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Diffstat (limited to 'src/protocol/internal/ccan_base64.h')
| -rw-r--r-- | src/protocol/internal/ccan_base64.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/protocol/internal/ccan_base64.h b/src/protocol/internal/ccan_base64.h new file mode 100644 index 0000000..3f1cd7c --- /dev/null +++ b/src/protocol/internal/ccan_base64.h @@ -0,0 +1,247 @@ +/* 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> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * 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: */ + +extern 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 */ + +#ifdef __cplusplus +} +#endif + +#endif /* CCAN_BASE64_H */ |