/* This file is in the public domain. */

#include <stdlib.h>
#include <strings.h>
#include <blowfish.h>

#include "algs.h"
#include "panic.h"
#include "verbose.h"
#include "alg-util.h"

typedef struct bf_state BF_STATE;

struct bf_state {
  BLOWFISH_KEY key;
  unsigned char iv[8];
  int direction;
#define ENCRYPT 1
#define DECRYPT 2
  } ;

static void *enc_blowfish_cbc_init_enc(const void *key, const void *iv)
{
 BF_STATE *s;

 s = malloc(sizeof(BF_STATE));
 if (s == 0) return(0);
 blowfish_setkey(&s->key,key,16);
 bcopy(iv,&s->iv[0],8);
 s->direction = ENCRYPT;
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"blowfish-cbc %p: enc key=",(void *)s);
    for (i=0;i<16;i++) verb(CRYPTO,"%02x",((const unsigned char *)key)[i]);
    verb(CRYPTO," iv=");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",s->iv[i]);
    verb(CRYPTO,"\n");
  }
 return(s);
}

static void *enc_blowfish_cbc_init_dec(const void *key, const void *iv)
{
 BF_STATE *s;

 s = malloc(sizeof(BF_STATE));
 if (s == 0) return(0);
 blowfish_setkey(&s->key,key,16);
 bcopy(iv,&s->iv[0],8);
 s->direction = DECRYPT;
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"blowfish-cbc %p: dec key=",(void *)s);
    for (i=0;i<16;i++) verb(CRYPTO,"%02x",((const unsigned char *)key)[i]);
    verb(CRYPTO," iv=");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",s->iv[i]);
    verb(CRYPTO,"\n");
  }
 return(s);
}

static void enc_blowfish_cbc_process(void *state, const void *in, void *out, int datalen)
{
 BF_STATE *s;
 const unsigned char *ip;
 unsigned char *op;
 int len0;

 s = state;
 ip = in;
 op = out;
 if (datalen & 7) panic("misaligned length");
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"blowfish-cbc %p\n in ",(void *)s);
    for (i=0;i<datalen;i++) verb(CRYPTO,"%02x",((const unsigned char *)in)[i]);
    verb(CRYPTO,"\n iv ");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",s->iv[i]);
    verb(CRYPTO,"\n");
    len0 = datalen;
  }
 switch (s->direction)
  { case ENCRYPT:
       while (datalen > 0)
	{ xor_block(&s->iv[0],ip,&s->iv[0],8);
	  blowfish_encrypt(&s->key,&s->iv[0],&s->iv[0]);
	  bcopy(&s->iv[0],op,8);
	  ip += 8;
	  op += 8;
	  datalen -= 8;
	}
       break;
    case DECRYPT:
       while (datalen > 0)
	{ unsigned char ib[8];
	  bcopy(ip,&ib[0],8);
	  blowfish_decrypt(&s->key,ip,op);
	  xor_block(&s->iv[0],op,op,8);
	  bcopy(ib,&s->iv[0],8);
	  ip += 8;
	  op += 8;
	  datalen -= 8;
	}
       break;
    default:
       panic("bad direction");
       break;
  }
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"out ");
    for (i=0;i<len0;i++) verb(CRYPTO,"%02x",((unsigned char *)out)[i]);
    verb(CRYPTO,"\nniv ");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",s->iv[i]);
    verb(CRYPTO,"\n");
  }
}

static void enc_blowfish_cbc_done(void *state)
{
 free(state);
}

static void *enc_blowfish_ctr_init(const void *key, const void *iv)
{
 BF_STATE *s;

 s = malloc(sizeof(BF_STATE));
 if (s == 0) return(0);
 blowfish_setkey(&s->key,key,32);
 bcopy(iv,&s->iv[0],8);
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"blowfish-ctr %p: key=",(void *)s);
    for (i=0;i<32;i++) verb(CRYPTO,"%02x",((const unsigned char *)key)[i]);
    verb(CRYPTO," iv=");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",s->iv[i]);
    verb(CRYPTO,"\n");
  }
 return(s);
}

static void enc_blowfish_ctr_process(void *state, const void *in, void *out, int datalen)
{
 BF_STATE *s;
 const unsigned char *ip;
 unsigned char *op;
 unsigned char *x;
 unsigned char xorbuf[8];
 int i;
 int left;

 s = state;
 ip = in;
 op = out;
 x = &s->iv[0];
 if (datalen & 7) panic("misaligned length");
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"blowfish-ctr %p\n in",(void *)s);
    for (i=0;i<datalen;i++) verb(CRYPTO,"%s%02x",(i&7)?"":" ",ip[i]);
    verb(CRYPTO,"\n  x ");
    for (i=0;i<8;i++) verb(CRYPTO,"%02x",x[i]);
    verb(CRYPTO,"\n");
  }
 for (left=datalen;left>0;left-=8)
  { blowfish_encrypt(&s->key,&x[0],&xorbuf[0]);
    xor_block(&xorbuf[0],ip,op,8);
    i = 7;
    while (1)
     { if (i < 0) break;
       if (x[i] != 0xff)
	{ x[i] ++;
	  break;
	}
       x[i] = 0;
       i --;
     }
    ip += 8;
    op += 8;
  }
 if (VERB(CRYPTO))
  { int i;
    verb(CRYPTO,"out");
    for (i=0;i<datalen;i++) verb(CRYPTO,"%s%02x",(i&7)?"":" ",op[i-datalen]);
    verb(CRYPTO,"\n");
  }
}

static void enc_blowfish_ctr_done(void *state)
{
 free(state);
}

ENCALG encalg_blowfish_cbc
 = { "blowfish-cbc", 0, 8, 8, 16, 0,
     &enc_blowfish_cbc_init_enc,
     &enc_blowfish_cbc_init_dec,
     &enc_blowfish_cbc_process,
     &enc_blowfish_cbc_done };

ENCALG encalg_blowfish_ctr
 = { "blowfish-ctr", 0, 8, 8, 32, 0,
     &enc_blowfish_ctr_init,
     &enc_blowfish_ctr_init,
     &enc_blowfish_ctr_process,
     &enc_blowfish_ctr_done };