ES_VerifySign (IOS59)

fn.c

int __fastcall ES_VerifySign(const u8 *hash, u32 hash_size, const u8 *ecc_signature, const u8 *certs, u32 certs_size)
{
  uint8_t *sha1; // r10
  uint8_t *hash_ctx; // r8
  IOSReturnCode ret; // r4
  Cert *_certs; // r0 MAPDST
  uint32_t inputSize; // r5
  int ap_handle; // [sp+20h] [bp-84h]
  int ng_cert_handle; // [sp+24h] [bp-80h]
  const char *ng_issuer; // [sp+28h] [bp-7Ch]
  int ng_cert_size; // [sp+2Ch] [bp-78h]
  Cert *ng_cert; // [sp+30h] [bp-74h]
  const char *ap_issuer; // [sp+34h] [bp-70h]
  int ap_cert_size; // [sp+38h] [bp-6Ch]
  Cert *ap_cert; // [sp+3Ch] [bp-68h]
  char ap[64]; // [sp+40h] [bp-64h]

  ap_cert_size = 0;
  ng_cert_size = 0;
  ap_cert = 0;
  ng_cert = 0;
  ng_cert_handle = 0;
  ap_handle = 0;
  _certs = 0;
  sha1 = 0;
  hash_ctx = 0;
  if ( (unsigned __int8)hash & 0x3F || !ecc_signature || !certs || !certs_size )
  {
    ret = ES_EINVAL;
  }
  else
  {
    memset(ap, 0, 0x40u);
    strcpy(ap, "AP");
    _certs = (Cert *)IOS_AllocAligned_es_(0, certs_size, 0x40u);
    if ( _certs )
    {
      memcpy(_certs, certs, certs_size);
      ret = ES_FindCert(ap, _certs, certs_size, &ap_cert, &ap_cert_size, &ap_issuer, 0);
      if ( ret == IPC_SUCCESS )
      {
        ret = ES_FindCert(ap_issuer, _certs, certs_size, &ng_cert, &ng_cert_size, &ng_issuer, 1);
        if ( ret == IPC_SUCCESS )
        {
          ret = IOSC_CreateObject_es_(&ng_cert_handle, IOSC_PUBLICKEY_TYPE, IOSC_ECC233_SUBTYPE);
          if ( ret == IPC_SUCCESS )
          {
            ret = ES_VerifyContainer(
                    (const u8 *)ng_cert,
                    ng_cert_size,
                    ng_cert->ecc.ecc.sig,
                    ng_cert->ecc.ecc.issuer,
                    _certs,
                    certs_size,
                    0u,
                    0u,
                    0,
                    ng_cert_handle,
                    VERIFY_TYPE_ECC);
            if ( ret == IPC_SUCCESS )
            {
              inputSize = ap_cert_size - 128;
              hash_ctx = (uint8_t *)IOS_AllocAligned_es_(0, 0x60u, 0x40u);
              if ( hash_ctx )
              {
                sha1 = (uint8_t *)IOS_AllocAligned_es_(0, 0x14u, 0x40u);
                if ( sha1 )
                {
                  ret = IOSC_GenerateHash_es_(hash_ctx, 0, 0, 0, 0);
                  if ( ret == IPC_SUCCESS )
                  {
                    ret = IOSC_GenerateHash_es_(hash_ctx, (const u8 *)ap_cert->ecc.ecc.issuer, inputSize, 2u, sha1);
                    if ( ret == IPC_SUCCESS )
                    {
                      ret = IOSC_VerifyPublicKeySign_es_(
                              sha1,
                              0x14u,
                              (IOSCDefaultKeyHandle)ng_cert_handle,
                              ap_cert->ecc.ecc.sig);
                      if ( ret == IPC_SUCCESS )
                      {
                        memset(hash_ctx, 0, 0x60u);
                        ret = IOSC_GenerateHash_es_(hash_ctx, 0, 0, 0, 0);
                        if ( ret == IPC_SUCCESS )
                        {
                          ret = IOSC_GenerateHash_es_(hash_ctx, hash, hash_size, 2u, sha1);
                          if ( ret == IPC_SUCCESS )
                          {
                            ret = IOSC_CreateObject_es_(&ap_handle, IOSC_PUBLICKEY_TYPE, IOSC_ECC233_SUBTYPE);
                            if ( ret == IPC_SUCCESS )
                            {
                              ret = IOSC_ImportPublicKey_es_(ap_cert->ecc.public_key, 0, ap_handle);
                              if ( ret == IPC_SUCCESS )
                                ret = IOSC_VerifyPublicKeySign_es_(
                                        sha1,
                                        0x14u,
                                        (IOSCDefaultKeyHandle)ap_handle,
                                        ecc_signature);
                            }
                          }
                        }
                      }
                    }
                  }
                }
                else
                {
                  ret = ES_ENOMEM;
                }
              }
              else
              {
                ret = ES_ENOMEM;
              }
            }
          }
        }
      }
    }
    else
    {
      ret = ES_ENOMEM;
    }
  }
  if ( ng_cert_handle || ap_handle )
    JUMPOUT(IOSC_DeleteObject__es__0);
  if ( _certs )
    IOS_Free_es_(0, _certs);
  if ( hash_ctx )
    IOS_Free_es_(0, hash_ctx);
  if ( sha1 )
    IOS_Free_es_(0, sha1);
  return ret;
}