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-rw-r--r--crypto/rand/drbg_ctr.c438
1 files changed, 438 insertions, 0 deletions
diff --git a/crypto/rand/drbg_ctr.c b/crypto/rand/drbg_ctr.c
new file mode 100644
index 000000000000..fe15164451e8
--- /dev/null
+++ b/crypto/rand/drbg_ctr.c
@@ -0,0 +1,438 @@
+/*
+ * Copyright 2011-2018 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 <stdlib.h>
+#include <string.h>
+#include <openssl/crypto.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+#include "internal/thread_once.h"
+#include "internal/thread_once.h"
+#include "rand_lcl.h"
+/*
+ * Implementation of NIST SP 800-90A CTR DRBG.
+ */
+
+static void inc_128(RAND_DRBG_CTR *ctr)
+{
+ int i;
+ unsigned char c;
+ unsigned char *p = &ctr->V[15];
+
+ for (i = 0; i < 16; i++, p--) {
+ c = *p;
+ c++;
+ *p = c;
+ if (c != 0) {
+ /* If we didn't wrap around, we're done. */
+ break;
+ }
+ }
+}
+
+static void ctr_XOR(RAND_DRBG_CTR *ctr, const unsigned char *in, size_t inlen)
+{
+ size_t i, n;
+
+ if (in == NULL || inlen == 0)
+ return;
+
+ /*
+ * Any zero padding will have no effect on the result as we
+ * are XORing. So just process however much input we have.
+ */
+ n = inlen < ctr->keylen ? inlen : ctr->keylen;
+ for (i = 0; i < n; i++)
+ ctr->K[i] ^= in[i];
+ if (inlen <= ctr->keylen)
+ return;
+
+ n = inlen - ctr->keylen;
+ if (n > 16) {
+ /* Should never happen */
+ n = 16;
+ }
+ for (i = 0; i < n; i++)
+ ctr->V[i] ^= in[i + ctr->keylen];
+}
+
+/*
+ * Process a complete block using BCC algorithm of SP 800-90A 10.3.3
+ */
+__owur static int ctr_BCC_block(RAND_DRBG_CTR *ctr, unsigned char *out,
+ const unsigned char *in)
+{
+ int i, outlen = AES_BLOCK_SIZE;
+
+ for (i = 0; i < 16; i++)
+ out[i] ^= in[i];
+
+ if (!EVP_CipherUpdate(ctr->ctx_df, out, &outlen, out, AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+ return 1;
+}
+
+
+/*
+ * Handle several BCC operations for as much data as we need for K and X
+ */
+__owur static int ctr_BCC_blocks(RAND_DRBG_CTR *ctr, const unsigned char *in)
+{
+ if (!ctr_BCC_block(ctr, ctr->KX, in)
+ || !ctr_BCC_block(ctr, ctr->KX + 16, in))
+ return 0;
+ if (ctr->keylen != 16 && !ctr_BCC_block(ctr, ctr->KX + 32, in))
+ return 0;
+ return 1;
+}
+
+/*
+ * Initialise BCC blocks: these have the value 0,1,2 in leftmost positions:
+ * see 10.3.1 stage 7.
+ */
+__owur static int ctr_BCC_init(RAND_DRBG_CTR *ctr)
+{
+ memset(ctr->KX, 0, 48);
+ memset(ctr->bltmp, 0, 16);
+ if (!ctr_BCC_block(ctr, ctr->KX, ctr->bltmp))
+ return 0;
+ ctr->bltmp[3] = 1;
+ if (!ctr_BCC_block(ctr, ctr->KX + 16, ctr->bltmp))
+ return 0;
+ if (ctr->keylen != 16) {
+ ctr->bltmp[3] = 2;
+ if (!ctr_BCC_block(ctr, ctr->KX + 32, ctr->bltmp))
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * Process several blocks into BCC algorithm, some possibly partial
+ */
+__owur static int ctr_BCC_update(RAND_DRBG_CTR *ctr,
+ const unsigned char *in, size_t inlen)
+{
+ if (in == NULL || inlen == 0)
+ return 1;
+
+ /* If we have partial block handle it first */
+ if (ctr->bltmp_pos) {
+ size_t left = 16 - ctr->bltmp_pos;
+
+ /* If we now have a complete block process it */
+ if (inlen >= left) {
+ memcpy(ctr->bltmp + ctr->bltmp_pos, in, left);
+ if (!ctr_BCC_blocks(ctr, ctr->bltmp))
+ return 0;
+ ctr->bltmp_pos = 0;
+ inlen -= left;
+ in += left;
+ }
+ }
+
+ /* Process zero or more complete blocks */
+ for (; inlen >= 16; in += 16, inlen -= 16) {
+ if (!ctr_BCC_blocks(ctr, in))
+ return 0;
+ }
+
+ /* Copy any remaining partial block to the temporary buffer */
+ if (inlen > 0) {
+ memcpy(ctr->bltmp + ctr->bltmp_pos, in, inlen);
+ ctr->bltmp_pos += inlen;
+ }
+ return 1;
+}
+
+__owur static int ctr_BCC_final(RAND_DRBG_CTR *ctr)
+{
+ if (ctr->bltmp_pos) {
+ memset(ctr->bltmp + ctr->bltmp_pos, 0, 16 - ctr->bltmp_pos);
+ if (!ctr_BCC_blocks(ctr, ctr->bltmp))
+ return 0;
+ }
+ return 1;
+}
+
+__owur static int ctr_df(RAND_DRBG_CTR *ctr,
+ const unsigned char *in1, size_t in1len,
+ const unsigned char *in2, size_t in2len,
+ const unsigned char *in3, size_t in3len)
+{
+ static unsigned char c80 = 0x80;
+ size_t inlen;
+ unsigned char *p = ctr->bltmp;
+ int outlen = AES_BLOCK_SIZE;
+
+ if (!ctr_BCC_init(ctr))
+ return 0;
+ if (in1 == NULL)
+ in1len = 0;
+ if (in2 == NULL)
+ in2len = 0;
+ if (in3 == NULL)
+ in3len = 0;
+ inlen = in1len + in2len + in3len;
+ /* Initialise L||N in temporary block */
+ *p++ = (inlen >> 24) & 0xff;
+ *p++ = (inlen >> 16) & 0xff;
+ *p++ = (inlen >> 8) & 0xff;
+ *p++ = inlen & 0xff;
+
+ /* NB keylen is at most 32 bytes */
+ *p++ = 0;
+ *p++ = 0;
+ *p++ = 0;
+ *p = (unsigned char)((ctr->keylen + 16) & 0xff);
+ ctr->bltmp_pos = 8;
+ if (!ctr_BCC_update(ctr, in1, in1len)
+ || !ctr_BCC_update(ctr, in2, in2len)
+ || !ctr_BCC_update(ctr, in3, in3len)
+ || !ctr_BCC_update(ctr, &c80, 1)
+ || !ctr_BCC_final(ctr))
+ return 0;
+ /* Set up key K */
+ if (!EVP_CipherInit_ex(ctr->ctx, ctr->cipher, NULL, ctr->KX, NULL, 1))
+ return 0;
+ /* X follows key K */
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->KX, &outlen, ctr->KX + ctr->keylen,
+ AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->KX + 16, &outlen, ctr->KX,
+ AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+ if (ctr->keylen != 16)
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->KX + 32, &outlen, ctr->KX + 16,
+ AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+ return 1;
+}
+
+/*
+ * NB the no-df Update in SP800-90A specifies a constant input length
+ * of seedlen, however other uses of this algorithm pad the input with
+ * zeroes if necessary and have up to two parameters XORed together,
+ * so we handle both cases in this function instead.
+ */
+__owur static int ctr_update(RAND_DRBG *drbg,
+ const unsigned char *in1, size_t in1len,
+ const unsigned char *in2, size_t in2len,
+ const unsigned char *nonce, size_t noncelen)
+{
+ RAND_DRBG_CTR *ctr = &drbg->data.ctr;
+ int outlen = AES_BLOCK_SIZE;
+
+ /* correct key is already set up. */
+ inc_128(ctr);
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->K, &outlen, ctr->V, AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+
+ /* If keylen longer than 128 bits need extra encrypt */
+ if (ctr->keylen != 16) {
+ inc_128(ctr);
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->K+16, &outlen, ctr->V,
+ AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+ }
+ inc_128(ctr);
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->V, &outlen, ctr->V, AES_BLOCK_SIZE)
+ || outlen != AES_BLOCK_SIZE)
+ return 0;
+
+ /* If 192 bit key part of V is on end of K */
+ if (ctr->keylen == 24) {
+ memcpy(ctr->V + 8, ctr->V, 8);
+ memcpy(ctr->V, ctr->K + 24, 8);
+ }
+
+ if ((drbg->flags & RAND_DRBG_FLAG_CTR_NO_DF) == 0) {
+ /* If no input reuse existing derived value */
+ if (in1 != NULL || nonce != NULL || in2 != NULL)
+ if (!ctr_df(ctr, in1, in1len, nonce, noncelen, in2, in2len))
+ return 0;
+ /* If this a reuse input in1len != 0 */
+ if (in1len)
+ ctr_XOR(ctr, ctr->KX, drbg->seedlen);
+ } else {
+ ctr_XOR(ctr, in1, in1len);
+ ctr_XOR(ctr, in2, in2len);
+ }
+
+ if (!EVP_CipherInit_ex(ctr->ctx, ctr->cipher, NULL, ctr->K, NULL, 1))
+ return 0;
+ return 1;
+}
+
+__owur static int drbg_ctr_instantiate(RAND_DRBG *drbg,
+ const unsigned char *entropy, size_t entropylen,
+ const unsigned char *nonce, size_t noncelen,
+ const unsigned char *pers, size_t perslen)
+{
+ RAND_DRBG_CTR *ctr = &drbg->data.ctr;
+
+ if (entropy == NULL)
+ return 0;
+
+ memset(ctr->K, 0, sizeof(ctr->K));
+ memset(ctr->V, 0, sizeof(ctr->V));
+ if (!EVP_CipherInit_ex(ctr->ctx, ctr->cipher, NULL, ctr->K, NULL, 1))
+ return 0;
+ if (!ctr_update(drbg, entropy, entropylen, pers, perslen, nonce, noncelen))
+ return 0;
+ return 1;
+}
+
+__owur static int drbg_ctr_reseed(RAND_DRBG *drbg,
+ const unsigned char *entropy, size_t entropylen,
+ const unsigned char *adin, size_t adinlen)
+{
+ if (entropy == NULL)
+ return 0;
+ if (!ctr_update(drbg, entropy, entropylen, adin, adinlen, NULL, 0))
+ return 0;
+ return 1;
+}
+
+__owur static int drbg_ctr_generate(RAND_DRBG *drbg,
+ unsigned char *out, size_t outlen,
+ const unsigned char *adin, size_t adinlen)
+{
+ RAND_DRBG_CTR *ctr = &drbg->data.ctr;
+
+ if (adin != NULL && adinlen != 0) {
+ if (!ctr_update(drbg, adin, adinlen, NULL, 0, NULL, 0))
+ return 0;
+ /* This means we reuse derived value */
+ if ((drbg->flags & RAND_DRBG_FLAG_CTR_NO_DF) == 0) {
+ adin = NULL;
+ adinlen = 1;
+ }
+ } else {
+ adinlen = 0;
+ }
+
+ for ( ; ; ) {
+ int outl = AES_BLOCK_SIZE;
+
+ inc_128(ctr);
+ if (outlen < 16) {
+ /* Use K as temp space as it will be updated */
+ if (!EVP_CipherUpdate(ctr->ctx, ctr->K, &outl, ctr->V,
+ AES_BLOCK_SIZE)
+ || outl != AES_BLOCK_SIZE)
+ return 0;
+ memcpy(out, ctr->K, outlen);
+ break;
+ }
+ if (!EVP_CipherUpdate(ctr->ctx, out, &outl, ctr->V, AES_BLOCK_SIZE)
+ || outl != AES_BLOCK_SIZE)
+ return 0;
+ out += 16;
+ outlen -= 16;
+ if (outlen == 0)
+ break;
+ }
+
+ if (!ctr_update(drbg, adin, adinlen, NULL, 0, NULL, 0))
+ return 0;
+ return 1;
+}
+
+static int drbg_ctr_uninstantiate(RAND_DRBG *drbg)
+{
+ EVP_CIPHER_CTX_free(drbg->data.ctr.ctx);
+ EVP_CIPHER_CTX_free(drbg->data.ctr.ctx_df);
+ OPENSSL_cleanse(&drbg->data.ctr, sizeof(drbg->data.ctr));
+ return 1;
+}
+
+static RAND_DRBG_METHOD drbg_ctr_meth = {
+ drbg_ctr_instantiate,
+ drbg_ctr_reseed,
+ drbg_ctr_generate,
+ drbg_ctr_uninstantiate
+};
+
+int drbg_ctr_init(RAND_DRBG *drbg)
+{
+ RAND_DRBG_CTR *ctr = &drbg->data.ctr;
+ size_t keylen;
+
+ switch (drbg->type) {
+ default:
+ /* This can't happen, but silence the compiler warning. */
+ return 0;
+ case NID_aes_128_ctr:
+ keylen = 16;
+ ctr->cipher = EVP_aes_128_ecb();
+ break;
+ case NID_aes_192_ctr:
+ keylen = 24;
+ ctr->cipher = EVP_aes_192_ecb();
+ break;
+ case NID_aes_256_ctr:
+ keylen = 32;
+ ctr->cipher = EVP_aes_256_ecb();
+ break;
+ }
+
+ drbg->meth = &drbg_ctr_meth;
+
+ ctr->keylen = keylen;
+ if (ctr->ctx == NULL)
+ ctr->ctx = EVP_CIPHER_CTX_new();
+ if (ctr->ctx == NULL)
+ return 0;
+ drbg->strength = keylen * 8;
+ drbg->seedlen = keylen + 16;
+
+ if ((drbg->flags & RAND_DRBG_FLAG_CTR_NO_DF) == 0) {
+ /* df initialisation */
+ static const unsigned char df_key[32] = {
+ 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
+ 0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
+ 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
+ 0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
+ };
+
+ if (ctr->ctx_df == NULL)
+ ctr->ctx_df = EVP_CIPHER_CTX_new();
+ if (ctr->ctx_df == NULL)
+ return 0;
+ /* Set key schedule for df_key */
+ if (!EVP_CipherInit_ex(ctr->ctx_df, ctr->cipher, NULL, df_key, NULL, 1))
+ return 0;
+
+ drbg->min_entropylen = ctr->keylen;
+ drbg->max_entropylen = DRBG_MINMAX_FACTOR * drbg->min_entropylen;
+ drbg->min_noncelen = drbg->min_entropylen / 2;
+ drbg->max_noncelen = DRBG_MINMAX_FACTOR * drbg->min_noncelen;
+ drbg->max_perslen = DRBG_MAX_LENGTH;
+ drbg->max_adinlen = DRBG_MAX_LENGTH;
+ } else {
+ drbg->min_entropylen = drbg->seedlen;
+ drbg->max_entropylen = drbg->seedlen;
+ /* Nonce not used */
+ drbg->min_noncelen = 0;
+ drbg->max_noncelen = 0;
+ drbg->max_perslen = drbg->seedlen;
+ drbg->max_adinlen = drbg->seedlen;
+ }
+
+ drbg->max_request = 1 << 16;
+
+ return 1;
+}