user: What would the C source look like for the assembly code provided here:

```asm
<ibm3624Offset>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x68(%rbp)
  mov    %rsi,-0x70(%rbp)
  mov    %rdx,-0x78(%rbp)
  mov    %rcx,-0x80(%rbp)
  mov    %r8,-0x88(%rbp)
  mov    %r9,-0x90(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%rbx
  movl   $0x0,-0x58(%rbp)
  mov    -0x90(%rbp),%rax
  mov    $0x65,%edx
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <memset@plt>
  mov    -0x90(%rbp),%rdx
  mov    -0x70(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <validatePin@plt>
  mov    %eax,-0x54(%rbp)
  cmpl   $0xffffffff,-0x54(%rbp)
  jne    L34
  mov    $0xffffffff,%eax
  jmp    L78
L34:
  addl   $0x1,-0x54(%rbp)
  mov    -0x54(%rbp),%eax
  movslq %eax,%rdx
  sub    $0x1,%rdx
  mov    %rdx,-0x48(%rbp)
  movslq %eax,%rdx
  mov    %rdx,%r14
  mov    $0x0,%r15d
  movslq %eax,%rdx
  mov    %rdx,%r12
  mov    $0x0,%r13d
  cltq
  mov    $0x10,%edx
  sub    $0x1,%rdx
  add    %rdx,%rax
  mov    $0x10,%edi
  mov    $0x0,%edx
  div    %rdi
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L13:
  cmp    %rdx,%rsp
  je     L0
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L13
L0:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L72
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L72:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x54(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x40(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <memset@plt>
  mov    -0x54(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x88(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <memset@plt>
  mov    -0x90(%rbp),%r8
  mov    -0x40(%rbp),%rdi
  mov    -0x80(%rbp),%rcx
  mov    -0x78(%rbp),%rdx
  mov    -0x54(%rbp),%esi
  mov    -0x68(%rbp),%rax
  mov    %r8,%r9
  mov    %rdi,%r8
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <naturalpin@plt>
  mov    %eax,-0x58(%rbp)
  cmpl   $0xffffffff,-0x58(%rbp)
  jne    L39
  mov    $0xffffffff,%eax
  jmp    L78
L39:
  movl   $0x0,-0x58(%rbp)
  jmp    L14
L60:
  mov    -0x58(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %eax,%edi
  mov    $0x0,%eax
  call   <getHexValue@plt>
  mov    %eax,-0x50(%rbp)
  mov    -0x58(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x70(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %eax,%edi
  mov    $0x0,%eax
  call   <getHexValue@plt>
  mov    %eax,-0x4c(%rbp)
  mov    $0xa,%eax
  sub    -0x50(%rbp),%eax
  mov    %eax,%edx
  mov    -0x4c(%rbp),%eax
  lea    (%rdx,%rax,1),%ecx
  movslq %ecx,%rax
  imul   $0x66666667,%rax,%rax
  shr    $0x20,%rax
  sar    $0x2,%eax
  mov    %ecx,%esi
  sar    $0x1f,%esi
  sub    %esi,%eax
  mov    %eax,%edx
  mov    %edx,%eax
  shl    $0x2,%eax
  add    %edx,%eax
  add    %eax,%eax
  sub    %eax,%ecx
  mov    %ecx,%edx
  mov    %edx,%edi
  mov    $0x0,%eax
  call   <getUChar@plt>
  mov    %eax,%edx
  mov    -0x58(%rbp),%eax
  movslq %eax,%rcx
  mov    -0x88(%rbp),%rax
  add    %rcx,%rax
  mov    %dl,(%rax)
  addl   $0x1,-0x58(%rbp)
L14:
  mov    -0x54(%rbp),%eax
  sub    $0x1,%eax
  cmp    %eax,-0x58(%rbp)
  jl     L60
  mov    $0x0,%eax
L78:
  mov    %rbx,%rsp
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L22
  call   <__stack_chk_fail@plt>
L22:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

assistant: ```c
int ibm3624Offset(unsigned const char *ipvk, unsigned const char *ipin, unsigned const char *idectable, unsigned const char *ipinvaldat, unsigned char *offset, char *errstatus) {
  int k = 0;
  memset(errstatus, '\0', 100 + 1);
  int pinLength = validatePin(ipin, errstatus);
  if (pinLength == -1)
    return -1;
  pinLength++;
  unsigned char natPin[pinLength];
  memset(natPin, '\0', pinLength);
  memset(offset, '\0', pinLength);
  k = naturalpin(ipvk, pinLength, idectable, ipinvaldat, natPin, errstatus);
  if (k == -1)
    return -1;
  for (k = 0; k < pinLength - 1; k++) {
    int i1nat = getHexValue(*(natPin + k));
    int i2pin = getHexValue(*(ipin + k));
    *(offset + k) = getUChar((10 - i1nat + i2pin) % 10);
  }
  return 0;
}
```