user: Converte this assembly snippet into its equivalent C code:

```asm
<MD5_String2binary>:
  endbr64
  push   %r15
  mov    %rdi,%r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x98,%rsp
  mov    %rsi,0x10(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x88(%rsp)
  movabs $0xefcdab8967452301,%rax
  mov    %rax,0x30(%rsp)
  movabs $0x1032547698badcfe,%rax
  mov    %rax,0x38(%rsp)
  call   <strlen@plt>
  mov    %rax,0x8(%rsp)
  cmp    $0x3f,%eax
  jle    L42
  lea    -0x40(%rax),%ebp
  lea    0x30(%rsp),%r12
  shr    $0x6,%ebp
  lea    0x3c(%rsp),%rbx
  lea    0x38(%rsp),%r14
  add    $0x1,%ebp
  lea    0x34(%rsp),%r13
  shl    $0x6,%rbp
  add    %r15,%rbp
  nopl   0x0(%rax,%rax,1)
L22:
  mov    %r15,%rdi
  mov    %rbx,%r8
  mov    %r14,%rcx
  mov    %r13,%rdx
  mov    %r12,%rsi
  add    $0x40,%r15
  call   <MD5_Round_Calculate@plt>
  cmp    %rbp,%r15
  jne    L22
L58:
  mov    0x8(%rsp),%ecx
  lea    0x40(%rsp),%r15
  mov    %rbp,%rsi
  mov    %r15,%rdi
  and    $0x3f,%ecx
  mov    %ecx,%edx
  mov    %ecx,0x1c(%rsp)
  call   <strncpy@plt>
  mov    0x1c(%rsp),%ebp
  mov    $0x40,%edx
  xor    %esi,%esi
  sub    %ebp,%edx
  lea    (%r15,%rbp,1),%rdi
  call   <memset@plt>
  mov    0x1c(%rsp),%ecx
  orb    $0x80,0x40(%rsp,%rbp,1)
  cmp    $0x37,%ecx
  ja     L25
L53:
  mov    0x8(%rsp),%rbp
  lea    0x28(%rsp),%rsi
  lea    0x78(%rsp),%rdi
  mov    $0x4,%edx
  mov    %ebp,%eax
  shl    $0x3,%eax
  mov    %eax,0x28(%rsp)
  call   <memcpy@plt>
  cmp    $0x1fffffff,%ebp
  jbe    L27
  lea    0x2c(%rsp),%rsi
  lea    0x7c(%rsp),%rdi
  mov    $0x4,%edx
  lea    0x8(,%rbp,8),%eax
  mov    %eax,0x2c(%rsp)
  call   <memcpy@plt>
L23:
  mov    %r13,%rdx
  mov    %r12,%rsi
  mov    %r15,%rdi
  mov    %rbx,%r8
  mov    %r14,%rcx
  call   <MD5_Round_Calculate@plt>
  mov    0x10(%rsp),%rdi
  mov    $0x10,%edx
  mov    %r12,%rsi
  call   <memcpy@plt>
  mov    0x88(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L56
  add    $0x98,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  xchg   %ax,%ax
L27:
  lea    0x7c(%rsp),%rdi
  mov    $0x4,%edx
  xor    %esi,%esi
  call   <memset@plt>
  jmp    L23
  nopl   0x0(%rax,%rax,1)
L25:
  mov    %r13,%rdx
  mov    %r12,%rsi
  mov    %r15,%rdi
  mov    %rbx,%r8
  mov    %r14,%rcx
  call   <MD5_Round_Calculate@plt>
  mov    $0x38,%edx
  xor    %esi,%esi
  mov    %r15,%rdi
  call   <memset@plt>
  jmp    L53
L42:
  mov    %r15,%rbp
  lea    0x30(%rsp),%r12
  lea    0x3c(%rsp),%rbx
  lea    0x38(%rsp),%r14
  lea    0x34(%rsp),%r13
  jmp    L58
L56:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void MD5_String2binary(const char *string, unsigned char *output) {
  unsigned char padding_message[64];
  unsigned char *pstring;
  unsigned int string_byte_len, string_bit_len, copy_len, msg_digest[4];
  unsigned int *A = &msg_digest[0], *B = &msg_digest[1], *C = &msg_digest[2], *D = &msg_digest[3];
  int i;
  *A = 0x67452301;
  *B = 0xefcdab89;
  *C = 0x98badcfe;
  *D = 0x10325476;
  string_byte_len = (unsigned int)strlen(string);
  pstring = (unsigned char *)string;
  for (i = string_byte_len; 64 <= i; i -= 64, pstring += 64)
    MD5_Round_Calculate(pstring, A, B, C, D);
  copy_len = string_byte_len % 64;
  strncpy((char *)padding_message, (char *)pstring, copy_len);
  memset(padding_message + copy_len, 0, 64 - copy_len);
  padding_message[copy_len] |= 0x80;
  if (56 <= copy_len) {
    MD5_Round_Calculate(padding_message, A, B, C, D);
    memset(padding_message, 0, 56);
  }
  string_bit_len = string_byte_len * 8;
  memcpy(&padding_message[56], &string_bit_len, 4);
  if (0xffffffff / 8 < string_byte_len) {
    unsigned int high = (string_byte_len - 0xffffffff / 8) * 8;
    memcpy(&padding_message[60], &high, 4);
  } else
    memset(&padding_message[60], 0, 4);
  MD5_Round_Calculate(padding_message, A, B, C, D);
  memcpy(output, msg_digest, 16);
}
```