diff --git a/ChangeLog b/ChangeLog
index 7859c142ffd2ae5f697c5808e80e197a96edf1fd..9ee8aeae11d1221898b40dcb3fff4cafbdbbd306 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+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
diff --git a/base64-decode.c b/base64-decode.c
index f622baac88a0c9d139ca55b3aa1ec469495e1621..337ea3953d6ab6d2f0f1c30f635f5609d90e63c1 100644
--- a/base64-decode.c
+++ b/base64-decode.c
@@ -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)
{
diff --git a/base64-encode.c b/base64-encode.c
index b0b921f605e8a3bf3ef3d3490286bd1375e0b11d..0e81b3f5e1abe3bd682e2751ce1170891c174910 100644
--- a/base64-encode.c
+++ b/base64-encode.c
@@ -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++] = '=';
diff --git a/base64.h b/base64.h
index a6fb8235c6eada43b32c1396b441e94dc9b3c9d4..07a8e2b716f45c36ddb8c815f5057cffe652e4e0 100644
--- a/base64.h
+++ b/base64.h
@@ -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);