/* * Copyright 2016 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 #include "internal/cryptlib.h" #include #include #include "internal/evp_int.h" static int tls1_prf_alg(const EVP_MD *md, const unsigned char *sec, size_t slen, const unsigned char *seed, size_t seed_len, unsigned char *out, size_t olen); #define TLS1_PRF_MAXBUF 1024 /* TLS KDF pkey context structure */ typedef struct { /* Digest to use for PRF */ const EVP_MD *md; /* Secret value to use for PRF */ unsigned char *sec; size_t seclen; /* Buffer of concatenated seed data */ unsigned char seed[TLS1_PRF_MAXBUF]; size_t seedlen; } TLS1_PRF_PKEY_CTX; static int pkey_tls1_prf_init(EVP_PKEY_CTX *ctx) { TLS1_PRF_PKEY_CTX *kctx; kctx = OPENSSL_zalloc(sizeof(*kctx)); if (kctx == NULL) return 0; ctx->data = kctx; return 1; } static void pkey_tls1_prf_cleanup(EVP_PKEY_CTX *ctx) { TLS1_PRF_PKEY_CTX *kctx = ctx->data; OPENSSL_clear_free(kctx->sec, kctx->seclen); OPENSSL_cleanse(kctx->seed, kctx->seedlen); OPENSSL_free(kctx); } static int pkey_tls1_prf_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) { TLS1_PRF_PKEY_CTX *kctx = ctx->data; switch (type) { case EVP_PKEY_CTRL_TLS_MD: kctx->md = p2; return 1; case EVP_PKEY_CTRL_TLS_SECRET: if (p1 < 0) return 0; if (kctx->sec != NULL) OPENSSL_clear_free(kctx->sec, kctx->seclen); OPENSSL_cleanse(kctx->seed, kctx->seedlen); kctx->seedlen = 0; kctx->sec = OPENSSL_memdup(p2, p1); if (kctx->sec == NULL) return 0; kctx->seclen = p1; return 1; case EVP_PKEY_CTRL_TLS_SEED: if (p1 == 0 || p2 == NULL) return 1; if (p1 < 0 || p1 > (int)(TLS1_PRF_MAXBUF - kctx->seedlen)) return 0; memcpy(kctx->seed + kctx->seedlen, p2, p1); kctx->seedlen += p1; return 1; default: return -2; } } static int pkey_tls1_prf_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value) { if (value == NULL) { KDFerr(KDF_F_PKEY_TLS1_PRF_CTRL_STR, KDF_R_VALUE_MISSING); return 0; } if (strcmp(type, "md") == 0) { TLS1_PRF_PKEY_CTX *kctx = ctx->data; const EVP_MD *md = EVP_get_digestbyname(value); if (md == NULL) { KDFerr(KDF_F_PKEY_TLS1_PRF_CTRL_STR, KDF_R_INVALID_DIGEST); return 0; } kctx->md = md; return 1; } if (strcmp(type, "secret") == 0) return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_TLS_SECRET, value); if (strcmp(type, "hexsecret") == 0) return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_TLS_SECRET, value); if (strcmp(type, "seed") == 0) return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_TLS_SEED, value); if (strcmp(type, "hexseed") == 0) return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_TLS_SEED, value); return -2; } static int pkey_tls1_prf_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen) { TLS1_PRF_PKEY_CTX *kctx = ctx->data; if (kctx->md == NULL || kctx->sec == NULL || kctx->seedlen == 0) { KDFerr(KDF_F_PKEY_TLS1_PRF_DERIVE, KDF_R_MISSING_PARAMETER); return 0; } return tls1_prf_alg(kctx->md, kctx->sec, kctx->seclen, kctx->seed, kctx->seedlen, key, *keylen); } const EVP_PKEY_METHOD tls1_prf_pkey_meth = { EVP_PKEY_TLS1_PRF, 0, pkey_tls1_prf_init, 0, pkey_tls1_prf_cleanup, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, pkey_tls1_prf_derive, pkey_tls1_prf_ctrl, pkey_tls1_prf_ctrl_str }; static int tls1_prf_P_hash(const EVP_MD *md, const unsigned char *sec, size_t sec_len, const unsigned char *seed, size_t seed_len, unsigned char *out, size_t olen) { int chunk; EVP_MD_CTX *ctx = NULL, *ctx_tmp = NULL, *ctx_init = NULL; EVP_PKEY *mac_key = NULL; unsigned char A1[EVP_MAX_MD_SIZE]; size_t A1_len; int ret = 0; chunk = EVP_MD_size(md); OPENSSL_assert(chunk >= 0); ctx = EVP_MD_CTX_new(); ctx_tmp = EVP_MD_CTX_new(); ctx_init = EVP_MD_CTX_new(); if (ctx == NULL || ctx_tmp == NULL || ctx_init == NULL) goto err; EVP_MD_CTX_set_flags(ctx_init, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW); mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, sec, sec_len); if (mac_key == NULL) goto err; if (!EVP_DigestSignInit(ctx_init, NULL, md, NULL, mac_key)) goto err; if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)) goto err; if (seed != NULL && !EVP_DigestSignUpdate(ctx, seed, seed_len)) goto err; if (!EVP_DigestSignFinal(ctx, A1, &A1_len)) goto err; for (;;) { /* Reinit mac contexts */ if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)) goto err; if (!EVP_DigestSignUpdate(ctx, A1, A1_len)) goto err; if (olen > (size_t)chunk && !EVP_MD_CTX_copy_ex(ctx_tmp, ctx)) goto err; if (seed && !EVP_DigestSignUpdate(ctx, seed, seed_len)) goto err; if (olen > (size_t)chunk) { size_t mac_len; if (!EVP_DigestSignFinal(ctx, out, &mac_len)) goto err; out += mac_len; olen -= mac_len; /* calc the next A1 value */ if (!EVP_DigestSignFinal(ctx_tmp, A1, &A1_len)) goto err; } else { /* last one */ if (!EVP_DigestSignFinal(ctx, A1, &A1_len)) goto err; memcpy(out, A1, olen); break; } } ret = 1; err: EVP_PKEY_free(mac_key); EVP_MD_CTX_free(ctx); EVP_MD_CTX_free(ctx_tmp); EVP_MD_CTX_free(ctx_init); OPENSSL_cleanse(A1, sizeof(A1)); return ret; } static int tls1_prf_alg(const EVP_MD *md, const unsigned char *sec, size_t slen, const unsigned char *seed, size_t seed_len, unsigned char *out, size_t olen) { if (EVP_MD_type(md) == NID_md5_sha1) { size_t i; unsigned char *tmp; if (!tls1_prf_P_hash(EVP_md5(), sec, slen/2 + (slen & 1), seed, seed_len, out, olen)) return 0; tmp = OPENSSL_malloc(olen); if (tmp == NULL) return 0; if (!tls1_prf_P_hash(EVP_sha1(), sec + slen/2, slen/2 + (slen & 1), 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; } if (!tls1_prf_P_hash(md, sec, slen, seed, seed_len, out, olen)) return 0; return 1; }