user: 下面的汇编指令对应的C源代码是什么：

```asm
<shahash>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x50,%rsp
  mov    %rdi,%r14
  mov    %fs:0x28,%rax
  mov    %rax,0x48(%rsp)
  xor    %eax,%eax
  mov    $0x14,%edi
  call   <malloc@plt>
  mov    %rax,%rbp
  mov    %rax,%rdi
  call   <sha_init@plt>
  mov    %r14,%rdi
  call   <strlen@plt>
  test   %eax,%eax
  je     L63
  mov    %eax,%r13d
  jle    L48
  mov    $0x0,%ebx
  mov    %rsp,%r12
L60:
  mov    $0x41,%edx
  mov    $0x0,%esi
  mov    %r12,%rdi
  call   <memset@plt>
  mov    $0x40,%edx
  mov    %r14,%rsi
  mov    %r12,%rdi
  call   <strncpy@plt>
  mov    %r12,%rdi
  call   <strlen@plt>
  movslq %eax,%rdx
  add    %rdx,%rbx
  sub    %eax,%r13d
  test   %r13d,%r13d
  jle    L108
  mov    %rbp,%rsi
  mov    %r12,%rdi
  call   <sha_hash@plt>
  add    $0x40,%r14
  jmp    L60
L63:
  mov    %rsp,%rbx
  mov    $0x41,%edx
  mov    $0x0,%esi
  mov    %rbx,%rdi
  call   <memset@plt>
  movb   $0x80,(%rsp)
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <sha_hash@plt>
  jmp    L48
L108:
  shl    $0x3,%rbx
  movb   $0x80,(%rsp,%rdx,1)
  lea    0x1(%rax),%edx
  cmp    $0x3f,%edx
  jg     L8
  movslq %edx,%rdx
L44:
  movb   $0x0,(%rsp,%rdx,1)
  add    $0x1,%rdx
  cmp    $0x3f,%edx
  jle    L44
L8:
  cmp    $0x37,%eax
  jg     L50
L105:
  lea    0x38(%rsp),%rax
  lea    0x40(%rsp),%rsi
  mov    $0x38,%ecx
L36:
  mov    %rbx,%rdx
  sar    %cl,%rdx
  mov    %dl,(%rax)
  sub    $0x8,%ecx
  add    $0x1,%rax
  cmp    %rax,%rsi
  jne    L36
  mov    %rsp,%rdi
  mov    %rbp,%rsi
  call   <sha_hash@plt>
L48:
  mov    %rbp,%rsi
  lea    D7(%rip),%rbx
  mov    %rbx,%rdi
  call   <strprintsha@plt>
  mov    %rbp,%rdi
  call   <free@plt>
  mov    0x48(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L97
  mov    %rbx,%rax
  add    $0x50,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L50:
  mov    %rsp,%r12
  mov    %rbp,%rsi
  mov    %r12,%rdi
  call   <sha_hash@plt>
  mov    %r12,%rax
  lea    0x38(%rsp),%rdx
L88:
  movl   $0x0,(%rax)
  add    $0x4,%rax
  cmp    %rdx,%rax
  jne    L88
  jmp    L105
L97:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char *shahash(const char *str) {
  char read_buffer[65];
  int c = 1, i;
  long long length = 0;
  int strsz;
  static char final[40];
  int *hashval;
  hashval = (int *)malloc(20);
  sha_init(hashval);
  strsz = strlen(str);
  if (strsz == 0) {
    memset(read_buffer, 0, 65);
    read_buffer[0] = 0x80;
    sha_hash((int *)read_buffer, hashval);
  }
  while (strsz > 0) {
    memset(read_buffer, 0, 65);
    strncpy((char *)read_buffer, str, 64);
    c = strlen((char *)read_buffer);
    length += c;
    strsz -= c;
    if (strsz <= 0) {
      length <<= 3;
      read_buffer[c] = (char)0x80;
      for (i = c + 1; i < 64; i++)
        read_buffer[i] = 0;
      if (c > 55) {
        sha_hash((int *)read_buffer, hashval);
        for (i = 0; i < 14; i++)
          ((int *)read_buffer)[i] = 0;
      }
      for (i = 0; i < 8; i++) {
        read_buffer[56 + i] = (char)(length >> (56 - (i * 8))) & 0xff;
      }
    }
    sha_hash((int *)read_buffer, hashval);
    str += 64;
  }
  strprintsha((char *) final, hashval);
  free(hashval);
  return (char *) final;
}
```