Fix some nits in parser crypto code.
- Initialize arrays with braces instead of memset().
- Use more size_t types.
- Use std::min() more.
Change-Id: I6132744f48f8744a9b8182836ee42d450263f610
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/63190
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.cpp b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
index 6ecc262..f551318 100644
--- a/core/fpdfapi/parser/cpdf_crypto_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
@@ -53,7 +53,7 @@
return;
}
uint8_t realkey[16];
- int realkeylen = 16;
+ size_t realkeylen = sizeof(realkey);
if (m_Cipher != FXCIPHER_AES || m_KeyLen != 32) {
uint8_t key1[32];
PopulateKey(objnum, gennum, key1);
@@ -63,10 +63,7 @@
}
CRYPT_MD5Generate(
key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
- realkeylen = m_KeyLen + 5;
- if (realkeylen > 16) {
- realkeylen = 16;
- }
+ realkeylen = std::min<size_t>(m_KeyLen + 5, sizeof(realkey));
}
if (m_Cipher == FXCIPHER_AES) {
CRYPT_AESSetKey(m_pAESContext.get(),
@@ -98,9 +95,8 @@
}
} else {
ASSERT(dest_size == source.size());
- if (dest_buf != source.data()) {
+ if (dest_buf != source.data())
memcpy(dest_buf, source.data(), source.size());
- }
CRYPT_ArcFourCryptBlock(dest_buf, dest_size, realkey, realkeylen);
}
}
diff --git a/core/fpdfapi/parser/cpdf_security_handler.cpp b/core/fpdfapi/parser/cpdf_security_handler.cpp
index 1c3ac75..e709181 100644
--- a/core/fpdfapi/parser/cpdf_security_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_security_handler.cpp
@@ -365,8 +365,7 @@
CRYPT_aes_context aes;
memset(&aes, 0, sizeof(aes));
CRYPT_AESSetKey(&aes, digest, 32, false);
- uint8_t iv[16];
- memset(iv, 0, 16);
+ uint8_t iv[16] = {};
CRYPT_AESSetIV(&aes, iv);
CRYPT_AESDecrypt(&aes, m_EncryptKey, ekey.raw_str(), 32);
CRYPT_AESSetKey(&aes, m_EncryptKey, 32, false);
@@ -375,8 +374,7 @@
if (perms.IsEmpty())
return false;
- uint8_t perms_buf[16];
- memset(perms_buf, 0, sizeof(perms_buf));
+ uint8_t perms_buf[16] = {};
size_t copy_len =
std::min(sizeof(perms_buf), static_cast<size_t>(perms.GetLength()));
memcpy(perms_buf, perms.raw_str(), copy_len);
@@ -442,14 +440,10 @@
return memcmp(ukey.c_str(), ukeybuf, 16) == 0;
}
- uint8_t test[32];
- uint8_t tmpkey[32];
- uint32_t copy_len = sizeof(test);
- if (copy_len > (uint32_t)ukey.GetLength())
- copy_len = ukey.GetLength();
+ uint8_t test[32] = {};
+ uint8_t tmpkey[32] = {};
+ uint32_t copy_len = std::min(sizeof(test), ukey.GetLength());
- memset(test, 0, sizeof(test));
- memset(tmpkey, 0, sizeof(tmpkey));
memcpy(test, ukey.c_str(), copy_len);
for (int32_t i = 19; i >= 0; i--) {
for (int j = 0; j < m_KeyLen; j++)
@@ -482,8 +476,7 @@
CRYPT_MD5Generate(digest, 16, digest);
}
}
- uint8_t enckey[32];
- memset(enckey, 0, sizeof(enckey));
+ uint8_t enckey[32] = {};
uint32_t copy_len = m_KeyLen;
if (copy_len > sizeof(digest))
copy_len = sizeof(digest);
@@ -496,17 +489,16 @@
CRYPT_ArcFourCryptBlock(okeybuf, okeylen, enckey, m_KeyLen);
} else {
for (int32_t i = 19; i >= 0; i--) {
- uint8_t tempkey[32];
- memset(tempkey, 0, sizeof(tempkey));
+ uint8_t tempkey[32] = {};
for (int j = 0; j < m_KeyLen; j++)
tempkey[j] = enckey[j] ^ static_cast<uint8_t>(i);
CRYPT_ArcFourCryptBlock(okeybuf, okeylen, tempkey, m_KeyLen);
}
}
- int len = 32;
- while (len && defpasscode[len - 1] == okeybuf[len - 1]) {
+ size_t len = 32;
+ while (len && defpasscode[len - 1] == okeybuf[len - 1])
len--;
- }
+
return ByteString(okeybuf, len);
}
@@ -586,9 +578,8 @@
}
ByteString fileId;
- if (pIdArray) {
+ if (pIdArray)
fileId = pIdArray->GetStringAt(0);
- }
CalcEncryptKey(m_pEncryptDict.Get(), user_password, m_EncryptKey, key_len,
false, fileId);
@@ -601,17 +592,16 @@
CRYPT_md5_context md5;
CRYPT_MD5Start(&md5);
CRYPT_MD5Update(&md5, defpasscode, 32);
- if (!fileId.IsEmpty()) {
+ if (!fileId.IsEmpty())
CRYPT_MD5Update(&md5, (uint8_t*)fileId.c_str(), fileId.GetLength());
- }
+
uint8_t digest[32];
CRYPT_MD5Finish(&md5, digest);
CRYPT_ArcFourCryptBlock(digest, 16, m_EncryptKey, key_len);
uint8_t tempkey[32];
for (uint8_t i = 1; i <= 19; i++) {
- for (int j = 0; j < key_len; j++) {
+ for (int j = 0; j < key_len; j++)
tempkey[j] = m_EncryptKey[j] ^ i;
- }
CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len);
}
CRYPT_MD5Generate(digest, 16, digest + 16);
@@ -679,8 +669,7 @@
CRYPT_aes_context aes;
memset(&aes, 0, sizeof(aes));
CRYPT_AESSetKey(&aes, digest1, 32, true);
- uint8_t iv[16];
- memset(iv, 0, 16);
+ uint8_t iv[16] = {};
CRYPT_AESSetIV(&aes, iv);
CRYPT_AESEncrypt(&aes, digest1, key, 32);
pEncryptDict->SetNewFor<CPDF_String>(bOwner ? "OE" : "UE",
@@ -709,8 +698,7 @@
memset(&aes, 0, sizeof(aes));
CRYPT_AESSetKey(&aes, key, 32, true);
- uint8_t iv[16];
- memset(iv, 0, 16);
+ uint8_t iv[16] = {};
CRYPT_AESSetIV(&aes, iv);
uint8_t buf1[16];
