X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/9fe2e812f140d580d1150ffcb5010515d8b68dae..4e7475c2fc07c8e588583d82d95221d8e6813757:/utils/gcm-ref diff --git a/utils/gcm-ref b/utils/gcm-ref index ccbf4321..bba76602 100755 --- a/utils/gcm-ref +++ b/utils/gcm-ref @@ -54,7 +54,7 @@ def poly(nbits): base = C.GF(0).setbit(nbits).setbit(0) for k in xrange(1, nbits, 2): for cc in combs(range(1, nbits), k): - p = base + sum(C.GF(0).setbit(c) for c in cc) + p = base + sum((C.GF(0).setbit(c) for c in cc), C.GF(0)) if p.irreduciblep(): POLYMAP[nbits] = p; return p raise ValueError, nbits @@ -127,7 +127,7 @@ def table_common(u, v, flip, getword, ixmask): """ Multiply U by V using table lookup; common for `table-b' and `table-l'. - This matches the `simple_mulk_...' implementation in `gcm.c'. One-entry + This matches the `simple_mulk_...' implementation in `gcm.c'. One entry per bit is the best we can manage if we want a constant-time implementation: processing n bits at a time means we need to scan (2^n - 1)/n times as much memory. @@ -140,7 +140,7 @@ def table_common(u, v, flip, getword, ixmask): are processed most-significant first. * IXMASK is a mask XORed into table indices to permute the table so that - it's order matches that induced by GETWORD. + its order matches that induced by GETWORD. The table is built such that tab[i XOR IXMASK] = U t^i. """ @@ -172,7 +172,7 @@ def demo_table_b(u, v): @demo def demo_table_l(u, v): """Little-endian table lookup.""" - return table_common(u, v, endswap_words, lambda b: b.getu32l(), 0x18) + return table_common(u, v, endswap_words_32, lambda b: b.getu32l(), 0x18) ###-------------------------------------------------------------------------- ### Implementation using 64×64->128-bit binary polynomial multiplication. @@ -258,6 +258,7 @@ def present_gf_pmull(tag, wd, x, w, n, what): if tag == TAG_PRODPIECE or tag == TAG_REDCFULL or tag == TAG_SHIFTED: return elif tag == TAG_INPUT_V or tag == TAG_KPIECE_V: + w = (w + 63)&~63 bx = C.ReadBuffer(x.storeb(w/8)) by = C.WriteBuffer() while bx.left: chunk = bx.get(8); by.put(chunk).put(chunk) @@ -281,7 +282,7 @@ def poly64_mul_simple(u, v, presfn, wd, dispwd, mulwd, uwhat, vwhat): ## straightforward except for the 96-bit case, where we end up with two ## short pieces which we pad at the beginning. if uw%mulwd: pad = (-uw)%mulwd; u += C.ByteString.zero(pad); uw += pad - if vw%mulwd: pad = (-uw)%mulwd; v += C.ByteString.zero(pad); vw += pad + if vw%mulwd: pad = (-vw)%mulwd; v += C.ByteString.zero(pad); vw += pad uu = split_gf(u, mulwd) vv = split_gf(v, mulwd)