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Start on a consolidated 4844-only copy of the code

This commit is contained in:
Ramana Kumar 2022-09-27 18:11:37 +01:00
parent 96e3fc9bd8
commit 4488ad3269
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GPG Key ID: ED471C788B900433
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INCLUDE_DIRS = ../inc
.PRECIOUS: %.o
%.o: %.c Makefile
clang -Wall -I$(INCLUDE_DIRS) $(CFLAGS) $(KZG_CFLAGS) -c $*.c
libckzg4844.a: c_kzg_4844.o Makefile
ar rc libckzg4844.a $<
lib: KZG_CFLAGS += -O
lib: clean libckzg4844.a
clean:
rm -f *.o
rm -f libckzg4844.a
rm -f a.out

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# C-KZG-4844: A minimal library for EIP-4844 Polynomial Commitments
This is a copy of C-KZG stripped down to support the [Polynomial Commitments](https://github.com/ethereum/consensus-specs/blob/dev/specs/eip4844/polynomial-commitments.md) API:
- `bytes_to_bls_field`
- `vector_lincomb`
- `g1_lincomb`
- `blob_to_kzg_commitment`
- `verify_kzg_proof`
- `compute_kzg_proof`
- `evaluate_polynomial_in_evaluation_form`
and `compute_powers` from the [Validator](https://github.com/ethereum/consensus-specs/blob/dev/specs/eip4844/validator.md) API.
We also provide `load_trusted_setup` and `free_trusted_setup` to load the
trusted setup data from a file into an object that can be passed to the API
functions.
The only dependency is [blst](https://github.com/supranational/blst).
Ensure `blst.h` is provided at `../inc` and `libblst.a` at `../lib`.
(`blst.h` includes `blst_aux.h`, but the latter is unused and can be empty.)

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/*
* Copyright 2021 Benjamin Edgington
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "c_kzg_4844.h"
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
/**
* Wrapped `malloc()` that reports failures to allocate.
*
* @param[out] x Pointer to the allocated space
* @param[in] n The number of bytes to be allocated
* @retval C_CZK_OK All is well
* @retval C_CZK_MALLOC Memory allocation failed
*/
static C_KZG_RET c_kzg_malloc(void **x, size_t n) {
if (n > 0) {
*x = malloc(n);
return *x != NULL ? C_KZG_OK : C_KZG_MALLOC;
}
*x = NULL;
return C_KZG_OK;
}
#define CHECK(cond) \
if (!(cond)) return C_KZG_BADARGS
#define TRY(result) \
{ \
C_KZG_RET ret = (result); \
if (ret == C_KZG_MALLOC) return ret; \
if (ret != C_KZG_OK) return C_KZG_ERROR; \
}
/**
* Allocate memory for an array of G1 group elements.
*
* @remark Free the space later using `free()`.
*
* @param[out] x Pointer to the allocated space
* @param[in] n The number of G1 elements to be allocated
* @retval C_CZK_OK All is well
* @retval C_CZK_MALLOC Memory allocation failed
*/
static C_KZG_RET new_g1_array(g1_t **x, size_t n) {
return c_kzg_malloc((void **)x, n * sizeof **x);
}
/**
* Allocate memory for an array of G2 group elements.
*
* @remark Free the space later using `free()`.
*
* @param[out] x Pointer to the allocated space
* @param[in] n The number of G2 elements to be allocated
* @retval C_CZK_OK All is well
* @retval C_CZK_MALLOC Memory allocation failed
*/
static C_KZG_RET new_g2_array(g2_t **x, size_t n) {
return c_kzg_malloc((void **)x, n * sizeof **x);
}
/**
* Allocate memory for an array of field elements.
*
* @remark Free the space later using `free()`.
*
* @param[out] x Pointer to the allocated space
* @param[in] n The number of field elements to be allocated
* @retval C_CZK_OK All is well
* @retval C_CZK_MALLOC Memory allocation failed
*/
static C_KZG_RET new_fr_array(fr_t **x, size_t n) {
return c_kzg_malloc((void **)x, n * sizeof **x);
}
/**
* Fast log base 2 of a byte.
*
* Corresponds to the index of the highest bit set in the byte. Adapted from
* https://graphics.stanford.edu/~seander/bithacks.html#IntegerLog.
*
* @param[in] b A non-zero byte
* @return The index of the highest set bit
*/
static int log_2_byte(byte b) {
int r, shift;
r = (b > 0xF) << 2;
b >>= r;
shift = (b > 0x3) << 1;
b >>= (shift + 1);
r |= shift | b;
return r;
}
/** This is 1 in Blst's `blst_fr` limb representation. Crazy but true. */
static const fr_t fr_one = {0x00000001fffffffeL, 0x5884b7fa00034802L, 0x998c4fefecbc4ff5L, 0x1824b159acc5056fL};
/**
* Create a field element from an array of four 64-bit unsigned integers.
*
* @param out The field element equivalent of @p vals
* @param vals The array of 64-bit integers to be converted, little-endian ordering of the 64-bit words
*/
static void fr_from_uint64s(fr_t *out, const uint64_t vals[4]) {
blst_fr_from_uint64(out, vals);
}
/**
* Test whether the operand is one in the finite field.
*
* @param p The field element to be checked
* @retval true The element is one
* @retval false The element is not one
*
* @todo See if there is a more efficient way to check for one in the finite field.
*/
static bool fr_is_one(const fr_t *p) {
uint64_t a[4];
blst_uint64_from_fr(a, p);
return a[0] == 1 && a[1] == 0 && a[2] == 0 && a[3] == 0;
}
/**
* Multiply two field elements.
*
* @param[out] out @p a multiplied by @p b in the field
* @param[in] a Multiplicand
* @param[in] b Multiplier
*/
static void fr_mul(fr_t *out, const fr_t *a, const fr_t *b) {
blst_fr_mul(out, a, b);
}
/**
* Create a field element from a single 64-bit unsigned integer.
*
* @remark This can only generate a tiny fraction of possible field elements, and is mostly useful for testing.
*
* @param out The field element equivalent of @p n
* @param n The 64-bit integer to be converted
*/
static void fr_from_uint64(fr_t *out, uint64_t n) {
uint64_t vals[] = {n, 0, 0, 0};
fr_from_uint64s(out, vals);
}
/**
* Inverse of a field element.
*
* @param[out] out The inverse of @p a
* @param[in] a A field element
*/
static void fr_inv(fr_t *out, const fr_t *a) {
blst_fr_eucl_inverse(out, a);
}
/** The G1 identity/infinity */
static const g1_t g1_identity = {{0L, 0L, 0L, 0L, 0L, 0L}, {0L, 0L, 0L, 0L, 0L, 0L}, {0L, 0L, 0L, 0L, 0L, 0L}};
/**
* Add or double G1 points.
*
* This is safe if the two points are the same.
*
* @param[out] out @p a plus @p b in the group
* @param[in] a G1 group point
* @param[in] b G1 group point
*/
static void g1_add_or_dbl(g1_t *out, const g1_t *a, const g1_t *b) {
blst_p1_add_or_double(out, a, b);
}
/**
* Multiply a G1 group element by a field element.
*
* This "undoes" the Blst constant-timedness. FFTs do a lot of multiplication by one, so constant time is rather slow.
*
* @param[out] out [@p b]@p a
* @param[in] a The G1 group element
* @param[in] b The multiplier
*/
static void g1_mul(g1_t *out, const g1_t *a, const fr_t *b) {
blst_scalar s;
blst_scalar_from_fr(&s, b);
// Count the number of bytes to be multiplied.
int i = sizeof(blst_scalar);
while (i && !s.b[i - 1]) --i;
if (i == 0) {
*out = g1_identity;
} else if (i == 1 && s.b[0] == 1) {
*out = *a;
} else {
// Count the number of bits to be multiplied.
blst_p1_mult(out, a, s.b, 8 * i - 7 + log_2_byte(s.b[i - 1]));
}
}
/**
* Subtraction of G1 group elements.
*
* @param[out] out @p a - @p b
* @param[in] a A G1 group element
* @param[in] b The G1 group element to be subtracted
*/
static void g1_sub(g1_t *out, const g1_t *a, const g1_t *b) {
g1_t bneg = *b;
blst_p1_cneg(&bneg, true);
blst_p1_add_or_double(out, a, &bneg);
}
/**
* Utility function to test whether the argument is a power of two.
*
* @remark This method returns `true` for `is_power_of_two(0)` which is a bit weird, but not an issue in the contexts in
* which we use it.
*
* @param[in] n The number to test
* @retval true if @p n is a power of two or zero
* @retval false otherwise
*/
static bool is_power_of_two(uint64_t n) {
return (n & (n - 1)) == 0;
}
/**
* The first 32 roots of unity in the finite field F_r.
*
* For element `{A, B, C, D}`, the field element value is `A + B * 2^64 + C * 2^128 + D * 2^192`. This format may be
* converted to an `fr_t` type via the #fr_from_uint64s library function.
*
* The decimal values may be calculated with the following Python code:
* @code{.py}
* MODULUS = 52435875175126190479447740508185965837690552500527637822603658699938581184513
* PRIMITIVE_ROOT = 7
* [pow(PRIMITIVE_ROOT, (MODULUS - 1) // (2**i), MODULUS) for i in range(32)]
* @endcode
*
* Note: Being a "primitive root" in this context means that r^k != 1 for any k < q-1 where q is the modulus. So
* powers of r generate the field. This is also known as being a "primitive element".
*
* This is easy to check for: we just require that r^((q-1)/2) != 1. Instead of 5, we could use 7, 10, 13, 14, 15, 20...
* to create the roots of unity below. There are a lot of primitive roots:
* https://crypto.stanford.edu/pbc/notes/numbertheory/gen.html
*/
static const uint64_t scale2_root_of_unity[][4] = {
{0x0000000000000001L, 0x0000000000000000L, 0x0000000000000000L, 0x0000000000000000L},
{0xffffffff00000000L, 0x53bda402fffe5bfeL, 0x3339d80809a1d805L, 0x73eda753299d7d48L},
{0x0001000000000000L, 0xec03000276030000L, 0x8d51ccce760304d0L, 0x0000000000000000L},
{0x7228fd3397743f7aL, 0xb38b21c28713b700L, 0x8c0625cd70d77ce2L, 0x345766f603fa66e7L},
{0x53ea61d87742bcceL, 0x17beb312f20b6f76L, 0xdd1c0af834cec32cL, 0x20b1ce9140267af9L},
{0x360c60997369df4eL, 0xbf6e88fb4c38fb8aL, 0xb4bcd40e22f55448L, 0x50e0903a157988baL},
{0x8140d032f0a9ee53L, 0x2d967f4be2f95155L, 0x14a1e27164d8fdbdL, 0x45af6345ec055e4dL},
{0x5130c2c1660125beL, 0x98d0caac87f5713cL, 0xb7c68b4d7fdd60d0L, 0x6898111413588742L},
{0x4935bd2f817f694bL, 0x0a0865a899e8deffL, 0x6b368121ac0cf4adL, 0x4f9b4098e2e9f12eL},
{0x4541b8ff2ee0434eL, 0xd697168a3a6000feL, 0x39feec240d80689fL, 0x095166525526a654L},
{0x3c28d666a5c2d854L, 0xea437f9626fc085eL, 0x8f4de02c0f776af3L, 0x325db5c3debf77a1L},
{0x4a838b5d59cd79e5L, 0x55ea6811be9c622dL, 0x09f1ca610a08f166L, 0x6d031f1b5c49c834L},
{0xe206da11a5d36306L, 0x0ad1347b378fbf96L, 0xfc3e8acfe0f8245fL, 0x564c0a11a0f704f4L},
{0x6fdd00bfc78c8967L, 0x146b58bc434906acL, 0x2ccddea2972e89edL, 0x485d512737b1da3dL},
{0x034d2ff22a5ad9e1L, 0xae4622f6a9152435L, 0xdc86b01c0d477fa6L, 0x56624634b500a166L},
{0xfbd047e11279bb6eL, 0xc8d5f51db3f32699L, 0x483405417a0cbe39L, 0x3291357ee558b50dL},
{0xd7118f85cd96b8adL, 0x67a665ae1fcadc91L, 0x88f39a78f1aeb578L, 0x2155379d12180caaL},
{0x08692405f3b70f10L, 0xcd7f2bd6d0711b7dL, 0x473a2eef772c33d6L, 0x224262332d8acbf4L},
{0x6f421a7d8ef674fbL, 0xbb97a3bf30ce40fdL, 0x652f717ae1c34bb0L, 0x2d3056a530794f01L},
{0x194e8c62ecb38d9dL, 0xad8e16e84419c750L, 0xdf625e80d0adef90L, 0x520e587a724a6955L},
{0xfece7e0e39898d4bL, 0x2f69e02d265e09d9L, 0xa57a6e07cb98de4aL, 0x03e1c54bcb947035L},
{0xcd3979122d3ea03aL, 0x46b3105f04db5844L, 0xc70d0874b0691d4eL, 0x47c8b5817018af4fL},
{0xc6e7a6ffb08e3363L, 0xe08fec7c86389beeL, 0xf2d38f10fbb8d1bbL, 0x0abe6a5e5abcaa32L},
{0x5616c57de0ec9eaeL, 0xc631ffb2585a72dbL, 0x5121af06a3b51e3cL, 0x73560252aa0655b2L},
{0x92cf4deb77bd779cL, 0x72cf6a8029b7d7bcL, 0x6e0bcd91ee762730L, 0x291cf6d68823e687L},
{0xce32ef844e11a51eL, 0xc0ba12bb3da64ca5L, 0x0454dc1edc61a1a3L, 0x019fe632fd328739L},
{0x531a11a0d2d75182L, 0x02c8118402867ddcL, 0x116168bffbedc11dL, 0x0a0a77a3b1980c0dL},
{0xe2d0a7869f0319edL, 0xb94f1101b1d7a628L, 0xece8ea224f31d25dL, 0x23397a9300f8f98bL},
{0xd7b688830a4f2089L, 0x6558e9e3f6ac7b41L, 0x99e276b571905a7dL, 0x52dd465e2f094256L},
{0x474650359d8e211bL, 0x84d37b826214abc6L, 0x8da40c1ef2bb4598L, 0x0c83ea7744bf1beeL},
{0x694341f608c9dd56L, 0xed3a181fabb30adcL, 0x1339a815da8b398fL, 0x2c6d4e4511657e1eL},
{0x63e7cb4906ffc93fL, 0xf070bb00e28a193dL, 0xad1715b02e5713b5L, 0x4b5371495990693fL}};
/**
* Discrete fourier transforms over arrays of G1 group elements.
*
* Also known as [number theoretic
* transforms](https://en.wikipedia.org/wiki/Discrete_Fourier_transform_(general)#Number-theoretic_transform).
*
* @remark Functions here work only for lengths that are a power of two.
*/
/**
* Fast Fourier Transform.
*
* Recursively divide and conquer.
*
* @param[out] out The results (array of length @p n)
* @param[in] in The input data (array of length @p n * @p stride)
* @param[in] stride The input data stride
* @param[in] roots Roots of unity (array of length @p n * @p roots_stride)
* @param[in] roots_stride The stride interval among the roots of unity
* @param[in] n Length of the FFT, must be a power of two
*/
static void fft_g1_fast(g1_t *out, const g1_t *in, uint64_t stride, const fr_t *roots, uint64_t roots_stride,
uint64_t n) {
uint64_t half = n / 2;
if (half > 0) { // Tunable parameter
fft_g1_fast(out, in, stride * 2, roots, roots_stride * 2, half);
fft_g1_fast(out + half, in + stride, stride * 2, roots, roots_stride * 2, half);
for (uint64_t i = 0; i < half; i++) {
g1_t y_times_root;
g1_mul(&y_times_root, &out[i + half], &roots[i * roots_stride]);
g1_sub(&out[i + half], &out[i], &y_times_root);
g1_add_or_dbl(&out[i], &out[i], &y_times_root);
}
} else {
*out = *in;
}
}
/**
* The main entry point for forward and reverse FFTs over the finite field.
*
* @param[out] out The results (array of length @p n)
* @param[in] in The input data (array of length @p n)
* @param[in] inverse `false` for forward transform, `true` for inverse transform
* @param[in] n Length of the FFT, must be a power of two
* @param[in] fs Pointer to previously initialised FFTSettings structure with `max_width` at least @p n.
* @retval C_CZK_OK All is well
* @retval C_CZK_BADARGS Invalid parameters were supplied
*/
static C_KZG_RET fft_g1(g1_t *out, const g1_t *in, bool inverse, uint64_t n, const FFTSettings *fs) {
uint64_t stride = fs->max_width / n;
CHECK(n <= fs->max_width);
CHECK(is_power_of_two(n));
if (inverse) {
fr_t inv_len;
fr_from_uint64(&inv_len, n);
fr_inv(&inv_len, &inv_len);
fft_g1_fast(out, in, 1, fs->reverse_roots_of_unity, stride, n);
for (uint64_t i = 0; i < n; i++) {
g1_mul(&out[i], &out[i], &inv_len);
}
} else {
fft_g1_fast(out, in, 1, fs->expanded_roots_of_unity, stride, n);
}
return C_KZG_OK;
}
/**
* Generate powers of a root of unity in the field for use in the FFTs.
*
* @remark @p root must be such that @p root ^ @p width is equal to one, but no smaller power of @p root is equal to
* one.
*
* @param[out] out The generated powers of the root of unity (array size @p width + 1)
* @param[in] root A root of unity
* @param[in] width One less than the size of @p out
* @retval C_CZK_OK All is well
* @retval C_CZK_BADARGS Invalid parameters were supplied
*/
static C_KZG_RET expand_root_of_unity(fr_t *out, const fr_t *root, uint64_t width) {
out[0] = fr_one;
out[1] = *root;
for (uint64_t i = 2; !fr_is_one(&out[i - 1]); i++) {
CHECK(i <= width);
fr_mul(&out[i], &out[i - 1], root);
}
CHECK(fr_is_one(&out[width]));
return C_KZG_OK;
}
/**
* Reverse the bits in a byte.
*
* From https://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64BitsDiv
*
* @param a A byte
* @return A byte that is bit-reversed with respect to @p a
*
* @todo Benchmark some of the other bit-reversal options in the list. Maybe.
*/
#define rev_byte(a) ((((a)&0xff) * 0x0202020202ULL & 0x010884422010ULL) % 1023)
/**
* Reverse the bits in a 32 bit word.
*
* @param a A 32 bit unsigned integer
* @return A 32 bit unsigned integer that is bit-reversed with respect to @p a
*/
#define rev_4byte(a) (rev_byte(a) << 24 | rev_byte((a) >> 8) << 16 | rev_byte((a) >> 16) << 8 | rev_byte((a) >> 24))
/**
* Calculate log base two of a power of two.
*
* In other words, the bit index of the one bit.
*
* @remark Works only for n a power of two, and only for n up to 2^31.
*
* @param[in] n The power of two
* @return the log base two of n
*/
static int log2_pow2(uint32_t n) {
const uint32_t b[] = {0xAAAAAAAA, 0xCCCCCCCC, 0xF0F0F0F0, 0xFF00FF00, 0xFFFF0000};
register uint32_t r;
r = (n & b[0]) != 0;
r |= ((n & b[1]) != 0) << 1;
r |= ((n & b[2]) != 0) << 2;
r |= ((n & b[3]) != 0) << 3;
r |= ((n & b[4]) != 0) << 4;
return r;
}
/**
* Reverse the bit order in a 32 bit integer.
*
* @remark This simply wraps the macro to enforce the type check.
*
* @param[in] a The integer to be reversed
* @return An integer with the bits of @p a reversed
*/
static uint32_t reverse_bits(uint32_t a) {
return rev_4byte(a);
}
/**
* Reorder an array in reverse bit order of its indices.
*
* @remark Operates in-place on the array.
* @remark Can handle arrays of any type: provide the element size in @p size.
*
* @param[in,out] values The array, which is re-ordered in-place
* @param[in] size The size in bytes of an element of the array
* @param[in] n The length of the array, must be a power of two less that 2^32
* @retval C_CZK_OK All is well
* @retval C_CZK_BADARGS Invalid parameters were supplied
*/
static C_KZG_RET reverse_bit_order(void *values, size_t size, uint64_t n) {
CHECK(n >> 32 == 0);
CHECK(is_power_of_two(n));
// Pointer arithmetic on `void *` is naughty, so cast to something definite
byte *v = values;
byte tmp[size];
int unused_bit_len = 32 - log2_pow2(n);
for (uint32_t i = 0; i < n; i++) {
uint32_t r = reverse_bits(i) >> unused_bit_len;
if (r > i) {
// Swap the two elements
memcpy(tmp, v + (i * size), size);
memcpy(v + (i * size), v + (r * size), size);
memcpy(v + (r * size), tmp, size);
}
}
return C_KZG_OK;
}
/**
* Initialise an FFTSettings structure.
*
* Space is allocated for, and arrays are populated with, powers of the roots of unity. The two arrays contain the same
* values in reverse order for convenience in inverse FFTs.
*
* `max_width` is the maximum size of FFT that can be calculated with these settings, and is a power of two by
* construction. The same settings may be used to calculated FFTs of smaller power sizes.
*
* @remark As with all functions prefixed `new_`, this allocates memory that needs to be reclaimed by calling the
* corresponding `free_` function. In this case, #free_fft_settings.
* @remark These settings may be used for FFTs on both field elements and G1 group elements.
*
* @param[out] fs The new settings
* @param[in] max_scale Log base 2 of the max FFT size to be used with these settings
* @retval C_CZK_OK All is well
* @retval C_CZK_BADARGS Invalid parameters were supplied
* @retval C_CZK_ERROR An internal error occurred
* @retval C_CZK_MALLOC Memory allocation failed
*/
static C_KZG_RET new_fft_settings(FFTSettings *fs, unsigned int max_scale) {
fr_t root_of_unity;
fs->max_width = (uint64_t)1 << max_scale;
CHECK((max_scale < sizeof scale2_root_of_unity / sizeof scale2_root_of_unity[0]));
fr_from_uint64s(&root_of_unity, scale2_root_of_unity[max_scale]);
// Allocate space for the roots of unity
TRY(new_fr_array(&fs->expanded_roots_of_unity, fs->max_width + 1));
TRY(new_fr_array(&fs->reverse_roots_of_unity, fs->max_width + 1));
TRY(new_fr_array(&fs->roots_of_unity, fs->max_width));
// Populate the roots of unity
TRY(expand_root_of_unity(fs->expanded_roots_of_unity, &root_of_unity, fs->max_width));
// Populate reverse roots of unity
for (uint64_t i = 0; i <= fs->max_width; i++) {
fs->reverse_roots_of_unity[i] = fs->expanded_roots_of_unity[fs->max_width - i];
}
// Permute the roots of unity
memcpy(fs->roots_of_unity, fs->expanded_roots_of_unity, sizeof(fr_t) * fs->max_width);
TRY(reverse_bit_order(fs->roots_of_unity, sizeof(fr_t), fs->max_width));
return C_KZG_OK;
}
/**
* Free the memory that was previously allocated by #new_fft_settings.
*
* @param fs The settings to be freed
*/
static void free_fft_settings(FFTSettings *fs) {
free(fs->expanded_roots_of_unity);
free(fs->reverse_roots_of_unity);
free(fs->roots_of_unity);
fs->max_width = 0;
}
/**
* Free the memory that was previously allocated by #new_kzg_settings.
*
* @param ks The settings to be freed
*/
static void free_kzg_settings(KZGSettings *ks) {
free(ks->g1_values);
free(ks->g2_values);
ks->length = 0;
}
C_KZG_RET load_trusted_setup(KZGSettings *out, FILE *in) {
uint64_t n2, i;
int j; uint8_t c[96];
blst_p1_affine g1_affine;
blst_p2_affine g2_affine;
g1_t *g1_projective;
fscanf(in, "%" SCNu64, &out->length);
fscanf(in, "%" SCNu64, &n2);
TRY(new_g1_array(&out->g1_values, out->length));
TRY(new_g2_array(&out->g2_values, n2));
TRY(new_g1_array(&g1_projective, out->length));
for (i = 0; i < out->length; i++) {
for (j = 0; j < 48; j++) {
fscanf(in, "%2hhx", &c[j]);
}
blst_p1_uncompress(&g1_affine, c);
blst_p1_from_affine(&g1_projective[i], &g1_affine);
}
for (i = 0; i < n2; i++) {
for (j = 0; j < 96; j++) {
fscanf(in, "%2hhx", &c[j]);
}
blst_p2_uncompress(&g2_affine, c);
blst_p2_from_affine(&out->g2_values[i], &g2_affine);
}
unsigned int max_scale = 0;
while (((uint64_t)1 << max_scale) < out->length) max_scale++;
out->fs = (FFTSettings*)malloc(sizeof(FFTSettings));
TRY(new_fft_settings((FFTSettings*)out->fs, max_scale));
TRY(fft_g1(out->g1_values, g1_projective, true, out->length, out->fs));
free(g1_projective);
return C_KZG_OK;
}
void free_trusted_setup(KZGSettings *s) {
free_fft_settings((FFTSettings*)s->fs);
free_kzg_settings(s);
}
/*
void compute_powers(BLSFieldElement out[], const BLSFieldElement *x, uint64_t n) { fr_pow(out, x, n); }
void vector_lincomb(BLSFieldElement out[], const BLSFieldElement *vectors, const BLSFieldElement *scalars, uint64_t num_vectors, uint64_t vector_len) {
fr_vector_lincomb(out, vectors, scalars, num_vectors, vector_len);
}
void g1_lincomb(KZGCommitment *out, const KZGCommitment points[], const BLSFieldElement scalars[], uint64_t num_points) {
g1_linear_combination(out, points, scalars, num_points);
void blob_to_kzg_commitment(KZGCommitment *out, const BLSFieldElement blob[], const KZGSettings *s) {
g1_linear_combination(out, s->secret_g1_l, blob, s->length);
}
void bytes_to_bls_field(BLSFieldElement *out, const scalar_t *bytes) {
fr_from_scalar(out, bytes);
}
C_KZG_RET evaluate_polynomial_in_evaluation_form(BLSFieldElement *out, const PolynomialEvalForm *polynomial, const BLSFieldElement *z, const KZGSettings *s) {
return eval_poly_l(out, polynomial, z, s->fs);
}
C_KZG_RET verify_kzg_proof(bool *out, const KZGCommitment *polynomial_kzg, const BLSFieldElement *z, const BLSFieldElement *y, const KZGProof *kzg_proof, const KZGSettings *s) {
return check_proof_single(out, polynomial_kzg, kzg_proof, z, y, s);
}
C_KZG_RET compute_kzg_proof(KZGProof *out, const PolynomialEvalForm *polynomial, const BLSFieldElement *z, const KZGSettings *s) {
BLSFieldElement value;
TRY(evaluate_polynomial_in_evaluation_form(&value, polynomial, z, s));
return compute_proof_single_l(out, polynomial, z, &value, s);
}
*/

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/*
* Copyright 2021 Benjamin Edgington
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file c_kzg_4844.h
*
* Minimal interface required for EIP-4844.
*/
#ifndef C_KZG_4844_H
#define C_KZG_4844_H
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include "blst.h"
typedef blst_p1 g1_t; /**< Internal G1 group element type */
typedef blst_p2 g2_t; /**< Internal G2 group element type */
typedef blst_fr fr_t; /**< Internal Fr field element type */
typedef blst_scalar scalar_t; /**< Internal scalar type */
typedef g1_t KZGCommitment;
typedef g1_t KZGProof;
typedef fr_t BLSFieldElement;
/**
* The common return type for all routines in which something can go wrong.
*
* @warning In the case of @p C_KZG_OK or @p C_KZG_BADARGS, the caller can assume that all memory allocated by the
* called routines has been deallocated. However, in the case of @p C_KZG_ERROR or @p C_KZG_MALLOC being returned, these
* are unrecoverable and memory may have been leaked.
*
* @todo Check that memory is not leaked anywhere in the case of C_KZG_BADARGS.
*/
typedef enum {
C_KZG_OK = 0, /**< Success! */
C_KZG_BADARGS, /**< The supplied data is invalid in some way */
C_KZG_ERROR, /**< Internal error - this should never occur and may indicate a bug in the library */
C_KZG_MALLOC, /**< Could not allocate memory */
} C_KZG_RET;
/**
* Stores the setup and parameters needed for performing FFTs.
*/
typedef struct {
uint64_t max_width; /**< The maximum size of FFT these settings support, a power of 2. */
fr_t *expanded_roots_of_unity; /**< Ascending powers of the root of unity, size `width + 1`. */
fr_t *reverse_roots_of_unity; /**< Descending powers of the root of unity, size `width + 1`. */
fr_t *roots_of_unity; /**< Powers of the root of unity in bit-reversal permutation, size `width`. */
} FFTSettings;
/**
* Stores the setup and parameters needed for computing KZG proofs.
*/
typedef struct {
const FFTSettings *fs; /**< The corresponding settings for performing FFTs */
g1_t *g1_values; /**< G1 group elements from the trusted setup, in Lagrange form bit-reversal permutation */
g2_t *g2_values; /**< G2 group elements from the trusted setup */
uint64_t length; /**< The number of elements in g1_values */
} KZGSettings;
/**
* Lagrange form polynomial, with values under the bit-reversal permutation
*/
typedef struct {
fr_t *values; /**< `values[i]` is value of the polynomial at `ω^brp(i)` */
uint64_t length; /**< One more than the polynomial's degree */
} PolynomialEvalForm;
C_KZG_RET alloc_polynomial(PolynomialEvalForm *out, uint64_t length);
void free_polynomial(PolynomialEvalForm *p);
/**
* Interface functions
*/
C_KZG_RET load_trusted_setup(KZGSettings *out, FILE *in);
void free_trusted_setup(KZGSettings *s);
void bytes_to_bls_field(BLSFieldElement *out, const scalar_t *bytes);
void vector_lincomb(BLSFieldElement out[], const BLSFieldElement *vectors, const BLSFieldElement *scalars, uint64_t num_vectors, uint64_t vector_len);
void g1_lincomb(KZGCommitment *out, const KZGCommitment points[], const BLSFieldElement scalars[], uint64_t num_points);
void blob_to_kzg_commitment(KZGCommitment *out, const BLSFieldElement blob[], const KZGSettings *s);
C_KZG_RET verify_kzg_proof(bool *out, const KZGCommitment *polynomial_kzg, const BLSFieldElement *z, const BLSFieldElement *y, const KZGProof *kzg_proof, const KZGSettings *s);
C_KZG_RET compute_kzg_proof(KZGProof *out, const PolynomialEvalForm *polynomial, const BLSFieldElement *z, const KZGSettings *s);
C_KZG_RET evaluate_polynomial_in_evaluation_form(BLSFieldElement *out, const PolynomialEvalForm *polynomial, const BLSFieldElement *z, const KZGSettings *s);
void compute_powers(BLSFieldElement out[], const BLSFieldElement *x, uint64_t n);
#endif // C_KZG_4844_H