`nx_p384_field.nx` source

↩ module page · 120 lines · 3687 B
1// nx_p384_field.nx -- NIST P-384 field arithmetic mod p.
2//
3// p = 2^384 - 2^128 - 2^96 + 2^32 - 1 (FIPS 186-5 D.1.2.4)
4//   = 0xffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
5//     ffffffff fffffffe ffffffff 00000000 00000000 ffffffff
6//
7// Mirrors nx_p256_field.nx structure on the 12-limb u384 layout.
8// Provides add / sub / neg mod p, plus shipped u384 wrappers under
9// the field name.  Mul + invert ship separately as
10// nx_p384_field_mul + nx_p384_field_inv (matching the P-256 split).
11//
12// API:
13//   p384_field_load_p(out)
14//   p384_field_zero/one/copy/eq    (wrappers over u384_*)
15//   p384_field_add(r, a, b)         r = (a + b) mod p
16//   p384_field_sub(r, a, b)         r = (a - b) mod p
17//   p384_field_neg(r, a)            r = (-a) mod p
18//
19// license_tier: INDEPENDENT_REDERIVE
20// genealogy_id: international-research-sources/nist/fips_186_5
21// lineage_id:   nishi_p384_field_q10
22
23// nx_safety_envelope:
24//   intended_use:       AUTO_APPLIED -- primitive-specific tuning queued
25//   sil_target:         SIL1
26//   evidence:           [bulk_applied_2026-05-20, p384-field-add-sub-neg]
27//   verdict:            NOT_YET_EVALUATED
28
29import "nx_syscalls.nx"
30import "nx_u384.nx"
31
32const NX_P384_FIELD_OK:       i64 = 1
33const NX_P384_FIELD_BAD:      i64 = 2
34const NX_P384_FIELD_VERDICT_N: i64 = 3
35
36func nx_p384_field_verdict_is_valid(v: i64) -> i64 {
37    if v < NX_P384_FIELD_OK { return 0 }
38    if v >= NX_P384_FIELD_VERDICT_N { return 0 }
39    return 1
40}
41
42// Load the NIST P-384 prime p into out (12-limb LE).
43// Hex (MSB first): ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
44//                  ffffffff fffffffe ffffffff 00000000 00000000 ffffffff
45// Limbs (LSB first):
46//   limb[0]  = 0xFFFFFFFF
47//   limb[1]  = 0x00000000
48//   limb[2]  = 0x00000000
49//   limb[3]  = 0xFFFFFFFF
50//   limb[4]  = 0xFFFFFFFE
51//   limb[5..11] = 0xFFFFFFFF
52func p384_field_load_p(out: *i64) -> i64 {
53    out[0]  = 0xFFFFFFFF
54    out[1]  = 0
55    out[2]  = 0
56    out[3]  = 0xFFFFFFFF
57    out[4]  = 0xFFFFFFFE
58    out[5]  = 0xFFFFFFFF
59    out[6]  = 0xFFFFFFFF
60    out[7]  = 0xFFFFFFFF
61    out[8]  = 0xFFFFFFFF
62    out[9]  = 0xFFFFFFFF
63    out[10] = 0xFFFFFFFF
64    out[11] = 0xFFFFFFFF
65    return 0
66}
67
68// Wrapper aliases.
69func p384_field_zero(out: *i64) -> i64 { return u384_zero(out) }
70func p384_field_one(out: *i64)  -> i64 { return u384_one(out) }
71func p384_field_copy(out: *i64, src: *i64) -> i64 { return u384_copy(out, src) }
72func p384_field_eq(a: *i64, b: *i64) -> i64 { return u384_eq(a, b) }
73
74// r = (a + b) mod p.  Algorithm same as P-256:
75//   1. (r, carry) = a + b
76//   2. (t, borrow) = r - p
77//   3. If carry == 1 OR borrow == 0: r = t  (overflowed or r >= p)
78//   4. Else: r already canonical
79func p384_field_add(r: *i64, a: *i64, b: *i64) -> i64 {
80    let t: *i64 = u384_alloc()
81    let p: *i64 = u384_alloc()
82    p384_field_load_p(p)
83    let carry: i64 = u384_add_with_carry(r, a, b)
84    let borrow: i64 = u384_sub_with_borrow(t, r, p)
85    if carry == 1 {
86        u384_copy(r, t)
87    } else {
88        if borrow == 0 {
89            u384_copy(r, t)
90        }
91    }
92    return 0
93}
94
95// r = (a - b) mod p.  If a < b, add p back to bring into [0, p).
96func p384_field_sub(r: *i64, a: *i64, b: *i64) -> i64 {
97    let p: *i64 = u384_alloc()
98    p384_field_load_p(p)
99    let borrow: i64 = u384_sub_with_borrow(r, a, b)
100    if borrow == 1 {
101        u384_add_with_carry(r, r, p)
102    }
103    return 0
104}
105
106// r = (-a) mod p.
107func p384_field_neg(r: *i64, a: *i64) -> i64 {
108    if u384_is_zero(a) == 1 {
109        u384_zero(r)
110        return 0
111    }
112    let p: *i64 = u384_alloc()
113    p384_field_load_p(p)
114    u384_sub_with_borrow(r, p, a)
115    return 0
116}
117
118func main() -> i64 {
119    return 0
120}
nx_p384_field.nx source

`nx_p384_field.nx` source
