/* * Copyright 1995-2020 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 #include #include "internal/cryptlib.h" #include #include #include "hmac_local.h" int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md, ENGINE *impl) { int rv = 0, reset = 0; int i, j; unsigned char pad[HMAC_MAX_MD_CBLOCK_SIZE]; unsigned int keytmp_length; unsigned char keytmp[HMAC_MAX_MD_CBLOCK_SIZE]; /* If we are changing MD then we must have a key */ if (md != NULL && md != ctx->md && (key == NULL || len < 0)) return 0; if (md != NULL) { ctx->md = md; } else if (ctx->md) { md = ctx->md; } else { return 0; } /* * The HMAC construction is not allowed to be used with the * extendable-output functions (XOF) shake128 and shake256. */ if ((EVP_MD_meth_get_flags(md) & EVP_MD_FLAG_XOF) != 0) return 0; if (key != NULL) { #ifdef OPENSSL_FIPS if (FIPS_mode() && !(EVP_MD_flags(md) & EVP_MD_FLAG_FIPS) && (!EVP_MD_CTX_test_flags(ctx->md_ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW) || !EVP_MD_CTX_test_flags(ctx->i_ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW) || !EVP_MD_CTX_test_flags(ctx->o_ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW))) goto err; #endif reset = 1; j = EVP_MD_block_size(md); if (!ossl_assert(j <= (int)sizeof(keytmp))) return 0; if (j < len) { if (!EVP_DigestInit_ex(ctx->md_ctx, md, impl) || !EVP_DigestUpdate(ctx->md_ctx, key, len) || !EVP_DigestFinal_ex(ctx->md_ctx, keytmp, &keytmp_length)) return 0; } else { if (len < 0 || len > (int)sizeof(keytmp)) return 0; memcpy(keytmp, key, len); keytmp_length = len; } if (keytmp_length != HMAC_MAX_MD_CBLOCK_SIZE) memset(&keytmp[keytmp_length], 0, HMAC_MAX_MD_CBLOCK_SIZE - keytmp_length); for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++) pad[i] = 0x36 ^ keytmp[i]; if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl) || !EVP_DigestUpdate(ctx->i_ctx, pad, EVP_MD_block_size(md))) goto err; for (i = 0; i < HMAC_MAX_MD_CBLOCK_SIZE; i++) pad[i] = 0x5c ^ keytmp[i]; if (!EVP_DigestInit_ex(ctx->o_ctx, md, impl) || !EVP_DigestUpdate(ctx->o_ctx, pad, EVP_MD_block_size(md))) goto err; } if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->i_ctx)) goto err; rv = 1; err: if (reset) { OPENSSL_cleanse(keytmp, sizeof(keytmp)); OPENSSL_cleanse(pad, sizeof(pad)); } return rv; } #if OPENSSL_API_COMPAT < 0x10100000L int HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md) { if (key && md) HMAC_CTX_reset(ctx); return HMAC_Init_ex(ctx, key, len, md, NULL); } #endif int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len) { if (!ctx->md) return 0; return EVP_DigestUpdate(ctx->md_ctx, data, len); } int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len) { unsigned int i; unsigned char buf[EVP_MAX_MD_SIZE]; if (!ctx->md) goto err; if (!EVP_DigestFinal_ex(ctx->md_ctx, buf, &i)) goto err; if (!EVP_MD_CTX_copy_ex(ctx->md_ctx, ctx->o_ctx)) goto err; if (!EVP_DigestUpdate(ctx->md_ctx, buf, i)) goto err; if (!EVP_DigestFinal_ex(ctx->md_ctx, md, len)) goto err; return 1; err: return 0; } size_t HMAC_size(const HMAC_CTX *ctx) { int size = EVP_MD_size((ctx)->md); return (size < 0) ? 0 : size; } HMAC_CTX *HMAC_CTX_new(void) { HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX)); if (ctx != NULL) { if (!HMAC_CTX_reset(ctx)) { HMAC_CTX_free(ctx); return NULL; } } return ctx; } static void hmac_ctx_cleanup(HMAC_CTX *ctx) { EVP_MD_CTX_reset(ctx->i_ctx); EVP_MD_CTX_reset(ctx->o_ctx); EVP_MD_CTX_reset(ctx->md_ctx); ctx->md = NULL; } void HMAC_CTX_free(HMAC_CTX *ctx) { if (ctx != NULL) { hmac_ctx_cleanup(ctx); EVP_MD_CTX_free(ctx->i_ctx); EVP_MD_CTX_free(ctx->o_ctx); EVP_MD_CTX_free(ctx->md_ctx); OPENSSL_free(ctx); } } static int hmac_ctx_alloc_mds(HMAC_CTX *ctx) { if (ctx->i_ctx == NULL) ctx->i_ctx = EVP_MD_CTX_new(); if (ctx->i_ctx == NULL) return 0; if (ctx->o_ctx == NULL) ctx->o_ctx = EVP_MD_CTX_new(); if (ctx->o_ctx == NULL) return 0; if (ctx->md_ctx == NULL) ctx->md_ctx = EVP_MD_CTX_new(); if (ctx->md_ctx == NULL) return 0; return 1; } int HMAC_CTX_reset(HMAC_CTX *ctx) { hmac_ctx_cleanup(ctx); if (!hmac_ctx_alloc_mds(ctx)) { hmac_ctx_cleanup(ctx); return 0; } return 1; } int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx) { if (!hmac_ctx_alloc_mds(dctx)) goto err; if (!EVP_MD_CTX_copy_ex(dctx->i_ctx, sctx->i_ctx)) goto err; if (!EVP_MD_CTX_copy_ex(dctx->o_ctx, sctx->o_ctx)) goto err; if (!EVP_MD_CTX_copy_ex(dctx->md_ctx, sctx->md_ctx)) goto err; dctx->md = sctx->md; return 1; err: hmac_ctx_cleanup(dctx); return 0; } unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d, size_t n, unsigned char *md, unsigned int *md_len) { HMAC_CTX *c = NULL; static unsigned char m[EVP_MAX_MD_SIZE]; static const unsigned char dummy_key[1] = {'\0'}; if (md == NULL) md = m; if ((c = HMAC_CTX_new()) == NULL) goto err; /* For HMAC_Init_ex, NULL key signals reuse. */ if (key == NULL && key_len == 0) { key = dummy_key; } if (!HMAC_Init_ex(c, key, key_len, evp_md, NULL)) goto err; if (!HMAC_Update(c, d, n)) goto err; if (!HMAC_Final(c, md, md_len)) goto err; HMAC_CTX_free(c); return md; err: HMAC_CTX_free(c); return NULL; } void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags) { EVP_MD_CTX_set_flags(ctx->i_ctx, flags); EVP_MD_CTX_set_flags(ctx->o_ctx, flags); EVP_MD_CTX_set_flags(ctx->md_ctx, flags); } const EVP_MD *HMAC_CTX_get_md(const HMAC_CTX *ctx) { return ctx->md; }