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libsec: remove aesCTRencrypt()/aesCTRdecrypt() (thanks mischief and qrstuv)

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as mischief and qrstuv point out, these functions are not very usefull
and are even implemented wrong (incrementCTR()), so deleting the code.
This commit is contained in:
cinap_lenrek 2015-04-29 02:58:10 +02:00
parent e9c9ea4235
commit 12bb7bcfff
3 changed files with 1 additions and 72 deletions
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3
sys/include/libsec.h
View file

@ -23,7 +23,6 @@ struct AESstate
ulong setup;
int rounds;
int keybytes;
uint ctrsz;
uchar key[AESmaxkey]; /* unexpanded key */
ulong ekey[4*(AESmaxrounds + 1)]; /* encryption key */
ulong dkey[4*(AESmaxrounds + 1)]; /* decryption key */
@ -38,8 +37,6 @@ void aes_decrypt(ulong rk[], int Nr, uchar ct[16], uchar pt[16]);
void setupAESstate(AESstate *s, uchar key[], int keybytes, uchar *ivec);
void aesCBCencrypt(uchar *p, int len, AESstate *s);
void aesCBCdecrypt(uchar *p, int len, AESstate *s);
void aesCTRdecrypt(uchar *p, int len, AESstate *s);
void aesCTRencrypt(uchar *p, int len, AESstate *s);
void setupAESXCBCstate(AESstate *s);
uchar* aesXCBCmac(uchar *p, int len, AESstate *s);

15
sys/man/2/aes
View file

@ -1,6 +1,6 @@
.TH AES 2
.SH NAME
setupAESstate, aesCBCencrypt, aesCBCdecrypt, aesCTRencrypt, aesCTRdecrypt, setupAESXCBCstate, aesXCBCmac - advanced encryption standard (rijndael)
setupAESstate, aesCBCencrypt, aesCBCdecrypt, setupAESXCBCstate, aesXCBCmac - advanced encryption standard (rijndael)
.SH SYNOPSIS
.B #include <u.h>
.br
@ -28,12 +28,6 @@ void aesCBCencrypt(uchar *p, int len, AESstate *s)
void aesCBCdecrypt(uchar *p, int len, AESstate *s)
.PP
.B
void aesCTRencrypt(uchar *p, int len, AESstate *s)
.PP
.B
void aesCTRdecrypt(uchar *p, int len, AESstate *s)
.PP
.B
void setupAESXCBCstate(AESstate *s)
.PP
.B
@ -52,11 +46,6 @@ are the block ciphers, corresponding to
and
.I aesCBCdecrypt
implement cipher-block-chaining encryption.
.I AesCTRencrypt
and
.I aesCTRdecrypt
implement counter mode, per RFC 3686;
they are identical operations.
.I setupAESXCBCstate
and
.I aesXCBCmac
@ -93,8 +82,6 @@ in
The functions
.IR aes_encrypt ,
.IR aes_decrypt ,
.IR aesCTRencrypt ,
.IR aesCTRdecrypt ,
.IR setupAESXCBCstate ,
and
.IR aesXCBCmac

55
sys/src/libsec/port/aes.c
View file

@ -220,61 +220,6 @@ aesCBCdecrypt(uchar *p, int len, AESstate *s)
}
}
/*
* AES-CTR mode, per rfc3686.
* CTRs could be precalculated for efficiency
* and there would also be less back and forth mp
*/
static void
incrementCTR(uchar *p, uint ctrsz)
{
int len;
uchar *ctr;
mpint *mpctr, *mpctrsz;
ctr = p + AESbsize - ctrsz;
mpctr = betomp(ctr, ctrsz, nil);
mpctrsz = itomp(1 << (ctrsz*8), nil);
mpadd(mpctr, mpone, mpctr);
mpmod(mpctr, mpctrsz, mpctr);
len = mptobe(mpctr, ctr, ctrsz, nil);
assert(len == ctrsz);
mpfree(mpctrsz);
mpfree(mpctr);
}
void
aesCTRencrypt(uchar *p, int len, AESstate *s)
{
uchar q[AESbsize];
uchar *ip, *eip, *ctr;
ctr = s->ivec;
for(; len >= AESbsize; len -= AESbsize){
ip = q;
aes_encrypt(s->ekey, s->rounds, ctr, q);
for(eip = p + AESbsize; p < eip; )
*p++ ^= *ip++;
incrementCTR(ctr, s->ctrsz);
}
if(len > 0){
ip = q;
aes_encrypt(s->ekey, s->rounds, ctr, q);
for(eip = p + len; p < eip; )
*p++ ^= *ip++;
incrementCTR(ctr, s->ctrsz);
}
}
void
aesCTRdecrypt(uchar *p, int len, AESstate *s)
{
aesCTRencrypt(p, len, s);
}
/* taken from sha1; TODO: verify suitability (esp. byte order) for aes */
/*
* encodes input (ulong) into output (uchar). Assumes len is