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

   1 From 0000000000000000000000000000000000000000 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] crypto: poly1305 - expose init/update/final library interface
   5
   6 commit a1d93064094cc5e24d64e35cf093e7191d0c9344 upstream.
   7
   8 Expose the existing generic Poly1305 code via a init/update/final
   9 library interface so that callers are not required to go through
  10 the crypto API's shash abstraction to access it. At the same time,
  11 make some preparations so that the library implementation can be
  12 superseded by an accelerated arch-specific version in the future.
  13
  14 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
  15 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  16 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
  17 ---
  18  crypto/poly1305_generic.c | 22 +-----------
  19  include/crypto/poly1305.h | 38 +++++++++++++++++++-
  20  lib/crypto/Kconfig        | 26 ++++++++++++++
  21  lib/crypto/poly1305.c     | 74 +++++++++++++++++++++++++++++++++++++++
  22  4 files changed, 138 insertions(+), 22 deletions(-)
  23
  24 --- a/crypto/poly1305_generic.c
  25 +++ b/crypto/poly1305_generic.c
  26 @@ -85,31 +85,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_update
  27  int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
  28  {
  29         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
  30 -       __le32 digest[4];
  31 -       u64 f = 0;
  32
  33         if (unlikely(!dctx->sset))
  34                 return -ENOKEY;
  35
  36 -       if (unlikely(dctx->buflen)) {
  37 -               dctx->buf[dctx->buflen++] = 1;
  38 -               memset(dctx->buf + dctx->buflen, 0,
  39 -                      POLY1305_BLOCK_SIZE - dctx->buflen);
  40 -               poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0);
  41 -       }
  42 -
  43 -       poly1305_core_emit(&dctx->h, digest);
  44 -
  45 -       /* mac = (h + s) % (2^128) */
  46 -       f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0];
  47 -       put_unaligned_le32(f, dst + 0);
  48 -       f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1];
  49 -       put_unaligned_le32(f, dst + 4);
  50 -       f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2];
  51 -       put_unaligned_le32(f, dst + 8);
  52 -       f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3];
  53 -       put_unaligned_le32(f, dst + 12);
  54 -
  55 +       poly1305_final_generic(dctx, dst);
  56         return 0;
  57  }
  58  EXPORT_SYMBOL_GPL(crypto_poly1305_final);
  59 --- a/include/crypto/poly1305.h
  60 +++ b/include/crypto/poly1305.h
  61 @@ -35,7 +35,43 @@ struct poly1305_desc_ctx {
  62         /* accumulator */
  63         struct poly1305_state h;
  64         /* key */
  65 -       struct poly1305_key r[1];
  66 +       struct poly1305_key r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE];
  67  };
  68
  69 +void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
  70 +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
  71 +
  72 +static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
  73 +{
  74 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
  75 +               poly1305_init_arch(desc, key);
  76 +       else
  77 +               poly1305_init_generic(desc, key);
  78 +}
  79 +
  80 +void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src,
  81 +                         unsigned int nbytes);
  82 +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
  83 +                            unsigned int nbytes);
  84 +
  85 +static inline void poly1305_update(struct poly1305_desc_ctx *desc,
  86 +                                  const u8 *src, unsigned int nbytes)
  87 +{
  88 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
  89 +               poly1305_update_arch(desc, src, nbytes);
  90 +       else
  91 +               poly1305_update_generic(desc, src, nbytes);
  92 +}
  93 +
  94 +void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest);
  95 +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest);
  96 +
  97 +static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest)
  98 +{
  99 +       if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
 100 +               poly1305_final_arch(desc, digest);
 101 +       else
 102 +               poly1305_final_generic(desc, digest);
 103 +}
 104 +
 105  #endif
 106 --- a/lib/crypto/Kconfig
 107 +++ b/lib/crypto/Kconfig
 108 @@ -37,8 +37,34 @@ config CRYPTO_LIB_CHACHA
 109  config CRYPTO_LIB_DES
 110         tristate
 111
 112 +config CRYPTO_LIB_POLY1305_RSIZE
 113 +       int
 114 +       default 1
 115 +
 116 +config CRYPTO_ARCH_HAVE_LIB_POLY1305
 117 +       tristate
 118 +       help
 119 +         Declares whether the architecture provides an arch-specific
 120 +         accelerated implementation of the Poly1305 library interface,
 121 +         either builtin or as a module.
 122 +
 123  config CRYPTO_LIB_POLY1305_GENERIC
 124         tristate
 125 +       help
 126 +         This symbol can be depended upon by arch implementations of the
 127 +         Poly1305 library interface that require the generic code as a
 128 +         fallback, e.g., for SIMD implementations. If no arch specific
 129 +         implementation is enabled, this implementation serves the users
 130 +         of CRYPTO_LIB_POLY1305.
 131 +
 132 +config CRYPTO_LIB_POLY1305
 133 +       tristate "Poly1305 library interface"
 134 +       depends on CRYPTO_ARCH_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_HAVE_LIB_POLY1305
 135 +       select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
 136 +       help
 137 +         Enable the Poly1305 library interface. This interface may be fulfilled
 138 +         by either the generic implementation or an arch-specific one, if one
 139 +         is available and enabled.
 140
 141  config CRYPTO_LIB_SHA256
 142         tristate
 143 --- a/lib/crypto/poly1305.c
 144 +++ b/lib/crypto/poly1305.c
 145 @@ -154,5 +154,79 @@ void poly1305_core_emit(const struct pol
 146  }
 147  EXPORT_SYMBOL_GPL(poly1305_core_emit);
 148
 149 +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
 150 +{
 151 +       poly1305_core_setkey(desc->r, key);
 152 +       desc->s[0] = get_unaligned_le32(key + 16);
 153 +       desc->s[1] = get_unaligned_le32(key + 20);
 154 +       desc->s[2] = get_unaligned_le32(key + 24);
 155 +       desc->s[3] = get_unaligned_le32(key + 28);
 156 +       poly1305_core_init(&desc->h);
 157 +       desc->buflen = 0;
 158 +       desc->sset = true;
 159 +       desc->rset = 1;
 160 +}
 161 +EXPORT_SYMBOL_GPL(poly1305_init_generic);
 162 +
 163 +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
 164 +                            unsigned int nbytes)
 165 +{
 166 +       unsigned int bytes;
 167 +
 168 +       if (unlikely(desc->buflen)) {
 169 +               bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
 170 +               memcpy(desc->buf + desc->buflen, src, bytes);
 171 +               src += bytes;
 172 +               nbytes -= bytes;
 173 +               desc->buflen += bytes;
 174 +
 175 +               if (desc->buflen == POLY1305_BLOCK_SIZE) {
 176 +                       poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1);
 177 +                       desc->buflen = 0;
 178 +               }
 179 +       }
 180 +
 181 +       if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
 182 +               poly1305_core_blocks(&desc->h, desc->r, src,
 183 +                                    nbytes / POLY1305_BLOCK_SIZE, 1);
 184 +               src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
 185 +               nbytes %= POLY1305_BLOCK_SIZE;
 186 +       }
 187 +
 188 +       if (unlikely(nbytes)) {
 189 +               desc->buflen = nbytes;
 190 +               memcpy(desc->buf, src, nbytes);
 191 +       }
 192 +}
 193 +EXPORT_SYMBOL_GPL(poly1305_update_generic);
 194 +
 195 +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
 196 +{
 197 +       __le32 digest[4];
 198 +       u64 f = 0;
 199 +
 200 +       if (unlikely(desc->buflen)) {
 201 +               desc->buf[desc->buflen++] = 1;
 202 +               memset(desc->buf + desc->buflen, 0,
 203 +                      POLY1305_BLOCK_SIZE - desc->buflen);
 204 +               poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0);
 205 +       }
 206 +
 207 +       poly1305_core_emit(&desc->h, digest);
 208 +
 209 +       /* mac = (h + s) % (2^128) */
 210 +       f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0];
 211 +       put_unaligned_le32(f, dst + 0);
 212 +       f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1];
 213 +       put_unaligned_le32(f, dst + 4);
 214 +       f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2];
 215 +       put_unaligned_le32(f, dst + 8);
 216 +       f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3];
 217 +       put_unaligned_le32(f, dst + 12);
 218 +
 219 +       *desc = (struct poly1305_desc_ctx){};
 220 +}
 221 +EXPORT_SYMBOL_GPL(poly1305_final_generic);
 222 +
 223  MODULE_LICENSE("GPL");
 224  MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");