diff options
| -rw-r--r-- | sys/crypto/idgen.c | 30 | ||||
| -rw-r--r-- | sys/crypto/idgen.h | 13 |
2 files changed, 24 insertions, 19 deletions
diff --git a/sys/crypto/idgen.c b/sys/crypto/idgen.c index e96de57c6a0..b5512a44ec3 100644 --- a/sys/crypto/idgen.c +++ b/sys/crypto/idgen.c @@ -22,12 +22,11 @@ #include <sys/types.h> #include <sys/systm.h> +#include <sys/time.h> + #include <dev/rndvar.h> -#include <crypto/idgen.h> -static u_int16_t idgen32_g(u_int8_t *, int, u_int16_t); -u_int32_t idgen32_permute(u_int8_t key[IDGEN32_KEYLEN], u_int32_t); -void idgen32_rekey(struct idgen32_ctx *); +#include <crypto/idgen.h> static const u_int8_t ftable[256] = { 0xa3, 0xd7, 0x09, 0x83, 0xf8, 0x48, 0xf6, 0xf4, @@ -81,7 +80,7 @@ idgen32_g(u_int8_t *key, int k, u_int16_t w) return (g5 << 8) | g6; } -u_int32_t +static u_int32_t idgen32_permute(u_int8_t key[IDGEN32_KEYLEN], u_int32_t in) { u_int i, r; @@ -102,19 +101,21 @@ idgen32_permute(u_int8_t key[IDGEN32_KEYLEN], u_int32_t in) return (wl << 16) | wr; } -void +static void idgen32_rekey(struct idgen32_ctx *ctx) { - ctx->counter = 0; - ctx->hibit ^= 0x80000000; - arc4random_buf(ctx->key, sizeof(ctx->key)); + ctx->id_counter = 0; + ctx->id_hibit ^= 0x80000000; + ctx->id_offset = arc4random(); + arc4random_buf(ctx->id_key, sizeof(ctx->id_key)); + ctx->id_rekey_time = time_second + IDGEN32_REKEY_TIME; } void idgen32_init(struct idgen32_ctx *ctx) { bzero(ctx, sizeof(ctx)); - ctx->hibit = arc4random() & 0x80000000; + ctx->id_hibit = arc4random() & 0x80000000; idgen32_rekey(ctx); } @@ -125,13 +126,14 @@ idgen32(struct idgen32_ctx *ctx) /* Avoid emitting a zero ID as they often have special meaning */ do { - ret = idgen32_permute(ctx->key, ctx->counter++) | ctx->hibit; + ret = idgen32_permute(ctx->id_key, + ctx->id_offset + ctx->id_counter++); /* Rekey a little early to avoid "card counting" attack */ - if (ctx->counter > IDGEN32_REKEY_LIMIT) + if (ctx->id_counter > IDGEN32_REKEY_LIMIT || + ctx->id_rekey_time > time_second) idgen32_rekey(ctx); } while (ret == 0); - return ret; + return ret | ctx->id_hibit; } - diff --git a/sys/crypto/idgen.h b/sys/crypto/idgen.h index 588aa15aa64..02d5110c767 100644 --- a/sys/crypto/idgen.h +++ b/sys/crypto/idgen.h @@ -1,4 +1,4 @@ -/* $OpenBSD: idgen.h,v 1.1 2008/06/09 22:47:41 djm Exp $ */ +/* $OpenBSD: idgen.h,v 1.2 2008/06/25 00:55:53 djm Exp $ */ /* * Copyright (c) 2008 Damien Miller <djm@mindrot.org> * @@ -17,12 +17,15 @@ #define IDGEN32_ROUNDS 31 #define IDGEN32_KEYLEN 32 -#define IDGEN32_REKEY_LIMIT 0x7ff00000 +#define IDGEN32_REKEY_LIMIT 0x60000000 +#define IDGEN32_REKEY_TIME 600 struct idgen32_ctx { - u_int32_t counter; - u_int32_t hibit; - u_int8_t key[IDGEN32_KEYLEN]; + u_int32_t id_counter; + u_int32_t id_offset; + u_int32_t id_hibit; + u_int8_t id_key[IDGEN32_KEYLEN]; + time_t id_rekey_time; }; void idgen32_init(struct idgen32_ctx *); |