X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmac%2Fpoly1305%2Fpoly1305.c;fp=libtomcrypt%2Fsrc%2Fmac%2Fpoly1305%2Fpoly1305.c;h=f709f72052e22e38362937ec4683fd205136ed47;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/mac/poly1305/poly1305.c b/libtomcrypt/src/mac/poly1305/poly1305.c new file mode 100644 index 0000000..f709f72 --- /dev/null +++ b/libtomcrypt/src/mac/poly1305/poly1305.c @@ -0,0 +1,268 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + */ + +/* The implementation is based on: + * Public Domain poly1305 from Andrew Moon + * https://github.com/floodyberry/poly1305-donna + */ + +#include "tomcrypt.h" + +#ifdef LTC_POLY1305 + +/* internal only */ +static void _poly1305_block(poly1305_state *st, const unsigned char *in, unsigned long inlen) +{ + const unsigned long hibit = (st->final) ? 0 : (1UL << 24); /* 1 << 128 */ + ulong32 r0,r1,r2,r3,r4; + ulong32 s1,s2,s3,s4; + ulong32 h0,h1,h2,h3,h4; + ulong32 tmp; + ulong64 d0,d1,d2,d3,d4; + ulong32 c; + + r0 = st->r[0]; + r1 = st->r[1]; + r2 = st->r[2]; + r3 = st->r[3]; + r4 = st->r[4]; + + s1 = r1 * 5; + s2 = r2 * 5; + s3 = r3 * 5; + s4 = r4 * 5; + + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; + + while (inlen >= 16) { + /* h += in[i] */ + LOAD32L(tmp, in+ 0); h0 += (tmp ) & 0x3ffffff; + LOAD32L(tmp, in+ 3); h1 += (tmp >> 2) & 0x3ffffff; + LOAD32L(tmp, in+ 6); h2 += (tmp >> 4) & 0x3ffffff; + LOAD32L(tmp, in+ 9); h3 += (tmp >> 6) & 0x3ffffff; + LOAD32L(tmp, in+12); h4 += (tmp >> 8) | hibit; + + /* h *= r */ + d0 = ((ulong64)h0 * r0) + ((ulong64)h1 * s4) + ((ulong64)h2 * s3) + ((ulong64)h3 * s2) + ((ulong64)h4 * s1); + d1 = ((ulong64)h0 * r1) + ((ulong64)h1 * r0) + ((ulong64)h2 * s4) + ((ulong64)h3 * s3) + ((ulong64)h4 * s2); + d2 = ((ulong64)h0 * r2) + ((ulong64)h1 * r1) + ((ulong64)h2 * r0) + ((ulong64)h3 * s4) + ((ulong64)h4 * s3); + d3 = ((ulong64)h0 * r3) + ((ulong64)h1 * r2) + ((ulong64)h2 * r1) + ((ulong64)h3 * r0) + ((ulong64)h4 * s4); + d4 = ((ulong64)h0 * r4) + ((ulong64)h1 * r3) + ((ulong64)h2 * r2) + ((ulong64)h3 * r1) + ((ulong64)h4 * r0); + + /* (partial) h %= p */ + c = (ulong32)(d0 >> 26); h0 = (ulong32)d0 & 0x3ffffff; + d1 += c; c = (ulong32)(d1 >> 26); h1 = (ulong32)d1 & 0x3ffffff; + d2 += c; c = (ulong32)(d2 >> 26); h2 = (ulong32)d2 & 0x3ffffff; + d3 += c; c = (ulong32)(d3 >> 26); h3 = (ulong32)d3 & 0x3ffffff; + d4 += c; c = (ulong32)(d4 >> 26); h4 = (ulong32)d4 & 0x3ffffff; + h0 += c * 5; c = (h0 >> 26); h0 = h0 & 0x3ffffff; + h1 += c; + + in += 16; + inlen -= 16; + } + + st->h[0] = h0; + st->h[1] = h1; + st->h[2] = h2; + st->h[3] = h3; + st->h[4] = h4; +} + +/** + Initialize an POLY1305 context. + @param st The POLY1305 state + @param key The secret key + @param keylen The length of the secret key (octets) + @return CRYPT_OK if successful +*/ +int poly1305_init(poly1305_state *st, const unsigned char *key, unsigned long keylen) +{ + LTC_ARGCHK(st != NULL); + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(keylen == 32); + + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + LOAD32L(st->r[0], key + 0); st->r[0] = (st->r[0] ) & 0x3ffffff; + LOAD32L(st->r[1], key + 3); st->r[1] = (st->r[1] >> 2) & 0x3ffff03; + LOAD32L(st->r[2], key + 6); st->r[2] = (st->r[2] >> 4) & 0x3ffc0ff; + LOAD32L(st->r[3], key + 9); st->r[3] = (st->r[3] >> 6) & 0x3f03fff; + LOAD32L(st->r[4], key + 12); st->r[4] = (st->r[4] >> 8) & 0x00fffff; + + /* h = 0 */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + + /* save pad for later */ + LOAD32L(st->pad[0], key + 16); + LOAD32L(st->pad[1], key + 20); + LOAD32L(st->pad[2], key + 24); + LOAD32L(st->pad[3], key + 28); + + st->leftover = 0; + st->final = 0; + return CRYPT_OK; +} + +/** + Process data through POLY1305 + @param st The POLY1305 state + @param in The data to send through HMAC + @param inlen The length of the data to HMAC (octets) + @return CRYPT_OK if successful +*/ +int poly1305_process(poly1305_state *st, const unsigned char *in, unsigned long inlen) +{ + unsigned long i; + + if (inlen == 0) return CRYPT_OK; /* nothing to do */ + LTC_ARGCHK(st != NULL); + LTC_ARGCHK(in != NULL); + + /* handle leftover */ + if (st->leftover) { + unsigned long want = (16 - st->leftover); + if (want > inlen) want = inlen; + for (i = 0; i < want; i++) st->buffer[st->leftover + i] = in[i]; + inlen -= want; + in += want; + st->leftover += want; + if (st->leftover < 16) return CRYPT_OK; + _poly1305_block(st, st->buffer, 16); + st->leftover = 0; + } + + /* process full blocks */ + if (inlen >= 16) { + unsigned long want = (inlen & ~(16 - 1)); + _poly1305_block(st, in, want); + in += want; + inlen -= want; + } + + /* store leftover */ + if (inlen) { + for (i = 0; i < inlen; i++) st->buffer[st->leftover + i] = in[i]; + st->leftover += inlen; + } + return CRYPT_OK; +} + +/** + Terminate a POLY1305 session + @param st The POLY1305 state + @param mac [out] The destination of the POLY1305 authentication tag + @param maclen [in/out] The max size and resulting size of the POLY1305 authentication tag + @return CRYPT_OK if successful +*/ +int poly1305_done(poly1305_state *st, unsigned char *mac, unsigned long *maclen) +{ + ulong32 h0,h1,h2,h3,h4,c; + ulong32 g0,g1,g2,g3,g4; + ulong64 f; + ulong32 mask; + + LTC_ARGCHK(st != NULL); + LTC_ARGCHK(mac != NULL); + LTC_ARGCHK(maclen != NULL); + LTC_ARGCHK(*maclen >= 16); + + /* process the remaining block */ + if (st->leftover) { + unsigned long i = st->leftover; + st->buffer[i++] = 1; + for (; i < 16; i++) st->buffer[i] = 0; + st->final = 1; + _poly1305_block(st, st->buffer, 16); + } + + /* fully carry h */ + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; + + 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 - (1UL << 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)) & 0xffffffff; + h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff; + h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff; + h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff; + + /* mac = (h + pad) % (2^128) */ + f = (ulong64)h0 + st->pad[0] ; h0 = (ulong32)f; + f = (ulong64)h1 + st->pad[1] + (f >> 32); h1 = (ulong32)f; + f = (ulong64)h2 + st->pad[2] + (f >> 32); h2 = (ulong32)f; + f = (ulong64)h3 + st->pad[3] + (f >> 32); h3 = (ulong32)f; + + STORE32L(h0, mac + 0); + STORE32L(h1, mac + 4); + STORE32L(h2, mac + 8); + STORE32L(h3, mac + 12); + + /* zero out the state */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + st->r[0] = 0; + st->r[1] = 0; + st->r[2] = 0; + st->r[3] = 0; + st->r[4] = 0; + st->pad[0] = 0; + st->pad[1] = 0; + st->pad[2] = 0; + st->pad[3] = 0; + + *maclen = 16; + return CRYPT_OK; +} + +#endif + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */