crypto/internal/fips140test: add CMAC-AES ACVP tests

Adds ACVP test coverage for CMAC-AES based on the NIST spec:
  https://pages.nist.gov/ACVP/draft-fussell-acvp-mac.html

Updates golang#69642

Change-Id: Ie731863b84c6f8d74c64daa6a6848354420151b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/635762
Reviewed-by: Roland Shoemaker <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: cpu

src/crypto/internal/fips140test/acvp_capabilities.json

@@ -53,5 +53,6 @@
   {"algorithm":"ACVP-AES-CBC","direction":["encrypt","decrypt"],"keyLen":[128,192,256],"revision":"1.0"},
   {"algorithm":"ACVP-AES-CTR","direction":["encrypt","decrypt"],"keyLen":[128,192,256],"payloadLen":[{"min":8,"max":128,"increment":8}],"incrementalCounter":true,"overflowCounter":true,"performCounterTests":true,"revision":"1.0"},
   {"algorithm":"ACVP-AES-GCM","direction":["encrypt","decrypt"],"keyLen":[128,192,256],"payloadLen":[{"min":0,"max":65536,"increment":8}],"aadLen":[{"min":0,"max":65536,"increment":8}],"tagLen":[96,104,112,120,128],"ivLen":[96],"ivGen":"external","revision":"1.0"},
-  {"algorithm":"ACVP-AES-GCM","direction":["encrypt","decrypt"],"keyLen":[128,192,256],"payloadLen":[{"min":0,"max":65536,"increment":8}],"aadLen":[{"min":0,"max":65536,"increment":8}],"tagLen":[128],"ivLen":[96],"ivGen":"internal","ivGenMode":"8.2.2","revision":"1.0"}
+  {"algorithm":"ACVP-AES-GCM","direction":["encrypt","decrypt"],"keyLen":[128,192,256],"payloadLen":[{"min":0,"max":65536,"increment":8}],"aadLen":[{"min":0,"max":65536,"increment":8}],"tagLen":[128],"ivLen":[96],"ivGen":"internal","ivGenMode":"8.2.2","revision":"1.0"},
+  {"algorithm":"CMAC-AES","capabilities":[{"direction":["gen","ver"],"msgLen":[{"min":0,"max":524288,"increment":8}],"keyLen":[128,256],"macLen":[{"min":8,"max":128,"increment":8}]}],"revision":"1.0"}
 ]

src/crypto/internal/fips140test/acvp_test.config.json

@@ -35,5 +35,7 @@
 
   {"Wrapper": "go", "In": "vectors/ACVP-AES-CBC.bz2", "Out": "expected/ACVP-AES-CBC.bz2"},
   {"Wrapper": "go", "In": "vectors/ACVP-AES-CTR.bz2", "Out": "expected/ACVP-AES-CTR.bz2"},
-  {"Wrapper": "go", "In": "vectors/ACVP-AES-GCM.bz2", "Out": "expected/ACVP-AES-GCM.bz2"}
+  {"Wrapper": "go", "In": "vectors/ACVP-AES-GCM.bz2", "Out": "expected/ACVP-AES-GCM.bz2"},
+
+  {"Wrapper": "go", "In": "vectors/CMAC-AES.bz2", "Out": "expected/CMAC-AES.bz2"}
 ]

src/crypto/internal/fips140test/acvp_test.go

@@ -35,6 +35,7 @@ import (
 	"crypto/internal/fips140/sha256"
 	"crypto/internal/fips140/sha3"
 	"crypto/internal/fips140/sha512"
+	"crypto/internal/fips140/subtle"
 	"crypto/rand"
 	_ "embed"
 	"encoding/binary"
@@ -189,6 +190,9 @@ var (
 		"AES-GCM/open":           cmdAesGcmOpen(false),
 		"AES-GCM-randnonce/seal": cmdAesGcmSeal(true),
 		"AES-GCM-randnonce/open": cmdAesGcmOpen(true),
+
+		"CMAC-AES":        cmdCmacAesAft(),
+		"CMAC-AES/verify": cmdCmacAesVerifyAft(),
 	}
 )
 
@@ -1154,6 +1158,57 @@ func cmdAesGcmOpen(randNonce bool) command {
 	}
 }
 
+func cmdCmacAesAft() command {
+	return command{
+		requiredArgs: 3, // Number of output bytes, key, message
+		handler: func(args [][]byte) ([][]byte, error) {
+			// safe to truncate to int based on our capabilities describing a max MAC output len of 128 bits.
+			outputLen := int(binary.LittleEndian.Uint32(args[0]))
+			key := args[1]
+			message := args[2]
+
+			blockCipher, err := aes.New(key)
+			if err != nil {
+				return nil, fmt.Errorf("creating AES block cipher with key len %d: %w", len(key), err)
+			}
+
+			cmac := gcm.NewCMAC(blockCipher)
+			tag := cmac.MAC(message)
+
+			if outputLen > len(tag) {
+				return nil, fmt.Errorf("invalid output length: expected %d, got %d", outputLen, len(tag))
+			}
+
+			return [][]byte{tag[:outputLen]}, nil
+		},
+	}
+}
+
+func cmdCmacAesVerifyAft() command {
+	return command{
+		requiredArgs: 3, // Key, message, claimed MAC
+		handler: func(args [][]byte) ([][]byte, error) {
+			key := args[0]
+			message := args[1]
+			claimedMAC := args[2]
+
+			blockCipher, err := aes.New(key)
+			if err != nil {
+				return nil, fmt.Errorf("creating AES block cipher with key len %d: %w", len(key), err)
+			}
+
+			cmac := gcm.NewCMAC(blockCipher)
+			tag := cmac.MAC(message)
+
+			if subtle.ConstantTimeCompare(tag[:len(claimedMAC)], claimedMAC) != 1 {
+				return [][]byte{{0}}, nil
+			}
+
+			return [][]byte{{1}}, nil
+		},
+	}
+}
+
 func TestACVP(t *testing.T) {
 	testenv.SkipIfShortAndSlow(t)