crypto/evp: add e_chacha20_poly1305.c.

Reviewed-by: Richard Levitte <levitte@openssl.org>

1 files changed, 490 insertions, 0 deletions

diff --git a/crypto/evp/e_chacha20_poly1305.c b/crypto/evp/e_chacha20_poly1305.c
new file mode 100644
index 0000000000..bce247d7b5
--- /dev/null
+++ b/crypto/evp/e_chacha20_poly1305.c
@@ -0,0 +1,490 @@
+/* ====================================================================
+ * Copyright (c) 2014 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ */
+
+#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 */
+    0,                      /* flags */
+    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];
+    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);
+    unsigned char temp[CHACHA_CTR_SIZE];
+
+    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;
+
+    /* pad on the left */
+    memset(temp, 0, sizeof(temp));
+    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];
+
+    return 1;
+}
+
+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;
+    static const unsigned char zero[POLY1305_BLOCK_SIZE] = { 0 };
+
+    if (!actx->mac_inited) {
+        actx->key.counter[0] = 0;
+        memset(actx->key.buf, 0, sizeof(actx->key.buf));
+        ChaCha20_ctr32(actx->key.buf, actx->key.buf, CHACHA_BLK_SIZE,
+                       actx->key.key.d, actx->key.counter);
+        Poly1305_Init(POLY1305_ctx(actx), actx->key.buf);
+        actx->key.counter[0] = 1;
+        actx->mac_inited = 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, 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(*ctx) + 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;
+        return 1;
+
+    case EVP_CTRL_COPY:
+        if (actx) {
+            if ((((EVP_CIPHER_CTX *)ptr)->cipher_data =
+                   BUF_memdup(actx,sizeof(*actx) + Poly1305_ctx_size()))
+                == 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 temp[POLY1305_BLOCK_SIZE];
+
+            /*
+             * compose padded aad
+             */
+            memset(temp, 0, sizeof(temp));
+            memcpy(temp, ptr, EVP_AEAD_TLS1_AAD_LEN);
+
+            len = temp[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 |
+                  temp[EVP_AEAD_TLS1_AAD_LEN - 1];
+            if (!ctx->encrypt) {
+                len -= POLY1305_BLOCK_SIZE;     /* discount attached tag */
+                temp[EVP_AEAD_TLS1_AAD_LEN - 2] = (unsigned char)(len >> 8);
+                temp[EVP_AEAD_TLS1_AAD_LEN - 1] = (unsigned char)len;
+            }
+            actx->tls_payload_length = len;
+
+            /*
+             * merge record sequence number as per
+             * draft-ietf-tls-chacha20-poly1305-03
+             */
+            actx->key.counter[1] = actx->nonce[0];
+            actx->key.counter[2] = actx->nonce[1] ^ CHACHA_U8TOU32(temp);
+            actx->key.counter[3] = actx->nonce[2] ^ CHACHA_U8TOU32(temp+4);
+            actx->mac_inited = 0;
+            chacha20_poly1305_cipher(ctx, NULL, temp, POLY1305_BLOCK_SIZE);
+            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