diff options
Diffstat (limited to 'crypto/src/asn1')
| -rw-r--r-- | crypto/src/asn1/DerBitString.cs | 36 |
1 files changed, 17 insertions, 19 deletions
diff --git a/crypto/src/asn1/DerBitString.cs b/crypto/src/asn1/DerBitString.cs index ad7a7e349..fa37e6c0c 100644 --- a/crypto/src/asn1/DerBitString.cs +++ b/crypto/src/asn1/DerBitString.cs @@ -95,29 +95,29 @@ namespace Org.BouncyCastle.Asn1 Debug.Assert(0 < bytes && bytes <= 4); - byte[] result = new byte[bytes]; + byte[] data = new byte[bytes]; --bytes; for (int i = 0; i < bytes; i++) { - result[i] = (byte)namedBits; + data[i] = (byte)namedBits; namedBits >>= 8; } Debug.Assert((namedBits & 0xFF) != 0); - result[bytes] = (byte)namedBits; + data[bytes] = (byte)namedBits; - int pad = 0; - while ((namedBits & (1 << pad)) == 0) + int padBits = 0; + while ((namedBits & (1 << padBits)) == 0) { - ++pad; + ++padBits; } - Debug.Assert(pad < 8); + Debug.Assert(padBits < 8); - this.mData = result; - this.mPadBits = pad; + this.mData = data; + this.mPadBits = padBits; } public DerBitString( @@ -187,20 +187,18 @@ namespace Org.BouncyCastle.Asn1 { int last = mData[mData.Length - 1]; int mask = (1 << mPadBits) - 1; + int unusedBits = last & mask; - if ((last & mask) != 0) + if (unusedBits != 0) { - byte[] result = Arrays.Prepend(mData, (byte)mPadBits); + byte[] contents = Arrays.Prepend(mData, (byte)mPadBits); /* - * X.690-0207 11.2.1: Each unused bit in the final octet of the encoding of a bit string value shall be set to zero. - * - * NOTE: 'pad' is constrained to be 0 if 'bytes' are empty, in which case this is a no-op. - */ - last ^= (last & mask); - result[result.Length - 1] &= (byte)last; - - derOut.WriteEncoded(Asn1Tags.BitString, result); + * X.690-0207 11.2.1: Each unused bit in the final octet of the encoding of a bit string value shall be set to zero. + */ + contents[contents.Length - 1] = (byte)(last ^ unusedBits); + + derOut.WriteEncoded(Asn1Tags.BitString, contents); return; } } |