EVP_DIGESTINIT(3SSL) | OpenSSL | EVP_DIGESTINIT(3SSL) |
EVP_MD_fetch, EVP_MD_up_ref, EVP_MD_free, EVP_MD_get_params, EVP_MD_gettable_params, EVP_MD_CTX_new, EVP_MD_CTX_reset, EVP_MD_CTX_free, EVP_MD_CTX_copy, EVP_MD_CTX_copy_ex, EVP_MD_CTX_ctrl, EVP_MD_CTX_set_params, EVP_MD_CTX_get_params, EVP_MD_settable_ctx_params, EVP_MD_gettable_ctx_params, EVP_MD_CTX_settable_params, EVP_MD_CTX_gettable_params, EVP_MD_CTX_set_flags, EVP_MD_CTX_clear_flags, EVP_MD_CTX_test_flags, EVP_Q_digest, EVP_Digest, EVP_DigestInit_ex2, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate, EVP_DigestFinal_ex, EVP_DigestFinalXOF, EVP_DigestFinal, EVP_MD_is_a, EVP_MD_get0_name, EVP_MD_get0_description, EVP_MD_names_do_all, EVP_MD_get0_provider, EVP_MD_get_type, EVP_MD_get_pkey_type, EVP_MD_get_size, EVP_MD_get_block_size, EVP_MD_get_flags, EVP_MD_CTX_get0_name, EVP_MD_CTX_md, EVP_MD_CTX_get0_md, EVP_MD_CTX_get1_md, EVP_MD_CTX_get_type, EVP_MD_CTX_get_size, EVP_MD_CTX_get_block_size, EVP_MD_CTX_get0_md_data, EVP_MD_CTX_update_fn, EVP_MD_CTX_set_update_fn, EVP_md_null, EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj, EVP_MD_CTX_get_pkey_ctx, EVP_MD_CTX_set_pkey_ctx, EVP_MD_do_all_provided, EVP_MD_type, EVP_MD_nid, EVP_MD_name, EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_flags, EVP_MD_CTX_size, EVP_MD_CTX_block_size, EVP_MD_CTX_type, EVP_MD_CTX_pkey_ctx, EVP_MD_CTX_md_data - EVP digest routines
#include <openssl/evp.h> EVP_MD *EVP_MD_fetch(OSSL_LIB_CTX *ctx, const char *algorithm, const char *properties); int EVP_MD_up_ref(EVP_MD *md); void EVP_MD_free(EVP_MD *md); int EVP_MD_get_params(const EVP_MD *digest, OSSL_PARAM params[]); const OSSL_PARAM *EVP_MD_gettable_params(const EVP_MD *digest); EVP_MD_CTX *EVP_MD_CTX_new(void); int EVP_MD_CTX_reset(EVP_MD_CTX *ctx); void EVP_MD_CTX_free(EVP_MD_CTX *ctx); void EVP_MD_CTX_ctrl(EVP_MD_CTX *ctx, int cmd, int p1, void* p2); int EVP_MD_CTX_get_params(EVP_MD_CTX *ctx, OSSL_PARAM params[]); int EVP_MD_CTX_set_params(EVP_MD_CTX *ctx, const OSSL_PARAM params[]); const OSSL_PARAM *EVP_MD_settable_ctx_params(const EVP_MD *md); const OSSL_PARAM *EVP_MD_gettable_ctx_params(const EVP_MD *md); const OSSL_PARAM *EVP_MD_CTX_settable_params(EVP_MD_CTX *ctx); const OSSL_PARAM *EVP_MD_CTX_gettable_params(EVP_MD_CTX *ctx); void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, int flags); void EVP_MD_CTX_clear_flags(EVP_MD_CTX *ctx, int flags); int EVP_MD_CTX_test_flags(const EVP_MD_CTX *ctx, int flags); int EVP_Q_digest(OSSL_LIB_CTX *libctx, const char *name, const char *propq, const void *data, size_t datalen, unsigned char *md, size_t *mdlen); int EVP_Digest(const void *data, size_t count, unsigned char *md, unsigned int *size, const EVP_MD *type, ENGINE *impl); int EVP_DigestInit_ex2(EVP_MD_CTX *ctx, const EVP_MD *type, const OSSL_PARAM params[]); int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s); int EVP_DigestFinalXOF(EVP_MD_CTX *ctx, unsigned char *md, size_t len); int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in); int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type); int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *s); int EVP_MD_CTX_copy(EVP_MD_CTX *out, EVP_MD_CTX *in); const char *EVP_MD_get0_name(const EVP_MD *md); const char *EVP_MD_get0_description(const EVP_MD *md); int EVP_MD_is_a(const EVP_MD *md, const char *name); int EVP_MD_names_do_all(const EVP_MD *md, void (*fn)(const char *name, void *data), void *data); const OSSL_PROVIDER *EVP_MD_get0_provider(const EVP_MD *md); int EVP_MD_get_type(const EVP_MD *md); int EVP_MD_get_pkey_type(const EVP_MD *md); int EVP_MD_get_size(const EVP_MD *md); int EVP_MD_get_block_size(const EVP_MD *md); unsigned long EVP_MD_get_flags(const EVP_MD *md); const EVP_MD *EVP_MD_CTX_get0_md(const EVP_MD_CTX *ctx); EVP_MD *EVP_MD_CTX_get1_md(EVP_MD_CTX *ctx); const char *EVP_MD_CTX_get0_name(const EVP_MD_CTX *ctx); int EVP_MD_CTX_get_size(const EVP_MD_CTX *ctx); int EVP_MD_CTX_get_block_size(const EVP_MD_CTX *ctx); int EVP_MD_CTX_get_type(const EVP_MD_CTX *ctx); void *EVP_MD_CTX_get0_md_data(const EVP_MD_CTX *ctx); const EVP_MD *EVP_md_null(void); const EVP_MD *EVP_get_digestbyname(const char *name); const EVP_MD *EVP_get_digestbynid(int type); const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *o); EVP_PKEY_CTX *EVP_MD_CTX_get_pkey_ctx(const EVP_MD_CTX *ctx); void EVP_MD_CTX_set_pkey_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pctx); void EVP_MD_do_all_provided(OSSL_LIB_CTX *libctx, void (*fn)(EVP_MD *mac, void *arg), void *arg); #define EVP_MD_type EVP_MD_get_type #define EVP_MD_nid EVP_MD_get_type #define EVP_MD_name EVP_MD_get0_name #define EVP_MD_pkey_type EVP_MD_get_pkey_type #define EVP_MD_size EVP_MD_get_size #define EVP_MD_block_size EVP_MD_get_block_size #define EVP_MD_flags EVP_MD_get_flags #define EVP_MD_CTX_size EVP_MD_CTX_get_size #define EVP_MD_CTX_block_size EVP_MD_CTX_get_block_size #define EVP_MD_CTX_type EVP_MD_CTX_get_type #define EVP_MD_CTX_pkey_ctx EVP_MD_CTX_get_pkey_ctx #define EVP_MD_CTX_md_data EVP_MD_CTX_get0_md_data
The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):
const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx); int (*EVP_MD_CTX_update_fn(EVP_MD_CTX *ctx))(EVP_MD_CTX *ctx, const void *data, size_t count); void EVP_MD_CTX_set_update_fn(EVP_MD_CTX *ctx, int (*update)(EVP_MD_CTX *ctx, const void *data, size_t count));
The EVP digest routines are a high-level interface to message digests, and should be used instead of the digest-specific functions.
The EVP_MD type is a structure for digest method implementation.
The returned value must eventually be freed with EVP_MD_free().
Fetched EVP_MD structures are reference counted.
Performs digest-specific control actions on context ctx. The control command is indicated in cmd and any additional arguments in p1 and p2. EVP_MD_CTX_ctrl() must be called after EVP_DigestInit_ex2(). Other restrictions may apply depending on the control type and digest implementation.
If this function happens to be used with a fetched EVP_MD, it will translate the controls that are known to OpenSSL into OSSL_PARAM(3) parameters with keys defined by OpenSSL and call EVP_MD_CTX_get_params() or EVP_MD_CTX_set_params() as is appropriate for each control command.
See "CONTROLS" below for more information, including what translations are being done.
The parameters params are set on the context after initialisation.
The type parameter can be NULL if ctx has been already initialized with another EVP_DigestInit_ex() call and has not been reset with EVP_MD_CTX_reset().
If impl is non-NULL, its implementation of the digest type is used if there is one, and if not, the default implementation is used.
The type parameter can be NULL if ctx has been already initialized with another EVP_DigestInit_ex() call and has not been reset with EVP_MD_CTX_reset().
If md is a legacy digest (it's the return value from the likes of EVP_sha256() rather than the result of an EVP_MD_fetch()), only cipher names registered with the default library context (see OSSL_LIB_CTX(3)) will be considered.
The EVP_get_digestbyname() function is present for backwards compatibility with OpenSSL prior to version 3 and is different to the EVP_MD_fetch() function since it does not attempt to "fetch" an implementation of the cipher. Additionally, it only knows about digests that are built-in to OpenSSL and have an associated NID. Similarly EVP_get_digestbynid() and EVP_get_digestbyobj() also return objects without an associated implementation.
When the digest objects returned by these functions are used (such as in a call to EVP_DigestInit_ex()) an implementation of the digest will be implicitly fetched from the loaded providers. This fetch could fail if no suitable implementation is available. Use EVP_MD_fetch() instead to explicitly fetch the algorithm and an associated implementation from a provider.
See "ALGORITHM FETCHING" in crypto(7) for more information about fetching.
The digest objects returned from these functions do not need to be freed with EVP_MD_free().
See OSSL_PARAM(3) for information about passing parameters.
EVP_MD_CTX_set_params() can be used with the following OSSL_PARAM keys:
EVP_MD_CTX_get_params() can be used with the following OSSL_PARAM keys:
EVP_MD_CTX_ctrl() can be used to send the following standard controls:
When used with a fetched EVP_MD, EVP_MD_CTX_get_params() gets called with an OSSL_PARAM(3) item with the key "micalg" (OSSL_DIGEST_PARAM_MICALG).
When used with a fetched EVP_MD, EVP_MD_CTX_get_params() gets called with an OSSL_PARAM(3) item with the key "xoflen" (OSSL_DIGEST_PARAM_XOFLEN).
EVP_MD_CTX_set_flags(), EVP_MD_CTX_clear_flags() and EVP_MD_CTX_test_flags() can be used the manipulate and test these EVP_MD_CTX flags:
The EVP interface to message digests should almost always be used in preference to the low-level interfaces. This is because the code then becomes transparent to the digest used and much more flexible.
New applications should use the SHA-2 (such as EVP_sha256(3)) or the SHA-3 digest algorithms (such as EVP_sha3_512(3)). The other digest algorithms are still in common use.
For most applications the impl parameter to EVP_DigestInit_ex() will be set to NULL to use the default digest implementation.
Ignoring failure returns of EVP_DigestInit_ex(), EVP_DigestInit_ex2(), or EVP_DigestInit() can lead to undefined behavior on subsequent calls updating or finalizing the EVP_MD_CTX such as the EVP_DigestUpdate() or EVP_DigestFinal() functions. The only valid calls on the EVP_MD_CTX when initialization fails are calls that attempt another initialization of the context or release the context.
The functions EVP_DigestInit(), EVP_DigestFinal() and EVP_MD_CTX_copy() are obsolete but are retained to maintain compatibility with existing code. New applications should use EVP_DigestInit_ex(), EVP_DigestFinal_ex() and EVP_MD_CTX_copy_ex() because they can efficiently reuse a digest context instead of initializing and cleaning it up on each call and allow non default implementations of digests to be specified.
If digest contexts are not cleaned up after use, memory leaks will occur.
EVP_MD_CTX_get0_name(), EVP_MD_CTX_get_size(), EVP_MD_CTX_get_block_size(), EVP_MD_CTX_get_type(), EVP_get_digestbynid() and EVP_get_digestbyobj() are defined as macros.
EVP_MD_CTX_ctrl() sends commands to message digests for additional configuration or control.
This example digests the data "Test Message\n" and "Hello World\n", using the digest name passed on the command line.
#include <stdio.h> #include <string.h> #include <openssl/evp.h> int main(int argc, char *argv[]) { EVP_MD_CTX *mdctx; const EVP_MD *md; char mess1[] = "Test Message\n"; char mess2[] = "Hello World\n"; unsigned char md_value[EVP_MAX_MD_SIZE]; unsigned int md_len, i; if (argv[1] == NULL) { printf("Usage: mdtest digestname\n"); exit(1); } md = EVP_get_digestbyname(argv[1]); if (md == NULL) { printf("Unknown message digest %s\n", argv[1]); exit(1); } mdctx = EVP_MD_CTX_new(); if (!EVP_DigestInit_ex2(mdctx, md, NULL)) { printf("Message digest initialization failed.\n"); EVP_MD_CTX_free(mdctx); exit(1); } if (!EVP_DigestUpdate(mdctx, mess1, strlen(mess1))) { printf("Message digest update failed.\n"); EVP_MD_CTX_free(mdctx); exit(1); } if (!EVP_DigestUpdate(mdctx, mess2, strlen(mess2))) { printf("Message digest update failed.\n"); EVP_MD_CTX_free(mdctx); exit(1); } if (!EVP_DigestFinal_ex(mdctx, md_value, &md_len)) { printf("Message digest finalization failed.\n"); EVP_MD_CTX_free(mdctx); exit(1); } EVP_MD_CTX_free(mdctx); printf("Digest is: "); for (i = 0; i < md_len; i++) printf("%02x", md_value[i]); printf("\n"); exit(0); }
EVP_MD_meth_new(3), openssl-dgst(1), evp(7), OSSL_PROVIDER(3), OSSL_PARAM(3), property(7), "ALGORITHM FETCHING" in crypto(7), provider-digest(7), life_cycle-digest(7)
The full list of digest algorithms are provided below.
EVP_blake2b512(3), EVP_md2(3), EVP_md4(3), EVP_md5(3), EVP_mdc2(3), EVP_ripemd160(3), EVP_sha1(3), EVP_sha224(3), EVP_sha3_224(3), EVP_sm3(3), EVP_whirlpool(3)
The EVP_MD_CTX_create() and EVP_MD_CTX_destroy() functions were renamed to EVP_MD_CTX_new() and EVP_MD_CTX_free() in OpenSSL 1.1.0, respectively.
The link between digests and signing algorithms was fixed in OpenSSL 1.0 and later, so now EVP_sha1() can be used with RSA and DSA.
The EVP_dss1() function was removed in OpenSSL 1.1.0.
The EVP_MD_CTX_set_pkey_ctx() function was added in OpenSSL 1.1.1.
The EVP_Q_digest(), EVP_DigestInit_ex2(), EVP_MD_fetch(), EVP_MD_free(), EVP_MD_up_ref(), EVP_MD_get_params(), EVP_MD_CTX_set_params(), EVP_MD_CTX_get_params(), EVP_MD_gettable_params(), EVP_MD_gettable_ctx_params(), EVP_MD_settable_ctx_params(), EVP_MD_CTX_settable_params() and EVP_MD_CTX_gettable_params() functions were added in OpenSSL 3.0.
The EVP_MD_type(), EVP_MD_nid(), EVP_MD_name(), EVP_MD_pkey_type(), EVP_MD_size(), EVP_MD_block_size(), EVP_MD_flags(), EVP_MD_CTX_size(), EVP_MD_CTX_block_size(), EVP_MD_CTX_type(), and EVP_MD_CTX_md_data() functions were renamed to include "get" or "get0" in their names in OpenSSL 3.0, respectively. The old names are kept as non-deprecated alias macros.
The EVP_MD_CTX_md() function was deprecated in OpenSSL 3.0; use EVP_MD_CTX_get0_md() instead. EVP_MD_CTX_update_fn() and EVP_MD_CTX_set_update_fn() were deprecated in OpenSSL 3.0.
Copyright 2000-2023 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>.
2023-10-23 | 3.0.11 |