/src/openssl33/providers/implementations/kdfs/tls1_prf.c

Source
/*
 * Copyright 2016-2023 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
 */

/*
 * Refer to "The TLS Protocol Version 1.0" Section 5
 * (https://tools.ietf.org/html/rfc2246#section-5) and
 * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
 * (https://tools.ietf.org/html/rfc5246#section-5).
 *
 * For TLS v1.0 and TLS v1.1 the TLS PRF algorithm is given by:
 *
 *   PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
 *                              P_SHA-1(S2, label + seed)
 *
 * where P_MD5 and P_SHA-1 are defined by P_<hash>, below, and S1 and S2 are
 * two halves of the secret (with the possibility of one shared byte, in the
 * case where the length of the original secret is odd).  S1 is taken from the
 * first half of the secret, S2 from the second half.
 *
 * For TLS v1.2 the TLS PRF algorithm is given by:
 *
 *   PRF(secret, label, seed) = P_<hash>(secret, label + seed)
 *
 * where hash is SHA-256 for all cipher suites defined in RFC 5246 as well as
 * those published prior to TLS v1.2 while the TLS v1.2 protocol is in effect,
 * unless defined otherwise by the cipher suite.
 *
 * P_<hash> is an expansion function that uses a single hash function to expand
 * a secret and seed into an arbitrary quantity of output:
 *
 *   P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
 *                            HMAC_<hash>(secret, A(2) + seed) +
 *                            HMAC_<hash>(secret, A(3) + seed) + ...
 *
 * where + indicates concatenation.  P_<hash> can be iterated as many times as
 * is necessary to produce the required quantity of data.
 *
 * A(i) is defined as:
 *     A(0) = seed
 *     A(i) = HMAC_<hash>(secret, A(i-1))
 */

/*
 * Low level APIs (such as DH) are deprecated for public use, but still ok for
 * internal use.
 */
#include "internal/deprecated.h"

#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/kdf.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/proverr.h>
#include "internal/cryptlib.h"
#include "internal/numbers.h"
#include "crypto/evp.h"
#include "prov/provider_ctx.h"
#include "prov/providercommon.h"
#include "prov/implementations.h"
#include "prov/provider_util.h"
#include "prov/securitycheck.h"
#include "internal/e_os.h"
#include "internal/safe_math.h"

OSSL_SAFE_MATH_UNSIGNED(size_t, size_t)

static OSSL_FUNC_kdf_newctx_fn kdf_tls1_prf_new;
static OSSL_FUNC_kdf_dupctx_fn kdf_tls1_prf_dup;
static OSSL_FUNC_kdf_freectx_fn kdf_tls1_prf_free;
static OSSL_FUNC_kdf_reset_fn kdf_tls1_prf_reset;
static OSSL_FUNC_kdf_derive_fn kdf_tls1_prf_derive;
static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_tls1_prf_settable_ctx_params;
static OSSL_FUNC_kdf_set_ctx_params_fn kdf_tls1_prf_set_ctx_params;
static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_tls1_prf_gettable_ctx_params;
static OSSL_FUNC_kdf_get_ctx_params_fn kdf_tls1_prf_get_ctx_params;

static int tls1_prf_alg(EVP_MAC_CTX *mdctx, EVP_MAC_CTX *sha1ctx,
    const unsigned char *sec, size_t slen,
    const unsigned char *seed, size_t seed_len,
    unsigned char *out, size_t olen);

#define TLS_MD_MASTER_SECRET_CONST "\x6d\x61\x73\x74\x65\x72\x20\x73\x65\x63\x72\x65\x74"
#define TLS_MD_MASTER_SECRET_CONST_SIZE 13

/* TLS KDF kdf context structure */
typedef struct {
    void *provctx;

    /* MAC context for the main digest */
    EVP_MAC_CTX *P_hash;
    /* MAC context for SHA1 for the MD5/SHA-1 combined PRF */
    EVP_MAC_CTX *P_sha1;

    /* Secret value to use for PRF */
    unsigned char *sec;
    size_t seclen;
    /* Concatenated seed data */
    unsigned char *seed;
    size_t seedlen;
} TLS1_PRF;

static void *kdf_tls1_prf_new(void *provctx)
{
    TLS1_PRF *ctx;

    if (!ossl_prov_is_running())
        return NULL;

    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL)
        ctx->provctx = provctx;
    return ctx;
}

static void kdf_tls1_prf_free(void *vctx)
{
    TLS1_PRF *ctx = (TLS1_PRF *)vctx;

    if (ctx != NULL) {
        kdf_tls1_prf_reset(ctx);
        OPENSSL_free(ctx);
    }
}

static void kdf_tls1_prf_reset(void *vctx)
{
    TLS1_PRF *ctx = (TLS1_PRF *)vctx;
    void *provctx = ctx->provctx;

    EVP_MAC_CTX_free(ctx->P_hash);
    EVP_MAC_CTX_free(ctx->P_sha1);
    OPENSSL_clear_free(ctx->sec, ctx->seclen);
    OPENSSL_clear_free(ctx->seed, ctx->seedlen);
    memset(ctx, 0, sizeof(*ctx));
    ctx->provctx = provctx;
}

static void *kdf_tls1_prf_dup(void *vctx)
{
    const TLS1_PRF *src = (const TLS1_PRF *)vctx;
    TLS1_PRF *dest;

    dest = kdf_tls1_prf_new(src->provctx);
    if (dest != NULL) {
        if (src->P_hash != NULL
            && (dest->P_hash = EVP_MAC_CTX_dup(src->P_hash)) == NULL)
            goto err;
        if (src->P_sha1 != NULL
            && (dest->P_sha1 = EVP_MAC_CTX_dup(src->P_sha1)) == NULL)
            goto err;
        if (!ossl_prov_memdup(src->sec, src->seclen, &dest->sec, &dest->seclen))
            goto err;
        if (!ossl_prov_memdup(src->seed, src->seedlen, &dest->seed,
                &dest->seedlen))
            goto err;
    }
    return dest;

err:
    kdf_tls1_prf_free(dest);
    return NULL;
}

static int kdf_tls1_prf_derive(void *vctx, unsigned char *key, size_t keylen,
    const OSSL_PARAM params[])
{
    TLS1_PRF *ctx = (TLS1_PRF *)vctx;
    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);

    if (!ossl_prov_is_running() || !kdf_tls1_prf_set_ctx_params(ctx, params))
        return 0;

    if (ctx->P_hash == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }
    if (ctx->sec == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
        return 0;
    }
    if (ctx->seedlen == 0) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SEED);
        return 0;
    }
    if (keylen == 0) {
        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
        return 0;
    }

    /*
     * The seed buffer is prepended with a label.
     * If EMS mode is enforced then the label "master secret" is not allowed,
     * We do the check this way since the PRF is used for other purposes, as well
     * as "extended master secret".
     */
    if (ossl_tls1_prf_ems_check_enabled(libctx)) {
        if (ctx->seedlen >= TLS_MD_MASTER_SECRET_CONST_SIZE
            && memcmp(ctx->seed, TLS_MD_MASTER_SECRET_CONST,
                   TLS_MD_MASTER_SECRET_CONST_SIZE)
                == 0) {
            ERR_raise(ERR_LIB_PROV, PROV_R_EMS_NOT_ENABLED);
            return 0;
        }
    }

    return tls1_prf_alg(ctx->P_hash, ctx->P_sha1,
        ctx->sec, ctx->seclen,
        ctx->seed, ctx->seedlen,
        key, keylen);
}

static int kdf_tls1_prf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
    const OSSL_PARAM *p;
    TLS1_PRF *ctx = vctx;
    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);

    if (params == NULL)
        return 1;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) {
        if (OPENSSL_strcasecmp(p->data, SN_md5_sha1) == 0) {
            if (!ossl_prov_macctx_load_from_params(&ctx->P_hash, params,
                    OSSL_MAC_NAME_HMAC,
                    NULL, SN_md5, libctx)
                || !ossl_prov_macctx_load_from_params(&ctx->P_sha1, params,
                    OSSL_MAC_NAME_HMAC,
                    NULL, SN_sha1, libctx))
                return 0;
        } else {
            EVP_MAC_CTX_free(ctx->P_sha1);
            if (!ossl_prov_macctx_load_from_params(&ctx->P_hash, params,
                    OSSL_MAC_NAME_HMAC,
                    NULL, NULL, libctx))
                return 0;
        }
    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL) {
        OPENSSL_clear_free(ctx->sec, ctx->seclen);
        ctx->sec = NULL;
        if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->sec, 0, &ctx->seclen))
            return 0;
    }
    /* The seed fields concatenate, so process them all */
    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED)) != NULL) {
        for (; p != NULL; p = OSSL_PARAM_locate_const(p + 1,
                              OSSL_KDF_PARAM_SEED)) {
            if (p->data_size != 0 && p->data != NULL) {
                const void *val = NULL;
                size_t sz = 0;
                unsigned char *seed;
                size_t seedlen;
                int err = 0;

                if (!OSSL_PARAM_get_octet_string_ptr(p, &val, &sz))
                    return 0;

                seedlen = safe_add_size_t(ctx->seedlen, sz, &err);
                if (err)
                    return 0;

                seed = OPENSSL_clear_realloc(ctx->seed, ctx->seedlen, seedlen);
                if (!seed)
                    return 0;

                ctx->seed = seed;
                if (ossl_assert(sz != 0))
                    memcpy(ctx->seed + ctx->seedlen, val, sz);
                ctx->seedlen = seedlen;
            }
        }
    }
    return 1;
}

static const OSSL_PARAM *kdf_tls1_prf_settable_ctx_params(
    ossl_unused void *ctx, ossl_unused void *provctx)
{
    static const OSSL_PARAM known_settable_ctx_params[] = {
        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_SECRET, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
        OSSL_PARAM_END
    };
    return known_settable_ctx_params;
}

static int kdf_tls1_prf_get_ctx_params(void *vctx, OSSL_PARAM params[])
{
    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
        return OSSL_PARAM_set_size_t(p, SIZE_MAX);
    return -2;
}

static const OSSL_PARAM *kdf_tls1_prf_gettable_ctx_params(
    ossl_unused void *ctx, ossl_unused void *provctx)
{
    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 ossl_kdf_tls1_prf_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void (*)(void))kdf_tls1_prf_new },
    { OSSL_FUNC_KDF_DUPCTX, (void (*)(void))kdf_tls1_prf_dup },
    { OSSL_FUNC_KDF_FREECTX, (void (*)(void))kdf_tls1_prf_free },
    { OSSL_FUNC_KDF_RESET, (void (*)(void))kdf_tls1_prf_reset },
    { OSSL_FUNC_KDF_DERIVE, (void (*)(void))kdf_tls1_prf_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
        (void (*)(void))kdf_tls1_prf_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS,
        (void (*)(void))kdf_tls1_prf_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
        (void (*)(void))kdf_tls1_prf_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS,
        (void (*)(void))kdf_tls1_prf_get_ctx_params },
    OSSL_DISPATCH_END
};

/*
 * Refer to "The TLS Protocol Version 1.0" Section 5
 * (https://tools.ietf.org/html/rfc2246#section-5) and
 * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
 * (https://tools.ietf.org/html/rfc5246#section-5).
 *
 * P_<hash> is an expansion function that uses a single hash function to expand
 * a secret and seed into an arbitrary quantity of output:
 *
 *   P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
 *                            HMAC_<hash>(secret, A(2) + seed) +
 *                            HMAC_<hash>(secret, A(3) + seed) + ...
 *
 * where + indicates concatenation.  P_<hash> can be iterated as many times as
 * is necessary to produce the required quantity of data.
 *
 * A(i) is defined as:
 *     A(0) = seed
 *     A(i) = HMAC_<hash>(secret, A(i-1))
 */
static int tls1_prf_P_hash(EVP_MAC_CTX *ctx_init,
    const unsigned char *sec, size_t sec_len,
    const unsigned char *seed, size_t seed_len,
    unsigned char *out, size_t olen)
{
    size_t chunk;
    EVP_MAC_CTX *ctx = NULL, *ctx_Ai = NULL;
    unsigned char Ai[EVP_MAX_MD_SIZE];
    size_t Ai_len;
    int ret = 0;

    if (!EVP_MAC_init(ctx_init, sec, sec_len, NULL))
        goto err;
    chunk = EVP_MAC_CTX_get_mac_size(ctx_init);
    if (chunk == 0)
        goto err;
    /* A(0) = seed */
    ctx_Ai = EVP_MAC_CTX_dup(ctx_init);
    if (ctx_Ai == NULL)
        goto err;
    if (seed != NULL && !EVP_MAC_update(ctx_Ai, seed, seed_len))
        goto err;

    for (;;) {
        /* calc: A(i) = HMAC_<hash>(secret, A(i-1)) */
        if (!EVP_MAC_final(ctx_Ai, Ai, &Ai_len, sizeof(Ai)))
            goto err;
        EVP_MAC_CTX_free(ctx_Ai);
        ctx_Ai = NULL;

        /* calc next chunk: HMAC_<hash>(secret, A(i) + seed) */
        ctx = EVP_MAC_CTX_dup(ctx_init);
        if (ctx == NULL)
            goto err;
        if (!EVP_MAC_update(ctx, Ai, Ai_len))
            goto err;
        /* save state for calculating next A(i) value */
        if (olen > chunk) {
            ctx_Ai = EVP_MAC_CTX_dup(ctx);
            if (ctx_Ai == NULL)
                goto err;
        }
        if (seed != NULL && !EVP_MAC_update(ctx, seed, seed_len))
            goto err;
        if (olen <= chunk) {
            /* last chunk - use Ai as temp bounce buffer */
            if (!EVP_MAC_final(ctx, Ai, &Ai_len, sizeof(Ai)))
                goto err;
            memcpy(out, Ai, olen);
            break;
        }
        if (!EVP_MAC_final(ctx, out, NULL, olen))
            goto err;
        EVP_MAC_CTX_free(ctx);
        ctx = NULL;
        out += chunk;
        olen -= chunk;
    }
    ret = 1;
err:
    EVP_MAC_CTX_free(ctx);
    EVP_MAC_CTX_free(ctx_Ai);
    OPENSSL_cleanse(Ai, sizeof(Ai));
    return ret;
}

/*
 * Refer to "The TLS Protocol Version 1.0" Section 5
 * (https://tools.ietf.org/html/rfc2246#section-5) and
 * "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
 * (https://tools.ietf.org/html/rfc5246#section-5).
 *
 * For TLS v1.0 and TLS v1.1:
 *
 *   PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
 *                              P_SHA-1(S2, label + seed)
 *
 * S1 is taken from the first half of the secret, S2 from the second half.
 *
 *   L_S = length in bytes of secret;
 *   L_S1 = L_S2 = ceil(L_S / 2);
 *
 * For TLS v1.2:
 *
 *   PRF(secret, label, seed) = P_<hash>(secret, label + seed)
 */
static int tls1_prf_alg(EVP_MAC_CTX *mdctx, EVP_MAC_CTX *sha1ctx,
    const unsigned char *sec, size_t slen,
    const unsigned char *seed, size_t seed_len,
    unsigned char *out, size_t olen)
{
    if (sha1ctx != NULL) {
        /* TLS v1.0 and TLS v1.1 */
        size_t i;
        unsigned char *tmp;
        /* calc: L_S1 = L_S2 = ceil(L_S / 2) */
        size_t L_S1 = (slen + 1) / 2;
        size_t L_S2 = L_S1;

        if (!tls1_prf_P_hash(mdctx, sec, L_S1,
                seed, seed_len, out, olen))
            return 0;

        if ((tmp = OPENSSL_malloc(olen)) == NULL)
            return 0;

        if (!tls1_prf_P_hash(sha1ctx, sec + slen - L_S2, L_S2,
                seed, seed_len, tmp, olen)) {
            OPENSSL_clear_free(tmp, olen);
            return 0;
        }
        for (i = 0; i < olen; i++)
            out[i] ^= tmp[i];
        OPENSSL_clear_free(tmp, olen);
        return 1;
    }

    /* TLS v1.2 */
    if (!tls1_prf_P_hash(mdctx, sec, slen, seed, seed_len, out, olen))
        return 0;

    return 1;
}

Coverage Report

Created: 2025-12-31 06:58

Line	Count	Source
1		/*
2		* Copyright 2016-2023 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		/*
11		* Refer to "The TLS Protocol Version 1.0" Section 5
12		* (https://tools.ietf.org/html/rfc2246#section-5) and
13		* "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
14		* (https://tools.ietf.org/html/rfc5246#section-5).
15		*
16		* For TLS v1.0 and TLS v1.1 the TLS PRF algorithm is given by:
17		*
18		* PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
19		* P_SHA-1(S2, label + seed)
20		*
21		* where P_MD5 and P_SHA-1 are defined by P_<hash>, below, and S1 and S2 are
22		* two halves of the secret (with the possibility of one shared byte, in the
23		* case where the length of the original secret is odd). S1 is taken from the
24		* first half of the secret, S2 from the second half.
25		*
26		* For TLS v1.2 the TLS PRF algorithm is given by:
27		*
28		* PRF(secret, label, seed) = P_<hash>(secret, label + seed)
29		*
30		* where hash is SHA-256 for all cipher suites defined in RFC 5246 as well as
31		* those published prior to TLS v1.2 while the TLS v1.2 protocol is in effect,
32		* unless defined otherwise by the cipher suite.
33		*
34		* P_<hash> is an expansion function that uses a single hash function to expand
35		* a secret and seed into an arbitrary quantity of output:
36		*
37		* P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
38		* HMAC_<hash>(secret, A(2) + seed) +
39		* HMAC_<hash>(secret, A(3) + seed) + ...
40		*
41		* where + indicates concatenation. P_<hash> can be iterated as many times as
42		* is necessary to produce the required quantity of data.
43		*
44		* A(i) is defined as:
45		* A(0) = seed
46		* A(i) = HMAC_<hash>(secret, A(i-1))
47		*/
48
49		/*
50		* Low level APIs (such as DH) are deprecated for public use, but still ok for
51		* internal use.
52		*/
53		#include "internal/deprecated.h"
54
55		#include <stdio.h>
56		#include <stdarg.h>
57		#include <string.h>
58		#include <openssl/evp.h>
59		#include <openssl/kdf.h>
60		#include <openssl/core_names.h>
61		#include <openssl/params.h>
62		#include <openssl/proverr.h>
63		#include "internal/cryptlib.h"
64		#include "internal/numbers.h"
65		#include "crypto/evp.h"
66		#include "prov/provider_ctx.h"
67		#include "prov/providercommon.h"
68		#include "prov/implementations.h"
69		#include "prov/provider_util.h"
70		#include "prov/securitycheck.h"
71		#include "internal/e_os.h"
72		#include "internal/safe_math.h"
73
74		OSSL_SAFE_MATH_UNSIGNED(size_t, size_t)
75
76		static OSSL_FUNC_kdf_newctx_fn kdf_tls1_prf_new;
77		static OSSL_FUNC_kdf_dupctx_fn kdf_tls1_prf_dup;
78		static OSSL_FUNC_kdf_freectx_fn kdf_tls1_prf_free;
79		static OSSL_FUNC_kdf_reset_fn kdf_tls1_prf_reset;
80		static OSSL_FUNC_kdf_derive_fn kdf_tls1_prf_derive;
81		static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_tls1_prf_settable_ctx_params;
82		static OSSL_FUNC_kdf_set_ctx_params_fn kdf_tls1_prf_set_ctx_params;
83		static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_tls1_prf_gettable_ctx_params;
84		static OSSL_FUNC_kdf_get_ctx_params_fn kdf_tls1_prf_get_ctx_params;
85
86		static int tls1_prf_alg(EVP_MAC_CTX mdctx, EVP_MAC_CTX sha1ctx,
87		const unsigned char *sec, size_t slen,
88		const unsigned char *seed, size_t seed_len,
89		unsigned char *out, size_t olen);
90
91	0	#define TLS_MD_MASTER_SECRET_CONST "\x6d\x61\x73\x74\x65\x72\x20\x73\x65\x63\x72\x65\x74"
92	0	#define TLS_MD_MASTER_SECRET_CONST_SIZE 13
93
94		/* TLS KDF kdf context structure */
95		typedef struct {
96		void *provctx;
97
98		/* MAC context for the main digest */
99		EVP_MAC_CTX *P_hash;
100		/* MAC context for SHA1 for the MD5/SHA-1 combined PRF */
101		EVP_MAC_CTX *P_sha1;
102
103		/* Secret value to use for PRF */
104		unsigned char *sec;
105		size_t seclen;
106		/* Concatenated seed data */
107		unsigned char *seed;
108		size_t seedlen;
109		} TLS1_PRF;
110
111		static void kdf_tls1_prf_new(void provctx)
112	65.0k	{
113	65.0k	TLS1_PRF *ctx;
114
115	65.0k	if (!ossl_prov_is_running())
116	0	return NULL;
117
118	65.0k	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL)
119	65.0k	ctx->provctx = provctx;
120	65.0k	return ctx;
121	65.0k	}
122
123		static void kdf_tls1_prf_free(void *vctx)
124	70.4k	{
125	70.4k	TLS1_PRF ctx = (TLS1_PRF )vctx;
126
127	70.4k	if (ctx != NULL) {
128	70.4k	kdf_tls1_prf_reset(ctx);
129	70.4k	OPENSSL_free(ctx);
130	70.4k	}
131	70.4k	}
132
133		static void kdf_tls1_prf_reset(void *vctx)
134	70.4k	{
135	70.4k	TLS1_PRF ctx = (TLS1_PRF )vctx;
136	70.4k	void *provctx = ctx->provctx;
137
138	70.4k	EVP_MAC_CTX_free(ctx->P_hash);
139	70.4k	EVP_MAC_CTX_free(ctx->P_sha1);
140	70.4k	OPENSSL_clear_free(ctx->sec, ctx->seclen);
141	70.4k	OPENSSL_clear_free(ctx->seed, ctx->seedlen);
142	70.4k	memset(ctx, 0, sizeof(*ctx));
143	70.4k	ctx->provctx = provctx;
144	70.4k	}
145
146		static void kdf_tls1_prf_dup(void vctx)
147	0	{
148	0	const TLS1_PRF src = (const TLS1_PRF )vctx;
149	0	TLS1_PRF *dest;
150
151	0	dest = kdf_tls1_prf_new(src->provctx);
152	0	if (dest != NULL) {
153	0	if (src->P_hash != NULL
154	0	&& (dest->P_hash = EVP_MAC_CTX_dup(src->P_hash)) == NULL)
155	0	goto err;
156	0	if (src->P_sha1 != NULL
157	0	&& (dest->P_sha1 = EVP_MAC_CTX_dup(src->P_sha1)) == NULL)
158	0	goto err;
159	0	if (!ossl_prov_memdup(src->sec, src->seclen, &dest->sec, &dest->seclen))
160	0	goto err;
161	0	if (!ossl_prov_memdup(src->seed, src->seedlen, &dest->seed,
162	0	&dest->seedlen))
163	0	goto err;
164	0	}
165	0	return dest;
166
167	0	err:
168	0	kdf_tls1_prf_free(dest);
169	0	return NULL;
170	0	}
171
172		static int kdf_tls1_prf_derive(void vctx, unsigned char key, size_t keylen,
173		const OSSL_PARAM params[])
174	13.8k	{
175	13.8k	TLS1_PRF ctx = (TLS1_PRF )vctx;
176	13.8k	OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
177
178	13.8k	if (!ossl_prov_is_running() \|\| !kdf_tls1_prf_set_ctx_params(ctx, params))
179	0	return 0;
180
181	13.8k	if (ctx->P_hash == NULL) {
182	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
183	0	return 0;
184	0	}
185	13.8k	if (ctx->sec == NULL) {
186	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
187	0	return 0;
188	0	}
189	13.8k	if (ctx->seedlen == 0) {
190	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SEED);
191	0	return 0;
192	0	}
193	13.8k	if (keylen == 0) {
194	0	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
195	0	return 0;
196	0	}
197
198		/*
199		* The seed buffer is prepended with a label.
200		* If EMS mode is enforced then the label "master secret" is not allowed,
201		* We do the check this way since the PRF is used for other purposes, as well
202		* as "extended master secret".
203		*/
204	13.8k	if (ossl_tls1_prf_ems_check_enabled(libctx)) {
205	0	if (ctx->seedlen >= TLS_MD_MASTER_SECRET_CONST_SIZE
206	0	&& memcmp(ctx->seed, TLS_MD_MASTER_SECRET_CONST,
207	0	TLS_MD_MASTER_SECRET_CONST_SIZE)
208	0	== 0) {
209	0	ERR_raise(ERR_LIB_PROV, PROV_R_EMS_NOT_ENABLED);
210	0	return 0;
211	0	}
212	0	}
213
214	13.8k	return tls1_prf_alg(ctx->P_hash, ctx->P_sha1,
215	13.8k	ctx->sec, ctx->seclen,
216	13.8k	ctx->seed, ctx->seedlen,
217	13.8k	key, keylen);
218	13.8k	}
219
220		static int kdf_tls1_prf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
221	13.8k	{
222	13.8k	const OSSL_PARAM *p;
223	13.8k	TLS1_PRF *ctx = vctx;
224	13.8k	OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
225
226	13.8k	if (params == NULL)
227	0	return 1;
228
229	13.8k	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) {
230	13.8k	if (OPENSSL_strcasecmp(p->data, SN_md5_sha1) == 0) {
231	5.62k	if (!ossl_prov_macctx_load_from_params(&ctx->P_hash, params,
232	5.62k	OSSL_MAC_NAME_HMAC,
233	5.62k	NULL, SN_md5, libctx)
234	5.62k	\|\| !ossl_prov_macctx_load_from_params(&ctx->P_sha1, params,
235	5.62k	OSSL_MAC_NAME_HMAC,
236	5.62k	NULL, SN_sha1, libctx))
237	0	return 0;
238	8.21k	} else {
239	8.21k	EVP_MAC_CTX_free(ctx->P_sha1);
240	8.21k	if (!ossl_prov_macctx_load_from_params(&ctx->P_hash, params,
241	8.21k	OSSL_MAC_NAME_HMAC,
242	8.21k	NULL, NULL, libctx))
243	0	return 0;
244	8.21k	}
245	13.8k	}
246
247	13.8k	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL) {
248	13.8k	OPENSSL_clear_free(ctx->sec, ctx->seclen);
249	13.8k	ctx->sec = NULL;
250	13.8k	if (!OSSL_PARAM_get_octet_string(p, (void **)&ctx->sec, 0, &ctx->seclen))
251	0	return 0;
252	13.8k	}
253		/* The seed fields concatenate, so process them all */
254	13.8k	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED)) != NULL) {
255	83.0k	for (; p != NULL; p = OSSL_PARAM_locate_const(p + 1,
256	69.1k	OSSL_KDF_PARAM_SEED)) {
257	69.1k	if (p->data_size != 0 && p->data != NULL) {
258	37.6k	const void *val = NULL;
259	37.6k	size_t sz = 0;
260	37.6k	unsigned char *seed;
261	37.6k	size_t seedlen;
262	37.6k	int err = 0;
263
264	37.6k	if (!OSSL_PARAM_get_octet_string_ptr(p, &val, &sz))
265	0	return 0;
266
267	37.6k	seedlen = safe_add_size_t(ctx->seedlen, sz, &err);
268	37.6k	if (err)
269	0	return 0;
270
271	37.6k	seed = OPENSSL_clear_realloc(ctx->seed, ctx->seedlen, seedlen);
272	37.6k	if (!seed)
273	0	return 0;
274
275	37.6k	ctx->seed = seed;
276	37.6k	if (ossl_assert(sz != 0))
277	37.6k	memcpy(ctx->seed + ctx->seedlen, val, sz);
278	37.6k	ctx->seedlen = seedlen;
279	37.6k	}
280	69.1k	}
281	13.8k	}
282	13.8k	return 1;
283	13.8k	}
284
285		static const OSSL_PARAM *kdf_tls1_prf_settable_ctx_params(
286		ossl_unused void ctx, ossl_unused void provctx)
287	2.39k	{
288	2.39k	static const OSSL_PARAM known_settable_ctx_params[] = {
289	2.39k	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
290	2.39k	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
291	2.39k	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
292	2.39k	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
293	2.39k	OSSL_PARAM_END
294	2.39k	};
295	2.39k	return known_settable_ctx_params;
296	2.39k	}
297
298		static int kdf_tls1_prf_get_ctx_params(void *vctx, OSSL_PARAM params[])
299	0	{
300	0	OSSL_PARAM *p;
301
302	0	if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
303	0	return OSSL_PARAM_set_size_t(p, SIZE_MAX);
304	0	return -2;
305	0	}
306
307		static const OSSL_PARAM *kdf_tls1_prf_gettable_ctx_params(
308		ossl_unused void ctx, ossl_unused void provctx)
309	0	{
310	0	static const OSSL_PARAM known_gettable_ctx_params[] = {
311	0	OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
312	0	OSSL_PARAM_END
313	0	};
314	0	return known_gettable_ctx_params;
315	0	}
316
317		const OSSL_DISPATCH ossl_kdf_tls1_prf_functions[] = {
318		{ OSSL_FUNC_KDF_NEWCTX, (void (*)(void))kdf_tls1_prf_new },
319		{ OSSL_FUNC_KDF_DUPCTX, (void (*)(void))kdf_tls1_prf_dup },
320		{ OSSL_FUNC_KDF_FREECTX, (void (*)(void))kdf_tls1_prf_free },
321		{ OSSL_FUNC_KDF_RESET, (void (*)(void))kdf_tls1_prf_reset },
322		{ OSSL_FUNC_KDF_DERIVE, (void (*)(void))kdf_tls1_prf_derive },
323		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
324		(void (*)(void))kdf_tls1_prf_settable_ctx_params },
325		{ OSSL_FUNC_KDF_SET_CTX_PARAMS,
326		(void (*)(void))kdf_tls1_prf_set_ctx_params },
327		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
328		(void (*)(void))kdf_tls1_prf_gettable_ctx_params },
329		{ OSSL_FUNC_KDF_GET_CTX_PARAMS,
330		(void (*)(void))kdf_tls1_prf_get_ctx_params },
331		OSSL_DISPATCH_END
332		};
333
334		/*
335		* Refer to "The TLS Protocol Version 1.0" Section 5
336		* (https://tools.ietf.org/html/rfc2246#section-5) and
337		* "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
338		* (https://tools.ietf.org/html/rfc5246#section-5).
339		*
340		* P_<hash> is an expansion function that uses a single hash function to expand
341		* a secret and seed into an arbitrary quantity of output:
342		*
343		* P_<hash>(secret, seed) = HMAC_<hash>(secret, A(1) + seed) +
344		* HMAC_<hash>(secret, A(2) + seed) +
345		* HMAC_<hash>(secret, A(3) + seed) + ...
346		*
347		* where + indicates concatenation. P_<hash> can be iterated as many times as
348		* is necessary to produce the required quantity of data.
349		*
350		* A(i) is defined as:
351		* A(0) = seed
352		* A(i) = HMAC_<hash>(secret, A(i-1))
353		*/
354		static int tls1_prf_P_hash(EVP_MAC_CTX *ctx_init,
355		const unsigned char *sec, size_t sec_len,
356		const unsigned char *seed, size_t seed_len,
357		unsigned char *out, size_t olen)
358	90.1k	{
359	90.1k	size_t chunk;
360	90.1k	EVP_MAC_CTX ctx = NULL, ctx_Ai = NULL;
361	90.1k	unsigned char Ai[EVP_MAX_MD_SIZE];
362	90.1k	size_t Ai_len;
363	90.1k	int ret = 0;
364
365	90.1k	if (!EVP_MAC_init(ctx_init, sec, sec_len, NULL))
366	0	goto err;
367	90.1k	chunk = EVP_MAC_CTX_get_mac_size(ctx_init);
368	90.1k	if (chunk == 0)
369	10	goto err;
370		/* A(0) = seed */
371	90.1k	ctx_Ai = EVP_MAC_CTX_dup(ctx_init);
372	90.1k	if (ctx_Ai == NULL)
373	0	goto err;
374	90.1k	if (seed != NULL && !EVP_MAC_update(ctx_Ai, seed, seed_len))
375	0	goto err;
376
377	238k	for (;;) {
378		/* calc: A(i) = HMAC_<hash>(secret, A(i-1)) */
379	238k	if (!EVP_MAC_final(ctx_Ai, Ai, &Ai_len, sizeof(Ai)))
380	0	goto err;
381	238k	EVP_MAC_CTX_free(ctx_Ai);
382	238k	ctx_Ai = NULL;
383
384		/* calc next chunk: HMAC_<hash>(secret, A(i) + seed) */
385	238k	ctx = EVP_MAC_CTX_dup(ctx_init);
386	238k	if (ctx == NULL)
387	0	goto err;
388	238k	if (!EVP_MAC_update(ctx, Ai, Ai_len))
389	0	goto err;
390		/* save state for calculating next A(i) value */
391	238k	if (olen > chunk) {
392	147k	ctx_Ai = EVP_MAC_CTX_dup(ctx);
393	147k	if (ctx_Ai == NULL)
394	0	goto err;
395	147k	}
396	238k	if (seed != NULL && !EVP_MAC_update(ctx, seed, seed_len))
397	0	goto err;
398	238k	if (olen <= chunk) {
399		/* last chunk - use Ai as temp bounce buffer */
400	90.1k	if (!EVP_MAC_final(ctx, Ai, &Ai_len, sizeof(Ai)))
401	0	goto err;
402	90.1k	memcpy(out, Ai, olen);
403	90.1k	break;
404	90.1k	}
405	147k	if (!EVP_MAC_final(ctx, out, NULL, olen))
406	0	goto err;
407	147k	EVP_MAC_CTX_free(ctx);
408	147k	ctx = NULL;
409	147k	out += chunk;
410	147k	olen -= chunk;
411	147k	}
412	90.1k	ret = 1;
413	90.1k	err:
414	90.1k	EVP_MAC_CTX_free(ctx);
415	90.1k	EVP_MAC_CTX_free(ctx_Ai);
416	90.1k	OPENSSL_cleanse(Ai, sizeof(Ai));
417	90.1k	return ret;
418	90.1k	}
419
420		/*
421		* Refer to "The TLS Protocol Version 1.0" Section 5
422		* (https://tools.ietf.org/html/rfc2246#section-5) and
423		* "The Transport Layer Security (TLS) Protocol Version 1.2" Section 5
424		* (https://tools.ietf.org/html/rfc5246#section-5).
425		*
426		* For TLS v1.0 and TLS v1.1:
427		*
428		* PRF(secret, label, seed) = P_MD5(S1, label + seed) XOR
429		* P_SHA-1(S2, label + seed)
430		*
431		* S1 is taken from the first half of the secret, S2 from the second half.
432		*
433		* L_S = length in bytes of secret;
434		* L_S1 = L_S2 = ceil(L_S / 2);
435		*
436		* For TLS v1.2:
437		*
438		* PRF(secret, label, seed) = P_<hash>(secret, label + seed)
439		*/
440		static int tls1_prf_alg(EVP_MAC_CTX mdctx, EVP_MAC_CTX sha1ctx,
441		const unsigned char *sec, size_t slen,
442		const unsigned char *seed, size_t seed_len,
443		unsigned char *out, size_t olen)
444	68.6k	{
445	68.6k	if (sha1ctx != NULL) {
446		/* TLS v1.0 and TLS v1.1 */
447	21.5k	size_t i;
448	21.5k	unsigned char *tmp;
449		/* calc: L_S1 = L_S2 = ceil(L_S / 2) */
450	21.5k	size_t L_S1 = (slen + 1) / 2;
451	21.5k	size_t L_S2 = L_S1;
452
453	21.5k	if (!tls1_prf_P_hash(mdctx, sec, L_S1,
454	21.5k	seed, seed_len, out, olen))
455	0	return 0;
456
457	21.5k	if ((tmp = OPENSSL_malloc(olen)) == NULL)
458	0	return 0;
459
460	21.5k	if (!tls1_prf_P_hash(sha1ctx, sec + slen - L_S2, L_S2,
461	21.5k	seed, seed_len, tmp, olen)) {
462	0	OPENSSL_clear_free(tmp, olen);
463	0	return 0;
464	0	}
465	1.17M	for (i = 0; i < olen; i++)
466	1.14M	out[i] ^= tmp[i];
467	21.5k	OPENSSL_clear_free(tmp, olen);
468	21.5k	return 1;
469	21.5k	}
470
471		/* TLS v1.2 */
472	47.1k	if (!tls1_prf_P_hash(mdctx, sec, slen, seed, seed_len, out, olen))
473	10	return 0;
474
475	47.0k	return 1;
476	47.1k	}