75 lines
2.1 KiB
C
75 lines
2.1 KiB
C
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/* SPDX-License-Identifier: LGPL-2.1+ */
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#include <errno.h>
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#include "modhex.h"
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#include "macro.h"
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#include "memory-util.h"
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const char modhex_alphabet[16] = {
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'c', 'b', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'n', 'r', 't', 'u', 'v'
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};
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int decode_modhex_char(char x) {
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for (size_t i = 0; i < ELEMENTSOF(modhex_alphabet); i++)
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/* Check both upper and lowercase */
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if (modhex_alphabet[i] == x || (modhex_alphabet[i] - 32) == x)
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return i;
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return -EINVAL;
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}
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int normalize_recovery_key(const char *password, char **ret) {
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_cleanup_(erase_and_freep) char *mangled = NULL;
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size_t l;
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assert(password);
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assert(ret);
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l = strlen(password);
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if (!IN_SET(l,
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MODHEX_RAW_LENGTH*2, /* syntax without dashes */
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MODHEX_FORMATTED_LENGTH-1)) /* syntax with dashes */
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return -EINVAL;
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mangled = new(char, MODHEX_FORMATTED_LENGTH);
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if (!mangled)
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return -ENOMEM;
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for (size_t i = 0, j = 0; i < MODHEX_RAW_LENGTH; i++) {
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size_t k;
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int a, b;
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if (l == MODHEX_RAW_LENGTH*2)
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/* Syntax without dashes */
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k = i * 2;
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else {
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/* Syntax with dashes */
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assert(l == MODHEX_FORMATTED_LENGTH-1);
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k = i * 2 + i / 4;
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if (i > 0 && i % 4 == 0 && password[k-1] != '-')
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return -EINVAL;
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}
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a = decode_modhex_char(password[k]);
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if (a < 0)
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return -EINVAL;
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b = decode_modhex_char(password[k+1]);
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if (b < 0)
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return -EINVAL;
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mangled[j++] = modhex_alphabet[a];
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mangled[j++] = modhex_alphabet[b];
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if (i % 4 == 3)
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mangled[j++] = '-';
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}
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mangled[MODHEX_FORMATTED_LENGTH-1] = 0;
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*ret = TAKE_PTR(mangled);
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return 0;
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}
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