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NOQTIS

nqprove(3)

nqprove, nqchkp — prove some files of a capsule, and check such a proof

libnoqtis, -lnoqtis

#include <noqtis.h>

int
nqprove(const char *dir, const char *const *paths, size_t np, char *out, size_t cap, size_t *outlen);

int
nqchkp(const char *proof, size_t n, const nqcopt *o, const char *dir, nqrep **rep);

() writes to out, of cap bytes, a proof (‘noqtis-proof-1, noqtis-capsule(5)’) that the files paths[0..np] are in the format 2 capsule in dir: the seal, the manifest's head and, per file, its entry, its index and its Merkle audit path (RFC 9162). The proof holds no name, size or digest of the capsule's other files. Paths are as the manifest lists them; repeats are proven once. *outlen gets the proof's size, also when cap is too small, so a call with out NULL and cap 0 gives the size to allocate. nqprove() reads the seal and the manifest with the checker's strict readers but does not check the capsule: call nqchkx(3) first.

() checks a proof of n bytes and returns a report as nqchk(3) does: the proof's form (‘proof.parse, proof.canonical, proof.fields’), the seal and its signature over the head with o->trust and its TSA anchors (the other members of o are not used; o may be NULL), and one ‘proof.entry’ row per entry whose audit path leads to the head's Merkle root. With dir not NULL, each proven file there is also checked against its entry (‘file’) rows, and a ‘partial’ row says the capsule's other files are not in the proof.

nqprove():

The proof was written.
[NQEBUF]
cap is too small; *outlen is the size needed.
[NQENOSUP]
The capsule is format 1.
[NQEIO]
A path is not in the manifest, or a file could not be read.
[NQEDEC]
The seal or the manifest does not parse.
[NQELIM]
More paths than a manifest may list.
[NQEARG]
A NULL argument, or np 0.
[NQEMEM]
The allocation hook returned NULL.

nqchkp() returns NQOK when every check passed and NQEVRFY when one failed, with the report in *rep either way; NQEARG and NQEMEM return no report.

const char *p[1] = {"data/in.csv"};
size_t n = 0;
char *b;
if (nqprove("results", p, 1, NULL, 0, &n) == NQEBUF &&
    (b = malloc(n)) != NULL &&
    nqprove("results", p, 1, b, n, &n) == NQOK) {
  nqcopt o = {0};
  nqrep *rep = NULL;
  o.trust = pk;
  o.trustlen = sizeof pk;
  if (nqchkp(b, n, &o, NULL, &rep) == NQOK)
    puts("data/in.csv is in the capsule that key sealed");
  nqrepfree(rep);
}

noqtis-check(1), noqtis-prove(1), nqchkx(3), nqrep(3), nqseal2(3), noqtis-capsule(5)

Certificate Transparency Version 2.0, RFC 9162, December 2021.