diff options
| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2019-08-29 17:02:26 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2019-08-29 17:02:26 +0700 |
| commit | afc774cffbeb9807882b053f21def5e3757a9133 (patch) | |
| tree | b9304970a7ef550638c72f5136524335a5ed3f6a | |
| parent | Check CCM tag length during initialization (diff) | |
| download | BouncyCastle.NET-ed25519-afc774cffbeb9807882b053f21def5e3757a9133.tar.xz | |
CCM: only enforce the tag length restrictions for encryption
| -rw-r--r-- | crypto/src/crypto/modes/CcmBlockCipher.cs | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/crypto/src/crypto/modes/CcmBlockCipher.cs b/crypto/src/crypto/modes/CcmBlockCipher.cs index 0e4bb7fc9..2981fdcb2 100644 --- a/crypto/src/crypto/modes/CcmBlockCipher.cs +++ b/crypto/src/crypto/modes/CcmBlockCipher.cs @@ -68,7 +68,7 @@ namespace Org.BouncyCastle.Crypto.Modes nonce = param.GetNonce(); initialAssociatedText = param.GetAssociatedText(); - macSize = GetMacSize(param.MacSize); + macSize = GetMacSize(forEncryption, param.MacSize); cipherParameters = param.Key; } else if (parameters is ParametersWithIV) @@ -77,7 +77,7 @@ namespace Org.BouncyCastle.Crypto.Modes nonce = param.GetIV(); initialAssociatedText = null; - macSize = GetMacSize(64); + macSize = GetMacSize(forEncryption, 64); cipherParameters = param.Parameters; } else @@ -434,9 +434,9 @@ namespace Org.BouncyCastle.Crypto.Modes return cMac.DoFinal(macBlock, 0); } - private int GetMacSize(int requestedMacBits) + private int GetMacSize(bool forEncryption, int requestedMacBits) { - if (requestedMacBits < 32 || requestedMacBits > 128 || 0 != (requestedMacBits & 15)) + if (forEncryption && (requestedMacBits < 32 || requestedMacBits > 128 || 0 != (requestedMacBits & 15))) throw new ArgumentException("tag length in octets must be one of {4,6,8,10,12,14,16}"); return requestedMacBits >> 3; |