From a6a8bfbd1e70579e7abae2e29d6d49da28a8706e Mon Sep 17 00:00:00 2001 From: Adrian Grigore Date: Mon, 24 Jun 2024 04:38:58 +0300 Subject: [PATCH] libsec: add poly1305 --- include/libsec.h | 5 +- libsec/Makefile | 1 + libsec/poly1305.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+), 1 deletion(-) create mode 100644 libsec/poly1305.c diff --git a/include/libsec.h b/include/libsec.h index cc86d3b..15280c9 100644 --- a/include/libsec.h +++ b/include/libsec.h @@ -183,6 +183,7 @@ enum MD4dlen= 16, /* MD4 digest length */ MD5dlen= 16, /* MD5 digest length */ AESdlen= 16, /* TODO: see rfc */ + Poly1305dlen= 16, /* Poly1305 digest length */ Hmacblksz = 64, /* in bytes; from rfc2104 */ }; @@ -192,7 +193,7 @@ struct DigestState { uvlong len; union { - u32int state[8]; + u32int state[16]; u64int bstate[8]; }; uchar buf[256]; @@ -234,6 +235,8 @@ MD5state* md5unpickle(char*); char* sha1pickle(SHA1state*); SHA1state* sha1unpickle(char*); +DigestState* poly1305(uchar*, ulong, uchar*, ulong, uchar*, DigestState*); + /* * random number generation */ diff --git a/libsec/Makefile b/libsec/Makefile index b3ce7e7..0039900 100644 --- a/libsec/Makefile +++ b/libsec/Makefile @@ -54,6 +54,7 @@ OFILES=\ smallprimes.$O\ pbkdf2.$O\ hkdf.$O\ + poly1305.$O\ default: $(LIB) $(LIB): $(OFILES) diff --git a/libsec/poly1305.c b/libsec/poly1305.c new file mode 100644 index 0000000..42f9ac4 --- /dev/null +++ b/libsec/poly1305.c @@ -0,0 +1,192 @@ +#include +#include +#include + +/* + poly1305 implementation using 32 bit * 32 bit = 64 bit multiplication and 64 bit addition + + derived from http://github.com/floodberry/poly1305-donna +*/ + +#define U8TO32(p) ((u32int)(p)[0] | (u32int)(p)[1]<<8 | (u32int)(p)[2]<<16 | (u32int)(p)[3]<<24) +#define U32TO8(p, v) (p)[0]=(v), (p)[1]=(v)>>8, (p)[2]=(v)>>16, (p)[3]=(v)>>24 + +/* (r,s) = (key[0:15],key[16:31]), the one time key */ +DigestState* +poly1305(uchar *m, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s) +{ + u32int r0,r1,r2,r3,r4, s1,s2,s3,s4, h0,h1,h2,h3,h4, g0,g1,g2,g3,g4; + u64int d0,d1,d2,d3,d4, f; + u32int hibit, mask, c; + + if(s == nil){ + s = malloc(sizeof(*s)); + if(s == nil) + return nil; + memset(s, 0, sizeof(*s)); + s->malloced = 1; + } + + if(s->seeded == 0){ + assert(klen == 32); + + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + s->state[0] = (U8TO32(&key[ 0]) ) & 0x3ffffff; + s->state[1] = (U8TO32(&key[ 3]) >> 2) & 0x3ffff03; + s->state[2] = (U8TO32(&key[ 6]) >> 4) & 0x3ffc0ff; + s->state[3] = (U8TO32(&key[ 9]) >> 6) & 0x3f03fff; + s->state[4] = (U8TO32(&key[12]) >> 8) & 0x00fffff; + + /* h = 0 */ + s->state[5] = 0; + s->state[6] = 0; + s->state[7] = 0; + s->state[8] = 0; + s->state[9] = 0; + + /* save pad for later */ + s->state[10] = U8TO32(&key[16]); + s->state[11] = U8TO32(&key[20]); + s->state[12] = U8TO32(&key[24]); + s->state[13] = U8TO32(&key[28]); + + s->seeded = 1; + } + + if(s->blen){ + c = 16 - s->blen; + if(c > len) + c = len; + memmove(s->buf + s->blen, m, c); + len -= c, m += c; + s->blen += c; + if(s->blen == 16){ + s->blen = 0; + poly1305(s->buf, 16, key, klen, nil, s); + } + } + + r0 = s->state[0]; + r1 = s->state[1]; + r2 = s->state[2]; + r3 = s->state[3]; + r4 = s->state[4]; + + h0 = s->state[5]; + h1 = s->state[6]; + h2 = s->state[7]; + h3 = s->state[8]; + h4 = s->state[9]; + + s1 = r1 * 5; + s2 = r2 * 5; + s3 = r3 * 5; + s4 = r4 * 5; + + hibit = 1<<24; /* 1<<128 */ + + while(len >= 16){ +Block: + /* h += m[i] */ + h0 += (U8TO32(&m[0]) ) & 0x3ffffff; + h1 += (U8TO32(&m[3]) >> 2) & 0x3ffffff; + h2 += (U8TO32(&m[6]) >> 4) & 0x3ffffff; + h3 += (U8TO32(&m[9]) >> 6) & 0x3ffffff; + h4 += (U8TO32(&m[12])>> 8) | hibit; + + /* h *= r */ + d0 = ((u64int)h0 * r0) + ((u64int)h1 * s4) + ((u64int)h2 * s3) + ((u64int)h3 * s2) + ((u64int)h4 * s1); + d1 = ((u64int)h0 * r1) + ((u64int)h1 * r0) + ((u64int)h2 * s4) + ((u64int)h3 * s3) + ((u64int)h4 * s2); + d2 = ((u64int)h0 * r2) + ((u64int)h1 * r1) + ((u64int)h2 * r0) + ((u64int)h3 * s4) + ((u64int)h4 * s3); + d3 = ((u64int)h0 * r3) + ((u64int)h1 * r2) + ((u64int)h2 * r1) + ((u64int)h3 * r0) + ((u64int)h4 * s4); + d4 = ((u64int)h0 * r4) + ((u64int)h1 * r3) + ((u64int)h2 * r2) + ((u64int)h3 * r1) + ((u64int)h4 * r0); + + /* (partial) h %= p */ + c = (u32int)(d0 >> 26); h0 = (u32int)d0 & 0x3ffffff; + d1 += c; c = (u32int)(d1 >> 26); h1 = (u32int)d1 & 0x3ffffff; + d2 += c; c = (u32int)(d2 >> 26); h2 = (u32int)d2 & 0x3ffffff; + d3 += c; c = (u32int)(d3 >> 26); h3 = (u32int)d3 & 0x3ffffff; + d4 += c; c = (u32int)(d4 >> 26); h4 = (u32int)d4 & 0x3ffffff; + h0 += c * 5; c = (h0 >> 26); h0 = h0 & 0x3ffffff; + h1 += c; + + len -= 16, m += 16; + } + + if(len){ + s->blen = len; + memmove(s->buf, m, len); + } + + if(digest == nil){ + s->state[5] = h0; + s->state[6] = h1; + s->state[7] = h2; + s->state[8] = h3; + s->state[9] = h4; + return s; + } + + if(len){ + m = s->buf; + m[len++] = 1; + while(len < 16) + m[len++] = 0; + hibit = 0; + goto Block; + } + + c = h1 >> 26; h1 = h1 & 0x3ffffff; + h2 += c; c = h2 >> 26; h2 = h2 & 0x3ffffff; + h3 += c; c = h3 >> 26; h3 = h3 & 0x3ffffff; + h4 += c; c = h4 >> 26; h4 = h4 & 0x3ffffff; + h0 += c * 5; c = h0 >> 26; h0 = h0 & 0x3ffffff; + h1 += c; + + /* compute h + -p */ + g0 = h0 + 5; c = g0 >> 26; g0 &= 0x3ffffff; + g1 = h1 + c; c = g1 >> 26; g1 &= 0x3ffffff; + g2 = h2 + c; c = g2 >> 26; g2 &= 0x3ffffff; + g3 = h3 + c; c = g3 >> 26; g3 &= 0x3ffffff; + g4 = h4 + c - (1 << 26); + + /* select h if h < p, or h + -p if h >= p */ + mask = (g4 >> 31) - 1; + g0 &= mask; + g1 &= mask; + g2 &= mask; + g3 &= mask; + g4 &= mask; + mask = ~mask; + h0 = (h0 & mask) | g0; + h1 = (h1 & mask) | g1; + h2 = (h2 & mask) | g2; + h3 = (h3 & mask) | g3; + h4 = (h4 & mask) | g4; + + /* h = h % (2^128) */ + h0 = (h0 ) | (h1 << 26); + h1 = (h1 >> 6) | (h2 << 20); + h2 = (h2 >> 12) | (h3 << 14); + h3 = (h3 >> 18) | (h4 << 8); + + /* digest = (h + pad) % (2^128) */ + f = (u64int)h0 + s->state[10] ; h0 = (u32int)f; + f = (u64int)h1 + s->state[11] + (f >> 32); h1 = (u32int)f; + f = (u64int)h2 + s->state[12] + (f >> 32); h2 = (u32int)f; + f = (u64int)h3 + s->state[13] + (f >> 32); h3 = (u32int)f; + + U32TO8(&digest[0], h0); + U32TO8(&digest[4], h1); + U32TO8(&digest[8], h2); + U32TO8(&digest[12], h3); + + if(s->malloced){ + memset(s, 0, sizeof(*s)); + free(s); + return nil; + } + + memset(s, 0, sizeof(*s)); + return nil; +}