mbedtls_ct_memcpy_if() function

Conditional memcpy. Functionally equivalent to: if (condition) { memcpy(dest, src1, len); } else { if (src2 != NULL) memcpy(dest, src2, len); } It will always read len bytes from src1. If src2 != NULL, it will always read len bytes from src2. If src2 == NULL, it will instead read len bytes from dest (as if src2 == dest).

Syntax

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Summary

Declaration

Definition

from constant_time_internal.h:495

void mbedtls_ct_memcpy_if(mbedtls_ct_condition_t condition, unsigned char *dest, const unsigned char *src1, const unsigned char *src2, size_t len );

Implemented in constant_time.c:170

Arguments

Argument

Description

condition

The condition

dest

Secret. Destination pointer.

src1

Secret. Pointer to copy from (if \p condition == MBEDTLS_CT_TRUE). This may be equal to \p dest, but may not overlap in other ways.

src2

Secret (contents only - may branch to determine if this parameter is NULL). Pointer to copy from (if \p condition == MBEDTLS_CT_FALSE and \p src2 is not NULL). May be NULL. This may be equal to \p dest, but may not overlap it in other ways. It may overlap with \p src1.

len

Number of bytes to copy.