target/linux/generic/backport-5.4/080-wireguard-0015-crypto-poly1305-expose-init-update-final-library-int.patch

   1 From fd966ddf025b8b62aab20d2e4eb242fe51ad5137 Mon Sep 17 00:00:00 2001
   2 From: Ard Biesheuvel <ardb@kernel.org>
   3 Date: Fri, 8 Nov 2019 13:22:21 +0100
   4 Subject: [PATCH 015/124] crypto: poly1305 - expose init/update/final library
   5  interface
   6
   7 commit a1d93064094cc5e24d64e35cf093e7191d0c9344 upstream.
   8
   9 Expose the existing generic Poly1305 code via a init/update/final
  10 library interface so that callers are not required to go through
  11 the crypto API's shash abstraction to access it. At the same time,
  12 make some preparations so that the library implementation can be
  13 superseded by an accelerated arch-specific version in the future.
  14
  15 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
  16 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  17 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  18 ---
  19  crypto/poly1305_generic.c | 22 +-----------
  20  include/crypto/poly1305.h | 38 +++++++++++++++++++-
  21  lib/crypto/Kconfig        | 26 ++++++++++++++
  22  lib/crypto/poly1305.c     | 74 +++++++++++++++++++++++++++++++++++++++
  23  4 files changed, 138 insertions(+), 22 deletions(-)
  24
  25 --- a/crypto/poly1305_generic.c
  26 +++ b/crypto/poly1305_generic.c
  27 @@ -85,31 +85,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_update
  28  int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
  29  {
  30         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
  31 -       __le32 digest[4];
  32 -       u64 f = 0;
  33
  34         if (unlikely(!dctx->sset))
  35                 return -ENOKEY;
  36
  37 -       if (unlikely(dctx->buflen)) {
  38 -               dctx->buf[dctx->buflen++] = 1;
  39 -               memset(dctx->buf + dctx->buflen, 0,
  40 -                      POLY1305_BLOCK_SIZE - dctx->buflen);
  41 -               poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0);
  42 -       }
  43 -
  44 -       poly1305_core_emit(&dctx->h, digest);
  45 -
  46 -       /* mac = (h + s) % (2^128) */
  47 -       f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0];
  48 -       put_unaligned_le32(f, dst + 0);
  49 -       f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1];
  50 -       put_unaligned_le32(f, dst + 4);
  51 -       f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2];
  52 -       put_unaligned_le32(f, dst + 8);
  53 -       f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3];
  54 -       put_unaligned_le32(f, dst + 12);
  55 -
  56 +       poly1305_final_generic(dctx, dst);
  57         return 0;
  58  }
  59  EXPORT_SYMBOL_GPL(crypto_poly1305_final);
  60 --- a/include/crypto/poly1305.h
  61 +++ b/include/crypto/poly1305.h
  62 @@ -35,7 +35,43 @@ struct poly1305_desc_ctx {
  63         /* accumulator */
  64         struct poly1305_state h;
  65         /* key */
  66 -       struct poly1305_key r[1];
  67 +       struct poly1305_key r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE];
  68  };
  69
  70 +void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
  71 +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
  72 +
  73 +static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
  74 +{
  75 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
  76 +               poly1305_init_arch(desc, key);
  77 +       else
  78 +               poly1305_init_generic(desc, key);
  79 +}
  80 +
  81 +void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src,
  82 +                         unsigned int nbytes);
  83 +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
  84 +                            unsigned int nbytes);
  85 +
  86 +static inline void poly1305_update(struct poly1305_desc_ctx *desc,
  87 +                                  const u8 *src, unsigned int nbytes)
  88 +{
  89 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
  90 +               poly1305_update_arch(desc, src, nbytes);
  91 +       else
  92 +               poly1305_update_generic(desc, src, nbytes);
  93 +}
  94 +
  95 +void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest);
  96 +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest);
  97 +
  98 +static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest)
  99 +{
 100 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
 101 +               poly1305_final_arch(desc, digest);
 102 +       else
 103 +               poly1305_final_generic(desc, digest);
 104 +}
 105 +
 106  #endif
 107 --- a/lib/crypto/Kconfig
 108 +++ b/lib/crypto/Kconfig
 109 @@ -37,8 +37,34 @@ config CRYPTO_LIB_CHACHA
 110  config CRYPTO_LIB_DES
 111         tristate
 112
 113 +config CRYPTO_LIB_POLY1305_RSIZE
 114 +       int
 115 +       default 1
 116 +
 117 +config CRYPTO_ARCH_HAVE_LIB_POLY1305
 118 +       tristate
 119 +       help
 120 +         Declares whether the architecture provides an arch-specific
 121 +         accelerated implementation of the Poly1305 library interface,
 122 +         either builtin or as a module.
 123 +
 124  config CRYPTO_LIB_POLY1305_GENERIC
 125         tristate
 126 +       help
 127 +         This symbol can be depended upon by arch implementations of the
 128 +         Poly1305 library interface that require the generic code as a
 129 +         fallback, e.g., for SIMD implementations. If no arch specific
 130 +         implementation is enabled, this implementation serves the users
 131 +         of CRYPTO_LIB_POLY1305.
 132 +
 133 +config CRYPTO_LIB_POLY1305
 134 +       tristate "Poly1305 library interface"
 135 +       depends on CRYPTO_ARCH_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_HAVE_LIB_POLY1305
 136 +       select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
 137 +       help
 138 +         Enable the Poly1305 library interface. This interface may be fulfilled
 139 +         by either the generic implementation or an arch-specific one, if one
 140 +         is available and enabled.
 141
 142  config CRYPTO_LIB_SHA256
 143         tristate
 144 --- a/lib/crypto/poly1305.c
 145 +++ b/lib/crypto/poly1305.c
 146 @@ -154,5 +154,79 @@ void poly1305_core_emit(const struct pol
 147  }
 148  EXPORT_SYMBOL_GPL(poly1305_core_emit);
 149
 150 +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
 151 +{
 152 +       poly1305_core_setkey(desc->r, key);
 153 +       desc->s[0] = get_unaligned_le32(key + 16);
 154 +       desc->s[1] = get_unaligned_le32(key + 20);
 155 +       desc->s[2] = get_unaligned_le32(key + 24);
 156 +       desc->s[3] = get_unaligned_le32(key + 28);
 157 +       poly1305_core_init(&desc->h);
 158 +       desc->buflen = 0;
 159 +       desc->sset = true;
 160 +       desc->rset = 1;
 161 +}
 162 +EXPORT_SYMBOL_GPL(poly1305_init_generic);
 163 +
 164 +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
 165 +                            unsigned int nbytes)
 166 +{
 167 +       unsigned int bytes;
 168 +
 169 +       if (unlikely(desc->buflen)) {
 170 +               bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
 171 +               memcpy(desc->buf + desc->buflen, src, bytes);
 172 +               src += bytes;
 173 +               nbytes -= bytes;
 174 +               desc->buflen += bytes;
 175 +
 176 +               if (desc->buflen == POLY1305_BLOCK_SIZE) {
 177 +                       poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1);
 178 +                       desc->buflen = 0;
 179 +               }
 180 +       }
 181 +
 182 +       if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
 183 +               poly1305_core_blocks(&desc->h, desc->r, src,
 184 +                                    nbytes / POLY1305_BLOCK_SIZE, 1);
 185 +               src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
 186 +               nbytes %= POLY1305_BLOCK_SIZE;
 187 +       }
 188 +
 189 +       if (unlikely(nbytes)) {
 190 +               desc->buflen = nbytes;
 191 +               memcpy(desc->buf, src, nbytes);
 192 +       }
 193 +}
 194 +EXPORT_SYMBOL_GPL(poly1305_update_generic);
 195 +
 196 +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
 197 +{
 198 +       __le32 digest[4];
 199 +       u64 f = 0;
 200 +
 201 +       if (unlikely(desc->buflen)) {
 202 +               desc->buf[desc->buflen++] = 1;
 203 +               memset(desc->buf + desc->buflen, 0,
 204 +                      POLY1305_BLOCK_SIZE - desc->buflen);
 205 +               poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0);
 206 +       }
 207 +
 208 +       poly1305_core_emit(&desc->h, digest);
 209 +
 210 +       /* mac = (h + s) % (2^128) */
 211 +       f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0];
 212 +       put_unaligned_le32(f, dst + 0);
 213 +       f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1];
 214 +       put_unaligned_le32(f, dst + 4);
 215 +       f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2];
 216 +       put_unaligned_le32(f, dst + 8);
 217 +       f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3];
 218 +       put_unaligned_le32(f, dst + 12);
 219 +
 220 +       *desc = (struct poly1305_desc_ctx){};
 221 +}
 222 +EXPORT_SYMBOL_GPL(poly1305_final_generic);
 223 +
 224  MODULE_LICENSE("GPL");
 225  MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");