openssl_sha(3) - NetBSD Manual Pages

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sha(3)                              OpenSSL                             sha(3)




NAME

       SHA1, SHA1_Init, SHA1_Update, SHA1_Final - Secure Hash Algorithm


LIBRARY

       libcrypto, -lcrypto


SYNOPSIS

        #include <openssl/sha.h>

        unsigned char *SHA1(const unsigned char *d, unsigned long n,
                         unsigned char *md);

        int SHA1_Init(SHA_CTX *c);
        int SHA1_Update(SHA_CTX *c, const void *data,
                         unsigned long len);
        int SHA1_Final(unsigned char *md, SHA_CTX *c);


DESCRIPTION

       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.

       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.

       Applications should use the higher level functions EVP_DigestInit(3)
       etc. instead of calling the hash functions directly.

       The predecessor of SHA-1, SHA, is also implemented, but it should be
       used only when backward compatibility is required.


RETURN VALUES

       SHA1() returns a pointer to the hash value.

       SHA1_Init(), SHA1_Update() and SHA1_Final() return 1 for success, 0
       otherwise.


CONFORMING TO

       SHA: US Federal Information Processing Standard FIPS PUB 180 (Secure
       Hash Standard), SHA-1: US Federal Information Processing Standard FIPS
       PUB 180-1 (Secure Hash Standard), ANSI X9.30


SEE ALSO

       openssl_ripemd(3), openssl_hmac(3), EVP_DigestInit(3)


HISTORY

       SHA1(), SHA1_Init(), SHA1_Update() and SHA1_Final() are available in
       all versions of SSLeay and OpenSSL.



1.0.1p                            2009-07-19                            sha(3)