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SP int: read_unsigned_bin and BIG_ENDIAN

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When unaligned access of sp_int_digit pointer causes segfault, define:
WOLFSSL_SP_INT_DIGIT_ALIGN
This commit is contained in:
Sean Parkinson
2021-03-08 15:17:12 +10:00
parent b6130513e3
commit 98683bf71c
1 changed files with 22 additions and 0 deletions
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22
wolfcrypt/src/sp_int.c
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@ -77,6 +77,8 @@ This library provides single precision (SP) integer math functions.
* called again until complete.
* WOLFSSL_SP_FAST_NCT_EXPTMOD Enables the faster non-constant time modular
* exponentation implementation.
* WOLFSSL_SP_INT_DIGIT_ALIGN Enable when unaligned access of sp_int_digit
* pointer is not allowed.
*/
#if defined(WOLFSSL_SP_MATH) || defined(WOLFSSL_SP_MATH_ALL)
@ -12118,9 +12120,29 @@ int sp_read_unsigned_bin(sp_int* a, const byte* in, word32 inSz)
int j;
int s;
#ifndef WOLFSSL_SP_INT_DIGIT_ALIGN
for (i = inSz-1,j = 0; i > SP_WORD_SIZEOF-1; i -= SP_WORD_SIZEOF,j++) {
a->dp[j] = *(sp_int_digit*)(in + i - (SP_WORD_SIZEOF - 1));
}
#else
for (i = inSz-1, j = 0; i >= SP_WORD_SIZEOF - 1; i -= SP_WORD_SIZEOF) {
a->dp[j] = ((sp_int_digit)in[i - 0] << 0);
#if SP_WORD_SIZE >= 16
a->dp[j] |= ((sp_int_digit)in[i - 1] << 8);
#endif
#if SP_WORD_SIZE >= 32
a->dp[j] |= ((sp_int_digit)in[i - 2] << 16) |
((sp_int_digit)in[i - 3] << 24);
#endif
#if SP_WORD_SIZE >= 64
a->dp[j] |= ((sp_int_digit)in[i - 4] << 32) |
((sp_int_digit)in[i - 5] << 40) |
((sp_int_digit)in[i - 6] << 48) |
((sp_int_digit)in[i - 7] << 56);
#endif
j++;
}
#endif
a->dp[j] = 0;
for (s = 0; i >= 0; i--,s += 8) {
a->dp[j] |= ((sp_int_digit)in[i]) << s;