Allow block ciphers to specify which modes they supportselect-modes

8 files changed, 64 insertions, 8 deletions

diff --git a/src/AES.c b/src/AES.c
index 1e705da..2f686d4 100644
--- a/src/AES.c
+++ b/src/AES.c
@@ -32,6 +32,12 @@
 #define BLOCK_SIZE 16
 #define KEY_SIZE 0
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 #define MAXKC	(256/32)
 #define MAXKB	(256/8)
 #define MAXNR	14
diff --git a/src/AESNI.c b/src/AESNI.c
index 50f0cd6..b8e0030 100644
--- a/src/AESNI.c
+++ b/src/AESNI.c
@@ -33,6 +33,12 @@
 #define BLOCK_SIZE 16
 #define KEY_SIZE 0
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 #define MAXKC (256/32)
 #define MAXKB (256/8)
 #define MAXNR 14
diff --git a/src/ARC2.c b/src/ARC2.c
index 71858f6..d6c6f17 100644
--- a/src/ARC2.c
+++ b/src/ARC2.c
@@ -49,6 +49,12 @@
 #define KEY_SIZE 0
 #define PCT_ARC2_MODULE  /* Defined to get ARC2's additional keyword arguments */
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 typedef uint32_t U32;
 typedef uint16_t U16;
 typedef uint8_t U8;
diff --git a/src/Blowfish.c b/src/Blowfish.c
index f1ab55a..cd0a54a 100644
--- a/src/Blowfish.c
+++ b/src/Blowfish.c
@@ -35,6 +35,12 @@
 #define BLOCK_SIZE 8    /* 64-bit block size */
 #define KEY_SIZE 0      /* variable key size */
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 #define BLOWFISH_MAGIC 0xf9d565deu
 typedef struct {
     uint32_t magic;
diff --git a/src/CAST.c b/src/CAST.c
index d7b00f3..9476683 100644
--- a/src/CAST.c
+++ b/src/CAST.c
@@ -48,6 +48,12 @@
 #define BLOCK_SIZE 8
 #define KEY_SIZE 0
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 /* adjust these according to your compiler/platform. On some machines
    uint32 will have to be a long. It's OK if uint32 is more than 32 bits. */
 typedef uint32_t uint32;
diff --git a/src/DES.c b/src/DES.c
index 65171fb..c0c6f02 100644
--- a/src/DES.c
+++ b/src/DES.c
@@ -37,6 +37,12 @@
 
 #include <assert.h>
 
+#define HAS_ENCRYPT 1
+#define HAS_MODE_CBC 1
+#define HAS_MODE_CFB 1
+#define HAS_MODE_OFB 1
+#define HAS_MODE_CTR 1
+
 typedef struct {
     symmetric_key sk;
 } block_state;
diff --git a/src/block_template.c b/src/block_template.c
index 99aee43..fcd5265 100644
--- a/src/block_template.c
+++ b/src/block_template.c
@@ -134,17 +134,30 @@ ALGnew(PyObject *self, PyObject *args, PyObject *kwdict)
 		return NULL;
 	}
 
-	if (mode<MODE_ECB || mode>MODE_CTR) 
-	{
-		PyErr_Format(PyExc_ValueError, 
-			     "Unknown cipher feedback mode %i",
-			     mode);
-		return NULL;
-	}
-	if (mode == MODE_PGP) {
+	switch (mode) {
+	case MODE_ECB:
+#ifdef HAS_MODE_CBC
+	case MODE_CBC:
+#endif
+#ifdef HAS_MODE_CFB
+	case MODE_CFB:
+#endif
+#ifdef HAS_MODE_OFB
+	case MODE_OFB:
+#endif
+#ifdef HAS_MODE_CTR
+	case MODE_CTR:
+#endif
+		break;
+	case MODE_PGP:
 		PyErr_Format(PyExc_ValueError, 
 			     "MODE_PGP is not supported anymore");
 		return NULL;
+	default:
+		PyErr_Format(PyExc_ValueError,
+			     "Unknown or unsupported cipher feedback mode %i",
+			     mode);
+		return NULL;
 	}
 	if (KEY_SIZE!=0 && keylen!=KEY_SIZE)
 	{
@@ -611,7 +624,9 @@ ALG_Decrypt(ALGobject *self, PyObject *args)
 /* ALG object methods */
 static PyMethodDef ALGmethods[] =
 {
+#ifdef HAS_ENCRYPT
  {"encrypt", (PyCFunction) ALG_Encrypt, METH_O, ALG_Encrypt__doc__},
+#endif
  {"decrypt", (PyCFunction) ALG_Decrypt, METH_O, ALG_Decrypt__doc__},
  {NULL, NULL}			/* sentinel */
 };
diff --git a/src/pycrypto_common.h b/src/pycrypto_common.h
index 3182ec1..626543e 100644
--- a/src/pycrypto_common.h
+++ b/src/pycrypto_common.h
@@ -37,5 +37,10 @@
 # error "stdint.h and inttypes.h not found"
 #endif
 
+#undef HAS_ENCRYPT
+#undef HAS_MODE_CBC
+#undef HAS_MODE_CFB
+#undef HAS_MODE_OFB
+#undef HAS_MODE_CTR
 
 #endif /* PYCRYPTO_COMMON_H */