Cleanup; assert in CTR mode implementations that there is always an

initialization vector, otherwise their use is unsafe

git-svn-id: svn://anonsvn.mit.edu/krb5/users/lhoward/camellia-ccm@24045 dc483132-0cff-0310-8789-dd5450dbe970

6 files changed, 32 insertions, 57 deletions

diff --git a/src/include/krb5/krb5.hin b/src/include/krb5/krb5.hin
index 85a9a85..9dd5a8b 100644
--- a/src/include/krb5/krb5.hin
+++ b/src/include/krb5/krb5.hin
@@ -424,11 +424,11 @@ typedef struct _krb5_crypto_iov {
 #define ENCTYPE_CAMELLIA128_CTS_HMAC_SHA1_96 0x0019
 #define ENCTYPE_CAMELLIA256_CTS_HMAC_SHA1_96 0x001a
 #ifdef AES_CCM
-#define ENCTYPE_AES128_CCM_128  -64
-#define ENCTYPE_AES256_CCM_128  -65
+#define ENCTYPE_AES128_CCM_128  -64     /* AES CCM mode with 128-bit key */
+#define ENCTYPE_AES256_CCM_128  -65     /* AES CCM mode with 256-bit key */
 #endif
-#define ENCTYPE_CAMELLIA128_CCM_128 -66
-#define ENCTYPE_CAMELLIA256_CCM_128 -67
+#define ENCTYPE_CAMELLIA128_CCM_128 -66 /* Camellia CCM mode with 128-bit key */
+#define ENCTYPE_CAMELLIA256_CCM_128 -67 /* Camellia CCM mode with 256-bit key */
 #define ENCTYPE_UNKNOWN         0x01ff
 
 #define CKSUMTYPE_CRC32         0x0001
@@ -446,11 +446,11 @@ typedef struct _krb5_crypto_iov {
 #define CKSUMTYPE_HMAC_SHA1_96_CAMELLIA128     -17
 #define CKSUMTYPE_HMAC_SHA1_96_CAMELLIA256     -18
 #ifdef AES_CCM
-#define CKSUMTYPE_CMAC_128_AES128              -64
-#define CKSUMTYPE_CMAC_128_AES256              -65
+#define CKSUMTYPE_CMAC_128_AES128              -64  /* CMAC with 128-bit AES key */
+#define CKSUMTYPE_CMAC_128_AES256              -65  /* CMAC with 256-bit AES key */
 #endif
-#define CKSUMTYPE_CMAC_128_CAMELLIA128         -66
-#define CKSUMTYPE_CMAC_128_CAMELLIA256         -67
+#define CKSUMTYPE_CMAC_128_CAMELLIA128         -66  /* CMAC with 128-bit Camellia key */
+#define CKSUMTYPE_CMAC_128_CAMELLIA256         -67  /* CMAC with 256-bit Camellia key */
 #define CKSUMTYPE_MD5_HMAC_ARCFOUR -137 /*Microsoft netlogon cksumtype*/
 #define CKSUMTYPE_HMAC_MD5_ARCFOUR -138 /*Microsoft md5 hmac cksumtype*/
 
diff --git a/src/lib/crypto/builtin/enc_provider/aes_ctr.c b/src/lib/crypto/builtin/enc_provider/aes_ctr.c
index 06c6545..e03bfad 100644
--- a/src/lib/crypto/builtin/enc_provider/aes_ctr.c
+++ b/src/lib/crypto/builtin/enc_provider/aes_ctr.c
@@ -122,15 +122,12 @@ krb5int_aes_encrypt_ctr(krb5_key key,
     input_pos.ignore_header = output_pos.ignore_header = 1;
     input_pos.pad_to_boundary = output_pos.pad_to_boundary = 1;
 
-    if (ivec != NULL) {
-	if (ivec->length != BLOCK_SIZE)
-	    return KRB5_BAD_MSIZE;
-
-	memcpy(ctr, ivec->data, BLOCK_SIZE);
-    } else {
-	memset(ctr, 0, BLOCK_SIZE);
-	ctr[0] = DEFAULT_COUNTER_LEN - 1;
-    }
+    assert(ivec != NULL);
+
+    if (ivec->length != BLOCK_SIZE)
+	return KRB5_BAD_MSIZE;
+
+    memcpy(ctr, ivec->data, BLOCK_SIZE);
 
     getctrblockno(&blockno, ctr);
 
diff --git a/src/lib/crypto/builtin/enc_provider/camellia_ctr.c b/src/lib/crypto/builtin/enc_provider/camellia_ctr.c
index 02603eb..a6d8224 100644
--- a/src/lib/crypto/builtin/enc_provider/camellia_ctr.c
+++ b/src/lib/crypto/builtin/enc_provider/camellia_ctr.c
@@ -122,15 +122,12 @@ krb5int_camellia_encrypt_ctr(krb5_key key,
     input_pos.ignore_header = output_pos.ignore_header = 1;
     input_pos.pad_to_boundary = output_pos.pad_to_boundary = 1;
 
-    if (ivec != NULL) {
-        if (ivec->length != BLOCK_SIZE)
-            return KRB5_BAD_MSIZE;
-
-        memcpy(ctr, ivec->data, BLOCK_SIZE);
-    } else {
-        memset(ctr, 0, BLOCK_SIZE);
-        ctr[0] = DEFAULT_COUNTER_LEN - 1;
-    }
+    assert(ivec != NULL);
+
+    if (ivec->length != BLOCK_SIZE)
+        return KRB5_BAD_MSIZE;
+
+    memcpy(ctr, ivec->data, BLOCK_SIZE);
 
     getctrblockno(&blockno, ctr);
 
diff --git a/src/lib/crypto/krb/checksum/cmac.c b/src/lib/crypto/krb/checksum/cmac.c
index fae5f1e..3b5cde5 100644
--- a/src/lib/crypto/krb/checksum/cmac.c
+++ b/src/lib/crypto/krb/checksum/cmac.c
@@ -52,11 +52,6 @@ static unsigned char const_Rb[BLOCK_SIZE] = {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87
 };
 
-static unsigned char const_Zero[BLOCK_SIZE] = {
-    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-};
-
 static void
 xor_128(unsigned char *a, unsigned char *b, unsigned char *out)
 {
@@ -103,18 +98,10 @@ generate_subkey(const struct krb5_enc_provider *enc,
 
     d = make_data((char *)L, BLOCK_SIZE);
 
-    /*
-     * CBC in terms of CBC-MAC; at the cost of an additional XOR,
-     * this avoids needing to extend the SPI interface (because we
-     * need both the CBC-MAC function from the CCM provider and
-     * the CBC function from the CTS provider).
-     */
     ret = enc->cbc_mac(key, iov, 1, NULL, &d);
     if (ret != 0)
         return ret;
 
-    xor_128(const_Zero, L, L);
-
     if ((L[0] & 0x80) == 0) {
         leftshift_onebit(L, K1);
     } else {
diff --git a/src/lib/crypto/openssl/enc_provider/aes_ctr.c b/src/lib/crypto/openssl/enc_provider/aes_ctr.c
index 27d6608..c9e8907 100644
--- a/src/lib/crypto/openssl/enc_provider/aes_ctr.c
+++ b/src/lib/crypto/openssl/enc_provider/aes_ctr.c
@@ -91,15 +91,12 @@ krb5int_aes_encrypt_ctr(krb5_key key,
     input_pos.ignore_header = output_pos.ignore_header = 1;
     input_pos.pad_to_boundary = output_pos.pad_to_boundary = 1;
 
-    if (ivec != NULL) {
-        if (ivec->length != AES_BLOCK_SIZE)
-            return KRB5_BAD_MSIZE;
-
-        memcpy(ctr, ivec->data, AES_BLOCK_SIZE);
-    } else {
-        memset(ctr, 0, AES_BLOCK_SIZE);
-        ctr[0] = DEFAULT_COUNTER_LEN - 1;
-    }
+    assert(ivec != NULL);
+
+    if (ivec->length != AES_BLOCK_SIZE)
+        return KRB5_BAD_MSIZE;
+
+    memcpy(ctr, ivec->data, AES_BLOCK_SIZE);
 
     for (blockno = 0; ; blockno++) {
         unsigned char storage[AES_BLOCK_SIZE], *block;
diff --git a/src/lib/crypto/openssl/enc_provider/camellia_ctr.c b/src/lib/crypto/openssl/enc_provider/camellia_ctr.c
index 0145ebd..2812c05 100644
--- a/src/lib/crypto/openssl/enc_provider/camellia_ctr.c
+++ b/src/lib/crypto/openssl/enc_provider/camellia_ctr.c
@@ -90,15 +90,12 @@ krb5int_camellia_encrypt_ctr(krb5_key key,
     input_pos.ignore_header = output_pos.ignore_header = 1;
     input_pos.pad_to_boundary = output_pos.pad_to_boundary = 1;
 
-    if (ivec != NULL) {
-        if (ivec->length != CAMELLIA_BLOCK_SIZE)
-            return KRB5_BAD_MSIZE;
-
-        memcpy(ctr, ivec->data, CAMELLIA_BLOCK_SIZE);
-    } else {
-        memset(ctr, 0, CAMELLIA_BLOCK_SIZE);
-        ctr[0] = DEFAULT_COUNTER_LEN - 1;
-    }
+    assert(ivec != NULL);
+
+    if (ivec->length != CAMELLIA_BLOCK_SIZE)
+        return KRB5_BAD_MSIZE;
+
+    memcpy(ctr, ivec->data, CAMELLIA_BLOCK_SIZE);
 
     for (blockno = 0; ; blockno++) {
         unsigned char storage[CAMELLIA_BLOCK_SIZE], *block;