure for the underlying cipher
  59  * @v _blocksize        Cipher block size
  60  */
  61 #define CBC_CIPHER( _cbc_name, _cbc_cipher, _raw_cipher, _raw_context,  \
  62                     _blocksize )                                        \
  63 struct _cbc_name ## _context {                                          \
  64         _raw_context raw_ctx;                                           \
  65         uint8_t cbc_ctx[_blocksize];                                    \
  66 };                                                                      \
  67 static int _cbc_name ## _setkey ( void *ctx, const void *key,           \
  68                                   size_t keylen ) {                     \
  69         struct _cbc_name ## _context * _cbc_name ## _ctx = ctx;         \
  70         return cbc_setkey ( &_cbc_name ## _ctx->raw_ctx, key, keylen,   \
  71                             &_raw_cipher, &_cbc_name ## _ctx->cbc_ctx );\
  72 }                                                                       \
  73 static void _cbc_name ## _setiv ( void *ctx, const void *iv ) {         \
  74         struct _cbc_name ## _context * _cbc_name ## _ctx = ctx;         \
  75         cbc_setiv ( &_cbc_name ## _ctx->raw_ctx, iv,                    \
  76                     &_raw_cipher, &aes_cbc_ctx->cbc_ctx );              \
  77 }                                                                       \
  78 static void _cbc_name ## _encrypt ( void *ctx, const void *src,         \
  79                                     void *dst, size_t len ) {           \
  80         struct _cbc_name ## _context * _cbc_name ## _ctx = ctx;         \
  81         cbc_encrypt ( &_cbc_name ## _ctx->raw_ctx, src, dst, len,       \
  82                       &_raw_cipher, &aes_cbc_ctx->cbc_ctx );            \
  83 }                                                                       \
  84 static void _cbc_name ## _decrypt ( void *ctx, const void *src,         \
  85                                     void *dst, size_t len ) {           \
  86         struct _cbc_name ## _context * _cbc_name ## _ctx = ctx;         \
  87         cbc_decrypt ( &_cbc_name ## _ctx->raw_ctx, src, dst, len,       \
  88                       &_raw_cipher, &aes_cbc_ctx->cbc_ctx );            \
  89 }                                                                       \
  90 struct cipher_algorithm _cbc_cipher = {                                 \
  91         .name           = #_cbc_name,                                   \
  92         .ctxsize        = sizeof ( struct _cbc_name ## _context ),      \
  93         .blocksize      = _blocksize,                                   \
  94         .setkey         = _cbc_name ## _setkey,                         \
  95         .setiv          = _cbc_name ## _setiv,                          \
  96         .encrypt        = _cbc_name ## _encrypt,                        \
  97         .decrypt        = _cbc_name ## _decrypt,                        \
  98 };
  99
 100 #endif /* _GPXE_CBC_H */