1 files changed, 97 insertions, 0 deletions
diff --git a/sha1.c b/sha1.c
new file mode 100644
index 0000000..2a8fda1
--- /dev/null
+++ b/sha1.c
@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <string.h>
+#include <openssl/sha.h>
+#include <openssl/pem.h>
+#include <limits.h>
+
+#define MIN(A, B) ((A) < (B) ? (A) : (B))
+#define MAXLEN (SHA512_DIGEST_LENGTH * 2)
+
+char *
+base64encode(const void *data, int len)
+{ /* Copied from http://stackoverflow.com/a/16511093/459915 */
+    BIO *b64_bio, *mem_bio;
+    BUF_MEM *mem_bio_mem_ptr;
+
+    b64_bio = BIO_new(BIO_f_base64());
+    mem_bio = BIO_new(BIO_s_mem());
+    BIO_push(b64_bio, mem_bio);
+    BIO_set_flags(b64_bio, BIO_FLAGS_BASE64_NO_NL);
+
+    BIO_write(b64_bio, data, len);
+    BIO_flush(b64_bio);
+
+    BIO_get_mem_ptr(mem_bio, &mem_bio_mem_ptr);
+    BIO_set_close(mem_bio, BIO_NOCLOSE);
+    BIO_free_all(b64_bio);
+
+    (*mem_bio_mem_ptr).data[(*mem_bio_mem_ptr).length] = '\0';
+
+    return (*mem_bio_mem_ptr).data;
+}
+
+void
+sha512_to_string(unsigned char *data, char *buff)
+{
+    int i;
+
+    for (i = 0; i < SHA512_DIGEST_LENGTH; i++) {
+        char sbuff[3] = { '\0' };
+        sprintf(sbuff, "%02x", data[i]);
+        strcat(buff, sbuff);
+    }
+}
+
+char *
+dispass1(char *label, char *password, int len, int seqno)
+{
+    int i;
+    unsigned char *d;
+    long tbufflen = strlen(label) + strlen(password) + 1;
+    char *tbuff = calloc(tbufflen, sizeof(char));
+    char buff[MAXLEN + 1] = { '\0' };
+    char *b64;
+
+    strcat(tbuff, label);
+    strcat(tbuff, password);
+    d = SHA512(tbuff, strlen(tbuff), 0);
+    free(tbuff);
+    sha512_to_string(d, buff);
+    b64 = base64encode(buff, strlen(buff));
+    b64[MIN(len, MAXLEN)] = '\0';
+
+    return b64;
+}
+
+char *
+dispass2(char *label, char *password, int len, int seqno)
+{
+    int i;
+    unsigned char *d;
+    char ibuff[300];
+    char *tbuff, *b64;
+    char buff[MAXLEN + 1] = { '\0' };
+
+    sprintf(ibuff, "%llu", seqno);
+    tbuff = calloc(strlen(label) + strlen(ibuff) + strlen(password) + 1,
+                   sizeof(char));
+    strcat(tbuff, label);
+    strcat(tbuff, ibuff);
+    strcat(tbuff, password);
+    d = SHA512(tbuff, strlen(tbuff), 0);
+    free(tbuff);
+    sha512_to_string(d, buff);
+    b64 = base64encode(buff, strlen(buff));
+    b64[MIN(len, MAXLEN)] = '\0';
+
+    return b64;
+}
+
+int main(int argc, char *argv[])
+{
+    printf("%s\n", dispass1("test", "qqqqqqqq", 30, 0));
+    printf("%s\n", dispass1("test2", "qqqqqqqq", 50, 0));
+    printf("%s\n", dispass2("test", "qqqqqqqq", 30, 1));
+    printf("%s\n", dispass2("test2", "qqqqqqqq", 50, 10));
+    return 0;
+}