EVP_DIGESTINIT(3SSL) | OpenSSL | EVP_DIGESTINIT(3SSL) |
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_flags, EVP_MD_CTX_clear_flags, EVP_MD_CTX_test_flags, EVP_Digest, EVP_DigestInit_ex, EVP_DigestInit, EVP_DigestUpdate, EVP_DigestFinal_ex, EVP_DigestFinalXOF, EVP_DigestFinal, EVP_MD_type, EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_flags, EVP_MD_CTX_md, EVP_MD_CTX_type, EVP_MD_CTX_size, EVP_MD_CTX_block_size, EVP_MD_CTX_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_pkey_ctx, EVP_MD_CTX_set_pkey_ctx - EVP digest routines
#include <openssl/evp.h> 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); 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_Digest(const void *data, size_t count, unsigned char *md, unsigned int *size, const EVP_MD *type, ENGINE *impl); 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); int EVP_MD_type(const EVP_MD *md); int EVP_MD_pkey_type(const EVP_MD *md); int EVP_MD_size(const EVP_MD *md); int EVP_MD_block_size(const EVP_MD *md); unsigned long EVP_MD_flags(const EVP_MD *md); const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx); int EVP_MD_CTX_size(const EVP_MD_CTX *ctx); int EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx); int EVP_MD_CTX_type(const EVP_MD_CTX *ctx); void *EVP_MD_CTX_md_data(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)); 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_pkey_ctx(const EVP_MD_CTX *ctx); void EVP_MD_CTX_set_pkey_ctx(EVP_MD_CTX *ctx, EVP_PKEY_CTX *pctx);
The EVP digest routines are a high-level interface to message digests, and should be used instead of the cipher-specific functions.
EVP_MD_CTX_ctrl() can be used to send the following standard controls:
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.
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_size(), EVP_MD_CTX_block_size(), EVP_MD_CTX_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(); EVP_DigestInit_ex(mdctx, md, NULL); EVP_DigestUpdate(mdctx, mess1, strlen(mess1)); EVP_DigestUpdate(mdctx, mess2, strlen(mess2)); EVP_DigestFinal_ex(mdctx, md_value, &md_len); 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), dgst(1), evp(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 1.1.1.
Copyright 2000-2020 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>.
2023-09-13 | 1.1.1w |