fat-setup.h

   1 /* fat-setup.h
   2
   3    Copyright (C) 2015 Niels Möller
   4
   5    This file is part of GNU Nettle.
   6
   7    GNU Nettle is free software: you can redistribute it and/or
   8    modify it under the terms of either:
   9
  10      * the GNU Lesser General Public License as published by the Free
  11        Software Foundation; either version 3 of the License, or (at your
  12        option) any later version.
  13
  14    or
  15
  16      * the GNU General Public License as published by the Free
  17        Software Foundation; either version 2 of the License, or (at your
  18        option) any later version.
  19
  20    or both in parallel, as here.
  21
  22    GNU Nettle is distributed in the hope that it will be useful,
  23    but WITHOUT ANY WARRANTY; without even the implied warranty of
  24    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25    General Public License for more details.
  26
  27    You should have received copies of the GNU General Public License and
  28    the GNU Lesser General Public License along with this program.  If
  29    not, see http://www.gnu.org/licenses/.
  30 */
  31
  32 /* Fat library initialization works as follows. The main function is
  33    fat_init. We try to do initialization only once, but since it is
  34    idempotent, there's no harm if it is in some cases called multiple
  35    times from several threads. For correctness, we rely on atomic
  36    writes, but not on memory barriers or any other synchronization
  37    mechanism.
  38
  39    The fat_init function checks the cpuid flags, and sets function
  40    pointers, e.g, _nettle_aes_encrypt_vec, to point to the appropriate
  41    implementation.
  42
  43    To get everything hooked in, we use a belt-and-suspenders approach.
  44
  45    We try to register fat_init as a constructor function to be called
  46    at load time. If this is unavailable or non-working, we instead
  47    arrange fat_init to be called lazily.
  48
  49    For the actual indirection, there are two cases.
  50
  51    * If ifunc support is available, function pointers are statically
  52      initialized to NULL, and we register resolver functions, e.g.,
  53      _nettle_aes_encrypt_resolve, which call fat_init, and then return
  54      the function pointer, e.g., the value of _nettle_aes_encrypt_vec.
  55
  56    * If ifunc is not available, we have to define a wrapper function
  57      to jump via the function pointer. (FIXME: For internal calls, we
  58      could do this as a macro).
  59
  60      We statically initialize each function pointer to point to a
  61      special initialization function, e.g., _nettle_aes_encrypt_init,
  62      which calls fat_init, and then invokes the right function. This
  63      way, all pointers are setup correctly at the first call to any
  64      fat function.
  65
  66      And atomic writes are required for correctness in the case that
  67      several threads do "first call to any fat function" at the same
  68      time.
  69 */
  70
  71 #if HAVE_GCC_ATTRIBUTE
  72 # define CONSTRUCTOR __attribute__ ((constructor))
  73 #else
  74 # define CONSTRUCTOR
  75 # if defined (__sun)
  76 #  pragma init(fat_init)
  77 # endif
  78 #endif
  79
  80 /* Disable use of ifunc for now. Problem is, there's no guarantee that
  81    one can call any libc functions from the ifunc resolver. On x86 and
  82    x86_64, the corresponding IRELATIVE relocs are supposed to be
  83    processed last, but that doesn't seem to happen, and its a
  84    platform-specific feature. To trigger problems, simply try dlopen
  85    ("libnettle.so", RTLD_NOW), which crashes in an uninitialized plt
  86    entry. */
  87 #undef HAVE_LINK_IFUNC
  88
  89 #if !HAVE_SECURE_GETENV
  90 #define secure_getenv(s) NULL
  91 #endif
  92
  93 #define ENV_VERBOSE "NETTLE_FAT_VERBOSE"
  94 #define ENV_OVERRIDE "NETTLE_FAT_OVERRIDE"
  95
  96 struct chacha_ctx;
  97 struct salsa20_ctx;
  98
  99 /* DECLARE_FAT_FUNC(name, ftype)
 100  *
 101  *   name is the public function, e.g., _nettle_aes_encrypt.
 102  *   ftype is its type, e.g., aes_crypt_internal_func.
 103  *
 104  * DECLARE_FAT_VAR(name, type, var)
 105  *
 106  *   name is name without _nettle prefix.
 107  *   type is its type.
 108  *   var is the variant, used as a suffix on the symbol name.
 109  *
 110  * DEFINE_FAT_FUNC(name, rtype, prototype, args)
 111  *
 112  *   name is the public function.
 113  *   rtype its return type.
 114  *   prototype is the list of formal arguments, with types.
 115  *   args contain the argument list without any types.
 116  */
 117
 118 #if HAVE_LINK_IFUNC
 119 #define IFUNC(resolve) __attribute__ ((ifunc (resolve)))
 120 #define DECLARE_FAT_FUNC(name, ftype)   \
 121   ftype name IFUNC(#name"_resolve");    \
 122   static ftype *name##_vec = NULL;
 123
 124 #define DEFINE_FAT_FUNC(name, rtype, prototype, args)             \
 125   static void_func * name##_resolve(void)                         \
 126   {                                                               \
 127     if (getenv (ENV_VERBOSE))                                     \
 128       fprintf (stderr, "libnettle: "#name"_resolve\n");           \
 129     if (!name##_vec)                                              \
 130       fat_init();                                                 \
 131     return (void_func *) name##_vec;                              \
 132   }
 133
 134 #else /* !HAVE_LINK_IFUNC */
 135 #define DECLARE_FAT_FUNC(name, ftype)           \
 136   ftype name;                                   \
 137   static ftype name##_init;                     \
 138   static ftype *name##_vec = name##_init;
 139
 140 #define DEFINE_FAT_FUNC(name, rtype, prototype, args)           \
 141   rtype name prototype                                          \
 142   {                                                             \
 143     return name##_vec args;                                     \
 144   }                                                             \
 145   static rtype name##_init prototype {                          \
 146     if (getenv (ENV_VERBOSE))                                   \
 147       fprintf (stderr, "libnettle: "#name"_init\n");            \
 148     if (name##_vec == name##_init)                              \
 149       fat_init();                                               \
 150     assert (name##_vec != name##_init);                         \
 151     return name##_vec args;                                     \
 152   }
 153 #endif /* !HAVE_LINK_IFUNC */
 154
 155 #define DECLARE_FAT_FUNC_VAR(name, type, var)   \
 156        type _nettle_##name##_##var;
 157
 158 typedef void void_func (void);
 159
 160 struct aes_table;
 161 typedef void aes_crypt_internal_func (unsigned rounds, const uint32_t *keys,
 162                                       const struct aes_table *T,
 163                                       size_t length, uint8_t *dst,
 164                                       const uint8_t *src);
 165 typedef void aes_invert_internal_func (unsigned rounds, uint32_t *dst, const uint32_t *src);
 166
 167 struct gcm_key;
 168 typedef void ghash_set_key_func (struct gcm_key *ctx, const union nettle_block16 *key);
 169 typedef const uint8_t *
 170 ghash_update_func (const struct gcm_key *ctx, union nettle_block16 *state,
 171                    size_t blocks, const uint8_t *data);
 172
 173 typedef size_t
 174 gcm_aes_crypt_func (struct gcm_key *key, unsigned rounds,
 175                     size_t len, uint8_t *dst, const uint8_t *src);
 176
 177 typedef void *(memxor_func)(void *dst, const void *src, size_t n);
 178 typedef void *(memxor3_func)(void *dst_in, const void *a_in, const void *b_in, size_t n);
 179
 180 typedef void salsa20_core_func (uint32_t *dst, const uint32_t *src, unsigned rounds);
 181 typedef void salsa20_crypt_func (struct salsa20_ctx *ctx, unsigned rounds,
 182                                  size_t length, uint8_t *dst,
 183                                  const uint8_t *src);
 184
 185 typedef void sha1_compress_func(uint32_t *state, const uint8_t *input);
 186 typedef const uint8_t *
 187 sha256_compress_n_func(uint32_t *state, const uint32_t *k,
 188                        size_t blocks, const uint8_t *input);
 189
 190 struct sha3_state;
 191 typedef void sha3_permute_func (struct sha3_state *state);
 192
 193 typedef void sha512_compress_func (uint64_t *state, const uint8_t *input, const uint64_t *k);
 194
 195 typedef uint64_t umac_nh_func (const uint32_t *key, unsigned length, const uint8_t *msg);
 196 typedef void umac_nh_n_func (uint64_t *out, unsigned n, const uint32_t *key,
 197                              unsigned length, const uint8_t *msg);
 198
 199 typedef void chacha_core_func(uint32_t *dst, const uint32_t *src, unsigned rounds);
 200
 201 typedef void chacha_crypt_func(struct chacha_ctx *ctx,
 202                                size_t length,
 203                                uint8_t *dst,
 204                                const uint8_t *src);
 205
 206 struct poly1305_ctx;
 207 typedef void poly1305_set_key_func(struct poly1305_ctx *ctx, const uint8_t *key);
 208 typedef void poly1305_digest_func(struct poly1305_ctx *ctx, union nettle_block16 *s);
 209 typedef void poly1305_block_func(struct poly1305_ctx *ctx, const uint8_t *m,
 210                              unsigned high);
 211 typedef const uint8_t * poly1305_blocks_func(struct poly1305_ctx *ctx, size_t blocks,
 212                              const uint8_t *m);
 213
 214 struct aes128_ctx;
 215 typedef void aes128_set_key_func (struct aes128_ctx *ctx, const uint8_t *key);
 216 typedef void aes128_invert_key_func (struct aes128_ctx *dst, const struct aes128_ctx *src);
 217 typedef void aes128_crypt_func (const struct aes128_ctx *ctx, size_t length, uint8_t *dst,
 218                const uint8_t *src);
 219
 220 struct aes192_ctx;
 221 typedef void aes192_set_key_func (struct aes192_ctx *ctx, const uint8_t *key);
 222 typedef void aes192_invert_key_func (struct aes192_ctx *dst, const struct aes192_ctx *src);
 223 typedef void aes192_crypt_func (const struct aes192_ctx *ctx, size_t length, uint8_t *dst,
 224                const uint8_t *src);
 225
 226 struct aes256_ctx;
 227 typedef void aes256_set_key_func (struct aes256_ctx *ctx, const uint8_t *key);
 228 typedef void aes256_invert_key_func (struct aes256_ctx *dst, const struct aes256_ctx *src);
 229 typedef void aes256_crypt_func (const struct aes256_ctx *ctx, size_t length, uint8_t *dst,
 230                const uint8_t *src);
 231
 232 typedef void cbc_aes128_encrypt_func (const struct aes128_ctx *ctx, uint8_t *iv,
 233                                       size_t length, uint8_t *dst, const uint8_t *src);
 234 typedef void cbc_aes192_encrypt_func (const struct aes192_ctx *ctx, uint8_t *iv,
 235                                       size_t length, uint8_t *dst, const uint8_t *src);
 236 typedef void cbc_aes256_encrypt_func (const struct aes256_ctx *ctx, uint8_t *iv,
 237                                       size_t length, uint8_t *dst, const uint8_t *src);