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Remove unsafe code from SmtpReplyReaderFactory.ProcessRead #121297

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Merged
merged 4 commits into from
Nov 8, 2025
Merged

Remove unsafe code from SmtpReplyReaderFactory.ProcessRead #121297

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30d4e8a
Initial plan
Copilot Nov 3, 2025
14b429a
Replace unsafe pointer code with safe ReadOnlySpan indexing in SmtpRe…
Copilot Nov 3, 2025
ccbde35
Fix logic bug in digit validation (change && to ||)
Copilot Nov 3, 2025
a8b6ff9
Apply suggestions from code review
EgorBo Nov 3, 2025
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240 changes: 116 additions & 124 deletions src/libraries/System.Net.Mail/src/System/Net/Mail/SmtpReplyReaderFactory.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -88,153 +88,145 @@ private int ProcessRead(ReadOnlySpan<byte> buffer, bool readLine)
throw new IOException(SR.Format(SR.net_io_readfailure, SR.net_io_connectionclosed));
}

unsafe
int i = 0;
int length = buffer.Length;

switch (_readState)
{
fixed (byte* pBuffer = buffer)
{
byte* start = pBuffer;
byte* ptr = start;
byte* end = ptr + buffer.Length;
case ReadState.Status0:
{
if (i < length)
{
byte b = buffer[i++];
if (!char.IsAsciiDigit((char)b))
{
throw new FormatException(SR.SmtpInvalidResponse);
}

_statusCode = (SmtpStatusCode)(100 * (b - '0'));

switch (_readState)
goto case ReadState.Status1;
}
_readState = ReadState.Status0;
break;
}
case ReadState.Status1:
{
case ReadState.Status0:
if (i < length)
{
byte b = buffer[i++];
if (!char.IsAsciiDigit((char)b))
{
if (ptr < end)
{
byte b = *ptr++;
if (b < '0' && b > '9')
{
throw new FormatException(SR.SmtpInvalidResponse);
}

_statusCode = (SmtpStatusCode)(100 * (b - '0'));

goto case ReadState.Status1;
}
_readState = ReadState.Status0;
break;
throw new FormatException(SR.SmtpInvalidResponse);
}
case ReadState.Status1:

_statusCode += 10 * (b - '0');

goto case ReadState.Status2;
}
_readState = ReadState.Status1;
break;
}
case ReadState.Status2:
{
if (i < length)
{
byte b = buffer[i++];
if (!char.IsAsciiDigit((char)b))
{
throw new FormatException(SR.SmtpInvalidResponse);
}

_statusCode += b - '0';

goto case ReadState.ContinueFlag;
}
_readState = ReadState.Status2;
break;
}
case ReadState.ContinueFlag:
{
if (i < length)
{
byte b = buffer[i++];
if (b == ' ') // last line
{
if (ptr < end)
{
byte b = *ptr++;
if (b < '0' && b > '9')
{
throw new FormatException(SR.SmtpInvalidResponse);
}

_statusCode += 10 * (b - '0');

goto case ReadState.Status2;
}
_readState = ReadState.Status1;
break;
goto case ReadState.LastCR;
}
case ReadState.Status2:
else if (b == '-') // more lines coming
{
if (ptr < end)
{
byte b = *ptr++;
if (b < '0' && b > '9')
{
throw new FormatException(SR.SmtpInvalidResponse);
}

_statusCode += b - '0';

goto case ReadState.ContinueFlag;
}
_readState = ReadState.Status2;
break;
goto case ReadState.ContinueCR;
}
case ReadState.ContinueFlag:
else // error
{
if (ptr < end)
{
byte b = *ptr++;
if (b == ' ') // last line
{
goto case ReadState.LastCR;
}
else if (b == '-') // more lines coming
{
goto case ReadState.ContinueCR;
}
else // error
{
throw new FormatException(SR.SmtpInvalidResponse);
}
}
_readState = ReadState.ContinueFlag;
break;
throw new FormatException(SR.SmtpInvalidResponse);
}
case ReadState.ContinueCR:
}
_readState = ReadState.ContinueFlag;
break;
}
case ReadState.ContinueCR:
{
while (i < length)
{
if (buffer[i++] == '\r')
{
while (ptr < end)
{
if (*ptr++ == '\r')
{
goto case ReadState.ContinueLF;
}
}
_readState = ReadState.ContinueCR;
break;
goto case ReadState.ContinueLF;
}
case ReadState.ContinueLF:
}
_readState = ReadState.ContinueCR;
break;
}
case ReadState.ContinueLF:
{
if (i < length)
{
if (buffer[i++] != '\n')
{
if (ptr < end)
{
if (*ptr++ != '\n')
{
throw new FormatException(SR.SmtpInvalidResponse);
}
if (readLine)
{
_readState = ReadState.Status0;
return (int)(ptr - start);
}
goto case ReadState.Status0;
}
_readState = ReadState.ContinueLF;
break;
throw new FormatException(SR.SmtpInvalidResponse);
}
case ReadState.LastCR:
if (readLine)
{
while (ptr < end)
{
if (*ptr++ == '\r')
{
goto case ReadState.LastLF;
}
}
_readState = ReadState.LastCR;
break;
_readState = ReadState.Status0;
return i;
}
case ReadState.LastLF:
goto case ReadState.Status0;
}
_readState = ReadState.ContinueLF;
break;
}
case ReadState.LastCR:
{
while (i < length)
{
if (buffer[i++] == '\r')
{
if (ptr < end)
{
if (*ptr++ != '\n')
{
throw new FormatException(SR.SmtpInvalidResponse);
}
goto case ReadState.Done;
}
_readState = ReadState.LastLF;
break;
goto case ReadState.LastLF;
}
case ReadState.Done:
}
_readState = ReadState.LastCR;
break;
}
case ReadState.LastLF:
{
if (i < length)
{
if (buffer[i++] != '\n')
{
int actual = (int)(ptr - start);
_readState = ReadState.Done;
return actual;
throw new FormatException(SR.SmtpInvalidResponse);
}
goto case ReadState.Done;
}
_readState = ReadState.LastLF;
break;
}
case ReadState.Done:
{
_readState = ReadState.Done;
return i;
}
return (int)(ptr - start);
}
}
return i;
}

internal int Read(SmtpReplyReader caller, Span<byte> buffer)
Expand Down
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