CCAN: add base64 module.

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

Makefile

@@ -146,6 +146,7 @@ CCAN_HEADERS :=						\
 	$(CCANDIR)/ccan/alignof/alignof.h		\
 	$(CCANDIR)/ccan/array_size/array_size.h		\
 	$(CCANDIR)/ccan/asort/asort.h			\
+	$(CCANDIR)/ccan/base64/base64.h			\
 	$(CCANDIR)/ccan/bitmap/bitmap.h			\
 	$(CCANDIR)/ccan/bitops/bitops.h			\
 	$(CCANDIR)/ccan/breakpoint/breakpoint.h		\

ccan/ccan/base64/LICENSE

@@ -0,0 +1 @@
+../../licenses/BSD-MIT

ccan/ccan/base64/_info

@@ -0,0 +1,41 @@
+#include "config.h"
+
+/**
+ * base64 - base64 encoding and decoding (rfc4648).
+ *
+ * base64 encoding is used to encode data in a 7-bit clean manner.
+ *  Commonly used for escaping data before encapsulation or transfer
+ *
+ * Example:
+ *      #include <stdio.h>
+ *      #include <string.h>
+ *      #include <ccan/base64/base64.h>
+ *
+ *      int main(int argc, char *argv[])
+ *      {
+ *      	char *base64_encoded_string;
+ *      	int i;
+ *
+ *      	// print the base64-encoded form of the program arguments
+ *      	for(i=1;i<argc;i++) {
+ *			size_t unencoded_length = strlen(argv[i]);
+ *      		size_t encoded_length = base64_encoded_length(unencoded_length);
+ *      		base64_encoded_string = malloc(encoded_length);
+ *      		base64_encode(base64_encoded_string, encoded_length,
+ *				 argv[i], unencoded_length);
+ *      		printf("%s\n", base64_encoded_string);
+ *      		free(base64_encoded_string);
+ *      	}
+ *
+ *      	return 0;
+ *      }
+ *
+ * License: BSD-MIT
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	return 1;
+}

ccan/ccan/base64/base64.c

@@ -0,0 +1,253 @@
+/* Licensed under BSD-MIT - see LICENSE file for details */
+#include "base64.h"
+
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <stdint.h>
+
+/**
+ * sixbit_to_b64 - maps a 6-bit value to the base64 alphabet
+ * @param map A base 64 map (see base64_init_map)
+ * @param sixbit Six-bit value to map
+ * @return a base 64 character
+ */
+static char sixbit_to_b64(const base64_maps_t *maps, const uint8_t sixbit)
+{
+	assert(sixbit <= 63);
+
+	return maps->encode_map[(unsigned char)sixbit];
+}
+
+/**
+ * sixbit_from_b64 - maps a base64-alphabet character to its 6-bit value
+ * @param maps A base 64 maps structure (see base64_init_maps)
+ * @param sixbit Six-bit value to map
+ * @return a six-bit value
+ */
+static int8_t sixbit_from_b64(const base64_maps_t *maps,
+			      const unsigned char b64letter)
+{
+	int8_t ret;
+
+	ret = maps->decode_map[(unsigned char)b64letter];
+	if (ret == (char)0xff) {
+		errno = EDOM;
+		return -1;
+	}
+
+	return ret;
+}
+
+bool base64_char_in_alphabet(const base64_maps_t *maps, const char b64char)
+{
+	return (maps->decode_map[(const unsigned char)b64char] != (char)0xff);
+}
+
+void base64_init_maps(base64_maps_t *dest, const char src[64])
+{
+	unsigned char i;
+
+	memcpy(dest->encode_map,src,64);
+	memset(dest->decode_map,0xff,256);
+	for (i=0; i<64; i++) {
+		dest->decode_map[(unsigned char)src[i]] = i;
+	}
+}
+
+size_t base64_encoded_length(size_t srclen)
+{
+	return ((srclen + 2) / 3) * 4;
+}
+
+void base64_encode_triplet_using_maps(const base64_maps_t *maps,
+				      char dest[4], const char src[3])
+{
+	char a = src[0];
+	char b = src[1];
+	char c = src[2];
+
+	dest[0] = sixbit_to_b64(maps, (a & 0xfc) >> 2);
+	dest[1] = sixbit_to_b64(maps, ((a & 0x3) << 4) | ((b & 0xf0) >> 4));
+	dest[2] = sixbit_to_b64(maps, ((c & 0xc0) >> 6) | ((b & 0xf) << 2));
+	dest[3] = sixbit_to_b64(maps, c & 0x3f);
+}
+
+void base64_encode_tail_using_maps(const base64_maps_t *maps, char dest[4],
+				   const char *src, const size_t srclen)
+{
+	char longsrc[3] = { 0 };
+
+	assert(srclen <= 3);
+
+	memcpy(longsrc, src, srclen);
+	base64_encode_triplet_using_maps(maps, dest, longsrc);
+	memset(dest+1+srclen, '=', 3-srclen);
+}
+
+ssize_t base64_encode_using_maps(const base64_maps_t *maps,
+				 char *dest, const size_t destlen,
+				 const char *src, const size_t srclen)
+{
+	size_t src_offset = 0;
+	size_t dest_offset = 0;
+
+	if (destlen < base64_encoded_length(srclen)) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+
+	while (srclen - src_offset >= 3) {
+		base64_encode_triplet_using_maps(maps, &dest[dest_offset], &src[src_offset]);
+		src_offset += 3;
+		dest_offset += 4;
+	}
+
+	if (src_offset < srclen) {
+		base64_encode_tail_using_maps(maps, &dest[dest_offset], &src[src_offset], srclen-src_offset);
+		dest_offset += 4;
+	}
+
+	memset(&dest[dest_offset], '\0', destlen-dest_offset);
+
+	return dest_offset;
+}
+
+size_t base64_decoded_length(size_t srclen)
+{
+	return ((srclen+3)/4*3);
+}
+
+int base64_decode_quartet_using_maps(const base64_maps_t *maps, char dest[3],
+				     const char src[4])
+{
+	signed char a;
+	signed char b;
+	signed char c;
+	signed char d;
+
+	a = sixbit_from_b64(maps, src[0]);
+	b = sixbit_from_b64(maps, src[1]);
+	c = sixbit_from_b64(maps, src[2]);
+	d = sixbit_from_b64(maps, src[3]);
+
+	if ((a == -1) || (b == -1) || (c == -1) || (d == -1)) {
+		return -1;
+	}
+
+	dest[0] = (a << 2) | (b >> 4);
+	dest[1] = ((b & 0xf) << 4) | (c >> 2);
+	dest[2] = ((c & 0x3) << 6) | d;
+
+	return 0;
+}
+
+
+int base64_decode_tail_using_maps(const base64_maps_t *maps, char dest[3],
+				  const char * src, const size_t srclen)
+{
+	char longsrc[4];
+	int quartet_result;
+	size_t insize = srclen;
+
+	while (insize != 0 &&
+	       src[insize-1] == '=') { /* throw away padding symbols */
+		insize--;
+	}
+	if (insize == 0) {
+		return 0;
+	}
+	if (insize == 1) {
+		/* the input is malformed.... */
+		errno = EINVAL;
+		return -1;
+	}
+	memcpy(longsrc, src, insize);
+	memset(longsrc+insize, 'A', 4-insize);
+	quartet_result = base64_decode_quartet_using_maps(maps, dest, longsrc);
+	if (quartet_result == -1) {
+		return -1;
+	}
+
+	return insize - 1;
+}
+
+ssize_t base64_decode_using_maps(const base64_maps_t *maps,
+				 char *dest, const size_t destlen,
+				 const char *src, const size_t srclen)
+{
+	ssize_t dest_offset = 0;
+	ssize_t i;
+	size_t more;
+
+	if (destlen < base64_decoded_length(srclen)) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+
+	for(i=0; srclen - i > 4; i+=4) {
+		if (base64_decode_quartet_using_maps(maps, &dest[dest_offset], &src[i]) == -1) {
+			return -1;
+		}
+		dest_offset += 3;
+	}
+
+	more = base64_decode_tail_using_maps(maps, &dest[dest_offset], &src[i], srclen - i);
+	if (more == -1) {
+		return -1;
+	}
+	dest_offset += more;
+
+	memset(&dest[dest_offset], '\0', destlen-dest_offset);
+
+	return dest_offset;
+}
+
+
+
+
+/**
+ * base64_maps_rfc4648 - pregenerated maps struct for rfc4648
+ */
+const base64_maps_t base64_maps_rfc4648 = {
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
+
+  "\xff\xff\xff\xff\xff" /* 0 */					\
+  "\xff\xff\xff\xff\xff" /* 5 */					\
+  "\xff\xff\xff\xff\xff" /* 10 */					\
+  "\xff\xff\xff\xff\xff" /* 15 */					\
+  "\xff\xff\xff\xff\xff" /* 20 */					\
+  "\xff\xff\xff\xff\xff" /* 25 */					\
+  "\xff\xff\xff\xff\xff" /* 30 */					\
+  "\xff\xff\xff\xff\xff" /* 35 */					\
+  "\xff\xff\xff\x3e\xff" /* 40 */					\
+  "\xff\xff\x3f\x34\x35" /* 45 */					\
+  "\x36\x37\x38\x39\x3a" /* 50 */					\
+  "\x3b\x3c\x3d\xff\xff" /* 55 */					\
+  "\xff\xff\xff\xff\xff" /* 60 */					\
+  "\x00\x01\x02\x03\x04" /* 65 A */					\
+  "\x05\x06\x07\x08\x09" /* 70 */					\
+  "\x0a\x0b\x0c\x0d\x0e" /* 75 */					\
+  "\x0f\x10\x11\x12\x13" /* 80 */					\
+  "\x14\x15\x16\x17\x18" /* 85 */					\
+  "\x19\xff\xff\xff\xff" /* 90 */					\
+  "\xff\xff\x1a\x1b\x1c" /* 95 */					\
+  "\x1d\x1e\x1f\x20\x21" /* 100 */					\
+  "\x22\x23\x24\x25\x26" /* 105 */					\
+  "\x27\x28\x29\x2a\x2b" /* 110 */					\
+  "\x2c\x2d\x2e\x2f\x30" /* 115 */					\
+  "\x31\x32\x33\xff\xff" /* 120 */					\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 125 */			\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 155 */			\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 185 */			\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 215 */			\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"				\
+  "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" /* 245 */
+};