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[CHDFile, Utilties] Add CHD v1/v2; fix byte[] comparisons

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This commit is contained in:
Matt Nadareski
2018-02-15 18:41:46 -08:00
parent fc1bde06c8
commit ea7a3aef6c
2 changed files with 181 additions and 36 deletions
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152
SabreTools.Library/FileTypes/CHDFile.cs
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@@ -24,6 +24,29 @@ namespace SabreTools.Library.FileTypes
/// 0x08-0x0B - Header size
/// 0x0C-0x0F - CHD version
/// ----------------------------------------------
/// CHD v1 header layout:
/// 0x10-0x13 - Flags (1: Has parent MD5, 2: Disallow writes)
/// 0x14-0x17 - Compression
/// 0x18-0x1B - 512-byte sectors per hunk
/// 0x1C-0x1F - Hunk count
/// 0x20-0x23 - Hard disk cylinder count
/// 0x24-0x27 - Hard disk head count
/// 0x28-0x2B - Hard disk sector count
/// 0x2C-0x3B - MD5
/// 0x3C-0x4B - Parent MD5
/// ----------------------------------------------
/// CHD v2 header layout:
/// 0x10-0x13 - Flags (1: Has parent MD5, 2: Disallow writes)
/// 0x14-0x17 - Compression
/// 0x18-0x1B - seclen-byte sectors per hunk
/// 0x1C-0x1F - Hunk count
/// 0x20-0x23 - Hard disk cylinder count
/// 0x24-0x27 - Hard disk head count
/// 0x28-0x2B - Hard disk sector count
/// 0x2C-0x3B - MD5
/// 0x3C-0x4B - Parent MD5
/// 0x4C-0x4F - Number of bytes per sector (seclen)
/// ----------------------------------------------
/// CHD v3 header layout:
/// 0x10-0x13 - Flags (1: Has parent SHA-1, 2: Disallow writes)
/// 0x14-0x17 - Compression
@@ -69,12 +92,13 @@ namespace SabreTools.Library.FileTypes
#region Private instance variables
// Core parameters from the header
private byte[] m_signature; // signature
private byte[] m_signature; // signature
private uint m_headersize; // size of the header
private uint m_version; // version of the header
private ulong m_logicalbytes; // logical size of the raw CHD data in bytes
private ulong m_mapoffset; // offset of map
private ulong m_metaoffset; // offset to first metadata bit
private uint m_sectorsperhunk; // number of sectors per hunk
private uint m_hunkbytes; // size of each raw hunk in bytes
private ulong m_hunkcount; // number of hunks represented
private uint m_unitbytes; // size of each unit in bytes
@@ -130,13 +154,10 @@ namespace SabreTools.Library.FileTypes
return null;
}
for(int i = 0; i < 8; i++)
if (!m_signature.StartsWith(Constants.CHDSignature, exact: true))
{
if (m_signature[i] != Constants.CHDSignatureBytes[i])
{
// throw CHDERR_INVALID_FILE;
return null;
}
// throw CHDERR_INVALID_FILE;
return null;
}
// Get the header size and version
@@ -144,10 +165,12 @@ namespace SabreTools.Library.FileTypes
m_version = m_br.ReadUInt32Reverse();
// If we have an invalid combination of size and version
if ((m_version == 3 && m_headersize != Constants.CHD_V3_HEADER_SIZE)
if ((m_version == 1 && m_headersize != Constants.CHD_V1_HEADER_SIZE)
|| (m_version == 2 && m_headersize != Constants.CHD_V2_HEADER_SIZE)
|| (m_version == 3 && m_headersize != Constants.CHD_V3_HEADER_SIZE)
|| (m_version == 4 && m_headersize != Constants.CHD_V4_HEADER_SIZE)
|| (m_version == 5 && m_headersize != Constants.CHD_V5_HEADER_SIZE)
|| (m_version < 3 || m_version > 5))
|| (m_version < 1 || m_version > 5))
{
// throw CHDERR_UNSUPPORTED_VERSION;
return null;
@@ -157,28 +180,34 @@ namespace SabreTools.Library.FileTypes
}
/// <summary>
/// Get the internal SHA-1 from the CHD
/// Get the internal MD5 (v1, v2) or SHA-1 (v3, v4, v5) from the CHD
/// </summary>
/// <returns>SHA-1 as a byte array, null on error</returns>
public byte[] GetSHA1FromHeader()
/// <returns>MD5 as a byte array, null on error</returns>
public byte[] GetHashFromHeader()
{
// Validate the header by default just in case
uint? version = ValidateHeaderVersion();
// Now get the SHA-1 hash, if possible
byte[] sha1 = new byte[20];
// Now get the hash, if possible
byte[] hash;
// Now parse the rest of the header according to the version
switch (version)
{
case 1:
hash = ParseCHDv1Header();
break;
case 2:
hash = ParseCHDv2Header();
break;
case 3:
sha1 = ParseCHDv3Header();
hash = ParseCHDv3Header();
break;
case 4:
sha1 = ParseCHDv4Header();
hash = ParseCHDv4Header();
break;
case 5:
sha1 = ParseCHDv5Header();
hash = ParseCHDv5Header();
break;
case null:
default:
@@ -186,7 +215,94 @@ namespace SabreTools.Library.FileTypes
return null;
}
return sha1;
return hash;
}
/// <summary>
/// Parse a CHD v1 header
/// </summary>
/// <returns>The extracted MD5 on success, null otherwise</returns>
private byte[] ParseCHDv1Header()
{
// Seek to after the signature to make sure we're reading the correct bytes
m_br.BaseStream.Seek(16, SeekOrigin.Begin);
// Set the blank MD5 hash
byte[] md5 = new byte[16];
// Set offsets and defaults
m_mapoffset = 0;
m_mapentrybytes = 0;
// Read the CHD flags
uint flags = m_br.ReadUInt32Reverse();
// Determine compression
switch (m_br.ReadUInt32())
{
case 0: m_compression[0] = CHDCodecType.CHD_CODEC_NONE; break;
case 1: m_compression[0] = CHDCodecType.CHD_CODEC_ZLIB; break;
case 2: m_compression[0] = CHDCodecType.CHD_CODEC_ZLIB; break;
case 3: m_compression[0] = CHDCodecType.CHD_CODEC_AVHUFF; break;
default: /* throw CHDERR_UNKNOWN_COMPRESSION; */ return null;
}
m_compression[1] = m_compression[2] = m_compression[3] = CHDCodecType.CHD_CODEC_NONE;
m_sectorsperhunk = m_br.ReadUInt32Reverse();
m_hunkcount = m_br.ReadUInt32Reverse();
m_br.ReadUInt32Reverse(); // Cylinder count
m_br.ReadUInt32Reverse(); // Head count
m_br.ReadUInt32Reverse(); // Sector count
md5 = m_br.ReadBytes(16);
m_br.ReadBytes(16); // Parent MD5
return md5;
}
/// <summary>
/// Parse a CHD v2 header
/// </summary>
/// <returns>The extracted MD5 on success, null otherwise</returns>
private byte[] ParseCHDv2Header()
{
// Seek to after the signature to make sure we're reading the correct bytes
m_br.BaseStream.Seek(16, SeekOrigin.Begin);
// Set the blank MD5 hash
byte[] md5 = new byte[16];
// Set offsets and defaults
m_mapoffset = 0;
m_mapentrybytes = 0;
// Read the CHD flags
uint flags = m_br.ReadUInt32Reverse();
// Determine compression
switch (m_br.ReadUInt32())
{
case 0: m_compression[0] = CHDCodecType.CHD_CODEC_NONE; break;
case 1: m_compression[0] = CHDCodecType.CHD_CODEC_ZLIB; break;
case 2: m_compression[0] = CHDCodecType.CHD_CODEC_ZLIB; break;
case 3: m_compression[0] = CHDCodecType.CHD_CODEC_AVHUFF; break;
default: /* throw CHDERR_UNKNOWN_COMPRESSION; */ return null;
}
m_compression[1] = m_compression[2] = m_compression[3] = CHDCodecType.CHD_CODEC_NONE;
m_sectorsperhunk = m_br.ReadUInt32Reverse();
m_hunkcount = m_br.ReadUInt32Reverse();
m_br.ReadUInt32Reverse(); // Cylinder count
m_br.ReadUInt32Reverse(); // Head count
m_br.ReadUInt32Reverse(); // Sector count
md5 = m_br.ReadBytes(16);
m_br.ReadBytes(16); // Parent MD5
m_br.ReadUInt32Reverse(); // Sector size
return md5;
}
/// <summary>