1 files changed, 463 insertions, 0 deletions
diff --git a/providers/implementations/kdfs/hkdf.c b/providers/implementations/kdfs/hkdf.c
new file mode 100644
index 0000000000..041811f0e1
--- /dev/null
+++ b/providers/implementations/kdfs/hkdf.c
@@ -0,0 +1,463 @@
+/*
+ * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (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 <stdarg.h>
+#include <string.h>
+#include <openssl/hmac.h>
+#include <openssl/evp.h>
+#include <openssl/kdf.h>
+#include <openssl/core_names.h>
+#include "internal/cryptlib.h"
+#include "internal/numbers.h"
+#include "crypto/evp.h"
+#include "internal/provider_ctx.h"
+#include "internal/providercommonerr.h"
+#include "internal/provider_algs.h"
+#include "internal/provider_util.h"
+#include "e_os.h"
+
+#define HKDF_MAXBUF 1024
+
+static OSSL_OP_kdf_newctx_fn kdf_hkdf_new;
+static OSSL_OP_kdf_freectx_fn kdf_hkdf_free;
+static OSSL_OP_kdf_reset_fn kdf_hkdf_reset;
+static OSSL_OP_kdf_derive_fn kdf_hkdf_derive;
+static OSSL_OP_kdf_settable_ctx_params_fn kdf_hkdf_settable_ctx_params;
+static OSSL_OP_kdf_set_ctx_params_fn kdf_hkdf_set_ctx_params;
+static OSSL_OP_kdf_gettable_ctx_params_fn kdf_hkdf_gettable_ctx_params;
+static OSSL_OP_kdf_get_ctx_params_fn kdf_hkdf_get_ctx_params;
+
+static int HKDF(const EVP_MD *evp_md,
+                const unsigned char *salt, size_t salt_len,
+                const unsigned char *key, size_t key_len,
+                const unsigned char *info, size_t info_len,
+                unsigned char *okm, size_t okm_len);
+static int HKDF_Extract(const EVP_MD *evp_md,
+                        const unsigned char *salt, size_t salt_len,
+                        const unsigned char *ikm, size_t ikm_len,
+                        unsigned char *prk, size_t prk_len);
+static int HKDF_Expand(const EVP_MD *evp_md,
+                       const unsigned char *prk, size_t prk_len,
+                       const unsigned char *info, size_t info_len,
+                       unsigned char *okm, size_t okm_len);
+
+typedef struct {
+    void *provctx;
+    int mode;
+    PROV_DIGEST digest;
+    unsigned char *salt;
+    size_t salt_len;
+    unsigned char *key;
+    size_t key_len;
+    unsigned char info[HKDF_MAXBUF];
+    size_t info_len;
+} KDF_HKDF;
+
+static void *kdf_hkdf_new(void *provctx)
+{
+    KDF_HKDF *ctx;
+
+    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
+        ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
+    else
+        ctx->provctx = provctx;
+    return ctx;
+}
+
+static void kdf_hkdf_free(void *vctx)
+{
+    KDF_HKDF *ctx = (KDF_HKDF *)vctx;
+
+    kdf_hkdf_reset(ctx);
+    OPENSSL_free(ctx);
+}
+
+static void kdf_hkdf_reset(void *vctx)
+{
+    KDF_HKDF *ctx = (KDF_HKDF *)vctx;
+
+    ossl_prov_digest_reset(&ctx->digest);
+    OPENSSL_free(ctx->salt);
+    OPENSSL_clear_free(ctx->key, ctx->key_len);
+    OPENSSL_cleanse(ctx->info, ctx->info_len);
+    memset(ctx, 0, sizeof(*ctx));
+}
+
+static size_t kdf_hkdf_size(KDF_HKDF *ctx)
+{
+    int sz;
+    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
+
+    if (ctx->mode != EVP_KDF_HKDF_MODE_EXTRACT_ONLY)
+        return SIZE_MAX;
+
+    if (md == NULL) {
+        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
+        return 0;
+    }
+    sz = EVP_MD_size(md);
+    if (sz < 0)
+        return 0;
+
+    return sz;
+}
+
+static int kdf_hkdf_derive(void *vctx, unsigned char *key, size_t keylen)
+{
+    KDF_HKDF *ctx = (KDF_HKDF *)vctx;
+    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
+
+    if (md == NULL) {
+        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
+        return 0;
+    }
+    if (ctx->key == NULL) {
+        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
+        return 0;
+    }
+
+    switch (ctx->mode) {
+    case EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND:
+        return HKDF(md, ctx->salt, ctx->salt_len, ctx->key,
+                    ctx->key_len, ctx->info, ctx->info_len, key,
+                    keylen);
+
+    case EVP_KDF_HKDF_MODE_EXTRACT_ONLY:
+        return HKDF_Extract(md, ctx->salt, ctx->salt_len, ctx->key,
+                            ctx->key_len, key, keylen);
+
+    case EVP_KDF_HKDF_MODE_EXPAND_ONLY:
+        return HKDF_Expand(md, ctx->key, ctx->key_len, ctx->info,
+                           ctx->info_len, key, keylen);
+
+    default:
+        return 0;
+    }
+}
+
+static int kdf_hkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
+{
+    const OSSL_PARAM *p;
+    KDF_HKDF *ctx = vctx;
+    OPENSSL_CTX *provctx = PROV_LIBRARY_CONTEXT_OF(ctx->provctx);
+    int n;
+
+    if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
+        return 0;
+
+    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE)) != NULL) {
+        if (p->data_type == OSSL_PARAM_UTF8_STRING) {
+            if (strcasecmp(p->data, "EXTRACT_AND_EXPAND") == 0) {
+                ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND;
+            } else if (strcasecmp(p->data, "EXTRACT_ONLY") == 0) {
+                ctx->mode = EVP_KDF_HKDF_MODE_EXTRACT_ONLY;
+            } else if (strcasecmp(p->data, "EXPAND_ONLY") == 0) {
+                ctx->mode = EVP_KDF_HKDF_MODE_EXPAND_ONLY;
+            } else {
+                ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
+                return 0;
+            }
+        } else if (OSSL_PARAM_get_int(p, &n)) {
+            if (n != EVP_KDF_HKDF_MODE_EXTRACT_AND_EXPAND
+                && n != EVP_KDF_HKDF_MODE_EXTRACT_ONLY
+                && n != EVP_KDF_HKDF_MODE_EXPAND_ONLY) {
+                ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
+                return 0;
+            }
+            ctx->mode = n;
+        } else {
+            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
+            return 0;
+        }
+    }
+
+    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) {
+        OPENSSL_clear_free(ctx->key, ctx->key_len);
+        ctx->key = NULL;
+        if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->key, 0,
+                                         &ctx->key_len))
+            return 0;
+    }
+
+    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL) {
+        if (p->data_size != 0 && p->data != NULL) {
+            OPENSSL_free(ctx->salt);
+            ctx->salt = NULL;
+            if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->salt, 0,
+                                             &ctx->salt_len))
+                return 0;
+        }
+    }
+    /* The info fields concatenate, so process them all */
+    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO)) != NULL) {
+        ctx->info_len = 0;
+        for (; p != NULL; p = OSSL_PARAM_locate_const(p + 1,
+                                                      OSSL_KDF_PARAM_INFO)) {
+            const void *q = ctx->info + ctx->info_len;
+            size_t sz = 0;
+
+            if (p->data_size != 0
+                && p->data != NULL
+                && !OSSL_PARAM_get_octet_string(p, (void **)&q,
+                                                HKDF_MAXBUF - ctx->info_len,
+                                                &sz))
+                return 0;
+            ctx->info_len += sz;
+        }
+    }
+    return 1;
+}
+
+static const OSSL_PARAM *kdf_hkdf_settable_ctx_params(void)
+{
+    static const OSSL_PARAM known_settable_ctx_params[] = {
+        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
+        OSSL_PARAM_int(OSSL_KDF_PARAM_MODE, NULL),
+        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
+        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
+        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
+        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
+        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
+        OSSL_PARAM_END
+    };
+    return known_settable_ctx_params;
+}
+
+static int kdf_hkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
+{
+    KDF_HKDF *ctx = (KDF_HKDF *)vctx;
+    OSSL_PARAM *p;
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
+        return OSSL_PARAM_set_size_t(p, kdf_hkdf_size(ctx));
+    return -2;
+}
+
+static const OSSL_PARAM *kdf_hkdf_gettable_ctx_params(void)
+{
+    static const OSSL_PARAM known_gettable_ctx_params[] = {
+        OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
+        OSSL_PARAM_END
+    };
+    return known_gettable_ctx_params;
+}
+
+const OSSL_DISPATCH kdf_hkdf_functions[] = {
+    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_hkdf_new },
+    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_hkdf_free },
+    { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_hkdf_reset },
+    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_hkdf_derive },
+    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
+      (void(*)(void))kdf_hkdf_settable_ctx_params },
+    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_hkdf_set_ctx_params },
+    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
+      (void(*)(void))kdf_hkdf_gettable_ctx_params },
+    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_hkdf_get_ctx_params },
+    { 0, NULL }
+};
+
+/*
+ * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
+ * Section 2 (https://tools.ietf.org/html/rfc5869#section-2) and
+ * "Cryptographic Extraction and Key Derivation: The HKDF Scheme"
+ * Section 4.2 (https://eprint.iacr.org/2010/264.pdf).
+ *
+ * From the paper:
+ *   The scheme HKDF is specified as:
+ *     HKDF(XTS, SKM, CTXinfo, L) = K(1) | K(2) | ... | K(t)
+ *
+ *     where:
+ *       SKM is source key material
+ *       XTS is extractor salt (which may be null or constant)
+ *       CTXinfo is context information (may be null)
+ *       L is the number of key bits to be produced by KDF
+ *       k is the output length in bits of the hash function used with HMAC
+ *       t = ceil(L/k)
+ *       the value K(t) is truncated to its first d = L mod k bits.
+ *
+ * From RFC 5869:
+ *   2.2.  Step 1: Extract
+ *     HKDF-Extract(salt, IKM) -> PRK
+ *   2.3.  Step 2: Expand
+ *     HKDF-Expand(PRK, info, L) -> OKM
+ */
+static int HKDF(const EVP_MD *evp_md,
+                const unsigned char *salt, size_t salt_len,
+                const unsigned char *ikm, size_t ikm_len,
+                const unsigned char *info, size_t info_len,
+                unsigned char *okm, size_t okm_len)
+{
+    unsigned char prk[EVP_MAX_MD_SIZE];
+    int ret, sz;
+    size_t prk_len;
+
+    sz = EVP_MD_size(evp_md);
+    if (sz < 0)
+        return 0;
+    prk_len = (size_t)sz;
+
+    /* Step 1: HKDF-Extract(salt, IKM) -> PRK */
+    if (!HKDF_Extract(evp_md, salt, salt_len, ikm, ikm_len, prk, prk_len))
+        return 0;
+
+    /* Step 2: HKDF-Expand(PRK, info, L) -> OKM */
+    ret = HKDF_Expand(evp_md, prk, prk_len, info, info_len, okm, okm_len);
+    OPENSSL_cleanse(prk, sizeof(prk));
+
+    return ret;
+}
+
+/*
+ * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
+ * Section 2.2 (https://tools.ietf.org/html/rfc5869#section-2.2).
+ *
+ * 2.2.  Step 1: Extract
+ *
+ *   HKDF-Extract(salt, IKM) -> PRK
+ *
+ *   Options:
+ *      Hash     a hash function; HashLen denotes the length of the
+ *               hash function output in octets
+ *
+ *   Inputs:
+ *      salt     optional salt value (a non-secret random value);
+ *               if not provided, it is set to a string of HashLen zeros.
+ *      IKM      input keying material
+ *
+ *   Output:
+ *      PRK      a pseudorandom key (of HashLen octets)
+ *
+ *   The output PRK is calculated as follows:
+ *
+ *   PRK = HMAC-Hash(salt, IKM)
+ */
+static int HKDF_Extract(const EVP_MD *evp_md,
+                        const unsigned char *salt, size_t salt_len,
+                        const unsigned char *ikm, size_t ikm_len,
+                        unsigned char *prk, size_t prk_len)
+{
+    int sz = EVP_MD_size(evp_md);
+
+    if (sz < 0)
+        return 0;
+    if (prk_len != (size_t)sz) {
+        ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_OUTPUT_BUFFER_SIZE);
+        return 0;
+    }
+    /* calc: PRK = HMAC-Hash(salt, IKM) */
+    return HMAC(evp_md, salt, salt_len, ikm, ikm_len, prk, NULL) != NULL;
+}
+
+/*
+ * Refer to "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)"
+ * Section 2.3 (https://tools.ietf.org/html/rfc5869#section-2.3).
+ *
+ * 2.3.  Step 2: Expand
+ *
+ *   HKDF-Expand(PRK, info, L) -> OKM
+ *
+ *   Options:
+ *      Hash     a hash function; HashLen denotes the length of the
+ *               hash function output in octets
+ *
+ *   Inputs:
+ *      PRK      a pseudorandom key of at least HashLen octets
+ *               (usually, the output from the extract step)
+ *      info     optional context and application specific information
+ *               (can be a zero-length string)
+ *      L        length of output keying material in octets
+ *               (<= 255*HashLen)
+ *
+ *   Output:
+ *      OKM      output keying material (of L octets)
+ *
+ *   The output OKM is calculated as follows:
+ *
+ *   N = ceil(L/HashLen)
+ *   T = T(1) | T(2) | T(3) | ... | T(N)
+ *   OKM = first L octets of T
+ *
+ *   where:
+ *   T(0) = empty string (zero length)
+ *   T(1) = HMAC-Hash(PRK, T(0) | info | 0x01)
+ *   T(2) = HMAC-Hash(PRK, T(1) | info | 0x02)
+ *   T(3) = HMAC-Hash(PRK, T(2) | info | 0x03)
+ *   ...
+ *
+ *   (where the constant concatenated to the end of each T(n) is a
+ *   single octet.)
+ */
+static int HKDF_Expand(const EVP_MD *evp_md,
+                       const unsigned char *prk, size_t prk_len,
+                       const unsigned char *info, size_t info_len,
+                       unsigned char *okm, size_t okm_len)
+{
+    HMAC_CTX *hmac;
+    int ret = 0, sz;
+    unsigned int i;
+    unsigned char prev[EVP_MAX_MD_SIZE];
+    size_t done_len = 0, dig_len, n;
+
+    sz = EVP_MD_size(evp_md);
+    if (sz <= 0)
+        return 0;
+    dig_len = (size_t)sz;
+
+    /* calc: N = ceil(L/HashLen) */
+    n = okm_len / dig_len;
+    if (okm_len % dig_len)
+        n++;
+
+    if (n > 255 || okm == NULL)
+        return 0;
+
+    if ((hmac = HMAC_CTX_new()) == NULL)
+        return 0;
+
+    if (!HMAC_Init_ex(hmac, prk, prk_len, evp_md, NULL))
+        goto err;
+
+    for (i = 1; i <= n; i++) {
+        size_t copy_len;
+        const unsigned char ctr = i;
+
+        /* calc: T(i) = HMAC-Hash(PRK, T(i - 1) | info | i) */
+        if (i > 1) {
+            if (!HMAC_Init_ex(hmac, NULL, 0, NULL, NULL))
+                goto err;
+
+            if (!HMAC_Update(hmac, prev, dig_len))
+                goto err;
+        }
+
+        if (!HMAC_Update(hmac, info, info_len))
+            goto err;
+
+        if (!HMAC_Update(hmac, &ctr, 1))
+            goto err;
+
+        if (!HMAC_Final(hmac, prev, NULL))
+            goto err;
+
+        copy_len = (done_len + dig_len > okm_len) ?
+                       okm_len - done_len :
+                       dig_len;
+
+        memcpy(okm + done_len, prev, copy_len);
+
+        done_len += copy_len;
+    }
+    ret = 1;
+
+ err:
+    OPENSSL_cleanse(prev, sizeof(prev));
+    HMAC_CTX_free(hmac);
+    return ret;
+}