text: /*
   * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include <string.h>
  #include <openssl/core_names.h>
  #include <openssl/crypto.h>
  #include <openssl/evp.h>
  #include <openssl/params.h>
  #include <openssl/err.h>
  #include <openssl/proverr.h>
  #include "internal/sha3.h"
  #include "prov/digestcommon.h"
  #include "prov/implementations.h"
  
  #define SHA3_FLAGS PROV_DIGEST_FLAG_ALGID_ABSENT
  #define SHAKE_FLAGS PROV_DIGEST_FLAG_XOF
  #define KMAC_FLAGS PROV_DIGEST_FLAG_XOF
  
  /*
   * Forward declaration of any unique methods implemented here. This is not strictly
   * necessary for the compiler, but provides an assurance that the signatures
   * of the functions in the dispatch table are correct.
   */
  static OSSL_FUNC_digest_init_fn keccak_init;
  static OSSL_FUNC_digest_update_fn keccak_update;
  static OSSL_FUNC_digest_final_fn keccak_final;
  static OSSL_FUNC_digest_freectx_fn keccak_freectx;
  static OSSL_FUNC_digest_dupctx_fn keccak_dupctx;
  static OSSL_FUNC_digest_set_ctx_params_fn shake_set_ctx_params;
  static OSSL_FUNC_digest_settable_ctx_params_fn shake_settable_ctx_params;
  static sha3_absorb_fn generic_sha3_absorb;
  static sha3_final_fn generic_sha3_final;
  
  #if defined(OPENSSL_CPUID_OBJ) && defined(__s390__) && defined(KECCAK1600_ASM)
  /*
   * IBM S390X support
   */
  # include "s390x_arch.h"
  # define S390_SHA3 1
  # define S390_SHA3_CAPABLE(name) \
      ((OPENSSL_s390xcap_P.kimd[0] & S390X_CAPBIT(S390X_##name)) && \
       (OPENSSL_s390xcap_P.klmd[0] & S390X_CAPBIT(S390X_##name)))
  
  #endif
  
  static int keccak_init(void *vctx)
  {
      if (!ossl_prov_is_running())
          return 0;
      /* The newctx() handles most of the ctx fixed setup. */
      ossl_sha3_reset((KECCAK1600_CTX *)vctx);
      return 1;
  }
  
  static int keccak_update(void *vctx, const unsigned char *inp, size_t len)
  {
      KECCAK1600_CTX *ctx = vctx;
      const size_t bsz = ctx->block_size;
      size_t num, rem;
  
      if (len == 0)
          return 1;
  
      /* Is there anything in the buffer already ? */
      if ((num = ctx->bufsz) != 0) {
          /* Calculate how much space is left in the buffer */
          rem = bsz - num;
          /* If the new input does not fill the buffer then just add it */
          if (len < rem) {
              memcpy(ctx->buf + num, inp, len);
              ctx->bufsz += len;
              return 1;
          }
          /* otherwise fill up the buffer and absorb the buffer */
          memcpy(ctx->buf + num, inp, rem);
          /* Update the input pointer */
          inp += rem;
          len -= rem;
          ctx->meth.absorb(ctx, ctx->buf, bsz);
          ctx->bufsz = 0;
      }
      /* Absorb the input - rem = leftover part of the input < blocksize) */
      rem = ctx->meth.absorb(ctx, inp, len);
      /* Copy the leftover bit of the input into the buffer */
      if (rem) {
          memcpy(ctx->buf, inp + len - rem, rem);
          ctx->bufsz = rem;
      }
      return 1;
  }
  
  static int keccak_final(void *vctx, unsigned char *out, size_t *outl,
                          size_t outsz)
  {
      int ret = 1;
      KECCAK1600_CTX *ctx = vctx;
  
      if (!ossl_prov_is_running())
          return 0;
      if (outsz > 0)
          ret = ctx->meth.final(out, ctx);
  
      *outl = ctx->md_size;
      return ret;
  }
  
  /*-
   * Generic software version of the absorb() and final().
   */
  static size_t generic_sha3_absorb(void *vctx, const void *inp, size_t len)
  {
      KECCAK1600_CTX *ctx = vctx;
  
      return SHA3_absorb(ctx->A, inp, len, ctx->block_size);
  }
  
  static int generic_sha3_final(unsigned char *md, void *vctx)
  {
      return ossl_sha3_final(md, (KECCAK1600_CTX *)vctx);
  }
  
  static PROV_SHA3_METHOD sha3_generic_md =
  {
      generic_sha3_absorb,
      generic_sha3_final
  };
  
  #if defined(S390_SHA3)
  
  static sha3_absorb_fn s390x_sha3_absorb;
  static sha3_final_fn s390x_sha3_final;
  static sha3_final_fn s390x_shake_final;
  
  /*-
   * The platform specific parts of the absorb() and final() for S390X.
   */
  static size_t s390x_sha3_absorb(void *vctx, const void *inp, size_t len)
  {
      KECCAK1600_CTX *ctx = vctx;
      size_t rem = len % ctx->block_size;
  
      s390x_kimd(inp, len - rem, ctx->pad, ctx->A);
      return rem;
  }
  
  static int s390x_sha3_final(unsigned char *md, void *vctx)
  {
      KECCAK1600_CTX *ctx = vctx;
  
      if (!ossl_prov_is_running())
          return 0;
      s390x_klmd(ctx->buf, ctx->bufsz, NULL, 0, ctx->pad, ctx->A);
      memcpy(md, ctx->A, ctx->md_size);
      return 1;
  }
  
  static int s390x_shake_final(unsigned char *md, void *vctx)
  {
      KECCAK1600_CTX *ctx = vctx;
  
      if (!ossl_prov_is_running())
          return 0;
      s390x_klmd(ctx->buf, ctx->bufsz, md, ctx->md_size, ctx->pad, ctx->A);
      return 1;
  }
  
  static PROV_SHA3_METHOD sha3_s390x_md =
  {
      s390x_sha3_absorb,
      s390x_sha3_final
  };
  
  static PROV_SHA3_METHOD shake_s390x_md =
  {
      s390x_sha3_absorb,
      s390x_shake_final
  };
  
  # define SHA3_SET_MD(uname, typ)                                               \
      if (S390_SHA3_CAPABLE(uname)) {                                            \
          ctx->pad = S390X_##uname;                                              \
          ctx->meth = typ##_s390x_md;                                            \
      } else {                                                                   \
          ctx->meth = sha3_generic_md;                                           \
      }
  #else
  # define SHA3_SET_MD(uname, typ) ctx->meth = sha3_generic_md;
  #endif /* S390_SHA3 */
  
  #define SHA3_newctx(typ, uname, name, bitlen, pad)                             \
  static OSSL_FUNC_digest_newctx_fn name##_newctx;                               \
  static void *name##_newctx(void *provctx)                                      \
  {                                                                              \
      KECCAK1600_CTX *ctx = ossl_prov_is_running() ? OPENSSL_zalloc(sizeof(*ctx)) \
                                                  : NULL;                        \
                                                                                 \
      if (ctx == NULL)                                                           \
          return NULL;                                                           \
      ossl_sha3_init(ctx, pad, bitlen);                                          \
      SHA3_SET_MD(uname, typ)                                                    \
      return ctx;                                                                \
  }
  
  #define KMAC_newctx(uname, bitlen, pad)                                        \
  static OSSL_FUNC_digest_newctx_fn uname##_newctx;                              \
  static void *uname##_newctx(void *provctx)                                     \
  {                                                                              \
      KECCAK1600_CTX *ctx = ossl_prov_is_running() ? OPENSSL_zalloc(sizeof(*ctx)) \
                                                  : NULL;                        \
                                                                                 \
      if (ctx == NULL)                                                           \
          return NULL;                                                           \
      ossl_keccak_kmac_init(ctx, pad, bitlen);                                   \
      ctx->meth = sha3_generic_md;                                               \
      return ctx;                                                                \
  }
  
  #define PROV_FUNC_SHA3_DIGEST_COMMON(name, bitlen, blksize, dgstsize, flags)   \
  PROV_FUNC_DIGEST_GET_PARAM(name, blksize, dgstsize, flags)                     \
  const OSSL_DISPATCH ossl_##name##_functions[] = {                              \
      { OSSL_FUNC_DIGEST_NEWCTX, (void (*)(void))name##_newctx },                \
      { OSSL_FUNC_DIGEST_INIT, (void (*)(void))keccak_init },                    \
      { OSSL_FUNC_DIGEST_UPDATE, (void (*)(void))keccak_update },                \
      { OSSL_FUNC_DIGEST_FINAL, (void (*)(void))keccak_final },                  \
      { OSSL_FUNC_DIGEST_FREECTX, (void (*)(void))keccak_freectx },              \
      { OSSL_FUNC_DIGEST_DUPCTX, (void (*)(void))keccak_dupctx },                \
      PROV_DISPATCH_FUNC_DIGEST_GET_PARAMS(name)
  
  #define PROV_FUNC_SHA3_DIGEST(name, bitlen, blksize, dgstsize, flags)          \
      PROV_FUNC_SHA3_DIGEST_COMMON(name, bitlen, blksize, dgstsize, flags),      \
      PROV_DISPATCH_FUNC_DIGEST_CONSTRUCT_END
  
  #define PROV_FUNC_SHAKE_DIGEST(name, bitlen, blksize, dgstsize, flags)         \
      PROV_FUNC_SHA3_DIGEST_COMMON(name, bitlen, blksize, dgstsize, flags),      \
      { OSSL_FUNC_DIGEST_SET_CTX_PARAMS, (void (*)(void))shake_set_ctx_params }, \
      { OSSL_FUNC_DIGEST_SETTABLE_CTX_PARAMS,                                    \
       (void (*)(void))shake_settable_ctx_params },                              \
      PROV_DISPATCH_FUNC_DIGEST_CONSTRUCT_END
  
  static void keccak_freectx(void *vctx)
  {
      KECCAK1600_CTX *ctx = (KECCAK1600_CTX *)vctx;
  
      OPENSSL_clear_free(ctx,  sizeof(*ctx));
  }
  
  static void *keccak_dupctx(void *ctx)
  {
      KECCAK1600_CTX *in = (KECCAK1600_CTX *)ctx;
      KECCAK1600_CTX *ret = ossl_prov_is_running() ? OPENSSL_malloc(sizeof(*ret))
                                                  : NULL;
  
      if (ret != NULL)
          *ret = *in;
      return ret;
  }
  
  static const OSSL_PARAM known_shake_settable_ctx_params[] = {
      {OSSL_DIGEST_PARAM_XOFLEN, OSSL_PARAM_UNSIGNED_INTEGER, NULL, 0, 0},
      OSSL_PARAM_END
  };
  static const OSSL_PARAM *shake_settable_ctx_params(ossl_unused void *provctx)
  {
      return known_shake_settable_ctx_params;
  }
  
  static int shake_set_ctx_params(void *vctx, const OSSL_PARAM params[])
  {
      const OSSL_PARAM *p;
      KECCAK1600_CTX *ctx = (KECCAK1600_CTX *)vctx;
  
      if (ctx != NULL && params != NULL) {
          p = OSSL_PARAM_locate_const(params, OSSL_DIGEST_PARAM_XOFLEN);
          if (p != NULL && !OSSL_PARAM_get_size_t(p, &ctx->md_size)) {
              ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
              return 0;
          }
          return 1;
      }
      return 0; /* Null Parameter */
  }
  
  #define IMPLEMENT_SHA3_functions(bitlen)                                       \
      SHA3_newctx(sha3, SHA3_##bitlen, sha3_##bitlen, bitlen, '\x06')            \
      PROV_FUNC_SHA3_DIGEST(sha3_##bitlen, bitlen,                               \
                            SHA3_BLOCKSIZE(bitlen), SHA3_MDSIZE(bitlen),         \
                            SHA3_FLAGS)
  
  #define IMPLEMENT_SHAKE_functions(bitlen)                                      \
      SHA3_newctx(shake, SHAKE_##bitlen, shake_##bitlen, bitlen, '\x1f')         \
      PROV_FUNC_SHAKE_DIGEST(shake_##bitlen, bitlen,                             \
                            SHA3_BLOCKSIZE(bitlen), SHA3_MDSIZE(bitlen),         \
                            SHAKE_FLAGS)
  #define IMPLEMENT_KMAC_functions(bitlen)                                       \
      KMAC_newctx(keccak_kmac_##bitlen, bitlen, '\x04')                          \
      PROV_FUNC_SHAKE_DIGEST(keccak_kmac_##bitlen, bitlen,                       \
                             SHA3_BLOCKSIZE(bitlen), KMAC_MDSIZE(bitlen),        \
                             KMAC_FLAGS)
  
  /* ossl_sha3_224_functions */
  IMPLEMENT_SHA3_functions(224)
  /* ossl_sha3_256_functions */
  IMPLEMENT_SHA3_functions(256)
  /* ossl_sha3_384_functions */
  IMPLEMENT_SHA3_functions(384)
  /* ossl_sha3_512_functions */
  IMPLEMENT_SHA3_functions(512)
  /* ossl_shake_128_functions */
  IMPLEMENT_SHAKE_functions(128)
  /* ossl_shake_256_functions */
  IMPLEMENT_SHAKE_functions(256)
  /* ossl_keccak_kmac_128_functions */
  IMPLEMENT_KMAC_functions(128)
  /* ossl_keccak_kmac_256_functions */
  IMPLEMENT_KMAC_functions(256)
  