版本：OpenSSL 3.0.2 15 Mar 2022 (Library: OpenSSL 3.0.2 15 Mar 2022)
SHAx 系列
如果对象完全存储在内存中，可以使用以下函数：
#include <openssl/sha.h>unsigned char *SHA1(const unsigned char *data, size_t count, unsigned char *md_buf);
unsigned char *SHA224(const unsigned char *data, size_t count, unsigned char *md_buf);
unsigned char *SHA256(const unsigned char *data, size_t count, unsigned char *md_buf);
unsigned char *SHA384(const unsigned char *data, size_t count, unsigned char *md_buf);
unsigned char *SHA512(const unsigned char *data, size_t count, unsigned char *md_buf);使用示例：
int i = 0;
const char *data = "Hello World";
unsigned char sha1[SHA_DIGEST_LENGTH];SHA1(data, strlen(data), sha1);printf("%s sha1 = ", data);
for (i = 0; i < SHA_DIGEST_LENGTH; i++) {printf("%02x", sha1[i]);
}SHAx_Init 系列
如果对象未完全存储在内存中，可以使用以下函数（注意：以下函数已经在 3.0 版本中废弃）：
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);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);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);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);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);使用示例：
#define OPENSSL_API_COMPAT 0x10100000L /* 在 >= 3.0 版本中需要定义该宏才能使用 SHAx_Init 系列函数，该宏详情见 https://www.openssl.org/docs/man3.2/man7/openssl_user_macros.html */SHA_CTX c;
int i = 0;
const char *data = "Hello World";
unsigned char sha1[SHA_DIGEST_LENGTH];SHA1_Init(&c);
SHA1_Update(&c, data, strlen(data));
SHA1_Final(sha1, &c);printf("%s sha1 = ", data);
for (i = 0; i < SHA_DIGEST_LENGTH; i++) {printf("%02x", sha1[i]);
}
#define OPENSSL_API_COMPAT 0x10100000L /* 在 >= 3.0 版本中需要定义该宏才能使用 SHAx_Init 系列函数，该宏详情见 https://www.openssl.org/docs/man3.2/man7/openssl_user_macros.html */int sha1_file(char *file)
{
#define READ_SIZE 128if (!file)return 0;int i = 0;int n = 0;SHA_CTX c;FILE *fp = NULL;unsigned char temp[READ_SIZE];unsigned char sha1[SHA_DIGEST_LENGTH];fp = fopen(file, "r");if (!fp)return -1;SHA1_Init(&c);do{memset(temp, 0, sizeof(temp));n = fread(temp, 1, READ_SIZE, fp);if (n > 0)SHA1_Update(&c, temp, n);} while (n > 0);SHA1_Final(sha1, &c);printf("file [%s] sha1 = ", file);for (i = 0; i < SHA_DIGEST_LENGTH; i++){printf("%02x", sha1[i]);}fclose(fp);return 0;
}3.0 版本
3.0 版本推荐使用用 EVP_DigestInit_ex(3), EVP_DigestUpdate(3) , EVP_DigestFinal_ex(3)
使用示例：
int i = 0;
EVP_MD_CTX *ctx = NULL;
const char *data = "Hello World";
unsigned char sha1[SHA_DIGEST_LENGTH];ctx = EVP_MD_CTX_new();
EVP_DigestInit_ex(ctx, EVP_sha1(), NULL);
EVP_DigestUpdate(ctx, data, strlen(data));
EVP_DigestFinal_ex(ctx, sha1, NULL);
EVP_MD_CTX_free(ctx);printf("%s sha1 = ", data);
for (i = 0; i < SHA_DIGEST_LENGTH; i++)
{printf("%02x", sha1[i]);
}快速哈希功能
EVP_Q_digest(3)
int EVP_Q_digest(OSSL_LIB_CTX *libctx, const char *name, const char *propq,const void *data, size_t datalen,unsigned char *md, size_t *mdlen);使用示例：
const char *data = "Hello World";
unsigned char sha1[SHA_DIGEST_LENGTH];EVP_Q_digest(NULL, "SHA1", NULL, data, strlen(data), sha1, NULL)
)
