[mLib] / codec / baseconv.c

/* -*-c-*-
 *
 * Binary base-conversion encoding and decoding (base64, base32, etc.)
 *
 * (c) 1997 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * mLib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "alloc.h"
#include "codec.h"
#include "dstr.h"
#include "sub.h"

#include "base64.h"
#include "base32.h"
#include "hex.h"

/*----- Important tables --------------------------------------------------*/

/* --- Magic constants --- */

#define NV -1				/* Not valid */
#define PC -2				/* Padding character */
#define NL -3				/* Newline character */

/* --- Base64 --- */

static const char
  encodemap_base64[] =    { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			    "abcdefghijklmnopqrstuvwxyz"
			    "0123456789+/" },
  encodemap_file64[] =    { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			    "abcdefghijklmnopqrstuvwxyz"
			    "0123456789+%" },
  encodemap_base64url[] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			    "abcdefghijklmnopqrstuvwxyz"
			    "0123456789-_" };

static const signed char decodemap_base64[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, 62, NV, NV, NV, 63,  /* 2x */
  52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV,  /* 3x */
  NV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,  /* 4x */
  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV,  /* 5x */
  NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40,  /* 6x */
  41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV   /* 7x */
}, decodemap_file64[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, 63, NV, NV, NV, NV, NV, 62, NV, NV, NV, NV,  /* 2x */
  52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV,  /* 3x */
  NV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,  /* 4x */
  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV,  /* 5x */
  NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40,  /* 6x */
  41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV   /* 7x */
}, decodemap_base64url[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, 62, NV, NV,  /* 2x */
  52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV,  /* 3x */
  NV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,  /* 4x */
  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, 63,  /* 5x */
  NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40,  /* 6x */
  41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV   /* 7x */
};

/* --- Base32 --- */

static const char
  encodemap_base32[]   =    { "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" },
  encodemap_base32hex[] =   { "0123456789ABCDEFGHIJKLMNOPQRSTUV" };

static const signed char decodemap_base32[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 2x */
  NV, NV, 26, 27, 28, 29, 30, 31, NV, NV, NV, NV, NV, PC, NV, NV,  /* 3x */
  NV,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,  /* 4x */
  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV,  /* 5x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 6x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 7x */
}, decodemap_base32hex[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 2x */
   0,  1,  2,  3,  4,  5,  6,  7,  8,  9, NV, NV, NV, PC, NV, NV,  /* 3x */
  NV, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,  /* 4x */
  25, 26, 27, 28, 29, 30, 31, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 5x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 6x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 7x */
};

/* --- Hex --- */

static const char
  encodemap_hex[] =   { "0123456789ABCDEF" };

static const signed char decodemap_hex[] = {
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV,  /* 0x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 1x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 2x */
   0,  1,  2,  3,  4,  5,  6,  7,  8,  9, NV, NV, NV, NV, NV, NV,  /* 3x */
  NV, 10, 11, 12, 13, 14, 15, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 4x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 5x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 6x */
  NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV,  /* 7x */
};

/*----- Base conversion macros --------------------------------------------*/

/* --- @BASECONV@ --- *
 *
 * Arguments:	@x@ = an input digit of width @IWD@ bits
 *		@iwd@ = input digit width in bits
 *		@owd@ = output digit width in bits
 *		@put@ = function or macro to output a digit
 *
 * Use:		Inserts the bits of @x@ into an accumulator.  As digits @y@
 *		of with @owd@ become ready, @put(y)@ is invoked to emit them.
 */

#define BASECONV(x, iwd, owd, put) do {					\
  a = (a << iwd) | x;							\
  nb += iwd;								\
  while (nb >= owd) {							\
    nb -= owd;								\
    put((a >> nb) & ((1 << owd) - 1));					\
  }									\
} while (0)

/* --- @BASECONV_FLUSH@ --- *
 *
 * Arguments:	@iwd@ = input digit width in bits
 *		@owd@ = output digit width in bits
 *		@put@ = function or macro to output a digit
 *
 * Use:		Flushes remaining digits from the base-conversion shift
 *		register.  The bits in the shift register are padded on the
 *		right with zeros.  Digits of width @owd@ are emitted by
 *		invoking @put@.
 */

#define BASECONV_FLUSH(iwd, owd, put) do {				\
  if (nb) {								\
    while (nb < owd) { a <<= iwd; nb += iwd; }				\
    nb -= owd;								\
    put((a >> nb) & ((1 << owd) - 1));					\
  }									\
} while (0)

/* --- @BASECONV_PAD@ --- *
 *
 * Arguments:	@iwd@ = input digit width in bits
 *		@owd@ = output digit width in bits
 *		@pad@ = function or macro to output padding
 *
 * Use:		Invokes @pad@ sufficiently often to realign the shift
 *		register.
 */

#define BASECONV_PAD(iwd, owd, pad) do {				\
  for (;;) {								\
    while (nb >= owd) { pad; nb -= owd; }				\
    if (!nb) break;							\
    nb += iwd;								\
  }									\
} while (0)

#define NULL_PAD(iwd, owd, pad) do ; while (0)

/*----- Lists of things to make -------------------------------------------*/

#define CODECS(_)							\
  /* NAME,      CTXN,    ACC */						\
  _(base64,	base64,	acc)						\
  _(file64,	base64,	acc)						\
  _(base64url,	base64,	acc)						\
  _(base32,	base32,	accl)						\
  _(base32hex,	base32,	accl)						\
  _(hex,	hex,	acc)

#define CTXS(_)								\
  /* CTXN,	WD,	ACC */						\
  _(base64,	6,	acc)						\
  _(base32,	5,	accl)						\
  _(hex,	4,	acc)

#define base64_PADDING BASECONV_PAD
#define base64_FLAGMASK ~(CDCF_LOWERC | CDCF_IGNCASE)
#define base64_FLAGXOR 0
#define base64_OLDFLAGS CDCF_IGNJUNK

#define base32_PADDING BASECONV_PAD
#define base32_FLAGMASK ~0
#define base32_FLAGXOR 0
#define base32_OLDFLAGS CDCF_IGNJUNK

#define hex_PADDING NULL_PAD
#define hex_FLAGMASK ~0
#define hex_FLAGXOR 0
#define hex_OLDFLAGS (CDCF_IGNJUNK | CDCF_LOWERC)

/*----- Data structures ---------------------------------------------------*/

#define OBJ(ctxn, wd, acc)						\
									\
typedef struct ctxn##_codec {						\
  codec c;								\
  ctxn##_ctx ctx;							\
  const char *encodemap;						\
  const signed char *decodemap;						\
} ctxn##_codec;

CTXS(OBJ)

/*----- State packing -----------------------------------------------------*
 *
 * These macros convert between the state required by the new encoding and
 * decoding core and the old externally-visible context structures.  It's
 * unpleasant, I know; maybe we can drop the old interface later.
 */

enum {
  ST_MAIN,				/* Main decoding state */
  ST_PAD,				/* Decoding trailing padding */
  ST_END				/* Finished decoding */
};

#define STATE_UNPACK(acc)						\
  unsigned long a = (ctx->acc >> 0) & 0xffff;				\
  unsigned nb = (ctx->acc >> 16) & 0xff;				\
  unsigned st = (ctx->acc >> 24) & 0xff;				\
  unsigned f = ctx->qsz;

#define STATE_PACK(acc) do {						\
  ctx->acc = (((a & 0xffff) << 0) |					\
	      (((unsigned long)nb & 0xff) << 16) |			\
	      (((unsigned long)st & 0xff) << 24));			\
} while (0)

/*----- Main encoder and decoder ------------------------------------------*/

#define WRAP(stuff) do {						\
  if (maxln && lnlen >= maxln) {					\
    dstr_puts(d, ctx->indent);						\
    lnlen = 0;								\
  }									\
  stuff									\
  lnlen++;								\
} while (0)

#define PUTWRAP(x) WRAP({						\
  char ch = encodemap[x];						\
  if (f & CDCF_LOWERC) ch = tolower((unsigned char)ch);			\
  DPUTC(d, ch);								\
})

#define PADWRAP WRAP({ DPUTC(d, '='); })

#define PUTRAW(x) DPUTC(d, x)

#define ENCODER(ctxn, wd, acc)						\
									\
/* --- @CTXN_doencode@ --- *						\
 *									\
 * Arguments:	@CTXN_ctx *ctx@ = pointer to a context block		\
 *		@const char *encodemap@ = pointer to encoding map	\
 *		@const unsigned char *p@ = pointer to a source buffer	\
 *		@size_t sz@ = size of the source buffer			\
 *		@dstr *d@ = pointer to destination string		\
 *									\
 * Returns:	Zero on success, or @CDCERR_@ error code.		\
 *									\
 * Use:		Main encoder function.					\
 */									\
									\
static int ctxn##_doencode(ctxn##_ctx *ctx, const char *encodemap,	\
			   const unsigned char *p, size_t sz, dstr *d)	\
{									\
  STATE_UNPACK(acc);							\
  const unsigned char *l = p + sz;					\
  unsigned lnlen = ctx->lnlen, maxln = ctx->maxline;			\
									\
  if (p) {								\
    while (p < l) BASECONV(*p++, 8, wd, PUTWRAP);			\
  } else {								\
    BASECONV_FLUSH(8, wd, PUTWRAP);					\
    if (!(f & CDCF_NOEQPAD)) ctxn##_PADDING(8, wd, PADWRAP);		\
  }									\
									\
  STATE_PACK(acc);							\
  ctx->lnlen = lnlen;							\
  return (0);								\
}									\
									\
/* --- @CTXN_dodecode@ --- *						\
 *									\
 * Arguments:	@CTXN_ctx *ctx@ = pointer to a context block		\
 *		@const signed char *decodemap@ = pointer to decode map	\
 *		@const char *p@ = pointer to a source buffer		\
 *		@size_t sz@ = size of the source buffer			\
 *		@dstr *d@ = pointer to destination string		\
 *									\
 * Returns:	Zero on success, or @CDCERR_@ error code.		\
 *									\
 * Use:		Main decoder function.					\
 */									\
									\
static int ctxn##_dodecode(ctxn##_ctx *ctx,				\
			   const signed char *decodemap,		\
			   const unsigned char *p, size_t sz, dstr *d)	\
{									\
  STATE_UNPACK(acc);							\
  const unsigned char *l = p + sz;					\
  int ch;								\
  int x;								\
									\
  if (p) {								\
    while (p < l) {							\
      ch = *p++;							\
      switch (f & (CDCF_LOWERC | CDCF_IGNCASE)) {			\
	case 0:								\
	  break;							\
	case CDCF_LOWERC:						\
	  if (isupper(ch)) goto badch;					\
	default:							\
	  ch = toupper(ch);						\
      }									\
      x = decodemap[ch];						\
      switch (x) {							\
	case NV:							\
	badch:								\
	  if (!(f & CDCF_IGNINVCH)) return (CDCERR_INVCH);		\
	  break;							\
	case PC:							\
	  if (f & CDCF_IGNEQMID) break;					\
	  if (f & CDCF_NOEQPAD) goto badch;				\
	  if (st == ST_MAIN &&						\
	      !(f & CDCF_IGNZPAD) && (a & ((1 << nb) - 1)))		\
	    return (CDCERR_INVZPAD);					\
	  st = ST_PAD;							\
	  if (!(f & CDCF_IGNEQPAD)) {					\
	    if (!nb) return (CDCERR_INVEQPAD);				\
	    nb = (nb + wd)%8;						\
	    st = ST_PAD;						\
	  }								\
	  break;							\
	case NL:							\
	  if (f & CDCF_IGNNEWL) break;					\
	  return (CDCERR_INVCH);					\
	default:							\
	  if (st != ST_MAIN)						\
	    return (CDCERR_INVEQPAD);					\
	  BASECONV(x, wd, 8, PUTRAW);					\
	  break;							\
      }									\
    }									\
  } else {								\
    if (st == ST_MAIN &&						\
	!(f & CDCF_IGNZPAD) && (a & ((1 << nb) - 1)))			\
      return (CDCERR_INVZPAD);						\
    if (!(f & (CDCF_IGNEQPAD | CDCF_IGNEQMID | CDCF_NOEQPAD)) && nb)	\
      return (CDCERR_INVEQPAD);						\
  }									\
									\
  STATE_PACK(acc);							\
  return (0);								\
}

CTXS(ENCODER)

/*----- Codec implementation ----------------------------------------------*/

#define OPS(ctxn, wd, acc)						\
									\
static int ctxn##_enc(codec *c, const void *p, size_t sz, dstr *d)	\
{									\
  ctxn##_codec *bc = (ctxn##_codec *)c;					\
  return (ctxn##_doencode(&bc->ctx, bc->encodemap, p, sz, d));		\
}									\
									\
static int ctxn##_dec(codec *c, const void *p, size_t sz, dstr *d)	\
{									\
  ctxn##_codec *bc = (ctxn##_codec *)c;					\
  return (ctxn##_dodecode(&bc->ctx, bc->decodemap, p, sz, d));		\
}									\
									\
static void ctxn##_destroy(codec *c)					\
{									\
  ctxn##_codec *bc = (ctxn##_codec *)c;					\
  if (bc->ctx.indent) xfree((/*unconst*/ char *)bc->ctx.indent);	\
  DESTROY(bc);								\
}									\
									\
static codec *ctxn##_docreate(unsigned flags,				\
			      const char *indent, unsigned maxline,	\
			      const codec_ops *ops,			\
			      const char *encodemap,			\
			      const signed char *decodemap)		\
{									\
  ctxn##_codec *bc = CREATE(ctxn##_codec);				\
  bc->c.ops = ops;							\
  bc->ctx.acc = 0;							\
  bc->ctx.qsz = (flags & ctxn##_FLAGMASK) ^ ctxn##_FLAGXOR;		\
  bc->ctx.lnlen = 0;							\
  bc->ctx.indent = indent ? xstrdup(indent) : 0;			\
  bc->ctx.maxline = maxline;						\
  bc->encodemap = encodemap;						\
  bc->decodemap = decodemap;						\
  return (&bc->c);							\
}

CTXS(OPS)

#define CLASS(name, ctxn, acc)						\
									\
static const codec_ops							\
  name##_encode_ops = { &name##_class, ctxn##_enc, ctxn##_destroy },	\
  name##_decode_ops = { &name##_class, ctxn##_dec, ctxn##_destroy };	\
									\
static codec *name##_encoder(unsigned flags,				\
			     const char *indent, unsigned maxline)	\
{									\
  return ctxn##_docreate(flags, indent, maxline,			\
			 &name##_encode_ops,				\
			 encodemap_##name,				\
			 decodemap_##name);				\
}									\
									\
static codec *name##_decoder(unsigned flags)				\
{									\
  return ctxn##_docreate(flags, 0, 0,					\
			 &name##_decode_ops,				\
			 encodemap_##name,				\
			 decodemap_##name);				\
}									\
									\
const codec_class name##_class =					\
  { #name, name##_encoder, name##_decoder };

CODECS(CLASS)

/*----- Compatibility veneers ---------------------------------------------*/

#define COMPAT(ctxn, wd, acc)						\
									\
void ctxn##_encode(ctxn##_ctx *ctx, const void *p, size_t sz, dstr *d)	\
  { ctxn##_doencode(ctx, encodemap_##ctxn, p, sz, d); }			\
									\
void ctxn##_decode(ctxn##_ctx *ctx, const void *p, size_t sz, dstr *d)	\
  { ctxn##_dodecode(ctx, decodemap_##ctxn, p, sz, d); }			\
									\
void ctxn##_init(ctxn##_ctx *ctx)					\
{									\
  ctx->acc = 0;								\
  ctx->qsz = (ctxn##_OLDFLAGS & ctxn##_FLAGMASK) ^ ctxn##_FLAGXOR;	\
  ctx->lnlen = 0;							\
  ctx->indent = "\n";							\
  ctx->maxline = 72;							\
}

CTXS(COMPAT)

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
236f657b MW	1	/* --c--
	2	*
	3	* Binary base-conversion encoding and decoding (base64, base32, etc.)
	4	*
	5	* (c) 1997 Straylight/Edgeware
	6	*/
	7
	8	/----- Licensing notice --------------------------------------------------
	9	*
	10	* This file is part of the mLib utilities library.
	11	*
	12	* mLib is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU Library General Public License as
	14	* published by the Free Software Foundation; either version 2 of the
	15	* License, or (at your option) any later version.
	16	*
	17	* mLib is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU Library General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU Library General Public
	23	* License along with mLib; if not, write to the Free
	24	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	25	* MA 02111-1307, USA.
	26	*/
	27
	28	/----- Header files ------------------------------------------------------/
	29
	30	#include <ctype.h>
	31	#include <stdio.h>
	32	#include <stdlib.h>
	33	#include <string.h>
	34
	35	#include "alloc.h"
	36	#include "codec.h"
	37	#include "dstr.h"
	38	#include "sub.h"
	39
	40	#include "base64.h"
	41	#include "base32.h"
	42	#include "hex.h"
	43
	44	/----- Important tables --------------------------------------------------/
	45
	46	/* --- Magic constants --- */
	47
	48	#define NV -1 /* Not valid */
	49	#define PC -2 /* Padding character */
	50	#define NL -3 /* Newline character */
	51
	52	/* --- Base64 --- */
	53
	54	static const char
	55	encodemap_base64[] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	56	"abcdefghijklmnopqrstuvwxyz"
	57	"0123456789+/" },
	58	encodemap_file64[] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	59	"abcdefghijklmnopqrstuvwxyz"
	60	"0123456789+%" },
	61	encodemap_base64url[] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	62	"abcdefghijklmnopqrstuvwxyz"
	63	"0123456789-_" };
	64
65	static const signed char decodemap_base64[] = {
66	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
67	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
68	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, 62, NV, NV, NV, 63, /* 2x */
69	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV, /* 3x */
70	NV, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 4x */
71	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV, /* 5x */
72	NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40, /* 6x */
73	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV /* 7x */
74	}, decodemap_file64[] = {
75	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
76	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
77	NV, NV, NV, NV, NV, 63, NV, NV, NV, NV, NV, 62, NV, NV, NV, NV, /* 2x */
78	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV, /* 3x */
79	NV, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 4x */
80	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV, /* 5x */
81	NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40, /* 6x */
82	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV /* 7x */
83	}, decodemap_base64url[] = {
84	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
85	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
86	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, 62, NV, NV, /* 2x */
87	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, NV, NV, NV, PC, NV, NV, /* 3x */
88	NV, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 4x */
89	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, 63, /* 5x */
90	NV, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 ,37, 38, 39, 40, /* 6x */
91	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, NV, NV, NV, NV, NV /* 7x */
92	};
93
94	/* --- Base32 --- */
95
96	static const char
97	encodemap_base32[] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" },
98	encodemap_base32hex[] = { "0123456789ABCDEFGHIJKLMNOPQRSTUV" };
99
100	static const signed char decodemap_base32[] = {
101	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
102	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
103	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 2x */
104	NV, NV, 26, 27, 28, 29, 30, 31, NV, NV, NV, NV, NV, PC, NV, NV, /* 3x */
105	NV, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 4x */
106	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, NV, NV, NV, NV, NV, /* 5x */
107	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 6x */
108	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 7x */
109	}, decodemap_base32hex[] = {
110	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
111	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
112	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 2x */
113	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, NV, NV, NV, PC, NV, NV, /* 3x */
114	NV, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, /* 4x */
115	25, 26, 27, 28, 29, 30, 31, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 5x */
116	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 6x */
117	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 7x */
118	};
119
120	/* --- Hex --- */
121
122	static const char
123	encodemap_hex[] = { "0123456789ABCDEF" };
124
125	static const signed char decodemap_hex[] = {
126	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NL, NV, NV, NL, NV, NV, /* 0x */
127	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 1x */
128	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 2x */
129	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, NV, NV, NV, NV, NV, NV, /* 3x */
130	NV, 10, 11, 12, 13, 14, 15, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 4x */
131	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 5x */
132	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 6x */
133	NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, NV, /* 7x */
134	};
135
136	/----- Base conversion macros --------------------------------------------/
137
138	/* --- @BASECONV@ --- *
139	*
140	* Arguments: @x@ = an input digit of width @IWD@ bits
141	* @iwd@ = input digit width in bits
142	* @owd@ = output digit width in bits
143	* @put@ = function or macro to output a digit
144	*
145	* Use: Inserts the bits of @x@ into an accumulator. As digits @y@
146	* of with @owd@ become ready, @put(y)@ is invoked to emit them.
147	*/
148
149	#define BASECONV(x, iwd, owd, put) do { \
150	a = (a << iwd) \| x; \
151	nb += iwd; \
152	while (nb >= owd) { \
153	nb -= owd; \
154	put((a >> nb) & ((1 << owd) - 1)); \
155	} \
156	} while (0)
157
158	/* --- @BASECONV_FLUSH@ --- *
159	*
160	* Arguments: @iwd@ = input digit width in bits
161	* @owd@ = output digit width in bits
162	* @put@ = function or macro to output a digit
163	*
164	* Use: Flushes remaining digits from the base-conversion shift
165	* register. The bits in the shift register are padded on the
166	* right with zeros. Digits of width @owd@ are emitted by
167	* invoking @put@.
168	*/
169
170	#define BASECONV_FLUSH(iwd, owd, put) do { \
171	if (nb) { \
172	while (nb < owd) { a <<= iwd; nb += iwd; } \
173	nb -= owd; \
174	put((a >> nb) & ((1 << owd) - 1)); \
175	} \
176	} while (0)
177
178	/* --- @BASECONV_PAD@ --- *
179	*
180	* Arguments: @iwd@ = input digit width in bits
181	* @owd@ = output digit width in bits
182	* @pad@ = function or macro to output padding
183	*
184	* Use: Invokes @pad@ sufficiently often to realign the shift
185	* register.
186	*/
187
188	#define BASECONV_PAD(iwd, owd, pad) do { \
189	for (;;) { \
190	while (nb >= owd) { pad; nb -= owd; } \
191	if (!nb) break; \
192	nb += iwd; \
193	} \
194	} while (0)
195
196	#define NULL_PAD(iwd, owd, pad) do ; while (0)
197
198	/----- Lists of things to make -------------------------------------------/
199
200	#define CODECS(_) \
201	/* NAME, CTXN, ACC */ \
202	_(base64, base64, acc) \
203	_(file64, base64, acc) \
204	_(base64url, base64, acc) \
205	_(base32, base32, accl) \
206	_(base32hex, base32, accl) \
207	_(hex, hex, acc)
208
209	#define CTXS(_) \
210	/* CTXN, WD, ACC */ \
211	_(base64, 6, acc) \
212	_(base32, 5, accl) \
213	_(hex, 4, acc)
214
215	#define base64_PADDING BASECONV_PAD
216	#define base64_FLAGMASK ~(CDCF_LOWERC \| CDCF_IGNCASE)
217	#define base64_FLAGXOR 0
218	#define base64_OLDFLAGS CDCF_IGNJUNK
219
220	#define base32_PADDING BASECONV_PAD
221	#define base32_FLAGMASK ~0
222	#define base32_FLAGXOR 0
223	#define base32_OLDFLAGS CDCF_IGNJUNK
224
225	#define hex_PADDING NULL_PAD
226	#define hex_FLAGMASK ~0
227	#define hex_FLAGXOR 0
228	#define hex_OLDFLAGS (CDCF_IGNJUNK \| CDCF_LOWERC)
229
230	/----- Data structures ---------------------------------------------------/
231
232	#define OBJ(ctxn, wd, acc) \
233	\
234	typedef struct ctxn##_codec { \
235	codec c; \
236	ctxn##_ctx ctx; \
237	const char *encodemap; \
238	const signed char *decodemap; \
239	} ctxn##_codec;
240
241	CTXS(OBJ)
242
243	/----- State packing -----------------------------------------------------
244	*
245	* These macros convert between the state required by the new encoding and
246	* decoding core and the old externally-visible context structures. It's
247	* unpleasant, I know; maybe we can drop the old interface later.
248	*/
249
250	enum {
251	ST_MAIN, /* Main decoding state */
252	ST_PAD, /* Decoding trailing padding */
253	ST_END /* Finished decoding */
254	};
255
256	#define STATE_UNPACK(acc) \
257	unsigned long a = (ctx->acc >> 0) & 0xffff; \
258	unsigned nb = (ctx->acc >> 16) & 0xff; \
259	unsigned st = (ctx->acc >> 24) & 0xff; \
260	unsigned f = ctx->qsz;
261
262	#define STATE_PACK(acc) do { \
263	ctx->acc = (((a & 0xffff) << 0) \| \
264	(((unsigned long)nb & 0xff) << 16) \| \
265	(((unsigned long)st & 0xff) << 24)); \
266	} while (0)
267
268	/----- Main encoder and decoder ------------------------------------------/
269
270	#define WRAP(stuff) do { \
271	if (maxln && lnlen >= maxln) { \
272	dstr_puts(d, ctx->indent); \
273	lnlen = 0; \
274	} \
275	stuff \
276	lnlen++; \
277	} while (0)
278
279	#define PUTWRAP(x) WRAP({ \
280	char ch = encodemap[x]; \
281	if (f & CDCF_LOWERC) ch = tolower((unsigned char)ch); \
282	DPUTC(d, ch); \
283	})
284
285	#define PADWRAP WRAP({ DPUTC(d, '='); })
286
287	#define PUTRAW(x) DPUTC(d, x)
288
289	#define ENCODER(ctxn, wd, acc) \
290	\
291	/* --- @CTXN_doencode@ --- * \
292	* \
293	* Arguments: @CTXN_ctx *ctx@ = pointer to a context block \
294	* @const char *encodemap@ = pointer to encoding map \
295	* @const unsigned char *p@ = pointer to a source buffer \
296	* @size_t sz@ = size of the source buffer \
297	* @dstr *d@ = pointer to destination string \
298	* \
299	* Returns: Zero on success, or @CDCERR_@ error code. \
300	* \
301	* Use: Main encoder function. \
302	*/ \
303	\
304	static int ctxn##_doencode(ctxn##_ctx ctx, const char encodemap, \
305	const unsigned char p, size_t sz, dstr d) \
306	{ \
307	STATE_UNPACK(acc); \
308	const unsigned char *l = p + sz; \
309	unsigned lnlen = ctx->lnlen, maxln = ctx->maxline; \
310	\
311	if (p) { \
312	while (p < l) BASECONV(*p++, 8, wd, PUTWRAP); \
313	} else { \
314	BASECONV_FLUSH(8, wd, PUTWRAP); \
315	if (!(f & CDCF_NOEQPAD)) ctxn##_PADDING(8, wd, PADWRAP); \
316	} \
317	\
318	STATE_PACK(acc); \
319	ctx->lnlen = lnlen; \
320	return (0); \
321	} \
322	\
323	/* --- @CTXN_dodecode@ --- * \
324	* \
325	* Arguments: @CTXN_ctx *ctx@ = pointer to a context block \
326	* @const signed char *decodemap@ = pointer to decode map \
327	* @const char *p@ = pointer to a source buffer \
328	* @size_t sz@ = size of the source buffer \
329	* @dstr *d@ = pointer to destination string \
330	* \
331	* Returns: Zero on success, or @CDCERR_@ error code. \
332	* \
333	* Use: Main decoder function. \
334	*/ \
335	\
336	static int ctxn##_dodecode(ctxn##_ctx *ctx, \
337	const signed char *decodemap, \
338	const unsigned char p, size_t sz, dstr d) \
339	{ \
340	STATE_UNPACK(acc); \
341	const unsigned char *l = p + sz; \
342	int ch; \
343	int x; \
344	\
345	if (p) { \
346	while (p < l) { \
347	ch = *p++; \
348	switch (f & (CDCF_LOWERC \| CDCF_IGNCASE)) { \
349	case 0: \
350	break; \
351	case CDCF_LOWERC: \
352	if (isupper(ch)) goto badch; \
353	default: \
354	ch = toupper(ch); \
355	} \
356	x = decodemap[ch]; \
357	switch (x) { \
358	case NV: \
359	badch: \
360	if (!(f & CDCF_IGNINVCH)) return (CDCERR_INVCH); \
361	break; \
362	case PC: \
363	if (f & CDCF_IGNEQMID) break; \
364	if (f & CDCF_NOEQPAD) goto badch; \
365	if (st == ST_MAIN && \
366	!(f & CDCF_IGNZPAD) && (a & ((1 << nb) - 1))) \
367	return (CDCERR_INVZPAD); \
368	st = ST_PAD; \
369	if (!(f & CDCF_IGNEQPAD)) { \
370	if (!nb) return (CDCERR_INVEQPAD); \
371	nb = (nb + wd)%8; \
372	st = ST_PAD; \
373	} \
374	break; \
375	case NL: \
376	if (f & CDCF_IGNNEWL) break; \
377	return (CDCERR_INVCH); \
378	default: \
379	if (st != ST_MAIN) \
380	return (CDCERR_INVEQPAD); \
381	BASECONV(x, wd, 8, PUTRAW); \
382	break; \
383	} \
384	} \
385	} else { \
386	if (st == ST_MAIN && \
387	!(f & CDCF_IGNZPAD) && (a & ((1 << nb) - 1))) \
388	return (CDCERR_INVZPAD); \
389	if (!(f & (CDCF_IGNEQPAD \| CDCF_IGNEQMID \| CDCF_NOEQPAD)) && nb) \
390	return (CDCERR_INVEQPAD); \
391	} \
392	\
393	STATE_PACK(acc); \
394	return (0); \
395	}
396
397	CTXS(ENCODER)
398
399	/----- Codec implementation ----------------------------------------------/
400
401	#define OPS(ctxn, wd, acc) \
402	\
403	static int ctxn##_enc(codec c, const void p, size_t sz, dstr *d) \
404	{ \
405	ctxn##_codec bc = (ctxn##_codec )c; \
406	return (ctxn##_doencode(&bc->ctx, bc->encodemap, p, sz, d)); \
407	} \
408	\
409	static int ctxn##_dec(codec c, const void p, size_t sz, dstr *d) \
410	{ \
411	ctxn##_codec bc = (ctxn##_codec )c; \
412	return (ctxn##_dodecode(&bc->ctx, bc->decodemap, p, sz, d)); \
413	} \
414	\
415	static void ctxn##_destroy(codec *c) \
416	{ \
417	ctxn##_codec bc = (ctxn##_codec )c; \
418	if (bc->ctx.indent) xfree((/unconst/ char *)bc->ctx.indent); \
419	DESTROY(bc); \
420	} \
421	\
422	static codec *ctxn##_docreate(unsigned flags, \
423	const char *indent, unsigned maxline, \
424	const codec_ops *ops, \
425	const char *encodemap, \
426	const signed char *decodemap) \
427	{ \
428	ctxn##_codec *bc = CREATE(ctxn##_codec); \
429	bc->c.ops = ops; \
430	bc->ctx.acc = 0; \
431	bc->ctx.qsz = (flags & ctxn##_FLAGMASK) ^ ctxn##_FLAGXOR; \
432	bc->ctx.lnlen = 0; \
433	bc->ctx.indent = indent ? xstrdup(indent) : 0; \
434	bc->ctx.maxline = maxline; \
435	bc->encodemap = encodemap; \
436	bc->decodemap = decodemap; \
437	return (&bc->c); \
438	}
439
440	CTXS(OPS)
441
442	#define CLASS(name, ctxn, acc) \
443	\
444	static const codec_ops \
445	name##_encode_ops = { &name##_class, ctxn##_enc, ctxn##_destroy }, \
446	name##_decode_ops = { &name##_class, ctxn##_dec, ctxn##_destroy }; \
447	\
448	static codec *name##_encoder(unsigned flags, \
449	const char *indent, unsigned maxline) \
450	{ \
451	return ctxn##_docreate(flags, indent, maxline, \
452	&name##_encode_ops, \
453	encodemap_##name, \
454	decodemap_##name); \
455	} \
456	\
457	static codec *name##_decoder(unsigned flags) \
458	{ \
459	return ctxn##_docreate(flags, 0, 0, \
460	&name##_decode_ops, \
461	encodemap_##name, \
462	decodemap_##name); \
463	} \
464	\
465	const codec_class name##_class = \
466	{ #name, name##_encoder, name##_decoder };
467
468	CODECS(CLASS)
469
470	/----- Compatibility veneers ---------------------------------------------/
471
472	#define COMPAT(ctxn, wd, acc) \
473	\
474	void ctxn##_encode(ctxn##_ctx ctx, const void p, size_t sz, dstr *d) \
475	{ ctxn##_doencode(ctx, encodemap_##ctxn, p, sz, d); } \
476	\
477	void ctxn##_decode(ctxn##_ctx ctx, const void p, size_t sz, dstr *d) \
478	{ ctxn##_dodecode(ctx, decodemap_##ctxn, p, sz, d); } \
479	\
480	void ctxn##_init(ctxn##_ctx *ctx) \
481	{ \
482	ctx->acc = 0; \
483	ctx->qsz = (ctxn##_OLDFLAGS & ctxn##_FLAGMASK) ^ ctxn##_FLAGXOR; \
484	ctx->lnlen = 0; \
485	ctx->indent = "\n"; \
486	ctx->maxline = 72; \
487	}
488
489	CTXS(COMPAT)
490
491	/----- That's all, folks -------------------------------------------------/