1=pod 2 3=head1 NAME 4 5SHA1, SHA1_Init, SHA1_Update, SHA1_Final, SHA224, SHA224_Init, SHA224_Update, 6SHA224_Final, SHA256, SHA256_Init, SHA256_Update, SHA256_Final, SHA384, 7SHA384_Init, SHA384_Update, SHA384_Final, SHA512, SHA512_Init, SHA512_Update, 8SHA512_Final - Secure Hash Algorithm 9 10=head1 SYNOPSIS 11 12 #include <openssl/sha.h> 13 14 unsigned char *SHA1(const unsigned char *data, size_t count, unsigned char *md_buf); 15 unsigned char *SHA224(const unsigned char *data, size_t count, unsigned char *md_buf); 16 unsigned char *SHA256(const unsigned char *data, size_t count, unsigned char *md_buf); 17 unsigned char *SHA384(const unsigned char *data, size_t count, unsigned char *md_buf); 18 unsigned char *SHA512(const unsigned char *data, size_t count, unsigned char *md_buf); 19 20The following functions have been deprecated since OpenSSL 3.0, and can be 21hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 22see L<openssl_user_macros(7)>: 23 24 int SHA1_Init(SHA_CTX *c); 25 int SHA1_Update(SHA_CTX *c, const void *data, size_t len); 26 int SHA1_Final(unsigned char *md, SHA_CTX *c); 27 28 int SHA224_Init(SHA256_CTX *c); 29 int SHA224_Update(SHA256_CTX *c, const void *data, size_t len); 30 int SHA224_Final(unsigned char *md, SHA256_CTX *c); 31 32 int SHA256_Init(SHA256_CTX *c); 33 int SHA256_Update(SHA256_CTX *c, const void *data, size_t len); 34 int SHA256_Final(unsigned char *md, SHA256_CTX *c); 35 36 int SHA384_Init(SHA512_CTX *c); 37 int SHA384_Update(SHA512_CTX *c, const void *data, size_t len); 38 int SHA384_Final(unsigned char *md, SHA512_CTX *c); 39 40 int SHA512_Init(SHA512_CTX *c); 41 int SHA512_Update(SHA512_CTX *c, const void *data, size_t len); 42 int SHA512_Final(unsigned char *md, SHA512_CTX *c); 43 44=head1 DESCRIPTION 45 46All of the functions described on this page 47except for SHA1(), SHA224(), SHA256(), SHA384() and SHA512() are deprecated. 48Applications should instead use L<EVP_DigestInit_ex(3)>, L<EVP_DigestUpdate(3)> 49and L<EVP_DigestFinal_ex(3)>, or the quick one-shot function L<EVP_Q_digest(3)>. 50SHA1(), SHA224(), SHA256(), SHA384(), and SHA256() 51can continue to be used. They can also be replaced by, e.g., 52 53 (EVP_Q_digest(d, n, md, NULL, NULL, "SHA256", NULL) ? md : NULL) 54 55SHA-1 (Secure Hash Algorithm) is a cryptographic hash function with a 56160 bit output. 57 58SHA1() computes the SHA-1 message digest of the B<n> 59bytes at B<d> and places it in B<md> (which must have space for 60SHA_DIGEST_LENGTH == 20 bytes of output). If B<md> is NULL, the digest 61is placed in a static array. Note: setting B<md> to NULL is B<not thread safe>. 62 63The following functions may be used if the message is not completely 64stored in memory: 65 66SHA1_Init() initializes a B<SHA_CTX> structure. 67 68SHA1_Update() can be called repeatedly with chunks of the message to 69be hashed (B<len> bytes at B<data>). 70 71SHA1_Final() places the message digest in B<md>, which must have space 72for SHA_DIGEST_LENGTH == 20 bytes of output, and erases the B<SHA_CTX>. 73 74The SHA224, SHA256, SHA384 and SHA512 families of functions operate in the 75same way as for the SHA1 functions. Note that SHA224 and SHA256 use a 76B<SHA256_CTX> object instead of B<SHA_CTX>. SHA384 and SHA512 use B<SHA512_CTX>. 77The buffer B<md> must have space for the output from the SHA variant being used 78(defined by SHA224_DIGEST_LENGTH, SHA256_DIGEST_LENGTH, SHA384_DIGEST_LENGTH and 79SHA512_DIGEST_LENGTH). Also note that, as for the SHA1() function above, the 80SHA224(), SHA256(), SHA384() and SHA512() functions are not thread safe if 81B<md> is NULL. 82 83=head1 RETURN VALUES 84 85SHA1(), SHA224(), SHA256(), SHA384() and SHA512() return a pointer to the hash 86value. 87 88SHA1_Init(), SHA1_Update() and SHA1_Final() and equivalent SHA224, SHA256, 89SHA384 and SHA512 functions return 1 for success, 0 otherwise. 90 91=head1 CONFORMING TO 92 93US Federal Information Processing Standard FIPS PUB 180-4 (Secure Hash 94Standard), 95ANSI X9.30 96 97=head1 SEE ALSO 98 99L<EVP_Q_digest(3)>, 100L<EVP_DigestInit(3)> 101 102=head1 HISTORY 103 104All of these functions except SHA*() were deprecated in OpenSSL 3.0. 105 106=head1 COPYRIGHT 107 108Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 109 110Licensed under the Apache License 2.0 (the "License"). You may not use 111this file except in compliance with the License. You can obtain a copy 112in the file LICENSE in the source distribution or at 113L<https://www.openssl.org/source/license.html>. 114 115=cut 116