diff options
Diffstat (limited to 'crypto/evp/e_chacha20_poly1305.c')
-rw-r--r-- | crypto/evp/e_chacha20_poly1305.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/crypto/evp/e_chacha20_poly1305.c b/crypto/evp/e_chacha20_poly1305.c new file mode 100644 index 000000000000..c1917bb86a6b --- /dev/null +++ b/crypto/evp/e_chacha20_poly1305.c @@ -0,0 +1,630 @@ +/* + * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +#include <stdio.h> +#include "internal/cryptlib.h" + +#ifndef OPENSSL_NO_CHACHA + +# include <openssl/evp.h> +# include <openssl/objects.h> +# include "evp_locl.h" +# include "internal/evp_int.h" +# include "internal/chacha.h" + +typedef struct { + union { + double align; /* this ensures even sizeof(EVP_CHACHA_KEY)%8==0 */ + unsigned int d[CHACHA_KEY_SIZE / 4]; + } key; + unsigned int counter[CHACHA_CTR_SIZE / 4]; + unsigned char buf[CHACHA_BLK_SIZE]; + unsigned int partial_len; +} EVP_CHACHA_KEY; + +#define data(ctx) ((EVP_CHACHA_KEY *)(ctx)->cipher_data) + +static int chacha_init_key(EVP_CIPHER_CTX *ctx, + const unsigned char user_key[CHACHA_KEY_SIZE], + const unsigned char iv[CHACHA_CTR_SIZE], int enc) +{ + EVP_CHACHA_KEY *key = data(ctx); + unsigned int i; + + if (user_key) + for (i = 0; i < CHACHA_KEY_SIZE; i+=4) { + key->key.d[i/4] = CHACHA_U8TOU32(user_key+i); + } + + if (iv) + for (i = 0; i < CHACHA_CTR_SIZE; i+=4) { + key->counter[i/4] = CHACHA_U8TOU32(iv+i); + } + + key->partial_len = 0; + + return 1; +} + +static int chacha_cipher(EVP_CIPHER_CTX * ctx, unsigned char *out, + const unsigned char *inp, size_t len) +{ + EVP_CHACHA_KEY *key = data(ctx); + unsigned int n, rem, ctr32; + + if ((n = key->partial_len)) { + while (len && n < CHACHA_BLK_SIZE) { + *out++ = *inp++ ^ key->buf[n++]; + len--; + } + key->partial_len = n; + + if (len == 0) + return 1; + + if (n == CHACHA_BLK_SIZE) { + key->partial_len = 0; + key->counter[0]++; + if (key->counter[0] == 0) + key->counter[1]++; + } + } + + rem = (unsigned int)(len % CHACHA_BLK_SIZE); + len -= rem; + ctr32 = key->counter[0]; + while (len >= CHACHA_BLK_SIZE) { + size_t blocks = len / CHACHA_BLK_SIZE; + /* + * 1<<28 is just a not-so-small yet not-so-large number... + * Below condition is practically never met, but it has to + * be checked for code correctness. + */ + if (sizeof(size_t)>sizeof(unsigned int) && blocks>(1U<<28)) + blocks = (1U<<28); + + /* + * As ChaCha20_ctr32 operates on 32-bit counter, caller + * has to handle overflow. 'if' below detects the + * overflow, which is then handled by limiting the + * amount of blocks to the exact overflow point... + */ + ctr32 += (unsigned int)blocks; + if (ctr32 < blocks) { + blocks -= ctr32; + ctr32 = 0; + } + blocks *= CHACHA_BLK_SIZE; + ChaCha20_ctr32(out, inp, blocks, key->key.d, key->counter); + len -= blocks; + inp += blocks; + out += blocks; + + key->counter[0] = ctr32; + if (ctr32 == 0) key->counter[1]++; + } + + if (rem) { + memset(key->buf, 0, sizeof(key->buf)); + ChaCha20_ctr32(key->buf, key->buf, CHACHA_BLK_SIZE, + key->key.d, key->counter); + for (n = 0; n < rem; n++) + out[n] = inp[n] ^ key->buf[n]; + key->partial_len = rem; + } + + return 1; +} + +static const EVP_CIPHER chacha20 = { + NID_chacha20, + 1, /* block_size */ + CHACHA_KEY_SIZE, /* key_len */ + CHACHA_CTR_SIZE, /* iv_len, 128-bit counter in the context */ + EVP_CIPH_CUSTOM_IV | EVP_CIPH_ALWAYS_CALL_INIT, + chacha_init_key, + chacha_cipher, + NULL, + sizeof(EVP_CHACHA_KEY), + NULL, + NULL, + NULL, + NULL +}; + +const EVP_CIPHER *EVP_chacha20(void) +{ + return &chacha20; +} + +# ifndef OPENSSL_NO_POLY1305 +# include "internal/poly1305.h" + +typedef struct { + EVP_CHACHA_KEY key; + unsigned int nonce[12/4]; + unsigned char tag[POLY1305_BLOCK_SIZE]; + unsigned char tls_aad[POLY1305_BLOCK_SIZE]; + struct { uint64_t aad, text; } len; + int aad, mac_inited, tag_len, nonce_len; + size_t tls_payload_length; +} EVP_CHACHA_AEAD_CTX; + +# define NO_TLS_PAYLOAD_LENGTH ((size_t)-1) +# define aead_data(ctx) ((EVP_CHACHA_AEAD_CTX *)(ctx)->cipher_data) +# define POLY1305_ctx(actx) ((POLY1305 *)(actx + 1)) + +static int chacha20_poly1305_init_key(EVP_CIPHER_CTX *ctx, + const unsigned char *inkey, + const unsigned char *iv, int enc) +{ + EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx); + + if (!inkey && !iv) + return 1; + + actx->len.aad = 0; + actx->len.text = 0; + actx->aad = 0; + actx->mac_inited = 0; + actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH; + + if (iv != NULL) { + unsigned char temp[CHACHA_CTR_SIZE] = { 0 }; + + /* pad on the left */ + if (actx->nonce_len <= CHACHA_CTR_SIZE) + memcpy(temp + CHACHA_CTR_SIZE - actx->nonce_len, iv, + actx->nonce_len); + + chacha_init_key(ctx, inkey, temp, enc); + + actx->nonce[0] = actx->key.counter[1]; + actx->nonce[1] = actx->key.counter[2]; + actx->nonce[2] = actx->key.counter[3]; + } else { + chacha_init_key(ctx, inkey, NULL, enc); + } + + return 1; +} + +# if !defined(OPENSSL_SMALL_FOOTPRINT) + +# if defined(POLY1305_ASM) && (defined(__x86_64) || defined(__x86_64__) || \ + defined(_M_AMD64) || defined(_M_X64)) +# define XOR128_HELPERS +void *xor128_encrypt_n_pad(void *out, const void *inp, void *otp, size_t len); +void *xor128_decrypt_n_pad(void *out, const void *inp, void *otp, size_t len); +static const unsigned char zero[4 * CHACHA_BLK_SIZE] = { 0 }; +# else +static const unsigned char zero[2 * CHACHA_BLK_SIZE] = { 0 }; +# endif + +static int chacha20_poly1305_tls_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, + const unsigned char *in, size_t len) +{ + EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx); + size_t tail, tohash_len, buf_len, plen = actx->tls_payload_length; + unsigned char *buf, *tohash, *ctr, storage[sizeof(zero) + 32]; + + if (len != plen + POLY1305_BLOCK_SIZE) + return -1; + + buf = storage + ((0 - (size_t)storage) & 15); /* align */ + ctr = buf + CHACHA_BLK_SIZE; + tohash = buf + CHACHA_BLK_SIZE - POLY1305_BLOCK_SIZE; + +# ifdef XOR128_HELPERS + if (plen <= 3 * CHACHA_BLK_SIZE) { + actx->key.counter[0] = 0; + buf_len = (plen + 2 * CHACHA_BLK_SIZE - 1) & (0 - CHACHA_BLK_SIZE); + ChaCha20_ctr32(buf, zero, buf_len, actx->key.key.d, + actx->key.counter); + Poly1305_Init(POLY1305_ctx(actx), buf); + actx->key.partial_len = 0; + memcpy(tohash, actx->tls_aad, POLY1305_BLOCK_SIZE); + tohash_len = POLY1305_BLOCK_SIZE; + actx->len.aad = EVP_AEAD_TLS1_AAD_LEN; + actx->len.text = plen; + + if (plen) { + if (ctx->encrypt) + ctr = xor128_encrypt_n_pad(out, in, ctr, plen); + else + ctr = xor128_decrypt_n_pad(out, in, ctr, plen); + + in += plen; + out += plen; + tohash_len = (size_t)(ctr - tohash); + } + } +# else + if (plen <= CHACHA_BLK_SIZE) { + size_t i; + + actx->key.counter[0] = 0; + ChaCha20_ctr32(buf, zero, (buf_len = 2 * CHACHA_BLK_SIZE), + actx->key.key.d, actx->key.counter); + Poly1305_Init(POLY1305_ctx(actx), buf); + actx->key.partial_len = 0; + memcpy(tohash, actx->tls_aad, POLY1305_BLOCK_SIZE); + tohash_len = POLY1305_BLOCK_SIZE; + actx->len.aad = EVP_AEAD_TLS1_AAD_LEN; + actx->len.text = plen; + + if (ctx->encrypt) { + for (i = 0; i < plen; i++) { + out[i] = ctr[i] ^= in[i]; + } + } else { + for (i = 0; i < plen; i++) { + unsigned char c = in[i]; + out[i] = ctr[i] ^ c; + ctr[i] = c; + } + } + + in += i; + out += i; + + tail = (0 - i) & (POLY1305_BLOCK_SIZE - 1); + memset(ctr + i, 0, tail); + ctr += i + tail; + tohash_len += i + tail; + } +# endif + else { + actx->key.counter[0] = 0; + ChaCha20_ctr32(buf, zero, (buf_len = CHACHA_BLK_SIZE), + actx->key.key.d, actx->key.counter); + Poly1305_Init(POLY1305_ctx(actx), buf); + actx->key.counter[0] = 1; + actx->key.partial_len = 0; + Poly1305_Update(POLY1305_ctx(actx), actx->tls_aad, POLY1305_BLOCK_SIZE); + tohash = ctr; + tohash_len = 0; + actx->len.aad = EVP_AEAD_TLS1_AAD_LEN; + actx->len.text = plen; + + if (ctx->encrypt) { + ChaCha20_ctr32(out, in, plen, actx->key.key.d, actx->key.counter); + Poly1305_Update(POLY1305_ctx(actx), out, plen); + } else { + Poly1305_Update(POLY1305_ctx(actx), in, plen); + ChaCha20_ctr32(out, in, plen, actx->key.key.d, actx->key.counter); + } + + in += plen; + out += plen; + tail = (0 - plen) & (POLY1305_BLOCK_SIZE - 1); + Poly1305_Update(POLY1305_ctx(actx), zero, tail); + } + + { + const union { + long one; + char little; + } is_endian = { 1 }; + + if (is_endian.little) { + memcpy(ctr, (unsigned char *)&actx->len, POLY1305_BLOCK_SIZE); + } else { + ctr[0] = (unsigned char)(actx->len.aad); + ctr[1] = (unsigned char)(actx->len.aad>>8); + ctr[2] = (unsigned char)(actx->len.aad>>16); + ctr[3] = (unsigned char)(actx->len.aad>>24); + ctr[4] = (unsigned char)(actx->len.aad>>32); + ctr[5] = (unsigned char)(actx->len.aad>>40); + ctr[6] = (unsigned char)(actx->len.aad>>48); + ctr[7] = (unsigned char)(actx->len.aad>>56); + + ctr[8] = (unsigned char)(actx->len.text); + ctr[9] = (unsigned char)(actx->len.text>>8); + ctr[10] = (unsigned char)(actx->len.text>>16); + ctr[11] = (unsigned char)(actx->len.text>>24); + ctr[12] = (unsigned char)(actx->len.text>>32); + ctr[13] = (unsigned char)(actx->len.text>>40); + ctr[14] = (unsigned char)(actx->len.text>>48); + ctr[15] = (unsigned char)(actx->len.text>>56); + } + tohash_len += POLY1305_BLOCK_SIZE; + } + + Poly1305_Update(POLY1305_ctx(actx), tohash, tohash_len); + OPENSSL_cleanse(buf, buf_len); + Poly1305_Final(POLY1305_ctx(actx), ctx->encrypt ? actx->tag + : tohash); + + actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH; + + if (ctx->encrypt) { + memcpy(out, actx->tag, POLY1305_BLOCK_SIZE); + } else { + if (CRYPTO_memcmp(tohash, in, POLY1305_BLOCK_SIZE)) { + memset(out - (len - POLY1305_BLOCK_SIZE), 0, + len - POLY1305_BLOCK_SIZE); + return -1; + } + } + + return len; +} +# else +static const unsigned char zero[CHACHA_BLK_SIZE] = { 0 }; +# endif + +static int chacha20_poly1305_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, + const unsigned char *in, size_t len) +{ + EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx); + size_t rem, plen = actx->tls_payload_length; + + if (!actx->mac_inited) { +# if !defined(OPENSSL_SMALL_FOOTPRINT) + if (plen != NO_TLS_PAYLOAD_LENGTH && out != NULL) + return chacha20_poly1305_tls_cipher(ctx, out, in, len); +# endif + actx->key.counter[0] = 0; + ChaCha20_ctr32(actx->key.buf, zero, CHACHA_BLK_SIZE, + actx->key.key.d, actx->key.counter); + Poly1305_Init(POLY1305_ctx(actx), actx->key.buf); + actx->key.counter[0] = 1; + actx->key.partial_len = 0; + actx->len.aad = actx->len.text = 0; + actx->mac_inited = 1; + if (plen != NO_TLS_PAYLOAD_LENGTH) { + Poly1305_Update(POLY1305_ctx(actx), actx->tls_aad, + EVP_AEAD_TLS1_AAD_LEN); + actx->len.aad = EVP_AEAD_TLS1_AAD_LEN; + actx->aad = 1; + } + } + + if (in) { /* aad or text */ + if (out == NULL) { /* aad */ + Poly1305_Update(POLY1305_ctx(actx), in, len); + actx->len.aad += len; + actx->aad = 1; + return len; + } else { /* plain- or ciphertext */ + if (actx->aad) { /* wrap up aad */ + if ((rem = (size_t)actx->len.aad % POLY1305_BLOCK_SIZE)) + Poly1305_Update(POLY1305_ctx(actx), zero, + POLY1305_BLOCK_SIZE - rem); + actx->aad = 0; + } + + actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH; + if (plen == NO_TLS_PAYLOAD_LENGTH) + plen = len; + else if (len != plen + POLY1305_BLOCK_SIZE) + return -1; + + if (ctx->encrypt) { /* plaintext */ + chacha_cipher(ctx, out, in, plen); + Poly1305_Update(POLY1305_ctx(actx), out, plen); + in += plen; + out += plen; + actx->len.text += plen; + } else { /* ciphertext */ + Poly1305_Update(POLY1305_ctx(actx), in, plen); + chacha_cipher(ctx, out, in, plen); + in += plen; + out += plen; + actx->len.text += plen; + } + } + } + if (in == NULL /* explicit final */ + || plen != len) { /* or tls mode */ + const union { + long one; + char little; + } is_endian = { 1 }; + unsigned char temp[POLY1305_BLOCK_SIZE]; + + if (actx->aad) { /* wrap up aad */ + if ((rem = (size_t)actx->len.aad % POLY1305_BLOCK_SIZE)) + Poly1305_Update(POLY1305_ctx(actx), zero, + POLY1305_BLOCK_SIZE - rem); + actx->aad = 0; + } + + if ((rem = (size_t)actx->len.text % POLY1305_BLOCK_SIZE)) + Poly1305_Update(POLY1305_ctx(actx), zero, + POLY1305_BLOCK_SIZE - rem); + + if (is_endian.little) { + Poly1305_Update(POLY1305_ctx(actx), + (unsigned char *)&actx->len, POLY1305_BLOCK_SIZE); + } else { + temp[0] = (unsigned char)(actx->len.aad); + temp[1] = (unsigned char)(actx->len.aad>>8); + temp[2] = (unsigned char)(actx->len.aad>>16); + temp[3] = (unsigned char)(actx->len.aad>>24); + temp[4] = (unsigned char)(actx->len.aad>>32); + temp[5] = (unsigned char)(actx->len.aad>>40); + temp[6] = (unsigned char)(actx->len.aad>>48); + temp[7] = (unsigned char)(actx->len.aad>>56); + + temp[8] = (unsigned char)(actx->len.text); + temp[9] = (unsigned char)(actx->len.text>>8); + temp[10] = (unsigned char)(actx->len.text>>16); + temp[11] = (unsigned char)(actx->len.text>>24); + temp[12] = (unsigned char)(actx->len.text>>32); + temp[13] = (unsigned char)(actx->len.text>>40); + temp[14] = (unsigned char)(actx->len.text>>48); + temp[15] = (unsigned char)(actx->len.text>>56); + + Poly1305_Update(POLY1305_ctx(actx), temp, POLY1305_BLOCK_SIZE); + } + Poly1305_Final(POLY1305_ctx(actx), ctx->encrypt ? actx->tag + : temp); + actx->mac_inited = 0; + + if (in != NULL && len != plen) { /* tls mode */ + if (ctx->encrypt) { + memcpy(out, actx->tag, POLY1305_BLOCK_SIZE); + } else { + if (CRYPTO_memcmp(temp, in, POLY1305_BLOCK_SIZE)) { + memset(out - plen, 0, plen); + return -1; + } + } + } + else if (!ctx->encrypt) { + if (CRYPTO_memcmp(temp, actx->tag, actx->tag_len)) + return -1; + } + } + return len; +} + +static int chacha20_poly1305_cleanup(EVP_CIPHER_CTX *ctx) +{ + EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx); + if (actx) + OPENSSL_cleanse(ctx->cipher_data, sizeof(*actx) + Poly1305_ctx_size()); + return 1; +} + +static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, + void *ptr) +{ + EVP_CHACHA_AEAD_CTX *actx = aead_data(ctx); + + switch(type) { + case EVP_CTRL_INIT: + if (actx == NULL) + actx = ctx->cipher_data + = OPENSSL_zalloc(sizeof(*actx) + Poly1305_ctx_size()); + if (actx == NULL) { + EVPerr(EVP_F_CHACHA20_POLY1305_CTRL, EVP_R_INITIALIZATION_ERROR); + return 0; + } + actx->len.aad = 0; + actx->len.text = 0; + actx->aad = 0; + actx->mac_inited = 0; + actx->tag_len = 0; + actx->nonce_len = 12; + actx->tls_payload_length = NO_TLS_PAYLOAD_LENGTH; + memset(actx->tls_aad, 0, POLY1305_BLOCK_SIZE); + return 1; + + case EVP_CTRL_COPY: + if (actx) { + EVP_CIPHER_CTX *dst = (EVP_CIPHER_CTX *)ptr; + + dst->cipher_data = + OPENSSL_memdup(actx, sizeof(*actx) + Poly1305_ctx_size()); + if (dst->cipher_data == NULL) { + EVPerr(EVP_F_CHACHA20_POLY1305_CTRL, EVP_R_COPY_ERROR); + return 0; + } + } + return 1; + + case EVP_CTRL_AEAD_SET_IVLEN: + if (arg <= 0 || arg > CHACHA_CTR_SIZE) + return 0; + actx->nonce_len = arg; + return 1; + + case EVP_CTRL_AEAD_SET_IV_FIXED: + if (arg != 12) + return 0; + actx->nonce[0] = actx->key.counter[1] + = CHACHA_U8TOU32((unsigned char *)ptr); + actx->nonce[1] = actx->key.counter[2] + = CHACHA_U8TOU32((unsigned char *)ptr+4); + actx->nonce[2] = actx->key.counter[3] + = CHACHA_U8TOU32((unsigned char *)ptr+8); + return 1; + + case EVP_CTRL_AEAD_SET_TAG: + if (arg <= 0 || arg > POLY1305_BLOCK_SIZE) + return 0; + if (ptr != NULL) { + memcpy(actx->tag, ptr, arg); + actx->tag_len = arg; + } + return 1; + + case EVP_CTRL_AEAD_GET_TAG: + if (arg <= 0 || arg > POLY1305_BLOCK_SIZE || !ctx->encrypt) + return 0; + memcpy(ptr, actx->tag, arg); + return 1; + + case EVP_CTRL_AEAD_TLS1_AAD: + if (arg != EVP_AEAD_TLS1_AAD_LEN) + return 0; + { + unsigned int len; + unsigned char *aad = ptr; + + memcpy(actx->tls_aad, ptr, EVP_AEAD_TLS1_AAD_LEN); + len = aad[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 | + aad[EVP_AEAD_TLS1_AAD_LEN - 1]; + aad = actx->tls_aad; + if (!ctx->encrypt) { + if (len < POLY1305_BLOCK_SIZE) + return 0; + len -= POLY1305_BLOCK_SIZE; /* discount attached tag */ + aad[EVP_AEAD_TLS1_AAD_LEN - 2] = (unsigned char)(len >> 8); + aad[EVP_AEAD_TLS1_AAD_LEN - 1] = (unsigned char)len; + } + actx->tls_payload_length = len; + + /* + * merge record sequence number as per RFC7905 + */ + actx->key.counter[1] = actx->nonce[0]; + actx->key.counter[2] = actx->nonce[1] ^ CHACHA_U8TOU32(aad); + actx->key.counter[3] = actx->nonce[2] ^ CHACHA_U8TOU32(aad+4); + actx->mac_inited = 0; + + return POLY1305_BLOCK_SIZE; /* tag length */ + } + + case EVP_CTRL_AEAD_SET_MAC_KEY: + /* no-op */ + return 1; + + default: + return -1; + } +} + +static EVP_CIPHER chacha20_poly1305 = { + NID_chacha20_poly1305, + 1, /* block_size */ + CHACHA_KEY_SIZE, /* key_len */ + 12, /* iv_len, 96-bit nonce in the context */ + EVP_CIPH_FLAG_AEAD_CIPHER | EVP_CIPH_CUSTOM_IV | + EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT | + EVP_CIPH_CUSTOM_COPY | EVP_CIPH_FLAG_CUSTOM_CIPHER, + chacha20_poly1305_init_key, + chacha20_poly1305_cipher, + chacha20_poly1305_cleanup, + 0, /* 0 moves context-specific structure allocation to ctrl */ + NULL, /* set_asn1_parameters */ + NULL, /* get_asn1_parameters */ + chacha20_poly1305_ctrl, + NULL /* app_data */ +}; + +const EVP_CIPHER *EVP_chacha20_poly1305(void) +{ + return(&chacha20_poly1305); +} +# endif +#endif |