x25519_multiply_workspace Union Reference

X25519 multiplication temporary working space. More...

Data Fields
struct {
uint8_t   pad [sizeof(union       x25519_multiply_step2)       - offsetof(union       x25519_multiply_step1,       parts.high_260bit)]
	Padding to avoid collision between steps 1 and 2. More...
union x25519_multiply_step1   step1
	Step 1 result. More...
};
	Step 1 result. More...
struct {
union x25519_multiply_step2   step2
	Step 2 result. More...
union x25519_multiply_step3   step3
	Step 3 result. More...
};
	Steps 2 and 3 results. More...

Detailed Description

X25519 multiplication temporary working space.

We overlap the buffers used by each step of the multiplication calculation to reduce the total stack space required:

|-----------------------------------------------------—| | <- pad -> | <---------— step 1 result ----------—> | | | <- low 256 bits -> | <– high 260 bits --> | | <----— step 2 result ---—> | <– step 3 result --> | |-----------------------------------------------------—|

Definition at line 216 of file x25519.c.

Field Documentation

pad

uint8_t x25519_multiply_workspace::pad[sizeof(union x25519_multiply_step2) - offsetof(union x25519_multiply_step1, parts.high_260bit)]

Padding to avoid collision between steps 1 and 2.

The step 2 multiplication consumes the high 260 bits of step 1, and so the step 2 multiplication result must not overlap this portion of the step 1 result.

Definition at line 228 of file x25519.c.

step1

union x25519_multiply_step1 x25519_multiply_workspace::step1

Step 1 result.

Definition at line 230 of file x25519.c.

@435

struct { ... }

Step 1 result.

step2

union x25519_multiply_step2 x25519_multiply_workspace::step2

Step 2 result.

Definition at line 235 of file x25519.c.

step3

union x25519_multiply_step3 x25519_multiply_workspace::step3

Step 3 result.

Definition at line 237 of file x25519.c.

@437

struct { ... }

Steps 2 and 3 results.

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The documentation for this union was generated from the following file:

• crypto/x25519.c