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surjectionproof: reduce stack usage

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This commit is contained in:
Andrew Poelstra
2019-04-30 22:46:05 +00:00
committed by Tim Ruffing
parent 68d937fe11
commit b8a3ff5f3b
3 changed files with 16 additions and 29 deletions
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22
src/modules/surjection/main_impl.h
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@@ -272,8 +272,6 @@ int secp256k1_surjectionproof_generate(const secp256k1_context* ctx, secp256k1_s
size_t ring_input_index = 0;
secp256k1_gej ring_pubkeys[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_scalar borromean_s[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_ge inputs[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_ge output;
unsigned char msg32[32];
VERIFY_CHECK(ctx != NULL);
@@ -312,17 +310,12 @@ int secp256k1_surjectionproof_generate(const secp256k1_context* ctx, secp256k1_s
return 0;
}
secp256k1_generator_load(&output, ephemeral_output_tag);
for (i = 0; i < n_total_pubkeys; i++) {
secp256k1_generator_load(&inputs[i], &ephemeral_input_tags[i]);
}
secp256k1_surjection_compute_public_keys(ring_pubkeys, n_used_pubkeys, inputs, n_total_pubkeys, proof->used_inputs, &output, input_index, &ring_input_index);
secp256k1_surjection_compute_public_keys(ring_pubkeys, n_used_pubkeys, ephemeral_input_tags, n_total_pubkeys, proof->used_inputs, ephemeral_output_tag, input_index, &ring_input_index);
/* Produce signature */
rsizes[0] = (int) n_used_pubkeys;
indices[0] = (int) ring_input_index;
secp256k1_surjection_genmessage(msg32, inputs, n_total_pubkeys, &output);
secp256k1_surjection_genmessage(msg32, ephemeral_input_tags, n_total_pubkeys, ephemeral_output_tag);
if (secp256k1_surjection_genrand(borromean_s, n_used_pubkeys, &blinding_key) == 0) {
return 0;
}
@@ -347,8 +340,6 @@ int secp256k1_surjectionproof_verify(const secp256k1_context* ctx, const secp256
size_t n_used_pubkeys;
secp256k1_gej ring_pubkeys[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_scalar borromean_s[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_ge inputs[SECP256K1_SURJECTIONPROOF_MAX_N_INPUTS];
secp256k1_ge output;
unsigned char msg32[32];
VERIFY_CHECK(ctx != NULL);
@@ -364,12 +355,7 @@ int secp256k1_surjectionproof_verify(const secp256k1_context* ctx, const secp256
return 0;
}
secp256k1_generator_load(&output, ephemeral_output_tag);
for (i = 0; i < n_total_pubkeys; i++) {
secp256k1_generator_load(&inputs[i], &ephemeral_input_tags[i]);
}
if (secp256k1_surjection_compute_public_keys(ring_pubkeys, n_used_pubkeys, inputs, n_total_pubkeys, proof->used_inputs, &output, 0, NULL) == 0) {
if (secp256k1_surjection_compute_public_keys(ring_pubkeys, n_used_pubkeys, ephemeral_input_tags, n_total_pubkeys, proof->used_inputs, ephemeral_output_tag, 0, NULL) == 0) {
return 0;
}
@@ -382,7 +368,7 @@ int secp256k1_surjectionproof_verify(const secp256k1_context* ctx, const secp256
return 0;
}
}
secp256k1_surjection_genmessage(msg32, inputs, n_total_pubkeys, &output);
secp256k1_surjection_genmessage(msg32, ephemeral_input_tags, n_total_pubkeys, ephemeral_output_tag);
return secp256k1_borromean_verify(&ctx->ecmult_ctx, NULL, &proof->data[0], borromean_s, ring_pubkeys, rsizes, 1, msg32, 32);
}