Drop internal SHA1 implementation

[locker]

Historically, we use our internal SHA1 implementation instead of the one provided by OpenSSL. The reason for that is that initially we didn't link OpenSSL. Instead, we loaded it dynamically on demand. We targeted to work even on those distributions where the OpenSSL library isn't installed, see #405. Those days are long gone. Now, we link the OpenSSL library unconditionally, see #1382. Let's drop our internal SHA1 implementation in favor of OpenSSL's.

While we are at it, let's also merge the scramble library into the 'chap-sha1' authentication method implementation. There's no need in it anymore, because the authentication methods now provide a clean API, see #7986.

Closes #7987

[coveralls]

Coverage decreased (-0.02%) to 84.831% when pulling 66f6ec2 on locker:drop-internal-sha1 into a392eb7
on tarantool:master.

[locker]

SHA1_Init is deprecated in OpenSSL 3.0. We should use EVP_DigestInit_ex instead.

[locker]

SHA1_Init is deprecated in OpenSSL 3.0. We should use EVP_DigestInit_ex instead.

Replaced with SHA1, which should be fine.

diff

diff --git a/src/box/auth_chap_sha1.c b/src/box/auth_chap_sha1.c
index 9ae4fee0aaa7..0665cf5dc2f5 100644
--- a/src/box/auth_chap_sha1.c
+++ b/src/box/auth_chap_sha1.c
@@ -84,17 +84,11 @@ scramble_prepare(void *out, const void *salt, const void *password,
 		 int password_len)
 {
 	unsigned char hash1[SCRAMBLE_SIZE];
-	unsigned char hash2[SCRAMBLE_SIZE];
-
 	SHA1(password, password_len, hash1);
-	SHA1(hash1, SCRAMBLE_SIZE, hash2);
-
-	SHA_CTX ctx;
-	SHA1_Init(&ctx);
-	SHA1_Update(&ctx, salt, SCRAMBLE_SIZE);
-	SHA1_Update(&ctx, hash2, SCRAMBLE_SIZE);
-	SHA1_Final(out, &ctx);
-
+	unsigned char salted_hash2[2 * SCRAMBLE_SIZE];
+	memcpy(salted_hash2, salt, SCRAMBLE_SIZE);
+	SHA1(hash1, SCRAMBLE_SIZE, salted_hash2 + SCRAMBLE_SIZE);
+	SHA1(salted_hash2, 2 * SCRAMBLE_SIZE, out);
 	xor(out, hash1, out, SCRAMBLE_SIZE);
 }
 
@@ -107,14 +101,11 @@ scramble_prepare(void *out, const void *salt, const void *password,
 static int
 scramble_check(const void *scramble, const void *salt, const void *hash2)
 {
+	unsigned char salted_hash2[2 * SCRAMBLE_SIZE];
+	memcpy(salted_hash2, salt, SCRAMBLE_SIZE);
+	memcpy(salted_hash2 + SCRAMBLE_SIZE, hash2, SCRAMBLE_SIZE);
 	unsigned char candidate_hash2[SCRAMBLE_SIZE];
-
-	SHA_CTX ctx;
-	SHA1_Init(&ctx);
-	SHA1_Update(&ctx, salt, SCRAMBLE_SIZE);
-	SHA1_Update(&ctx, hash2, SCRAMBLE_SIZE);
-	SHA1_Final(candidate_hash2, &ctx);
-
+	SHA1(salted_hash2, 2 * SCRAMBLE_SIZE, candidate_hash2);
 	xor(candidate_hash2, candidate_hash2, scramble, SCRAMBLE_SIZE);
 	/*
 	 * candidate_hash2 now supposedly contains hash1, turn it