Add secondary rc2 setup function

...to be able to pass the effective key length.

src/ciphers/rc2.c

@@ -63,23 +63,27 @@ static const unsigned char permute[256] = {
     Initialize the RC2 block cipher
     @param key The symmetric key you wish to pass
     @param keylen The key length in bytes
+    @param bits The effective key length in bits
     @param num_rounds The number of rounds desired (0 for default)
     @param skey The key in as scheduled by this function.
     @return CRYPT_OK if successful
  */
-int rc2_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
+int rc2_setup_ex(const unsigned char *key, int keylen, int bits, int num_rounds, symmetric_key *skey)
 {
    unsigned *xkey = skey->rc2.xkey;
    unsigned char tmp[128];
    unsigned T8, TM;
-   int i, bits;
+   int i;
 
    LTC_ARGCHK(key  != NULL);
    LTC_ARGCHK(skey != NULL);
 
-   if (keylen < 5 || keylen > 128) {
+   if (keylen == 0 || keylen > 128 || bits > 1024) {
       return CRYPT_INVALID_KEYSIZE;
    }
+   if (bits == 0) {
+      bits = 1024;
+   }
 
    if (num_rounds != 0 && num_rounds != 16) {
       return CRYPT_INVALID_ROUNDS;
@@ -97,7 +101,6 @@ int rc2_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_ke
    }
 
    /* Phase 2 - reduce effective key size to "bits" */
-   bits = keylen<<3;
    T8   = (unsigned)(bits+7)>>3;
    TM   = (255 >> (unsigned)(7 & -bits));
    tmp[128 - T8] = permute[tmp[128 - T8] & TM];
@@ -117,6 +120,22 @@ int rc2_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_ke
    return CRYPT_OK;
 }
 
+/**
+   Initialize the RC2 block cipher
+
+     The effective key length is here always keylen * 8
+
+   @param key The symmetric key you wish to pass
+   @param keylen The key length in bytes
+   @param num_rounds The number of rounds desired (0 for default)
+   @param skey The key in as scheduled by this function.
+   @return CRYPT_OK if successful
+*/
+int rc2_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
+{
+   return rc2_setup_ex(key, keylen, keylen * 8, num_rounds, skey);
+}
+
 /**********************************************************************\
 * Encrypt an 8-byte block of plaintext using the given key.            *
 \**********************************************************************/
@@ -284,37 +303,47 @@ int rc2_test(void)
     return CRYPT_NOP;
  #else
    static const struct {
-        int keylen;
+        int keylen, bits;
         unsigned char key[16], pt[8], ct[8];
    } tests[] = {
 
-#if 0
+   { 8, 63,
-   { 1,
+     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-     { 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
      { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
-     { 0x61, 0xa8, 0xa2, 0x44, 0xad, 0xac, 0xcc, 0xf0 }
+     { 0xeb, 0xb7, 0x73, 0xf9, 0x93, 0x27, 0x8e, 0xff }
    },
-#endif
+   { 8, 64,
-   { 7,
-     { 0x88, 0xbc, 0xa9, 0x0e, 0x90, 0x87, 0x5a, 0x00,
-       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
-     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
-     { 0x6c, 0xcf, 0x43, 0x08, 0x97, 0x4c, 0x26, 0x7f }
-   },
-   { 8,
      { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
      { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
      { 0x27, 0x8b, 0x27, 0xe4, 0x2e, 0x2f, 0x0d, 0x49 }
    },
-   { 8,
+   { 8, 64,
      { 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
      { 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
      { 0x30, 0x64, 0x9e, 0xdf, 0x9b, 0xe7, 0xd2, 0xc2 }
    },
-   { 16,
+   { 1, 64,
+     { 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+     { 0x61, 0xa8, 0xa2, 0x44, 0xad, 0xac, 0xcc, 0xf0 }
+   },
+   { 7, 64,
+     { 0x88, 0xbc, 0xa9, 0x0e, 0x90, 0x87, 0x5a, 0x00,
+       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+     { 0x6c, 0xcf, 0x43, 0x08, 0x97, 0x4c, 0x26, 0x7f }
+   },
+   { 16, 64,
+     { 0x88, 0xbc, 0xa9, 0x0e, 0x90, 0x87, 0x5a, 0x7f,
+       0x0f, 0x79, 0xc3, 0x84, 0x62, 0x7b, 0xaf, 0xb2 },
+     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+     { 0x1a, 0x80, 0x7d, 0x27, 0x2b, 0xbe, 0x5d, 0xb1 }
+   },
+   { 16, 128,
      { 0x88, 0xbc, 0xa9, 0x0e, 0x90, 0x87, 0x5a, 0x7f,
        0x0f, 0x79, 0xc3, 0x84, 0x62, 0x7b, 0xaf, 0xb2 },
      { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
@@ -327,8 +356,15 @@ int rc2_test(void)
 
     for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) {
         zeromem(tmp, sizeof(tmp));
-        if ((err = rc2_setup(tests[x].key, tests[x].keylen, 0, &skey)) != CRYPT_OK) {
+        if (tests[x].bits == (tests[x].keylen * 8)) {
-           return err;
+           if ((err = rc2_setup(tests[x].key, tests[x].keylen, 0, &skey)) != CRYPT_OK) {
+              return err;
+           }
+        }
+        else {
+           if ((err = rc2_setup_ex(tests[x].key, tests[x].keylen, tests[x].bits, 0, &skey)) != CRYPT_OK) {
+              return err;
+           }
         }
 
         rc2_ecb_encrypt(tests[x].pt, tmp[0], &skey);

src/headers/tomcrypt_cipher.h

@@ -617,6 +617,7 @@ extern const struct ltc_cipher_descriptor rc6_desc;
 
 #ifdef LTC_RC2
 int rc2_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey);
+int rc2_setup_ex(const unsigned char *key, int keylen, int bits, int num_rounds, symmetric_key *skey);
 int rc2_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey);
 int rc2_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey);
 int rc2_test(void);