Updates c based hmac wrapper to support non byte boundary MAC.

* #46
usnistgov · Dec 2, 2020 · 02e6963 · 02e6963
1 parent 69d9efa
commit 02e6963
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Showing 2 changed files with 17 additions and 9 deletions.
diff --git a/gen-val/src/crypto/src/NIST.CVP.Crypto/HMAC/FastHmac/FastHmacSha.cs b/gen-val/src/crypto/src/NIST.CVP.Crypto/HMAC/FastHmac/FastHmacSha.cs
@@ -4,6 +4,7 @@
 using NIST.CVP.Crypto.Common.MAC;
 using NIST.CVP.Crypto.Common.MAC.HMAC;
 using NIST.CVP.Math;
+using NIST.CVP.Math.Helpers;
 
 namespace NIST.CVP.Crypto.HMAC.FastHmac
 {
@@ -36,12 +37,15 @@ public MacResult Generate(BitString key, BitString message, int macLength = 0)
                 hashLength = 512256;
             }
 
+            var macLengthInBytes = (uint) macLength.CeilingDivide(BitString.BITSINBYTE);
+
             // C expects securityStrength, keyLen and macLen to all be in BYTES, but msgLen is in BITS
-            void osxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_osx(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
-            void winAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_win(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
-            void linuxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_linux(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
+            void osxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_osx(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
+            void winAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_win(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
+            void linuxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA_linux(hashLength, key.GetPaddedBytes(), (uint)key.BitLength/8, message.GetPaddedBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
 
-            var mac = new BitString(DllHelper.PickOS(osxAction, winAction, linuxAction, macLength/8));
+            var mac = new BitString(DllHelper.PickOS(osxAction, winAction, linuxAction, (int)macLengthInBytes))
+                .GetMostSignificantBits(macLength);
             return new MacResult(mac);
         }
     }

diff --git a/gen-val/src/crypto/src/NIST.CVP.Crypto/HMAC/FastHmac/FastHmacSha3.cs b/gen-val/src/crypto/src/NIST.CVP.Crypto/HMAC/FastHmac/FastHmacSha3.cs
@@ -4,6 +4,7 @@
 using NIST.CVP.Crypto.Common.MAC;
 using NIST.CVP.Crypto.Common.MAC.HMAC;
 using NIST.CVP.Math;
+using NIST.CVP.Math.Helpers;
 
 namespace NIST.CVP.Crypto.HMAC.FastHmac
 {
@@ -27,13 +28,16 @@ public MacResult Generate(BitString key, BitString message, int macLength = 0)
             {
                 macLength = OutputLength;
             }
-
+
+            var macLengthInBytes = (uint) macLength.CeilingDivide(BitString.BITSINBYTE);
+
             // C expects securityStrength, keyLen and macLen to all be in BYTES, but msgLen is in BITS
-            void osxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_osx((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
-            void winAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_win((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
-            void linuxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_linux((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, (uint)macLength/8);
+            void osxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_osx((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
+            void winAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_win((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
+            void linuxAction(IntPtr digPtr) => HmacDllLoader.hmac_SHA3_linux((uint)_hashFunction.OutputLen/8, paddedKey.ToBytes(), (uint)key.BitLength/8, paddedMsg.ToBytes(), (uint)message.BitLength, digPtr, macLengthInBytes);
 
-            var mac = new BitString(DllHelper.PickOS(osxAction, winAction, linuxAction, macLength/8));
+            var mac = new BitString(DllHelper.PickOS(osxAction, winAction, linuxAction, (int)macLengthInBytes))
+                .GetMostSignificantBits(macLength);
             return new MacResult(mac);
         }
     }