/* lib/evp/encode.c */
/* Copyright (C) 1995 Eric Young (eay@mincom.oz.au)
 * All rights reserved.
 * 
 * This file is part of an SSL implementation written
 * by Eric Young (eay@mincom.oz.au).
 * The implementation was written so as to conform with Netscapes SSL
 * specification.  This library and applications are
 * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
 * as long as the following conditions are aheared to.
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.  If this code is used in a product,
 * Eric Young should be given attribution as the author of the parts used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Eric Young (eay@mincom.oz.au)
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "crypto.h"
#include "envelope.h"

#define conv_bin2ascii(a)	(data_bin2ascii[(a)&0x3f])
#define conv_ascii2bin(a)	(data_ascii2bin[(a)&0x7f])

/* 64 char lines
 * pad input with 0
 * left over chars are set to =
 * 1 byte  => xx==
 * 2 bytes => xxx=
 * 3 bytes => xxxx
 */
#define BIN_PER_LINE    (64/4*3)
#define CHUNKS_PER_LINE (64/4)
#define CHAR_PER_LINE   (64+1)

static unsigned char data_bin2ascii[65]="ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz0123456789+/";

/* 0xF0 is a EOLN
 * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
 * 0xF2 is EOF
 * 0xE0 is ignore at start of line.
 * 0xFF is error
 */
static unsigned char data_ascii2bin[128]={
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xE0,0xF0,0xFF,0xFF,0xF1,0xFF,0xFF,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xE0,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0xFF,0xFF,0x3E,0xFF,0xF2,0xFF,0x3F,
	0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,
	0x3C,0x3D,0xFF,0xFF,0xFF,0x00,0xFF,0xFF,
	0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06,
	0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,
	0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16,
	0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF,
	0xFF,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,0x20,
	0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,
	0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,0x30,
	0x31,0x32,0x33,0xFF,0xFF,0xFF,0xFF,0xFF,
	};

void EVP_EncodeInit(ctx)
EVP_ENCODE_CTX *ctx;
	{
	ctx->length=48;
	ctx->num=0;
	}

void EVP_EncodeUpdate(ctx,out,outl,in,inl)
EVP_ENCODE_CTX *ctx;
unsigned char *out;
int *outl;
unsigned char *in;
int inl;
	{
	int i,j;
	unsigned int total=0;

	*outl=0;
	if (inl == 0) return;
	if ((ctx->num+inl) < ctx->length)
		{
		memcpy(&(ctx->enc_data[ctx->num]),in,inl);
		ctx->num+=inl;
		return;
		}
	if (ctx->num != 0)
		{
		i=ctx->length-ctx->num;
		memcpy(&(ctx->enc_data[ctx->num]),in,i);
		in+=i;
		inl-=i;
		j=EVP_EncodeBlock(out,ctx->enc_data,ctx->length);
		ctx->num=0;
		out+=j;
		*(out++)='\n';
		out[1]='\0';
		total=j+1;
		}
	while (inl >= ctx->length)
		{
		j=EVP_EncodeBlock(out,in,ctx->length);
		in+=ctx->length;
		inl-=ctx->length;
		out+=j;
		*(out++)='\n';
		out[1]='\0';
		total+=j+1;
		}
	if (inl != 0)
		memcpy(&(ctx->enc_data[0]),in,inl);
	ctx->num=inl;
	*outl=total;
	}

void EVP_EncodeFinal(ctx,out,outl)
EVP_ENCODE_CTX *ctx;
unsigned char *out;
int *outl;
	{
	unsigned char *f;
	unsigned int ret=0;

	f=ctx->enc_data;
	if (ctx->num != 0)
		{
		ret=EVP_EncodeBlock(out,ctx->enc_data,ctx->num);
		out[ret++]='\n';
		out[ret]='\0';
		}
	*outl=ret;
	}

int EVP_EncodeBlock(t,f,dlen)
unsigned char *t,*f;
int dlen;
	{
	int i,ret=0;
	unsigned long l;

	for (i=dlen; i > 0; i-=3)
		{
		if (i >= 3)
			{
			l=	((unsigned long)f[0]<<16L)|
				((unsigned long)f[1]<< 8L)|f[2];
			*(t++)=conv_bin2ascii(l>>18L);
			*(t++)=conv_bin2ascii(l>>12L);
			*(t++)=conv_bin2ascii(l>> 6L);
			*(t++)=conv_bin2ascii(l     );
			}
		else
			{
			l=(f[0]<<16L);
			if (i == 2) l|=(f[1]<<8L);

			*(t++)=conv_bin2ascii(l>>18L);
			*(t++)=conv_bin2ascii(l>>12L);
			*(t++)=(i == 1)?'=':conv_bin2ascii(l>> 6L);
			*(t++)='=';
			}
		ret+=4;
		f+=3;
		}

	*(t++)='\0';
	return(ret);
	}

void EVP_DecodeInit(ctx)
EVP_ENCODE_CTX *ctx;
	{
	ctx->length=76;
	ctx->num=0;
	}

/* -1 for error
 *  0 for last line
 *  1 for full line
 */
int EVP_DecodeUpdate(ctx,out,outl,in,inl)
EVP_ENCODE_CTX *ctx;
unsigned char *out;
int *outl;
unsigned char *in;
int inl;
	{
	int seof=-1,eof=0,rv=-1,ret=0,i,v,n,j;
	unsigned char *d;

	n=ctx->num;
	d=ctx->enc_data;

	if (inl == 0) 
		return(-1);
	if ((n == 0) && (conv_ascii2bin(in[0]) == 0xF2))
		return(0);
		
	for (i=0; i<inl; i++)
		{
		if (n >= 80) return(-1);
		v= *(in++);
		if (v == '=')
			{
			if (seof == -1) seof=n;
			eof++;
			}
		d[n++]=v;
		v=conv_ascii2bin(v);
		if ((n == 0) && (v == 0xF2))
			{
			rv=0;
			goto end;
			}
		if (v == 0xF0)
			{
			if (seof >= 0)
				{
				if (eof > 2)
					goto end;
				j=n-1;
				while ((conv_ascii2bin(d[j]) | 0x13) == 0xF3)
					j--;
				if ((seof+eof) != (j+1))
					goto end;
				}
			v=EVP_DecodeBlock(out,d,n);
			if (v < 0)
				goto end;
			n=0;
			ret+=(v-eof);
			if (seof >= 0)
				{
				rv=0;
				goto end;
				}
			out+=v;
			}
		}
	rv=1;
end:
	*outl=ret;
	ctx->num=n;
	return(rv);
	}

int EVP_DecodeBlock(t,f,n)
unsigned char *t,*f;
int n;
	{
	int i,ret=0,a,b,c,d;
	unsigned long l;

	/* trim white space from the start of the line. */
	while ((conv_ascii2bin(*f) == 0xE0) && (n > 0))
		{
		f++;
		n--;
		}

	/* trip off stuff at the end of the line
	 * ascii2bin values 0xE0, 0xF0, 0xF1 and 0xF2 */
	while ((n > 3) && ((conv_ascii2bin(f[n-1]) | 0x13) == 0xF3))
		n--;

	if (n%4 != 0) return(-1);

	for (i=0; i<n; i+=4)
		{
		a=conv_ascii2bin(*(f++));
		b=conv_ascii2bin(*(f++));
		c=conv_ascii2bin(*(f++));
		d=conv_ascii2bin(*(f++));
		if (	(a & 0x80) || (b & 0x80) ||
			(c & 0x80) || (d & 0x80))
			return(-1);
		l=(	(unsigned long)(a<<18L)|
			(unsigned long)(b<<12L)|
			(unsigned long)(c<< 6L)|
			(unsigned long)(d     ));
		*(t++)=(unsigned char)(l>>16L)&0xff;
		*(t++)=(unsigned char)(l>> 8L)&0xff;
		*(t++)=(unsigned char)(l     )&0xff;
		ret+=3;
		}
	return(ret);
	}

int EVP_DecodeFinal(ctx,out,outl)
EVP_ENCODE_CTX *ctx;
unsigned char *out;
int *outl;
	{
	int i;

	*outl=0;
	if (ctx->num != 0)
		{
		i=EVP_DecodeBlock(out,ctx->enc_data,ctx->num);
		if (i < 0) return(-1);
		*outl=i;
		return(1);
		}
	else
		return(1);
	}

#ifdef undef
int EVP_DecodeValid(buf,len)
unsigned char *buf;
int len;
	{
	int i,num=0,bad=0;

	if (len == 0) return(-1);
	while (conv_ascii2bin(*buf) == 0xE0)
		{
		buf++;
		len--;
		if (len == 0) return(-1);
		}

	for (i=len; i >= 4; i-=4)
		{
		if (	(conv_ascii2bin(buf[0]) >= 0x40) ||
			(conv_ascii2bin(buf[1]) >= 0x40) ||
			(conv_ascii2bin(buf[2]) >= 0x40) ||
			(conv_ascii2bin(buf[3]) >= 0x40))
			return(-1);
		buf+=4;
		num+=1+(buf[2] != '=')+(buf[3] != '=');
		}
	if ((i == 1) && (conv_ascii2bin(buf[0]) == 0xF0))
		return(num);
	if ((i == 2) && (conv_ascii2bin(buf[0]) == 0xF1) &&
		(conv_ascii2bin(buf[0]) == 0xF1))
		return(num);
	return(1);
	}
#endif
