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- #include <limits.h>
- #include <stdint.h>
- #include <string.h>
- #include "crypto_hash_sha512.h"
- #include "crypto_sign_edwards25519sha512batch.h"
- #include "crypto_verify_32.h"
- #include "private/ed25519_ref10.h"
- #include "randombytes.h"
- #include "utils.h"
- /* LCOV_EXCL_START */
- int
- crypto_sign_edwards25519sha512batch_keypair(unsigned char *pk,
- unsigned char *sk)
- {
- ge25519_p3 A;
- randombytes_buf(sk, 32);
- crypto_hash_sha512(sk, sk, 32);
- sk[0] &= 248;
- sk[31] &= 127;
- sk[31] |= 64;
- ge25519_scalarmult_base(&A, sk);
- ge25519_p3_tobytes(pk, &A);
- return 0;
- }
- int
- crypto_sign_edwards25519sha512batch(unsigned char *sm,
- unsigned long long *smlen_p,
- const unsigned char *m,
- unsigned long long mlen,
- const unsigned char *sk)
- {
- crypto_hash_sha512_state hs;
- unsigned char nonce[64];
- unsigned char hram[64];
- unsigned char sig[64];
- ge25519_p3 A;
- ge25519_p3 R;
- crypto_hash_sha512_init(&hs);
- crypto_hash_sha512_update(&hs, sk + 32, 32);
- crypto_hash_sha512_update(&hs, m, mlen);
- crypto_hash_sha512_final(&hs, nonce);
- ge25519_scalarmult_base(&A, sk);
- ge25519_p3_tobytes(sig + 32, &A);
- sc25519_reduce(nonce);
- ge25519_scalarmult_base(&R, nonce);
- ge25519_p3_tobytes(sig, &R);
- crypto_hash_sha512_init(&hs);
- crypto_hash_sha512_update(&hs, sig, 32);
- crypto_hash_sha512_update(&hs, m, mlen);
- crypto_hash_sha512_final(&hs, hram);
- sc25519_reduce(hram);
- sc25519_muladd(sig + 32, hram, nonce, sk);
- sodium_memzero(hram, sizeof hram);
- memmove(sm + 32, m, (size_t) mlen);
- memcpy(sm, sig, 32);
- memcpy(sm + 32 + mlen, sig + 32, 32);
- *smlen_p = mlen + 64U;
- return 0;
- }
- int
- crypto_sign_edwards25519sha512batch_open(unsigned char *m,
- unsigned long long *mlen_p,
- const unsigned char *sm,
- unsigned long long smlen,
- const unsigned char *pk)
- {
- unsigned char h[64];
- unsigned char t1[32], t2[32];
- unsigned long long mlen;
- ge25519_cached Ai;
- ge25519_p1p1 csa;
- ge25519_p2 cs;
- ge25519_p3 A;
- ge25519_p3 R;
- ge25519_p3 cs3;
- *mlen_p = 0;
- if (smlen < 64 || smlen - 64 > crypto_sign_edwards25519sha512batch_MESSAGEBYTES_MAX) {
- return -1;
- }
- mlen = smlen - 64;
- if (sm[smlen - 1] & 224) {
- return -1;
- }
- if (ge25519_has_small_order(pk) != 0 ||
- ge25519_frombytes_negate_vartime(&A, pk) != 0 ||
- ge25519_has_small_order(sm) != 0 ||
- ge25519_frombytes_negate_vartime(&R, sm) != 0) {
- return -1;
- }
- ge25519_p3_to_cached(&Ai, &A);
- crypto_hash_sha512(h, sm, mlen + 32);
- sc25519_reduce(h);
- ge25519_scalarmult(&cs3, h, &R);
- ge25519_add(&csa, &cs3, &Ai);
- ge25519_p1p1_to_p2(&cs, &csa);
- ge25519_tobytes(t1, &cs);
- t1[31] ^= 1 << 7;
- ge25519_scalarmult_base(&R, sm + 32 + mlen);
- ge25519_p3_tobytes(t2, &R);
- if (crypto_verify_32(t1, t2) != 0) {
- return -1;
- }
- *mlen_p = mlen;
- memmove(m, sm + 32, mlen);
- return 0;
- }
- /* LCOV_EXCL_END */
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