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https://github.com/ElementsProject/lightning.git
synced 2025-03-01 17:47:30 +01:00
common/sphinx: don't use temporary to xor in cipher stream.
The chacha API makes this a bit awkward, to we use a helper. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell
Christian Decker
parent
0701f74878
commit
b5ab7e3ce3
2 changed files with 212 additions and 17 deletions
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@ -170,14 +170,6 @@ enum onion_wire parse_onionpacket(const u8 *src,
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return 0;
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}
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static void xorbytes(uint8_t *d, const uint8_t *a, const uint8_t *b, size_t len)
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{
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size_t i;
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for (i = 0; i < len; i++)
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d[i] = a[i] ^ b[i];
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}
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/*
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* Generate a pseudo-random byte stream of length `dstlen` from key `k` and
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* store it in `dst`. `dst must be at least `dstlen` bytes long.
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@ -197,6 +189,45 @@ static void xor_cipher_stream(void *dst, const struct secret *k, size_t dstlen)
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crypto_stream_chacha20_xor(dst, dst, dstlen, nonce, k->data);
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}
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#define CHACHA20_BLOCK_BYTES 64
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static void xor_cipher_stream_off(const struct secret *k,
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size_t off,
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void *dst, size_t dstlen)
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{
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const u8 nonce[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
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u8 block[CHACHA20_BLOCK_BYTES];
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size_t block_off;
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size_t ic = off / CHACHA20_BLOCK_BYTES;
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/* From https://libsodium.gitbook.io/doc/advanced/stream_ciphers/chacha20:
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*
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* The crypto_stream_chacha20_xor_ic() function is similar to
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* crypto_stream_chacha20_xor() but adds the ability to set
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* the initial value of the block counter to a non-zero value,
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* ic.
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*
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* This permits direct access to any block without having to
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* compute the previous ones.
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*/
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block_off = (off % CHACHA20_BLOCK_BYTES);
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if (block_off != 0) {
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size_t rem = CHACHA20_BLOCK_BYTES - block_off;
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if (rem > dstlen)
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rem = dstlen;
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memcpy(block + block_off, dst, rem);
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crypto_stream_chacha20_xor_ic(block, block, block_off + rem,
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nonce,
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ic,
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k->data);
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ic++;
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memcpy(dst, block + block_off, rem);
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dst = (char *)dst + rem;
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dstlen -= rem;
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}
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crypto_stream_chacha20_xor_ic(dst, dst, dstlen, nonce, ic, k->data);
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}
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/* Convenience function: s2/s2len can be NULL/0 if unwanted */
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static void compute_hmac(const struct secret *key,
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const u8 *s1, size_t s1len,
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@ -226,7 +257,6 @@ static void generate_header_padding(void *dst, size_t dstlen,
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const struct sphinx_path *path,
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struct hop_params *params)
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{
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u8 stream[2 * ROUTING_INFO_SIZE];
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struct secret key;
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size_t fillerStart, fillerEnd, fillerSize;
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@ -234,8 +264,6 @@ static void generate_header_padding(void *dst, size_t dstlen,
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for (int i = 0; i < tal_count(path->hops) - 1; i++) {
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subkey_from_hmac("rho", ¶ms[i].secret, &key);
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generate_cipher_stream(stream, &key, sizeof(stream));
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/* Sum up how many bytes have been used by previous hops,
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* that gives us the start in the stream */
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fillerSize = 0;
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@ -250,8 +278,8 @@ static void generate_header_padding(void *dst, size_t dstlen,
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/* Apply the cipher-stream to the part of the filler that'll
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* be added by this hop */
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xorbytes(dst, dst, stream + fillerStart,
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fillerEnd - fillerStart);
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xor_cipher_stream_off(&key, fillerStart,
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dst, fillerEnd - fillerStart);
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}
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}
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@ -259,7 +287,6 @@ static void generate_prefill(void *dst, size_t dstlen,
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const struct sphinx_path *path,
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struct hop_params *params)
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{
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u8 stream[2 * ROUTING_INFO_SIZE];
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struct secret key;
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size_t fillerStart, fillerSize;
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@ -267,8 +294,6 @@ static void generate_prefill(void *dst, size_t dstlen,
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for (int i = 0; i < tal_count(path->hops); i++) {
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subkey_from_hmac("rho", ¶ms[i].secret, &key);
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generate_cipher_stream(stream, &key, sizeof(stream));
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/* Sum up how many bytes have been used by previous hops,
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* that gives us the start in the stream */
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fillerSize = 0;
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@ -278,7 +303,7 @@ static void generate_prefill(void *dst, size_t dstlen,
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/* Apply the cipher-stream to the part of the filler that'll
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* be added by this hop */
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xorbytes(dst, dst, stream + fillerStart, dstlen);
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xor_cipher_stream_off(&key, fillerStart, dst, dstlen);
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}
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}
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170
common/test/run-sphinx-xor_cipher_stream.c
Normal file
170
common/test/run-sphinx-xor_cipher_stream.c
Normal file
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@ -0,0 +1,170 @@
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#include "../sphinx.c"
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#include <assert.h>
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#include <common/setup.h>
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#include <stdio.h>
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#include <unistd.h>
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/* AUTOGENERATED MOCKS START */
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/* Generated stub for amount_asset_is_main */
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bool amount_asset_is_main(struct amount_asset *asset UNNEEDED)
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{ fprintf(stderr, "amount_asset_is_main called!\n"); abort(); }
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/* Generated stub for amount_asset_to_sat */
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struct amount_sat amount_asset_to_sat(struct amount_asset *asset UNNEEDED)
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{ fprintf(stderr, "amount_asset_to_sat called!\n"); abort(); }
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/* Generated stub for amount_sat */
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struct amount_sat amount_sat(u64 satoshis UNNEEDED)
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{ fprintf(stderr, "amount_sat called!\n"); abort(); }
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/* Generated stub for amount_sat_add */
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bool amount_sat_add(struct amount_sat *val UNNEEDED,
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struct amount_sat a UNNEEDED,
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struct amount_sat b UNNEEDED)
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{ fprintf(stderr, "amount_sat_add called!\n"); abort(); }
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/* Generated stub for amount_sat_eq */
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bool amount_sat_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
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{ fprintf(stderr, "amount_sat_eq called!\n"); abort(); }
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/* Generated stub for amount_sat_greater_eq */
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bool amount_sat_greater_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
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{ fprintf(stderr, "amount_sat_greater_eq called!\n"); abort(); }
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/* Generated stub for amount_sat_sub */
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bool amount_sat_sub(struct amount_sat *val UNNEEDED,
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struct amount_sat a UNNEEDED,
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struct amount_sat b UNNEEDED)
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{ fprintf(stderr, "amount_sat_sub called!\n"); abort(); }
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/* Generated stub for amount_sat_to_asset */
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struct amount_asset amount_sat_to_asset(struct amount_sat *sat UNNEEDED, const u8 *asset UNNEEDED)
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{ fprintf(stderr, "amount_sat_to_asset called!\n"); abort(); }
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/* Generated stub for amount_tx_fee */
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struct amount_sat amount_tx_fee(u32 fee_per_kw UNNEEDED, size_t weight UNNEEDED)
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{ fprintf(stderr, "amount_tx_fee called!\n"); abort(); }
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/* Generated stub for fromwire */
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const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy UNNEEDED, size_t n UNNEEDED)
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{ fprintf(stderr, "fromwire called!\n"); abort(); }
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/* Generated stub for fromwire_amount_sat */
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struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
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/* Generated stub for fromwire_bool */
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bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_bool called!\n"); abort(); }
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/* Generated stub for fromwire_fail */
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void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_fail called!\n"); abort(); }
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/* Generated stub for fromwire_hmac */
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void fromwire_hmac(const u8 **ptr UNNEEDED, size_t *max UNNEEDED, struct hmac *hmac UNNEEDED)
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{ fprintf(stderr, "fromwire_hmac called!\n"); abort(); }
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/* Generated stub for fromwire_secp256k1_ecdsa_signature */
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void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,
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secp256k1_ecdsa_signature *signature UNNEEDED)
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{ fprintf(stderr, "fromwire_secp256k1_ecdsa_signature called!\n"); abort(); }
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/* Generated stub for fromwire_sha256 */
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void fromwire_sha256(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct sha256 *sha256 UNNEEDED)
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{ fprintf(stderr, "fromwire_sha256 called!\n"); abort(); }
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/* Generated stub for fromwire_tal_arrn */
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u8 *fromwire_tal_arrn(const tal_t *ctx UNNEEDED,
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const u8 **cursor UNNEEDED, size_t *max UNNEEDED, size_t num UNNEEDED)
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{ fprintf(stderr, "fromwire_tal_arrn called!\n"); abort(); }
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/* Generated stub for fromwire_u16 */
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u16 fromwire_u16(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_u16 called!\n"); abort(); }
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/* Generated stub for fromwire_u32 */
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u32 fromwire_u32(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_u32 called!\n"); abort(); }
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/* Generated stub for fromwire_u64 */
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u64 fromwire_u64(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_u64 called!\n"); abort(); }
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/* Generated stub for fromwire_u8 */
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u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
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{ fprintf(stderr, "fromwire_u8 called!\n"); abort(); }
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/* Generated stub for fromwire_u8_array */
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void fromwire_u8_array(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, u8 *arr UNNEEDED, size_t num UNNEEDED)
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{ fprintf(stderr, "fromwire_u8_array called!\n"); abort(); }
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/* Generated stub for hmac_done */
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void hmac_done(crypto_auth_hmacsha256_state *state UNNEEDED,
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struct hmac *hmac UNNEEDED)
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{ fprintf(stderr, "hmac_done called!\n"); abort(); }
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/* Generated stub for hmac_start */
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void hmac_start(crypto_auth_hmacsha256_state *state UNNEEDED,
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const void *key UNNEEDED, size_t klen UNNEEDED)
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{ fprintf(stderr, "hmac_start called!\n"); abort(); }
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/* Generated stub for hmac_update */
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void hmac_update(crypto_auth_hmacsha256_state *state UNNEEDED,
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const void *src UNNEEDED, size_t slen UNNEEDED)
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{ fprintf(stderr, "hmac_update called!\n"); abort(); }
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/* Generated stub for new_onionreply */
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struct onionreply *new_onionreply(const tal_t *ctx UNNEEDED, const u8 *contents TAKES UNNEEDED)
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{ fprintf(stderr, "new_onionreply called!\n"); abort(); }
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/* Generated stub for onion_payload_length */
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size_t onion_payload_length(const u8 *raw_payload UNNEEDED, size_t len UNNEEDED,
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bool has_realm UNNEEDED,
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bool *valid UNNEEDED,
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enum onion_payload_type *type UNNEEDED)
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{ fprintf(stderr, "onion_payload_length called!\n"); abort(); }
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/* Generated stub for pubkey_from_node_id */
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bool pubkey_from_node_id(struct pubkey *key UNNEEDED, const struct node_id *id UNNEEDED)
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{ fprintf(stderr, "pubkey_from_node_id called!\n"); abort(); }
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/* Generated stub for subkey_from_hmac */
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void subkey_from_hmac(const char *prefix UNNEEDED,
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const struct secret *base UNNEEDED,
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struct secret *key UNNEEDED)
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{ fprintf(stderr, "subkey_from_hmac called!\n"); abort(); }
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/* Generated stub for towire */
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void towire(u8 **pptr UNNEEDED, const void *data UNNEEDED, size_t len UNNEEDED)
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{ fprintf(stderr, "towire called!\n"); abort(); }
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/* Generated stub for towire_amount_sat */
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void towire_amount_sat(u8 **pptr UNNEEDED, const struct amount_sat sat UNNEEDED)
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{ fprintf(stderr, "towire_amount_sat called!\n"); abort(); }
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/* Generated stub for towire_bool */
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void towire_bool(u8 **pptr UNNEEDED, bool v UNNEEDED)
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{ fprintf(stderr, "towire_bool called!\n"); abort(); }
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/* Generated stub for towire_hmac */
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void towire_hmac(u8 **pptr UNNEEDED, const struct hmac *hmac UNNEEDED)
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{ fprintf(stderr, "towire_hmac called!\n"); abort(); }
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/* Generated stub for towire_pad */
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void towire_pad(u8 **pptr UNNEEDED, size_t num UNNEEDED)
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{ fprintf(stderr, "towire_pad called!\n"); abort(); }
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/* Generated stub for towire_secp256k1_ecdsa_signature */
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void towire_secp256k1_ecdsa_signature(u8 **pptr UNNEEDED,
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const secp256k1_ecdsa_signature *signature UNNEEDED)
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{ fprintf(stderr, "towire_secp256k1_ecdsa_signature called!\n"); abort(); }
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/* Generated stub for towire_sha256 */
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void towire_sha256(u8 **pptr UNNEEDED, const struct sha256 *sha256 UNNEEDED)
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{ fprintf(stderr, "towire_sha256 called!\n"); abort(); }
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/* Generated stub for towire_u16 */
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void towire_u16(u8 **pptr UNNEEDED, u16 v UNNEEDED)
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{ fprintf(stderr, "towire_u16 called!\n"); abort(); }
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/* Generated stub for towire_u32 */
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void towire_u32(u8 **pptr UNNEEDED, u32 v UNNEEDED)
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{ fprintf(stderr, "towire_u32 called!\n"); abort(); }
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/* Generated stub for towire_u64 */
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void towire_u64(u8 **pptr UNNEEDED, u64 v UNNEEDED)
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{ fprintf(stderr, "towire_u64 called!\n"); abort(); }
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/* Generated stub for towire_u8 */
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void towire_u8(u8 **pptr UNNEEDED, u8 v UNNEEDED)
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{ fprintf(stderr, "towire_u8 called!\n"); abort(); }
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/* Generated stub for towire_u8_array */
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void towire_u8_array(u8 **pptr UNNEEDED, const u8 *arr UNNEEDED, size_t num UNNEEDED)
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{ fprintf(stderr, "towire_u8_array called!\n"); abort(); }
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/* AUTOGENERATED MOCKS END */
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#define PARTIAL_SIZE 128
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int main(int argc, char **argv)
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{
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const u8 nonce[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
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struct secret k;
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u8 normal[1024];
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common_setup(argv[0]);
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memset(&k, 1, sizeof(k));
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crypto_stream_chacha20(normal, sizeof(normal), nonce, k.data);
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for (size_t i = 0; i < sizeof(normal) - PARTIAL_SIZE; i++) {
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for (size_t len = 0; len < PARTIAL_SIZE; len++) {
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u8 *partial = tal_arrz(tmpctx, u8, len);
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xor_cipher_stream_off(&k, i, partial, len);
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assert(memcmp(partial, normal + i, len) == 0);
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}
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}
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common_shutdown();
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return 0;
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}
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