Merge pull request #626 from reaperhulk/cast5-ctr-vectors

CAST5 CTR vectors

2 files changed, 27 insertions, 2 deletions

diff --git a/docs/development/custom-vectors/cast5/generate_cast5.py b/docs/development/custom-vectors/cast5/generate_cast5.py
index c3f579e7..32ef3b43 100644
--- a/docs/development/custom-vectors/cast5/generate_cast5.py
+++ b/docs/development/custom-vectors/cast5/generate_cast5.py
@@ -1,6 +1,6 @@
 import binascii
 
-from cryptography.hazmat.backends.openssl.backend import backend
+from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives.ciphers import base, algorithms, modes
 
 
@@ -8,7 +8,7 @@ def encrypt(mode, key, iv, plaintext):
     cipher = base.Cipher(
         algorithms.CAST5(binascii.unhexlify(key)),
         mode(binascii.unhexlify(iv)),
-        backend
+        default_backend()
     )
     encryptor = cipher.encryptor()
     ct = encryptor.update(binascii.unhexlify(plaintext))
@@ -57,3 +57,5 @@ ofb_path = "tests/hazmat/primitives/vectors/ciphers/AES/OFB/OFBMMT128.rsp"
 write_file(build_vectors(modes.OFB, ofb_path), "cast5-ofb.txt")
 cfb_path = "tests/hazmat/primitives/vectors/ciphers/AES/CFB/CFB128MMT128.rsp"
 write_file(build_vectors(modes.CFB, cfb_path), "cast5-cfb.txt")
+ctr_path = "tests/hazmat/primitives/vectors/ciphers/AES/CTR/aes-128-ctr.txt"
+write_file(build_vectors(modes.CTR, ctr_path), "cast5-ctr.txt")
diff --git a/docs/development/custom-vectors/cast5/verify_cast5.go b/docs/development/custom-vectors/cast5/verify_cast5.go
index 49e1023d..f735d989 100644
--- a/docs/development/custom-vectors/cast5/verify_cast5.go
+++ b/docs/development/custom-vectors/cast5/verify_cast5.go
@@ -91,6 +91,26 @@ func (o cfbVerifier) validate(count string, key, iv, plaintext, expected_ciphert
 	}
 }
 
+type ctrVerifier struct{}
+
+func (o ctrVerifier) validate(count string, key, iv, plaintext, expected_ciphertext []byte) {
+	block, err := cast5.NewCipher(key)
+	if err != nil {
+		panic(err)
+	}
+
+	ciphertext := make([]byte, len(plaintext))
+	stream := cipher.NewCTR(block, iv)
+	stream.XORKeyStream(ciphertext, plaintext)
+
+	if !bytes.Equal(ciphertext, expected_ciphertext) {
+		panic(fmt.Errorf("vector mismatch @ COUNT = %s:\n  %s != %s\n",
+			count,
+			hex.EncodeToString(expected_ciphertext),
+			hex.EncodeToString(ciphertext)))
+	}
+}
+
 func validateVectors(verifier VectorVerifier, filename string) {
 	vectors, err := os.Open(filename)
 	if err != nil {
@@ -138,4 +158,7 @@ func main() {
 	validateVectors(cbcVerifier{},
 		"tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-cbc.txt")
 	fmt.Println("CBC OK.")
+	validateVectors(ctrVerifier{},
+		"tests/hazmat/primitives/vectors/ciphers/CAST5/cast5-ctr.txt")
+	fmt.Println("CTR OK.")
 }