| =pod |
| |
| =head1 NAME |
| |
| SHA1, SHA1_Init, SHA1_Update, SHA1_Final - Secure Hash Algorithm |
| |
| =head1 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); |
| |
| =head1 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 B<n> |
| bytes at B<d> and places it in B<md> (which must have space for |
| SHA_DIGEST_LENGTH == 20 bytes of output). If B<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 B<SHA_CTX> structure. |
| |
| SHA1_Update() can be called repeatedly with chunks of the message to |
| be hashed (B<len> bytes at B<data>). |
| |
| SHA1_Final() places the message digest in B<md>, which must have space |
| for SHA_DIGEST_LENGTH == 20 bytes of output, and erases the B<SHA_CTX>. |
| |
| Applications should use the higher level functions |
| L<EVP_DigestInit(3)|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. |
| |
| =head1 RETURN VALUES |
| |
| SHA1() returns a pointer to the hash value. |
| |
| SHA1_Init(), SHA1_Update() and SHA1_Final() return 1 for success, 0 otherwise. |
| |
| =head1 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 |
| |
| =head1 SEE ALSO |
| |
| L<ripemd(3)|ripemd(3)>, L<hmac(3)|hmac(3)>, L<EVP_DigestInit(3)|EVP_DigestInit(3)> |
| |
| =head1 HISTORY |
| |
| SHA1(), SHA1_Init(), SHA1_Update() and SHA1_Final() are available in all |
| versions of SSLeay and OpenSSL. |
| |
| =cut |
