NAME¶
SHA1, SHA1_Init, SHA1_Update, SHA1_Final, SHA224, SHA224_Init, SHA224_Update,
SHA224_Final, SHA256, SHA256_Init, SHA256_Update, SHA256_Final, SHA384,
SHA384_Init, SHA384_Update, SHA384_Final, SHA512, SHA512_Init, SHA512_Update,
SHA512_Final - Secure Hash Algorithm
SYNOPSIS¶
#include <openssl/sha.h>
int SHA1_Init(SHA_CTX *c);
int SHA1_Update(SHA_CTX *c, const void *data, size_t len);
int SHA1_Final(unsigned char *md, SHA_CTX *c);
unsigned char *SHA1(const unsigned char *d, size_t n,
unsigned char *md);
int SHA224_Init(SHA256_CTX *c);
int SHA224_Update(SHA256_CTX *c, const void *data, size_t len);
int SHA224_Final(unsigned char *md, SHA256_CTX *c);
unsigned char *SHA224(const unsigned char *d, size_t n,
unsigned char *md);
int SHA256_Init(SHA256_CTX *c);
int SHA256_Update(SHA256_CTX *c, const void *data, size_t len);
int SHA256_Final(unsigned char *md, SHA256_CTX *c);
unsigned char *SHA256(const unsigned char *d, size_t n,
unsigned char *md);
int SHA384_Init(SHA512_CTX *c);
int SHA384_Update(SHA512_CTX *c, const void *data, size_t len);
int SHA384_Final(unsigned char *md, SHA512_CTX *c);
unsigned char *SHA384(const unsigned char *d, size_t n,
unsigned char *md);
int SHA512_Init(SHA512_CTX *c);
int SHA512_Update(SHA512_CTX *c, const void *data, size_t len);
int SHA512_Final(unsigned char *md, SHA512_CTX *c);
unsigned char *SHA512(const unsigned char *d, size_t n,
unsigned char *md);
DESCRIPTION¶
Applications should use the higher level functions
EVP_DigestInit(3) etc.
instead of calling the hash functions directly.
SHA-1 (Secure Hash Algorithm) is a cryptographic hash function with a 160 bit
output.
SHA1() computes the SHA-1 message digest of the
n bytes at
d and places it in
md (which must have space for
SHA_DIGEST_LENGTH == 20 bytes of output). If
md is NULL, the digest is
placed in a static array. Note: setting
md to NULL is
not thread
safe.
The following functions may be used if the message is not completely stored in
memory:
SHA1_Init() initializes a
SHA_CTX structure.
SHA1_Update() can be called repeatedly with chunks of the message to be
hashed (
len bytes at
data).
SHA1_Final() places the message digest in
md, which must have
space for SHA_DIGEST_LENGTH == 20 bytes of output, and erases the
SHA_CTX.
The SHA224, SHA256, SHA384 and SHA512 families of functions operate in the same
way as for the SHA1 functions. Note that SHA224 and SHA256 use a
SHA256_CTX object instead of
SHA_CTX. SHA384 and SHA512 use
SHA512_CTX. The buffer
md must have space for the output from
the SHA variant being used (defined by SHA224_DIGEST_LENGTH,
SHA256_DIGEST_LENGTH, SHA384_DIGEST_LENGTH and SHA512_DIGEST_LENGTH). Also
note that, as for the
SHA1() function above, the
SHA224(),
SHA256(),
SHA384() and
SHA512() functions are not thread
safe if
md is NULL.
The predecessor of SHA-1, SHA, is also implemented, but it should be used only
when backward compatibility is required.
RETURN VALUES¶
SHA1(),
SHA224(),
SHA256(),
SHA384() and
SHA512() return a pointer to the hash value.
SHA1_Init(),
SHA1_Update() and
SHA1_Final() and equivalent
SHA224, SHA256, SHA384 and SHA512 functions return 1 for success, 0 otherwise.
US Federal Information Processing Standard FIPS PUB 180-4 (Secure Hash
Standard), ANSI X9.30
SEE ALSO¶
ripemd(3),
hmac(3),
EVP_DigestInit(3)
HISTORY¶
SHA1(),
SHA1_Init(),
SHA1_Update() and
SHA1_Final()
are available in all versions of SSLeay and OpenSSL.