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| author | Conrad Meyer <cem@FreeBSD.org> | 2019-03-01 23:30:23 +0000 |
|---|---|---|
| committer | Conrad Meyer <cem@FreeBSD.org> | 2019-03-01 23:30:23 +0000 |
| commit | 7d93ab5e35d97eb23cb4772be4d431a782a65395 (patch) | |
| tree | 38aff87422d781af33355ec267dac63a5d2796ab /sys/crypto | |
| parent | e66ccbeaa3613d022dbc07b9f7403c6bfbe40be6 (diff) | |
| download | src-7d93ab5e35d97eb23cb4772be4d431a782a65395.tar.gz src-7d93ab5e35d97eb23cb4772be4d431a782a65395.zip | |
Embedded chacha: Add 0-bit iv + 128-bit counter mode
This mode might be suitable for a Fortuna keystream primitive.
Reviewed by: markm
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D19410
Notes
Notes:
svn path=/head/; revision=344714
Diffstat (limited to 'sys/crypto')
| -rw-r--r-- | sys/crypto/chacha20/chacha.c | 33 | ||||
| -rw-r--r-- | sys/crypto/chacha20/chacha.h | 11 |
2 files changed, 43 insertions, 1 deletions
diff --git a/sys/crypto/chacha20/chacha.c b/sys/crypto/chacha20/chacha.c index c882078c0bbe..c0458dcd5b22 100644 --- a/sys/crypto/chacha20/chacha.c +++ b/sys/crypto/chacha20/chacha.c @@ -84,12 +84,32 @@ chacha_keysetup(chacha_ctx *x,const u8 *k,u32 kbits) LOCAL void chacha_ivsetup(chacha_ctx *x, const u8 *iv, const u8 *counter) { +#ifndef CHACHA_NONCE0_CTR128 x->input[12] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 0); x->input[13] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 4); x->input[14] = U8TO32_LITTLE(iv + 0); x->input[15] = U8TO32_LITTLE(iv + 4); +#else + // CHACHA_STATELEN + (void)iv; + x->input[12] = U8TO32_LITTLE(counter + 0); + x->input[13] = U8TO32_LITTLE(counter + 4); + x->input[14] = U8TO32_LITTLE(counter + 8); + x->input[15] = U8TO32_LITTLE(counter + 12); +#endif } +#ifdef CHACHA_NONCE0_CTR128 +LOCAL void +chacha_ctrsave(const chacha_ctx *x, u8 *counter) +{ + U32TO8_LITTLE(counter + 0, x->input[12]); + U32TO8_LITTLE(counter + 4, x->input[13]); + U32TO8_LITTLE(counter + 8, x->input[14]); + U32TO8_LITTLE(counter + 12, x->input[15]); +} +#endif + LOCAL void chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes) { @@ -192,7 +212,16 @@ chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes) j12 = PLUSONE(j12); if (!j12) { j13 = PLUSONE(j13); +#ifndef CHACHA_NONCE0_CTR128 /* stopping at 2^70 bytes per nonce is user's responsibility */ +#else + if (!j13) { + j14 = PLUSONE(j14); + if (!j14) { + j15 = PLUSONE(j15); + } + } +#endif } U32TO8_LITTLE(c + 0,x0); @@ -218,6 +247,10 @@ chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes) } x->input[12] = j12; x->input[13] = j13; +#ifdef CHACHA_NONCE0_CTR128 + x->input[14] = j14; + x->input[15] = j15; +#endif return; } bytes -= 64; diff --git a/sys/crypto/chacha20/chacha.h b/sys/crypto/chacha20/chacha.h index 73548331cc85..32262b04d568 100644 --- a/sys/crypto/chacha20/chacha.h +++ b/sys/crypto/chacha20/chacha.h @@ -26,10 +26,19 @@ Public domain. #define LOCAL #endif +#ifdef CHACHA_NONCE0_CTR128 +#define CHACHA_UNUSED __unused +#else +#define CHACHA_UNUSED +#endif + LOCAL void chacha_keysetup(struct chacha_ctx *x, const u_char *k, u_int kbits); -LOCAL void chacha_ivsetup(struct chacha_ctx *x, const u_char *iv, const u_char *ctr); +LOCAL void chacha_ivsetup(struct chacha_ctx *x, const u_char *iv CHACHA_UNUSED, + const u_char *ctr); LOCAL void chacha_encrypt_bytes(struct chacha_ctx *x, const u_char *m, u_char *c, u_int bytes); +#undef CHACHA_UNUSED + #endif /* CHACHA_H */ |