--- /dev/null
+/* Licensed under BSD-MIT - see LICENSE file for details */
+#ifndef CCAN_BASE64_H
+#define CCAN_BASE64_H
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+/**
+ * base64_maps_t - structure to hold maps for encode/decode
+ */
+typedef struct {
+ char encode_map[64];
+ signed char decode_map[256];
+} base64_maps_t;
+
+/**
+ * base64_encoded_length - Calculate encode buffer length
+ * @param srclen the size of the data to be encoded
+ * @note add 1 to this to get null-termination
+ * @return Buffer length required for encode
+ */
+size_t base64_encoded_length(size_t srclen);
+
+/**
+ * base64_decoded_length - Calculate decode buffer length
+ * @param srclen Length of the data to be decoded
+ * @note This does not return the size of the decoded data! see base64_decode
+ * @return Minimum buffer length for safe decode
+ */
+size_t base64_decoded_length(size_t srclen);
+
+/**
+ * base64_init_maps - populate a base64_maps_t based on a supplied alphabet
+ * @param dest A base64 maps object
+ * @param src Alphabet to populate the maps from (e.g. base64_alphabet_rfc4648)
+ */
+void base64_init_maps(base64_maps_t *dest, const char src[64]);
+
+
+/**
+ * base64_encode_triplet_using_maps - encode 3 bytes into base64 using a specific alphabet
+ * @param maps Maps to use for encoding (see base64_init_maps)
+ * @param dest Buffer containing 3 bytes
+ * @param src Buffer containing 4 characters
+ */
+void base64_encode_triplet_using_maps(const base64_maps_t *maps,
+ char dest[4], const char src[3]);
+
+/**
+ * base64_encode_tail_using_maps - encode the final bytes of a source using a specific alphabet
+ * @param maps Maps to use for encoding (see base64_init_maps)
+ * @param dest Buffer containing 4 bytes
+ * @param src Buffer containing srclen bytes
+ * @param srclen Number of bytes (<= 3) to encode in src
+ */
+void base64_encode_tail_using_maps(const base64_maps_t *maps, char dest[4],
+ const char *src, size_t srclen);
+
+/**
+ * base64_encode_using_maps - encode a buffer into base64 using a specific alphabet
+ * @param maps Maps to use for encoding (see base64_init_maps)
+ * @param dest Buffer to encode into
+ * @param destlen Length of dest
+ * @param src Buffer to encode
+ * @param srclen Length of the data to encode
+ * @return Number of encoded bytes set in dest. -1 on error (and errno set)
+ * @note dest will be nul-padded to destlen (past any required padding)
+ * @note sets errno = EOVERFLOW if destlen is too small
+ */
+ssize_t base64_encode_using_maps(const base64_maps_t *maps,
+ char *dest, size_t destlen,
+ const char *src, size_t srclen);
+
+/*
+ * base64_char_in_alphabet - returns true if character can be part of an encoded string
+ * @param maps A base64 maps object (see base64_init_maps)
+ * @param b64char Character to check
+ */
+bool base64_char_in_alphabet(const base64_maps_t *maps, char b64char);
+
+/**
+ * base64_decode_using_maps - decode a base64-encoded string using a specific alphabet
+ * @param maps A base64 maps object (see base64_init_maps)
+ * @param dest Buffer to decode into
+ * @param destlen length of dest
+ * @param src the buffer to decode
+ * @param srclen the length of the data to decode
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note dest will be nul-padded to destlen
+ * @note sets errno = EOVERFLOW if destlen is too small
+ * @note sets errno = EDOM if src contains invalid characters
+ */
+ssize_t base64_decode_using_maps(const base64_maps_t *maps,
+ char *dest, size_t destlen,
+ const char *src, size_t srclen);
+
+/**
+ * base64_decode_quartet_using_maps - decode 4 bytes from base64 using a specific alphabet
+ * @param maps A base64 maps object (see base64_init_maps)
+ * @param dest Buffer containing 3 bytes
+ * @param src Buffer containing 4 bytes
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note sets errno = EDOM if src contains invalid characters
+ */
+int base64_decode_quartet_using_maps(const base64_maps_t *maps,
+ char dest[3], const char src[4]);
+
+/**
+ * base64_decode_tail_using_maps - decode the final bytes of a base64 string using a specific alphabet
+ * @param maps A base64 maps object (see base64_init_maps)
+ * @param dest Buffer containing 3 bytes
+ * @param src Buffer containing 4 bytes - padded with '=' as required
+ * @param srclen Number of bytes to decode in src
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note sets errno = EDOM if src contains invalid characters
+ * @note sets errno = EINVAL if src is an invalid base64 tail
+ */
+int base64_decode_tail_using_maps(const base64_maps_t *maps, char *dest,
+ const char *src, size_t srclen);
+
+
+/* the rfc4648 functions: */
+
+static const base64_maps_t base64_maps_rfc4648;
+
+/**
+ * base64_encode - Encode a buffer into base64 according to rfc4648
+ * @param dest Buffer to encode into
+ * @param destlen Length of the destination buffer
+ * @param src Buffer to encode
+ * @param srclen Length of the data to encode
+ * @return Number of encoded bytes set in dest. -1 on error (and errno set)
+ * @note dest will be nul-padded to destlen (past any required padding)
+ * @note sets errno = EOVERFLOW if destlen is too small
+ *
+ * This function encodes src according to http://tools.ietf.org/html/rfc4648
+ *
+ * Example:
+ * size_t encoded_length;
+ * char dest[100];
+ * const char *src = "This string gets encoded";
+ * encoded_length = base64_encode(dest, sizeof(dest), src, strlen(src));
+ * printf("Returned data of length %zd @%p\n", encoded_length, &dest);
+ */
+static inline
+ssize_t base64_encode(char *dest, size_t destlen,
+ const char *src, size_t srclen)
+{
+ return base64_encode_using_maps(&base64_maps_rfc4648,
+ dest, destlen, src, srclen);
+}
+
+/**
+ * base64_encode_triplet - encode 3 bytes into base64 according to rfc4648
+ * @param dest Buffer containing 4 bytes
+ * @param src Buffer containing 3 bytes
+ */
+static inline
+void base64_encode_triplet(char dest[4], const char src[3])
+{
+ base64_encode_triplet_using_maps(&base64_maps_rfc4648, dest, src);
+}
+
+/**
+ * base64_encode_tail - encode the final bytes of a source according to rfc4648
+ * @param dest Buffer containing 4 bytes
+ * @param src Buffer containing srclen bytes
+ * @param srclen Number of bytes (<= 3) to encode in src
+ */
+static inline
+void base64_encode_tail(char dest[4], const char *src, size_t srclen)
+{
+ base64_encode_tail_using_maps(&base64_maps_rfc4648, dest, src, srclen);
+}
+
+
+/**
+ * base64_decode - decode An rfc4648 base64-encoded string
+ * @param dest Buffer to decode into
+ * @param destlen Length of the destination buffer
+ * @param src Buffer to decode
+ * @param srclen Length of the data to decode
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note dest will be nul-padded to destlen
+ * @note sets errno = EOVERFLOW if destlen is too small
+ * @note sets errno = EDOM if src contains invalid characters
+ *
+ * This function decodes the buffer according to
+ * http://tools.ietf.org/html/rfc4648
+ *
+ * Example:
+ * size_t decoded_length;
+ * char ret[100];
+ * const char *src = "Zm9vYmFyYmF6";
+ * decoded_length = base64_decode(ret, sizeof(ret), src, strlen(src));
+ * printf("Returned data of length %zd @%p\n", decoded_length, &ret);
+ */
+static inline
+ssize_t base64_decode(char *dest, size_t destlen,
+ const char *src, size_t srclen)
+{
+ return base64_decode_using_maps(&base64_maps_rfc4648,
+ dest, destlen, src, srclen);
+}
+
+/**
+ * base64_decode_quartet - decode the first 4 characters in src into dest
+ * @param dest Buffer containing 3 bytes
+ * @param src Buffer containing 4 characters
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note sets errno = EDOM if src contains invalid characters
+ */
+static inline
+int base64_decode_quartet(char dest[3], const char src[4])
+{
+ return base64_decode_quartet_using_maps(&base64_maps_rfc4648,
+ dest, src);
+}
+
+/**
+ * @brief decode the final bytes of a base64 string from src into dest
+ * @param dest Buffer containing 3 bytes
+ * @param src Buffer containing 4 bytes - padded with '=' as required
+ * @param srclen Number of bytes to decode in src
+ * @return Number of decoded bytes set in dest. -1 on error (and errno set)
+ * @note sets errno = EDOM if src contains invalid characters
+ * @note sets errno = EINVAL if src is an invalid base64 tail
+ */
+static inline
+ssize_t base64_decode_tail(char dest[3], const char *src, size_t srclen)
+{
+ return base64_decode_tail_using_maps(&base64_maps_rfc4648,
+ dest, src, srclen);
+}
+
+/* end rfc4648 functions */
+
+
+
+#endif /* CCAN_BASE64_H */
projects / ccan / blobdiff