Add secondary rc2 setup function

...to be able to pass the effective key length.
This commit is contained in:
Steffen Jaeckel 2017-02-27 22:30:18 +01:00 committed by Karel Miko
parent 43c50423ad
commit 9a29428f8e
2 changed files with 58 additions and 21 deletions

View File

@ -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
{ 1,
{ 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
{ 8, 63,
{ 0x00, 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
{ 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,
{ 8, 64,
{ 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) {
return err;
if (tests[x].bits == (tests[x].keylen * 8)) {
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);

View File

@ -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);