1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright (C) 2018 Intel Corporation.
3 * All rights reserved.
4 */
5
6 /**
7 * \file
8 * Base64 utility functions
9 */
10
11 #ifndef SPDK_BASE64_H
12 #define SPDK_BASE64_H
13
14 #include "spdk/stdinc.h"
15
16 #ifdef __cplusplus
17 extern "C" {
18 #endif
19
20 /**
21 * Following the Base64 part in RFC4648:
22 * https://tools.ietf.org/html/rfc4648.html
23 */
24
25 /**
26 * Calculate strlen of encoded Base64 string based on raw buffer length.
27 *
28 * \param raw_len Length of raw buffer.
29 * \return Encoded Base64 string length, excluding the terminating null byte ('\0').
30 */
spdk_base64_get_encoded_strlen(size_t raw_len)31 static inline size_t spdk_base64_get_encoded_strlen(size_t raw_len)
32 {
33 return (raw_len + 2) / 3 * 4;
34 }
35
36 /**
37 * Calculate length of raw buffer based on strlen of encoded Base64.
38 *
39 * This length will be the max possible decoded len. The exact decoded length could be
40 * shorter depending on if there was padding in the Base64 string.
41 *
42 * \param encoded_strlen Length of encoded Base64 string, excluding terminating null
43 * byte ('\0').
44 * \return Length of raw buffer.
45 */
spdk_base64_get_decoded_len(size_t encoded_strlen)46 static inline size_t spdk_base64_get_decoded_len(size_t encoded_strlen)
47 {
48 /* text_strlen and raw_len should be (4n,3n), (4n+2, 3n+1) or (4n+3, 3n+2) */
49 return encoded_strlen / 4 * 3 + ((encoded_strlen % 4 + 1) / 2);
50 }
51
52 /**
53 * Base 64 Encoding with Standard Base64 Alphabet defined in RFC4684.
54 *
55 * \param dst Buffer address of encoded Base64 string. Its length should be enough
56 * to contain Base64 string and the terminating null byte ('\0'), so it needs to be at
57 * least as long as 1 + spdk_base64_get_encoded_strlen(src_len).
58 * \param src Raw data buffer to be encoded.
59 * \param src_len Length of raw data buffer.
60 *
61 * \return 0 on success.
62 * \return -EINVAL if dst or src is NULL, or binary_len <= 0.
63 */
64 int spdk_base64_encode(char *dst, const void *src, size_t src_len);
65
66 /**
67 * Base 64 Encoding with URL and Filename Safe Alphabet.
68 *
69 * \param dst Buffer address of encoded Base64 string. Its length should be enough
70 * to contain Base64 string and the terminating null byte ('\0'), so it needs to be at
71 * least as long as 1 + spdk_base64_get_encoded_strlen(src_len).
72 * \param src Raw data buffer to be encoded.
73 * \param src_len Length of raw data buffer.
74 *
75 * \return 0 on success.
76 * \return -EINVAL if dst or src is NULL, or binary_len <= 0.
77 */
78 int spdk_base64_urlsafe_encode(char *dst, const void *src, size_t src_len);
79
80 /**
81 * Base 64 Decoding with Standard Base64 Alphabet defined in RFC4684.
82 *
83 * \param dst Buffer address of decoded raw data. Its length should be enough
84 * to contain decoded raw data, so it needs to be at least as long as
85 * spdk_base64_get_decoded_len(encoded_strlen). If NULL, only dst_len will be populated
86 * indicating the exact decoded length.
87 * \param dst_len Output parameter for the length of actual decoded raw data.
88 * If NULL, the actual decoded length won't be returned.
89 * \param src Data buffer for base64 string to be decoded.
90 *
91 * \return 0 on success.
92 * \return -EINVAL if src is NULL, or content of src is illegal.
93 */
94 int spdk_base64_decode(void *dst, size_t *dst_len, const char *src);
95
96 /**
97 * Base 64 Decoding with URL and Filename Safe Alphabet.
98 *
99 * \param dst Buffer address of decoded raw data. Its length should be enough
100 * to contain decoded raw data, so it needs to be at least as long as
101 * spdk_base64_get_decoded_len(encoded_strlen). If NULL, only dst_len will be populated
102 * indicating the exact decoded length.
103 * \param dst_len Output parameter for the length of actual decoded raw data.
104 * If NULL, the actual decoded length won't be returned.
105 * \param src Data buffer for base64 string to be decoded.
106 *
107 * \return 0 on success.
108 * \return -EINVAL if src is NULL, or content of src is illegal.
109 */
110 int spdk_base64_urlsafe_decode(void *dst, size_t *dst_len, const char *src);
111
112 #ifdef __cplusplus
113 }
114 #endif
115
116 #endif /* SPDK_BASE64_H */
117