1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2014 Paul Sokolovsky
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include <stdio.h>
28#include <assert.h>
29#include <string.h>
30
31#include "py/runtime.h"
32#include "py/binary.h"
33
34#if MICROPY_PY_UBINASCII
35
36STATIC mp_obj_t mod_binascii_hexlify(size_t n_args, const mp_obj_t *args) {
37 // First argument is the data to convert.
38 // Second argument is an optional separator to be used between values.
39 const char *sep = NULL;
40 mp_buffer_info_t bufinfo;
41 mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);
42
43 // Code below assumes non-zero buffer length when computing size with
44 // separator, so handle the zero-length case here.
45 if (bufinfo.len == 0) {
46 return mp_const_empty_bytes;
47 }
48
49 vstr_t vstr;
50 size_t out_len = bufinfo.len * 2;
51 if (n_args > 1) {
52 // 1-char separator between hex numbers
53 out_len += bufinfo.len - 1;
54 sep = mp_obj_str_get_str(args[1]);
55 }
56 vstr_init_len(&vstr, out_len);
57 byte *in = bufinfo.buf, *out = (byte *)vstr.buf;
58 for (mp_uint_t i = bufinfo.len; i--;) {
59 byte d = (*in >> 4);
60 if (d > 9) {
61 d += 'a' - '9' - 1;
62 }
63 *out++ = d + '0';
64 d = (*in++ & 0xf);
65 if (d > 9) {
66 d += 'a' - '9' - 1;
67 }
68 *out++ = d + '0';
69 if (sep != NULL && i != 0) {
70 *out++ = *sep;
71 }
72 }
73 return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
74}
75STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_binascii_hexlify_obj, 1, 2, mod_binascii_hexlify);
76
77STATIC mp_obj_t mod_binascii_unhexlify(mp_obj_t data) {
78 mp_buffer_info_t bufinfo;
79 mp_get_buffer_raise(data, &bufinfo, MP_BUFFER_READ);
80
81 if ((bufinfo.len & 1) != 0) {
82 mp_raise_ValueError(MP_ERROR_TEXT("odd-length string"));
83 }
84 vstr_t vstr;
85 vstr_init_len(&vstr, bufinfo.len / 2);
86 byte *in = bufinfo.buf, *out = (byte *)vstr.buf;
87 byte hex_byte = 0;
88 for (mp_uint_t i = bufinfo.len; i--;) {
89 byte hex_ch = *in++;
90 if (unichar_isxdigit(hex_ch)) {
91 hex_byte += unichar_xdigit_value(hex_ch);
92 } else {
93 mp_raise_ValueError(MP_ERROR_TEXT("non-hex digit found"));
94 }
95 if (i & 1) {
96 hex_byte <<= 4;
97 } else {
98 *out++ = hex_byte;
99 hex_byte = 0;
100 }
101 }
102 return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
103}
104STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_binascii_unhexlify_obj, mod_binascii_unhexlify);
105
106// If ch is a character in the base64 alphabet, and is not a pad character, then
107// the corresponding integer between 0 and 63, inclusively, is returned.
108// Otherwise, -1 is returned.
109static int mod_binascii_sextet(byte ch) {
110 if (ch >= 'A' && ch <= 'Z') {
111 return ch - 'A';
112 } else if (ch >= 'a' && ch <= 'z') {
113 return ch - 'a' + 26;
114 } else if (ch >= '0' && ch <= '9') {
115 return ch - '0' + 52;
116 } else if (ch == '+') {
117 return 62;
118 } else if (ch == '/') {
119 return 63;
120 } else {
121 return -1;
122 }
123}
124
125STATIC mp_obj_t mod_binascii_a2b_base64(mp_obj_t data) {
126 mp_buffer_info_t bufinfo;
127 mp_get_buffer_raise(data, &bufinfo, MP_BUFFER_READ);
128 byte *in = bufinfo.buf;
129
130 vstr_t vstr;
131 vstr_init(&vstr, (bufinfo.len / 4) * 3 + 1); // Potentially over-allocate
132 byte *out = (byte *)vstr.buf;
133
134 uint shift = 0;
135 int nbits = 0; // Number of meaningful bits in shift
136 bool hadpad = false; // Had a pad character since last valid character
137 for (size_t i = 0; i < bufinfo.len; i++) {
138 if (in[i] == '=') {
139 if ((nbits == 2) || ((nbits == 4) && hadpad)) {
140 nbits = 0;
141 break;
142 }
143 hadpad = true;
144 }
145
146 int sextet = mod_binascii_sextet(in[i]);
147 if (sextet == -1) {
148 continue;
149 }
150 hadpad = false;
151 shift = (shift << 6) | sextet;
152 nbits += 6;
153
154 if (nbits >= 8) {
155 nbits -= 8;
156 out[vstr.len++] = (shift >> nbits) & 0xFF;
157 }
158 }
159
160 if (nbits) {
161 mp_raise_ValueError(MP_ERROR_TEXT("incorrect padding"));
162 }
163
164 return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
165}
166STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_binascii_a2b_base64_obj, mod_binascii_a2b_base64);
167
168STATIC mp_obj_t mod_binascii_b2a_base64(mp_obj_t data) {
169 mp_buffer_info_t bufinfo;
170 mp_get_buffer_raise(data, &bufinfo, MP_BUFFER_READ);
171
172 vstr_t vstr;
173 vstr_init_len(&vstr, ((bufinfo.len != 0) ? (((bufinfo.len - 1) / 3) + 1) * 4 : 0) + 1);
174
175 // First pass, we convert input buffer to numeric base 64 values
176 byte *in = bufinfo.buf, *out = (byte *)vstr.buf;
177 mp_uint_t i;
178 for (i = bufinfo.len; i >= 3; i -= 3) {
179 *out++ = (in[0] & 0xFC) >> 2;
180 *out++ = (in[0] & 0x03) << 4 | (in[1] & 0xF0) >> 4;
181 *out++ = (in[1] & 0x0F) << 2 | (in[2] & 0xC0) >> 6;
182 *out++ = in[2] & 0x3F;
183 in += 3;
184 }
185 if (i != 0) {
186 *out++ = (in[0] & 0xFC) >> 2;
187 if (i == 2) {
188 *out++ = (in[0] & 0x03) << 4 | (in[1] & 0xF0) >> 4;
189 *out++ = (in[1] & 0x0F) << 2;
190 } else {
191 *out++ = (in[0] & 0x03) << 4;
192 *out++ = 64;
193 }
194 *out = 64;
195 }
196
197 // Second pass, we convert number base 64 values to actual base64 ascii encoding
198 out = (byte *)vstr.buf;
199 for (mp_uint_t j = vstr.len - 1; j--;) {
200 if (*out < 26) {
201 *out += 'A';
202 } else if (*out < 52) {
203 *out += 'a' - 26;
204 } else if (*out < 62) {
205 *out += '0' - 52;
206 } else if (*out == 62) {
207 *out = '+';
208 } else if (*out == 63) {
209 *out = '/';
210 } else {
211 *out = '=';
212 }
213 out++;
214 }
215 *out = '\n';
216 return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
217}
218STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_binascii_b2a_base64_obj, mod_binascii_b2a_base64);
219
220#if MICROPY_PY_UBINASCII_CRC32
221#include "uzlib/tinf.h"
222
223STATIC mp_obj_t mod_binascii_crc32(size_t n_args, const mp_obj_t *args) {
224 mp_buffer_info_t bufinfo;
225 mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);
226 uint32_t crc = (n_args > 1) ? mp_obj_get_int_truncated(args[1]) : 0;
227 crc = uzlib_crc32(bufinfo.buf, bufinfo.len, crc ^ 0xffffffff);
228 return mp_obj_new_int_from_uint(crc ^ 0xffffffff);
229}
230STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_binascii_crc32_obj, 1, 2, mod_binascii_crc32);
231#endif
232
233STATIC const mp_rom_map_elem_t mp_module_binascii_globals_table[] = {
234 { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ubinascii) },
235 { MP_ROM_QSTR(MP_QSTR_hexlify), MP_ROM_PTR(&mod_binascii_hexlify_obj) },
236 { MP_ROM_QSTR(MP_QSTR_unhexlify), MP_ROM_PTR(&mod_binascii_unhexlify_obj) },
237 { MP_ROM_QSTR(MP_QSTR_a2b_base64), MP_ROM_PTR(&mod_binascii_a2b_base64_obj) },
238 { MP_ROM_QSTR(MP_QSTR_b2a_base64), MP_ROM_PTR(&mod_binascii_b2a_base64_obj) },
239 #if MICROPY_PY_UBINASCII_CRC32
240 { MP_ROM_QSTR(MP_QSTR_crc32), MP_ROM_PTR(&mod_binascii_crc32_obj) },
241 #endif
242};
243
244STATIC MP_DEFINE_CONST_DICT(mp_module_binascii_globals, mp_module_binascii_globals_table);
245
246const mp_obj_module_t mp_module_ubinascii = {
247 .base = { &mp_type_module },
248 .globals = (mp_obj_dict_t *)&mp_module_binascii_globals,
249};
250
251#endif // MICROPY_PY_UBINASCII
252