user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<EVP_BytesToKey>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x70(%rbp)
  mov    %rsi,-0x48(%rbp)
  mov    %rdx,-0x60(%rbp)
  mov    %rcx,-0x58(%rbp)
  mov    %r8d,-0x50(%rbp)
  mov    %r9d,%r14d
  mov    0x10(%rbp),%rax
  mov    %rax,-0x78(%rbp)
  mov    0x18(%rbp),%rax
  mov    %rax,-0x80(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    D13(%rip),%rax
  mov    (%rax),%eax
  mov    %eax,-0x64(%rbp)
  cltq
  add    $0xf,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffffff0,%rcx
  and    $0xfffffffffffff000,%rax
  mov    %rsp,%rdx
  sub    %rax,%rdx
L53:
  cmp    %rdx,%rsp
  je     L312
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L53
L312:
  mov    %rcx,%rax
  and    $0xfff,%eax
  sub    %rax,%rsp
  test   %rax,%rax
  je     L322
  orq    $0x0,-0x8(%rsp,%rax,1)
L322:
  mov    %rsp,%r13
  movl   $0x0,-0x3c(%rbp)
  mov    -0x70(%rbp),%r15
  mov    %r15,%rdi
  call   <EVP_CIPHER_key_length@plt>
  mov    %eax,%ebx
  mov    %eax,-0x4c(%rbp)
  mov    %r15,%rdi
  call   <EVP_CIPHER_iv_length@plt>
  mov    %eax,%r15d
  mov    %eax,-0x84(%rbp)
  mov    D25(%rip),%rax
  cmp    %ebx,(%rax)
  setge  %dil
  movzbl %dil,%edi
  call   <OPENSSL_assert@plt>
  mov    D17(%rip),%rax
  cmp    %r15d,(%rax)
  setge  %dil
  movzbl %dil,%edi
  call   <OPENSSL_assert@plt>
  cmpq   $0x0,-0x58(%rbp)
  je     L238
  mov    $0x0,%eax
  call   <EVP_MD_CTX_new@plt>
  mov    %rax,%rbx
  test   %rax,%rax
  je     L176
  movl   $0x0,-0x68(%rbp)
  lea    -0x3c(%rbp),%r15
L353:
  mov    $0x0,%edx
  mov    -0x48(%rbp),%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestInit_ex@plt>
  test   %eax,%eax
  je     L393
  cmpl   $0x0,-0x68(%rbp)
  je     L243
  mov    -0x3c(%rbp),%edx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestUpdate@plt>
  test   %eax,%eax
  je     L281
L243:
  mov    -0x50(%rbp),%edx
  mov    -0x58(%rbp),%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestUpdate@plt>
  test   %eax,%eax
  je     L162
  mov    -0x60(%rbp),%rsi
  test   %rsi,%rsi
  je     L311
  mov    D2(%rip),%rax
  mov    (%rax),%edx
  mov    %rbx,%rdi
  call   <EVP_DigestUpdate@plt>
  test   %eax,%eax
  je     L439
L311:
  mov    %r15,%rdx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestFinal_ex@plt>
  test   %eax,%eax
  je     L91
  cmp    $0x1,%r14d
  jbe    L193
  mov    $0x1,%r12d
L398:
  mov    $0x0,%edx
  mov    -0x48(%rbp),%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestInit_ex@plt>
  test   %eax,%eax
  je     L350
  mov    -0x3c(%rbp),%edx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestUpdate@plt>
  test   %eax,%eax
  je     L229
  mov    %r15,%rdx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <EVP_DigestFinal_ex@plt>
  test   %eax,%eax
  je     L268
  add    $0x1,%r12d
  cmp    %r14d,%r12d
  jne    L398
L193:
  mov    $0x0,%edx
  cmpl   $0x0,-0x4c(%rbp)
  jne    L437
L163:
  cmpl   $0x0,-0x84(%rbp)
  je     L248
  movl   $0x0,-0x4c(%rbp)
L254:
  mov    -0x3c(%rbp),%eax
  cmp    %edx,%eax
  je     L55
  mov    -0x84(%rbp),%esi
  mov    -0x80(%rbp),%rcx
  jmp    L122
L437:
  mov    -0x3c(%rbp),%edi
  mov    -0x4c(%rbp),%eax
  mov    %eax,%esi
  mov    %eax,%r8d
  mov    $0x0,%eax
  mov    -0x78(%rbp),%rcx
  jmp    L412
L236:
  add    $0x1,%edx
  add    $0x1,%rax
  cmp    %r8,%rax
  je     L276
L412:
  mov    %eax,%edx
  mov    %esi,%r9d
  sub    %eax,%r9d
  cmp    %rax,%rdi
  je     L232
  test   %rcx,%rcx
  je     L236
  movzbl 0x0(%r13,%rax,1),%r9d
  mov    %r9b,(%rcx)
  lea    0x1(%rcx),%rcx
  jmp    L236
L276:
  mov    %rcx,-0x78(%rbp)
  jmp    L163
L232:
  mov    %r9d,-0x4c(%rbp)
  mov    %rcx,-0x78(%rbp)
  cmpl   $0x0,-0x84(%rbp)
  jne    L254
L290:
  mov    -0x84(%rbp),%eax
  or     -0x4c(%rbp),%eax
  je     L248
L55:
  addl   $0x1,-0x68(%rbp)
  jmp    L353
L445:
  sub    $0x1,%esi
  add    $0x1,%edx
  cmp    %edx,%eax
  je     L159
  test   %esi,%esi
  je     L446
L122:
  test   %rcx,%rcx
  je     L445
  mov    %edx,%edi
  movzbl 0x0(%r13,%rdi,1),%edi
  mov    %dil,(%rcx)
  lea    0x1(%rcx),%rcx
  jmp    L445
L446:
  mov    %esi,-0x84(%rbp)
  mov    %rcx,-0x80(%rbp)
  jmp    L290
L159:
  mov    %esi,-0x84(%rbp)
  mov    %rcx,-0x80(%rbp)
  jmp    L290
L248:
  mov    -0x70(%rbp),%rdi
  call   <EVP_CIPHER_key_length@plt>
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L176:
  movl   $0x0,-0x4c(%rbp)
  jmp    L362
L393:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L281:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L162:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L439:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L91:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L350:
  mov    %eax,-0x4c(%rbp)
L362:
  mov    %rbx,%rdi
  call   <EVP_MD_CTX_free@plt>
  mov    -0x64(%rbp),%esi
  mov    %r13,%rdi
  call   <OPENSSL_cleanse@plt>
L238:
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  jne    L287
  mov    -0x4c(%rbp),%eax
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
L229:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L268:
  mov    %eax,-0x4c(%rbp)
  jmp    L362
L287:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md, const unsigned char *salt, const unsigned char *data, int datal, int count, unsigned char *key, unsigned char *iv) {
  EVP_MD_CTX *c;
  unsigned char md_buf[EVP_MAX_MD_SIZE];
  int niv, nkey, addmd = 0;
  unsigned int mds = 0, i;
  int rv = 0;
  nkey = EVP_CIPHER_key_length(type);
  niv = EVP_CIPHER_iv_length(type);
  OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
  OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
  if (data == NULL)
    return nkey;
  c = EVP_MD_CTX_new();
  if (c == NULL)
    goto err;
  for (;;) {
    if (!EVP_DigestInit_ex(c, md, NULL))
      goto err;
    if (addmd++)
      if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
        goto err;
    if (!EVP_DigestUpdate(c, data, datal))
      goto err;
    if (salt != NULL)
      if (!EVP_DigestUpdate(c, salt, PKCS5_SALT_LEN))
        goto err;
    if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
      goto err;
    for (i = 1; i < (unsigned int)count; i++) {
      if (!EVP_DigestInit_ex(c, md, NULL))
        goto err;
      if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
        goto err;
      if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
        goto err;
    }
    i = 0;
    if (nkey) {
      for (;;) {
        if (nkey == 0)
          break;
        if (i == mds)
          break;
        if (key != NULL)
          *(key++) = md_buf[i];
        nkey--;
        i++;
      }
    }
    if (niv && (i != mds)) {
      for (;;) {
        if (niv == 0)
          break;
        if (i == mds)
          break;
        if (iv != NULL)
          *(iv++) = md_buf[i];
        niv--;
        i++;
      }
    }
    if ((nkey == 0) && (niv == 0))
      break;
  }
  rv = EVP_CIPHER_key_length(type);
err:
  EVP_MD_CTX_free(c);
  OPENSSL_cleanse(md_buf, sizeof(md_buf));
  return rv;
}
```