user: Demonstrate the C code that generates the assembly output below:

```asm
<lwe_key_gen_server_gen_a>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,0x18(%rsp)
  mov    %rsi,%rbx
  mov    %rdx,%r13
  mov    %rcx,%r12
  mov    %fs:0x28,%rax
  mov    %rax,0x38(%rsp)
  xor    %eax,%eax
  call   <EVP_CIPHER_CTX_new@plt>
  mov    %rax,%rbp
  test   %rax,%rax
  je     L78
  mov    $0x0,%eax
  call   <EVP_aes_128_ecb@plt>
  mov    %eax,%esi
  mov    $0x0,%r8d
  mov    %rbx,%rcx
  mov    $0x0,%edx
  mov    %rbp,%rdi
  call   <EVP_EncryptInit_ex@plt>
  cmp    $0x1,%eax
  je     L188
  movq   $0x0,0x8(%rsp)
  mov    $0x0,%r13d
  movq   $0x0,0x10(%rsp)
  mov    $0x0,%ebx
L3:
  mov    %rbp,%rdi
  call   <EVP_CIPHER_CTX_free@plt>
  mov    0x8(%rsp),%rbp
  cmpq   $0x0,0x10(%rsp)
  je     L1
  mov    $0x5e00,%esi
  mov    0x10(%rsp),%r15
  mov    %r15,%rdi
  call   <OPENSSL_cleanse@plt>
  mov    %r15,%rdi
  call   <OPENSSL_free@plt>
  mov    0x8(%rsp),%rbp
L1:
  test   %r13,%r13
  je     L137
  mov    $0xbc0,%esi
  mov    %r13,%rdi
  call   <OPENSSL_cleanse@plt>
  mov    %r13,%rdi
  call   <OPENSSL_free@plt>
L137:
  test   %rbp,%rbp
  je     L17
  mov    $0x5e00,%esi
  mov    %rbp,%rdi
  call   <OPENSSL_cleanse@plt>
  mov    %rbp,%rdi
  call   <OPENSSL_free@plt>
L17:
  mov    0x38(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L194
  mov    %ebx,%eax
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L188:
  mov    $0x0,%esi
  mov    %rbp,%rdi
  call   <EVP_CIPHER_CTX_set_padding@plt>
  mov    $0x5e00,%edi
  call   <OPENSSL_malloc@plt>
  mov    %rax,%r14
  mov    $0x0,%ebx
  test   %rax,%rax
  je     L17
  mov    %rax,0x10(%rsp)
  lea    0x20(%rax),%rcx
  lea    0x5e20(%rax),%rsi
  sub    %rax,%r12
  jmp    L100
L22:
  add    $0x20,%rcx
  cmp    %rsi,%rcx
  je     L181
L100:
  lea    -0x20(%rcx),%rax
L77:
  mov    (%r12,%rax,1),%edx
  mov    %edx,(%rax)
  add    $0x4,%rax
  cmp    %rcx,%rax
  jne    L77
  jmp    L22
L181:
  mov    $0xbc0,%edi
  call   <OPENSSL_malloc@plt>
  mov    %rax,%r12
  mov    $0x0,%ebx
  test   %rax,%rax
  je     L17
  mov    $0x5e00,%edi
  call   <OPENSSL_malloc@plt>
  mov    %rax,0x20(%rsp)
  test   %rax,%rax
  je     L17
  mov    %rax,0x8(%rsp)
  lea    0x5e00(%rax),%rsi
  mov    $0x0,%edi
  jmp    L72
L170:
  add    $0x1,%edi
  add    $0x20,%r13
  add    $0x4,%rsi
  cmp    $0x2f0,%edi
  je     L154
L72:
  lea    -0x5e00(%rsi),%rax
  mov    %r13,%rdx
L193:
  mov    (%rdx),%ecx
  mov    %ecx,(%rax)
  add    $0x4,%rdx
  add    $0xbc0,%rax
  cmp    %rsi,%rax
  jne    L193
  jmp    L170
L154:
  mov    %r12,%r13
  mov    $0x0,%r15d
  lea    0x34(%rsp),%rax
  mov    %rax,0x28(%rsp)
  jmp    L53
L108:
  add    $0x1,%r15
  cmp    $0x2f0,%r15
  je     L76
L53:
  mov    %r15d,%ebx
  mov    $0xbc0,%edx
  mov    $0x0,%esi
  mov    %r13,%rdi
  call   <memset@plt>
  mov    %r12,%rdx
  mov    $0x0,%eax
L13:
  mov    %ebx,(%rdx)
  mov    %eax,0x4(%rdx)
  add    $0x8,%eax
  add    $0x20,%rdx
  cmp    $0x2f0,%eax
  jne    L13
  mov    $0xbc0,%r8d
  mov    %r13,%rcx
  mov    0x28(%rsp),%rbx
  mov    %rbx,%rdx
  mov    %r13,%rsi
  mov    %rbp,%rdi
  call   <EVP_EncryptUpdate@plt>
  cmp    $0x1,%eax
  jne    L215
  cmpl   $0xbc0,0x34(%rsp)
  jne    L215
  mov    %rbx,%rdx
  mov    %r13,%rsi
  mov    %rbp,%rdi
  call   <EVP_EncryptFinal_ex@plt>
  mov    %eax,%ebx
  cmp    $0x1,%eax
  jne    L215
  mov    %r15,%r8
  shl    $0x5,%r8
  add    %r14,%r8
  mov    0x20(%rsp),%rsi
  sub    %r12,%rsi
  mov    $0x0,%r9d
  lea    0xbc0(%r12),%rdi
L132:
  mov    %r12,%rax
  mov    $0x0,%ecx
L234:
  mov    (%rax,%rsi,1),%edx
  imul   (%rax),%edx
  add    %edx,%ecx
  add    $0x4,%rax
  cmp    %rax,%rdi
  jne    L234
  add    (%r8),%ecx
  mov    %ecx,%eax
  sar    $0x1f,%eax
  shr    $0x11,%eax
  add    %eax,%ecx
  and    $0x7fff,%ecx
  sub    %eax,%ecx
  mov    %ecx,(%r8)
  add    $0x4,%r8
  add    $0x2f0,%r9d
  add    $0xbc0,%rsi
  cmp    $0x1780,%r9d
  jne    L132
  jmp    L108
L215:
  mov    $0x0,%ebx
  jmp    L3
L76:
  mov    $0xf,%r8d
  mov    $0x1780,%ecx
  mov    %r14,%rdx
  mov    $0x2c10,%esi
  mov    0x18(%rsp),%rdi
  call   <lwe_pack@plt>
  jmp    L3
L78:
  mov    %rax,%r13
  mov    $0x0,%ebx
  jmp    L1
L194:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int lwe_key_gen_server_gen_a(unsigned char *out, const uint8_t *seed, const uint16_t *s, const uint16_t *e) {
  int i, j, k;
  int ret = 0;
  uint16_t *out_unpacked = NULL;
  uint16_t *a_row = NULL;
  uint16_t *s_transpose = NULL;
  EVP_CIPHER_CTX *aes_ctx = EVP_CIPHER_CTX_new();
  if (aes_ctx == NULL) {
    goto err;
  }
  if (1 != EVP_EncryptInit_ex(aes_ctx, EVP_aes_128_ecb(), NULL, seed, NULL)) {
    goto err;
  }
  EVP_CIPHER_CTX_set_padding(aes_ctx, 0);
  out_unpacked = (uint16_t *)OPENSSL_malloc(8 * 752 * sizeof(int16_t));
  if (out_unpacked == NULL) {
    return 0;
  }
  for (i = 0; i < 752; i++)
    for (j = 0; j < 8; j++) {
      out_unpacked[i * 8 + j] = e[i * 8 + j];
    }
  size_t a_rowlen = 752 * sizeof(int16_t);
  a_row = (uint16_t *)OPENSSL_malloc(a_rowlen);
  if (a_row == NULL) {
    return 0;
  }
  s_transpose = (uint16_t *)OPENSSL_malloc(8 * 752 * sizeof(int16_t));
  if (s_transpose == NULL) {
    return 0;
  }
  for (j = 0; j < 752; j++)
    for (k = 0; k < 8; k++) {
      s_transpose[k * 752 + j] = s[j * 8 + k];
    }
  for (i = 0; i < 752; i++) {
    memset(a_row, 0, a_rowlen);
    for (j = 0; j < 752; j += 8) {
      a_row[j] = i;
      a_row[j + 1] = j;
    }
    int outlen;
    if (1 != EVP_EncryptUpdate(aes_ctx, (unsigned char *)a_row, &outlen, (unsigned char *)a_row, a_rowlen) || ((size_t)outlen != a_rowlen)) {
      goto err;
    }
    if (1 != EVP_EncryptFinal_ex(aes_ctx, (unsigned char *)a_row, &outlen)) {
      goto err;
    }
    for (k = 0; k < 8; k++) {
      uint16_t sum = 0;
      for (j = 0; j < 752; j++) {
        sum += a_row[j] * s_transpose[k * 752 + j];
      }
      out_unpacked[i * 8 + k] += sum;
      out_unpacked[i * 8 + k] %= (1 << 15);
    }
  }
  lwe_pack(out, (((8 * 752 * 15) + (8) - 1) / 8), out_unpacked, 752 * 8, 15);
  ret = 1;
err:
  if (aes_ctx != NULL) {
    EVP_CIPHER_CTX_free(aes_ctx);
  }
  if (out_unpacked != NULL) {
    OPENSSL_cleanse(out_unpacked, 8 * 752 * sizeof(uint16_t));
    OPENSSL_free(out_unpacked);
  }
  if (a_row != NULL) {
    OPENSSL_cleanse(a_row, a_rowlen);
    OPENSSL_free(a_row);
  }
  if (s_transpose != NULL) {
    OPENSSL_cleanse(s_transpose, 8 * 752 * sizeof(uint16_t));
    OPENSSL_free(s_transpose);
  }
  return ret;
}
```