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SHA-1 Hash (sha1)

SHA-1 secure hash algorithm, 160-bit digest computation. Supports one-shot and streaming interfaces.

Constants and Data Structure​

#define SHA1_DIGEST_SIZE (20)

struct sha1_ctx_t {
    uint64_t count;
    uint8_t buf[64];
    uint32_t state[5];
};

API​

One-shot​

const uint8_t * sha1_hash(const void * data, int len, uint8_t * digest);
  • data — Input data
  • len — Data length
  • digest — Output 20-byte digest

Returns digest pointer.

Streaming​

void sha1_init(struct sha1_ctx_t * ctx);
void sha1_update(struct sha1_ctx_t * ctx, const void * data, int len);
const uint8_t * sha1_final(struct sha1_ctx_t * ctx);
  • sha1_init — Initialize context
  • sha1_update — Feed data, may be called multiple times
  • sha1_final — Finalize and return digest pointer (points to internal context buffer)

Example​

One-shot​

uint8_t msg[] = { 'x', 'b', 'o', 'o', 't' };
uint8_t digest[SHA1_DIGEST_SIZE];
sha1_hash(msg, sizeof(msg), digest);
/* digest = 0x7182df07 c7f20675 0fe2ed98 580ab526 cb839f5d */

Streaming​

struct sha1_ctx_t ctx;
uint8_t digest[SHA1_DIGEST_SIZE];

sha1_init(&ctx);
sha1_update(&ctx, chunk1, len1);
sha1_update(&ctx, chunk2, len2);
sha1_final(&ctx);