1   
//
1   
//
2   
// Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
2   
// Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
3   
//
3   
//
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
4   
// Distributed under the Boost Software License, Version 1.0. (See accompanying
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5   
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   
//
6   
//
7   
// Official repository: https://github.com/cppalliance/http
7   
// Official repository: https://github.com/cppalliance/http
8   
//
8   
//
9  
9  
10   
#include "base64.hpp"
10   
#include "base64.hpp"
11  
11  
12   
namespace boost {
12   
namespace boost {
13   
namespace http {
13   
namespace http {
14   
namespace bcrypt {
14   
namespace bcrypt {
15   
namespace detail {
15   
namespace detail {
16  
16  
17   
namespace {
17   
namespace {
18  
18  
19   
// bcrypt's non-standard base64 alphabet
19   
// bcrypt's non-standard base64 alphabet
20   
constexpr char encode_table[] =
20   
constexpr char encode_table[] =
21   
    "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
21   
    "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
22  
22  
23   
// Decode table: maps ASCII char to 6-bit value, or 0xFF for invalid
23   
// Decode table: maps ASCII char to 6-bit value, or 0xFF for invalid
24   
constexpr std::uint8_t decode_table[256] = {
24   
constexpr std::uint8_t decode_table[256] = {
25   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 0-7
25   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 0-7
26   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 8-15
26   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 8-15
27   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 16-23
27   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 16-23
28   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 24-31
28   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 24-31
29   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 32-39
29   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 32-39
30   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01,  // 40-47  (. /)
30   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01,  // 40-47  (. /)
31   
    0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,  // 48-55  (0-7)
31   
    0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,  // 48-55  (0-7)
32   
    0x3E, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 56-63  (8-9)
32   
    0x3E, 0x3F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 56-63  (8-9)
33   
    0xFF, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,  // 64-71  (A-G)
33   
    0xFF, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,  // 64-71  (A-G)
34   
    0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,  // 72-79  (H-O)
34   
    0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,  // 72-79  (H-O)
35   
    0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,  // 80-87  (P-W)
35   
    0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,  // 80-87  (P-W)
36   
    0x19, 0x1A, 0x1B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 88-95  (X-Z)
36   
    0x19, 0x1A, 0x1B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 88-95  (X-Z)
37   
    0xFF, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22,  // 96-103 (a-g)
37   
    0xFF, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22,  // 96-103 (a-g)
38   
    0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A,  // 104-111 (h-o)
38   
    0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A,  // 104-111 (h-o)
39   
    0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32,  // 112-119 (p-w)
39   
    0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32,  // 112-119 (p-w)
40   
    0x33, 0x34, 0x35, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 120-127 (x-z)
40   
    0x33, 0x34, 0x35, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 120-127 (x-z)
41   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
41   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
42   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
42   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
43   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
43   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
44   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
44   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
45   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
45   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
46   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
46   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
47   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
47   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
48   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
48   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
49   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
49   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
50   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
50   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
51   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
51   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
52   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
52   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
53   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
53   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
54   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
54   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
55   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
55   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
56   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
56   
    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
57   
};
57   
};
58  
58  
59   
} // namespace
59   
} // namespace
60  
60  
61   
std::size_t
61   
std::size_t
62   
base64_encode(
62   
base64_encode(
63   
    char* dest,
63   
    char* dest,
64   
    std::uint8_t const* src,
64   
    std::uint8_t const* src,
65   
    std::size_t n)
65   
    std::size_t n)
66   
{
66   
{
67   
    char* out = dest;
67   
    char* out = dest;
68  
68  
69   
    while (n >= 3)
69   
    while (n >= 3)
70   
    {
70   
    {
71   
        std::uint32_t v =
71   
        std::uint32_t v =
72   
            (static_cast<std::uint32_t>(src[0]) << 16) |
72   
            (static_cast<std::uint32_t>(src[0]) << 16) |
73   
            (static_cast<std::uint32_t>(src[1]) << 8) |
73   
            (static_cast<std::uint32_t>(src[1]) << 8) |
74   
            static_cast<std::uint32_t>(src[2]);
74   
            static_cast<std::uint32_t>(src[2]);
75  
75  
76   
        *out++ = encode_table[(v >> 18) & 0x3F];
76   
        *out++ = encode_table[(v >> 18) & 0x3F];
77   
        *out++ = encode_table[(v >> 12) & 0x3F];
77   
        *out++ = encode_table[(v >> 12) & 0x3F];
78   
        *out++ = encode_table[(v >> 6) & 0x3F];
78   
        *out++ = encode_table[(v >> 6) & 0x3F];
79   
        *out++ = encode_table[v & 0x3F];
79   
        *out++ = encode_table[v & 0x3F];
80  
80  
81   
        src += 3;
81   
        src += 3;
82   
        n -= 3;
82   
        n -= 3;
83   
    }
83   
    }
84  
84  
85   
    if (n == 2)
85   
    if (n == 2)
86   
    {
86   
    {
87   
        std::uint32_t v =
87   
        std::uint32_t v =
88   
            (static_cast<std::uint32_t>(src[0]) << 16) |
88   
            (static_cast<std::uint32_t>(src[0]) << 16) |
89   
            (static_cast<std::uint32_t>(src[1]) << 8);
89   
            (static_cast<std::uint32_t>(src[1]) << 8);
90  
90  
91   
        *out++ = encode_table[(v >> 18) & 0x3F];
91   
        *out++ = encode_table[(v >> 18) & 0x3F];
92   
        *out++ = encode_table[(v >> 12) & 0x3F];
92   
        *out++ = encode_table[(v >> 12) & 0x3F];
93   
        *out++ = encode_table[(v >> 6) & 0x3F];
93   
        *out++ = encode_table[(v >> 6) & 0x3F];
94   
    }
94   
    }
95   
    else if (n == 1)
95   
    else if (n == 1)
96   
    {
96   
    {
97   
        std::uint32_t v =
97   
        std::uint32_t v =
98   
            static_cast<std::uint32_t>(src[0]) << 16;
98   
            static_cast<std::uint32_t>(src[0]) << 16;
99  
99  
100   
        *out++ = encode_table[(v >> 18) & 0x3F];
100   
        *out++ = encode_table[(v >> 18) & 0x3F];
101   
        *out++ = encode_table[(v >> 12) & 0x3F];
101   
        *out++ = encode_table[(v >> 12) & 0x3F];
102   
    }
102   
    }
103  
103  
104   
    return static_cast<std::size_t>(out - dest);
104   
    return static_cast<std::size_t>(out - dest);
105   
}
105   
}
106  
106  
107   
int
107   
int
108   
base64_decode(
108   
base64_decode(
109   
    std::uint8_t* dest,
109   
    std::uint8_t* dest,
110   
    char const* src,
110   
    char const* src,
111   
    std::size_t n)
111   
    std::size_t n)
112   
{
112   
{
113   
    std::uint8_t* out = dest;
113   
    std::uint8_t* out = dest;
114   
    std::size_t i = 0;
114   
    std::size_t i = 0;
115  
115  
116   
    while (i + 4 <= n)
116   
    while (i + 4 <= n)
117   
    {
117   
    {
118   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
118   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
119   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
119   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
120   
        std::uint8_t c = decode_table[static_cast<unsigned char>(src[i + 2])];
120   
        std::uint8_t c = decode_table[static_cast<unsigned char>(src[i + 2])];
121   
        std::uint8_t d = decode_table[static_cast<unsigned char>(src[i + 3])];
121   
        std::uint8_t d = decode_table[static_cast<unsigned char>(src[i + 3])];
122  
122  
123   
        if ((a | b | c | d) & 0x80)
123   
        if ((a | b | c | d) & 0x80)
124   
            return -1;
124   
            return -1;
125  
125  
126   
        std::uint32_t v =
126   
        std::uint32_t v =
127   
            (static_cast<std::uint32_t>(a) << 18) |
127   
            (static_cast<std::uint32_t>(a) << 18) |
128   
            (static_cast<std::uint32_t>(b) << 12) |
128   
            (static_cast<std::uint32_t>(b) << 12) |
129   
            (static_cast<std::uint32_t>(c) << 6) |
129   
            (static_cast<std::uint32_t>(c) << 6) |
130   
            static_cast<std::uint32_t>(d);
130   
            static_cast<std::uint32_t>(d);
131  
131  
132   
        *out++ = static_cast<std::uint8_t>(v >> 16);
132   
        *out++ = static_cast<std::uint8_t>(v >> 16);
133   
        *out++ = static_cast<std::uint8_t>(v >> 8);
133   
        *out++ = static_cast<std::uint8_t>(v >> 8);
134   
        *out++ = static_cast<std::uint8_t>(v);
134   
        *out++ = static_cast<std::uint8_t>(v);
135  
135  
136   
        i += 4;
136   
        i += 4;
137   
    }
137   
    }
138  
138  
139   
    // Handle remaining 2 or 3 characters
139   
    // Handle remaining 2 or 3 characters
140   
    if (i + 3 == n)
140   
    if (i + 3 == n)
141   
    {
141   
    {
142   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
142   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
143   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
143   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
144   
        std::uint8_t c = decode_table[static_cast<unsigned char>(src[i + 2])];
144   
        std::uint8_t c = decode_table[static_cast<unsigned char>(src[i + 2])];
145  
145  
146   
        if ((a | b | c) & 0x80)
146   
        if ((a | b | c) & 0x80)
147   
            return -1;
147   
            return -1;
148  
148  
149   
        std::uint32_t v =
149   
        std::uint32_t v =
150   
            (static_cast<std::uint32_t>(a) << 18) |
150   
            (static_cast<std::uint32_t>(a) << 18) |
151   
            (static_cast<std::uint32_t>(b) << 12) |
151   
            (static_cast<std::uint32_t>(b) << 12) |
152   
            (static_cast<std::uint32_t>(c) << 6);
152   
            (static_cast<std::uint32_t>(c) << 6);
153  
153  
154   
        *out++ = static_cast<std::uint8_t>(v >> 16);
154   
        *out++ = static_cast<std::uint8_t>(v >> 16);
155   
        *out++ = static_cast<std::uint8_t>(v >> 8);
155   
        *out++ = static_cast<std::uint8_t>(v >> 8);
156   
    }
156   
    }
157   
    else if (i + 2 == n)
157   
    else if (i + 2 == n)
158   
    {
158   
    {
159   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
159   
        std::uint8_t a = decode_table[static_cast<unsigned char>(src[i])];
160   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
160   
        std::uint8_t b = decode_table[static_cast<unsigned char>(src[i + 1])];
161  
161  
162   
        if ((a | b) & 0x80)
162   
        if ((a | b) & 0x80)
163   
            return -1;
163   
            return -1;
164  
164  
165   
        std::uint32_t v =
165   
        std::uint32_t v =
166   
            (static_cast<std::uint32_t>(a) << 18) |
166   
            (static_cast<std::uint32_t>(a) << 18) |
167   
            (static_cast<std::uint32_t>(b) << 12);
167   
            (static_cast<std::uint32_t>(b) << 12);
168  
168  
169   
        *out++ = static_cast<std::uint8_t>(v >> 16);
169   
        *out++ = static_cast<std::uint8_t>(v >> 16);
170   
    }
170   
    }
171   
    else if (i + 1 == n)
171   
    else if (i + 1 == n)
172   
    {
172   
    {
173   
        // Single trailing character is invalid
173   
        // Single trailing character is invalid
174   
        return -1;
174   
        return -1;
175   
    }
175   
    }
176  
176  
177   
    return static_cast<int>(out - dest);
177   
    return static_cast<int>(out - dest);
178   
}
178   
}
179  
179  
180   
} // detail
180   
} // detail
181   
} // bcrypt
181   
} // bcrypt
182   
} // http
182   
} // http
183   
} // boost
183   
} // boost