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Revert "New vtable API for keygen progress reporting."

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This reverts commit a7bdefb394.

I had accidentally mashed it together with another commit. I did
actually want to push both of them, but I'd rather push them
separately! So I'm backing out the combined blob, and I'll re-push
them with their proper comments and explanations.
This commit is contained in:
Simon Tatham
2020-02-29 16:32:16 +00:00
parent a7bdefb394
commit 62733a8389
13 changed files with 396 additions and 565 deletions
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56
sshrsag.c
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@ -14,12 +14,49 @@
static void invent_firstbits(unsigned *one, unsigned *two,
unsigned min_separation);
int rsa_generate(RSAKey *key, int bits, ProgressReceiver *prog)
int rsa_generate(RSAKey *key, int bits, progfn_t pfn,
void *pfnparam)
{
unsigned pfirst, qfirst;
key->sshk.vt = &ssh_rsa;
/*
* Set up the phase limits for the progress report. We do this
* by passing minus the phase number.
*
* For prime generation: our initial filter finds things
* coprime to everything below 2^16. Computing the product of
* (p-1)/p for all prime p below 2^16 gives about 20.33; so
* among B-bit integers, one in every 20.33 will get through
* the initial filter to be a candidate prime.
*
* Meanwhile, we are searching for primes in the region of 2^B;
* since pi(x) ~ x/log(x), when x is in the region of 2^B, the
* prime density will be d/dx pi(x) ~ 1/log(B), i.e. about
* 1/0.6931B. So the chance of any given candidate being prime
* is 20.33/0.6931B, which is roughly 29.34 divided by B.
*
* So now we have this probability P, we're looking at an
* exponential distribution with parameter P: we will manage in
* one attempt with probability P, in two with probability
* P(1-P), in three with probability P(1-P)^2, etc. The
* probability that we have still not managed to find a prime
* after N attempts is (1-P)^N.
*
* We therefore inform the progress indicator of the number B
* (29.34/B), so that it knows how much to increment by each
* time. We do this in 16-bit fixed point, so 29.34 becomes
* 0x1D.57C4.
*/
pfn(pfnparam, PROGFN_PHASE_EXTENT, 1, 0x10000);
pfn(pfnparam, PROGFN_EXP_PHASE, 1, -0x1D57C4 / (bits / 2));
pfn(pfnparam, PROGFN_PHASE_EXTENT, 2, 0x10000);
pfn(pfnparam, PROGFN_EXP_PHASE, 2, -0x1D57C4 / (bits - bits / 2));
pfn(pfnparam, PROGFN_PHASE_EXTENT, 3, 0x4000);
pfn(pfnparam, PROGFN_LIN_PHASE, 3, 5);
pfn(pfnparam, PROGFN_READY, 0, 0);
/*
* We don't generate e; we just use a standard one always.
*/
@ -43,23 +80,15 @@ int rsa_generate(RSAKey *key, int bits, ProgressReceiver *prog)
int pbits = bits - qbits;
assert(pbits >= qbits);
ProgressPhase phase_p = primegen_add_progress_phase(prog, pbits);
ProgressPhase phase_q = primegen_add_progress_phase(prog, qbits);
progress_ready(prog);
PrimeCandidateSource *pcs;
progress_start_phase(prog, phase_p);
pcs = pcs_new_with_firstbits(pbits, pfirst, NFIRSTBITS);
pcs_avoid_residue_small(pcs, RSA_EXPONENT, 1);
mp_int *p = primegen(pcs, prog);
progress_report_phase_complete(prog);
mp_int *p = primegen(pcs, 1, pfn, pfnparam);
progress_start_phase(prog, phase_q);
pcs = pcs_new_with_firstbits(qbits, qfirst, NFIRSTBITS);
pcs_avoid_residue_small(pcs, RSA_EXPONENT, 1);
mp_int *q = primegen(pcs, prog);
progress_report_phase_complete(prog);
mp_int *q = primegen(pcs, 2, pfn, pfnparam);
/*
* Ensure p > q, by swapping them if not.
@ -79,17 +108,22 @@ int rsa_generate(RSAKey *key, int bits, ProgressReceiver *prog)
* the other helpful quantities: n=pq, d=e^-1 mod (p-1)(q-1),
* and (q^-1 mod p).
*/
pfn(pfnparam, PROGFN_PROGRESS, 3, 1);
mp_int *modulus = mp_mul(p, q);
pfn(pfnparam, PROGFN_PROGRESS, 3, 2);
mp_int *pm1 = mp_copy(p);
mp_sub_integer_into(pm1, pm1, 1);
mp_int *qm1 = mp_copy(q);
mp_sub_integer_into(qm1, qm1, 1);
mp_int *phi_n = mp_mul(pm1, qm1);
pfn(pfnparam, PROGFN_PROGRESS, 3, 3);
mp_free(pm1);
mp_free(qm1);
mp_int *private_exponent = mp_invert(exponent, phi_n);
pfn(pfnparam, PROGFN_PROGRESS, 3, 4);
mp_free(phi_n);
mp_int *iqmp = mp_invert(q, p);
pfn(pfnparam, PROGFN_PROGRESS, 3, 5);
/*
* Populate the returned structure.