Skip to content
GitLab
Commit 400c2228 authored by Niels Möller's avatar Niels Möller
Browse files

Generalized base64, adding lookup table pointers to the contexts.

parent 5495424b
Hide whitespace changes
Inline Side-by-side
ChangeLog
View file @ 400c2228
2015-02-10 Niels Möller <nisse@lysator.liu.se>
Base-64 generalization, contributed by Amos Jeffries.
* base64.h (struct base64_encode_ctx): Added pointer to alphabet.
(struct base64_decode_ctx): Added pointer to decoding table.
* base64-decode.c (base64_decode_init): Initialize table pointer.
Moved definition of table to local scope.
(base64_decode_single): Use the context's decoding table.
* base64-encode.c (ENCODE): Added alphabet argument. Updated all
uses.
(encode_raw): New static function, like base64_encode_raw
but with an alphabet argument.
(base64_encode_raw): Call encode_raw.
(base64_encode_init): Initialize alphabet pointer.
(base64_encode_single, base64_encode_update, base64_encode_final):
Use the context's alphabet.
2015-02-09 Niels Möller <nisse@lysator.liu.se>
* base64-encode.c (base64_encode): Deleted old #if:ed out
......
base64-decode.c
View file @ 400c2228
......@@ -42,32 +42,32 @@
#define TABLE_SPACE -2
#define TABLE_END -3
static const signed char
decode_table[0x100] =
{
/* White space is HT, VT, FF, CR, LF and SPC */
-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -2, -2, -2, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
void
base64_decode_init(struct base64_decode_ctx *ctx)
{
static const signed char base64_decode_table[0x100] =
{
/* White space is HT, VT, FF, CR, LF and SPC */
-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -2, -2, -2, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
ctx->word = ctx->bits = ctx->padding = 0;
ctx->table = base64_decode_table;
}
int
......@@ -75,9 +75,7 @@ base64_decode_single(struct base64_decode_ctx *ctx,
uint8_t *dst,
uint8_t src)
{
int data;
data = decode_table[src];
int data = ctx->table[src];
switch(data)
{
......
base64-encode.c
View file @ 400c2228
......@@ -38,15 +38,11 @@
#include "base64.h"
static const uint8_t encode_table[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
#define ENCODE(x) (encode_table[0x3F & (x)])
#define ENCODE(alphabet,x) ((alphabet)[0x3F & (x)])
void
base64_encode_raw(uint8_t *dst, size_t length, const uint8_t *src)
static void
encode_raw(const char *alphabet,
uint8_t *dst, size_t length, const uint8_t *src)
{
const uint8_t *in = src + length;
uint8_t *out = dst + BASE64_ENCODE_RAW_LENGTH(length);
......@@ -61,45 +57,57 @@ base64_encode_raw(uint8_t *dst, size_t length, const uint8_t *src)
{
case 1:
*--out = '=';
*--out = ENCODE(in[0] << 4);
*--out = ENCODE(alphabet, (in[0] << 4));
break;
case 2:
*--out = ENCODE( in[1] << 2);
*--out = ENCODE((in[0] << 4) | (in[1] >> 4));
*--out = ENCODE(alphabet, (in[1] << 2));
*--out = ENCODE(alphabet, ((in[0] << 4) | (in[1] >> 4)));
break;
default:
abort();
}
*--out = ENCODE(in[0] >> 2);
*--out = ENCODE(alphabet, (in[0] >> 2));
}
while (in > src)
{
in -= 3;
*--out = ENCODE( in[2]);
*--out = ENCODE((in[1] << 2) | (in[2] >> 6));
*--out = ENCODE((in[0] << 4) | (in[1] >> 4));
*--out = ENCODE( in[0] >> 2);
*--out = ENCODE(alphabet, (in[2]));
*--out = ENCODE(alphabet, ((in[1] << 2) | (in[2] >> 6)));
*--out = ENCODE(alphabet, ((in[0] << 4) | (in[1] >> 4)));
*--out = ENCODE(alphabet, (in[0] >> 2));
}
assert(in == src);
assert(out == dst);
}
static const uint8_t base64_encode_table[64] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
void
base64_encode_raw(uint8_t *dst, size_t length, const uint8_t *src)
{
encode_raw(base64_encode_table, dst, length, src);
}
void
base64_encode_group(uint8_t *dst, uint32_t group)
{
*dst++ = ENCODE(group >> 18);
*dst++ = ENCODE(group >> 12);
*dst++ = ENCODE(group >> 6);
*dst++ = ENCODE(group);
*dst++ = ENCODE(base64_encode_table, (group >> 18));
*dst++ = ENCODE(base64_encode_table, (group >> 12));
*dst++ = ENCODE(base64_encode_table, (group >> 6));
*dst++ = ENCODE(base64_encode_table, group);
}
void
base64_encode_init(struct base64_encode_ctx *ctx)
{
ctx->word = ctx->bits = 0;
ctx->alphabet = base64_encode_table;
}
/* Encodes a single byte. */
......@@ -115,7 +123,7 @@ base64_encode_single(struct base64_encode_ctx *ctx,
while (bits >= 6)
{
bits -= 6;
dst[done++] = ENCODE(word >> bits);
dst[done++] = ENCODE(ctx->alphabet, (word >> bits));
}
ctx->bits = bits;
......@@ -152,7 +160,7 @@ base64_encode_update(struct base64_encode_ctx *ctx,
{
assert(!(bulk % 3));
base64_encode_raw(dst + done, bulk, src);
encode_raw(ctx->alphabet, dst + done, bulk, src);
done += BASE64_ENCODE_RAW_LENGTH(bulk);
src += bulk;
left = left_over;
......@@ -180,7 +188,7 @@ base64_encode_final(struct base64_encode_ctx *ctx,
if (bits)
{
dst[done++] = ENCODE(ctx->word << (6 - ctx->bits));
dst[done++] = ENCODE(ctx->alphabet, (ctx->word << (6 - ctx->bits)));
for (; bits < 6; bits += 2)
dst[done++] = '=';
......
base64.h
View file @ 400c2228
......@@ -73,8 +73,10 @@ struct base64_encode_ctx
{
unsigned word; /* Leftover bits */
unsigned bits; /* Number of bits, always 0, 2, or 4. */
const uint8_t *alphabet; /* Alphabet to use for encoding */
};
/* Initialize encoding context for base-64 */
void
base64_encode_init(struct base64_encode_ctx *ctx);
......@@ -123,8 +125,10 @@ struct base64_decode_ctx
/* Number of padding characters encountered */
unsigned padding;
const signed char *table; /* Decoding table */
};
/* Initialize decoding context for base-64 */
void
base64_decode_init(struct base64_decode_ctx *ctx);
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment