Update base64 algorithms to include a decode function, and add unit testing. Moved SHA1 algorthm to its own function as the original algorithm in libxcrypt is not able to encode all data lengths correctly. Added blowfish/bcrypt algorithm that should be libxcrypt compatible.

README.md

@@ -52,4 +52,3 @@ $ ./test
 ## Known issues
 
  - It is possible to generate password hashes that are incompatible with libxcrypt by setting a large round count. This may be mitigated in the future by adding an option to disable compatibility and otherwise require compatible parameters to be set.
- - The bcrypt hashing algorithms are not implemented yet, it may be implemented in the near futre.

bcrypt.go

@@ -0,0 +1,186 @@
+package passwd
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	BCRYPT_MAX_HASH_SIZE = 23
+)
+
+// BCrypt implementation of the PasswdInterface.
+type BCrypt struct {
+	Passwd
+}
+
+// Creates a new BCrypt password instance.
+func NewBCryptPasswd() PasswdInterface {
+	m := new(BCrypt)
+	m.Magic = BCRYPT_MAGIC
+	// Default parameters: cost 14, minor 'a'.
+	m.Params = "a$14"
+	m.SaltLength = 16
+	m.i = m
+	return m
+}
+
+// IV for the 64 Blowfish encryption calls in bcrypt().
+// It is the string "OrpheanBeholderScryDoubt" in big-endian bytes.
+var magicCipherData = []byte{
+	0x4f, 0x72, 0x70, 0x68,
+	0x65, 0x61, 0x6e, 0x42,
+	0x65, 0x68, 0x6f, 0x6c,
+	0x64, 0x65, 0x72, 0x53,
+	0x63, 0x72, 0x79, 0x44,
+	0x6f, 0x75, 0x62, 0x74,
+}
+
+// Sets up the Blowfish cipher state with the expensive key expansion and salt mixing required by BCrypt.
+func (a *BCrypt) setupBlowfishCipher(key []byte, cost uint32, salt []byte, bug bool, safety bool) (*BfCipher, error) {
+	csalt, err := BCryptBase64Decode(salt)
+	if err != nil {
+		return nil, err
+	}
+
+	// Base64 decoding 22 chars produces 18 bytes (due to padding/alignment).
+	// We must truncate to 16 bytes to match libxcrypt behavior.
+	if len(csalt) > 16 {
+		csalt = csalt[:16]
+	}
+
+	// Bug compatibility with C bcrypt implementations. They use the trailing
+	// NULL in the key string during expansion.
+	// We copy the key to prevent changing the underlying array.
+	ckey := append(key[:len(key):len(key)], 0)
+
+	c := NewBfCipher()
+	c.SetKey(ckey, bug, safety)
+	c.ExpandKeyWithSalt(csalt)
+
+	var i, rounds uint64
+	rounds = 1 << cost
+	for i = 0; i < rounds; i++ {
+		c.ExpandKey(ckey)
+		c.ExpandKey(csalt)
+	}
+
+	return c, nil
+}
+
+// Generates a hash for the given password and salt using BCrypt.
+func (a *BCrypt) Hash(password []byte, salt []byte) ([]byte, error) {
+	// Defaults.
+	var cost uint32 = 14
+	var minor byte = 'a'
+
+	// Parse parameters: "minor$cost".
+	if a.Params != "" {
+		idx := strings.Index(a.Params, "$")
+		if idx != -1 {
+			// Found separator.
+			if idx > 0 {
+				minor = a.Params[0]
+			}
+			// Parse cost.
+			if len(a.Params) > idx+1 {
+				cStr := a.Params[idx+1:]
+				if c, cErr := strconv.ParseUint(cStr, 10, 32); cErr == nil {
+					cost = uint32(c)
+				}
+			}
+		}
+	}
+
+	// Ensure salt is truncated to 22 bytes.
+	if len(salt) > 22 {
+		salt = salt[:22]
+	}
+
+	cipherData := make([]byte, len(magicCipherData))
+	copy(cipherData, magicCipherData)
+
+	// Determine Blowfish flags based on minor version.
+	var bug, safety bool
+	switch minor {
+	case 'a':
+		safety = true
+	case 'x':
+		bug = true
+	case 'b', 'y':
+		// No bug, no safety hack needed (standard).
+	default:
+		// Unknown minor version defaults to standard (safe).
+	}
+
+	c, err := a.setupBlowfishCipher(password, cost, salt, bug, safety)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := 0; i < 24; i += 8 {
+		for j := 0; j < 64; j++ {
+			c.Encrypt(cipherData[i:i+8], cipherData[i:i+8])
+		}
+	}
+
+	// Bug compatibility with C bcrypt implementations. We only encode 23 of
+	// the 24 bytes encrypted.
+	hashed := BCryptBase64Encode(cipherData[:BCRYPT_MAX_HASH_SIZE])
+
+	// Format output.
+	// $2<minor>$<cost>$<salt><hash>.
+	magic := "$2"
+	if minor != 0 {
+		magic += string(minor)
+	}
+
+	output := fmt.Sprintf("%s$%02d$%s%s", magic, cost, salt, hashed)
+	return []byte(output), nil
+}
+
+// Hashes the password using BCrypt with the provided salt.
+func (a *BCrypt) HashPasswordWithSalt(password []byte, salt []byte) (hash []byte, err error) {
+	return a.Hash(password, salt)
+}
+
+// Hash an password using default parameters with BCrypt.
+func HashBCryptPassword(password []byte) (hash []byte, err error) {
+	passwd := NewBCryptPasswd()
+	hash, err = passwd.HashPassword(password)
+	if err != nil {
+		return
+	}
+	return
+}
+
+// Hash an password with salt using default parameters with BCrypt.
+func HashBCryptPasswordWithSalt(password []byte, salt []byte) (hash []byte, err error) {
+	passwd := NewBCryptPasswd()
+	hash, err = passwd.HashPasswordWithSalt(password, salt)
+	if err != nil {
+		return
+	}
+	return
+}
+
+// Hash an password string using default parameters with BCrypt.
+func SHashBCryptPassword(password string) (hash string, err error) {
+	passwd := NewBCryptPasswd()
+	hash, err = passwd.SHashPassword(password)
+	if err != nil {
+		return
+	}
+	return
+}
+
+// Hash an password string with salt using default parameters with BCrypt.
+func SHashBCryptPasswordWithSalt(password string, salt string) (hash string, err error) {
+	passwd := NewBCryptPasswd()
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
+	if err != nil {
+		return
+	}
+	return
+}

blowfish.go

@@ -0,0 +1,441 @@
+package passwd
+
+import (
+	"strconv"
+)
+
+const BlowfishBlockSize = 8
+
+// Instance of Blowfish encryption using a particular key.
+type BfCipher struct {
+	p              [18]uint32
+	s0, s1, s2, s3 [256]uint32
+}
+
+// Returns the Blowfish block size in bytes.
+func (c *BfCipher) BlockSize() int {
+	return BlowfishBlockSize
+}
+
+// Error returned when an invalid key size is provided.
+type KeySizeError int
+
+func (k KeySizeError) Error() string {
+	return "passwd/blowfish: invalid key size " + strconv.Itoa(int(k))
+}
+
+// Fixed constants derived from the digits of pi for the initial subkey and S-box state.
+var bfP = [18]uint32{
+	0x243f6a88, 0x85a308d3, 0x13198a2e, 0x03707344, 0xa4093822, 0x299f31d0,
+	0x082efa98, 0xec4e6c89, 0x452821e6, 0x38d01377, 0xbe5466cf, 0x34e90c6c,
+	0xc0ac29b7, 0xc97c50dd, 0x3f84d5b5, 0xb5470917, 0x9216d5d9, 0x8979fb1b,
+}
+var bfS0 = [256]uint32{
+	0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96,
+	0xba7c9045, 0xf12c7f99, 0x24a19947, 0xb3916cf7, 0x0801f2e2, 0x858efc16,
+	0x636920d8, 0x71574e69, 0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658,
+	0x718bcd58, 0x82154aee, 0x7b54a41d, 0xc25a59b5, 0x9c30d539, 0x2af26013,
+	0xc5d1b023, 0x286085f0, 0xca417918, 0xb8db38ef, 0x8e79dcb0, 0x603a180e,
+	0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda, 0x55605c60,
+	0xe65525f3, 0xaa55ab94, 0x57489862, 0x63e81440, 0x55ca396a, 0x2aab10b6,
+	0xb4cc5c34, 0x1141e8ce, 0xa15486af, 0x7c72e993, 0xb3ee1411, 0x636fbc2a,
+	0x2ba9c55d, 0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c,
+	0x7a325381, 0x28958677, 0x3b8f4898, 0x6b4bb9af, 0xc4bfe81b, 0x66282193,
+	0x61d809cc, 0xfb21a991, 0x487cac60, 0x5dec8032, 0xef845d5d, 0xe98575b1,
+	0xdc262302, 0xeb651b88, 0x23893e81, 0xd396acc5, 0x0f6d6ff3, 0x83f44239,
+	0x2e0b4482, 0xa4842004, 0x69c8f04a, 0x9e1f9b5e, 0x21c66842, 0xf6e96c9a,
+	0x670c9c61, 0xabd388f0, 0x6a51a0d2, 0xd8542f68, 0x960fa728, 0xab5133a3,
+	0x6eef0b6c, 0x137a3be4, 0xba3bf050, 0x7efb2a98, 0xa1f1651d, 0x39af0176,
+	0x66ca593e, 0x82430e88, 0x8cee8619, 0x456f9fb4, 0x7d84a5c3, 0x3b8b5ebe,
+	0xe06f75d8, 0x85c12073, 0x401a449f, 0x56c16aa6, 0x4ed3aa62, 0x363f7706,
+	0x1bfedf72, 0x429b023d, 0x37d0d724, 0xd00a1248, 0xdb0fead3, 0x49f1c09b,
+	0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7, 0xe3fe501a, 0xb6794c3b,
+	0x976ce0bd, 0x04c006ba, 0xc1a94fb6, 0x409f60c4, 0x5e5c9ec2, 0x196a2463,
+	0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c,
+	0xcc814544, 0xaf5ebd09, 0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3,
+	0xc0cba857, 0x45c8740f, 0xd20b5f39, 0xb9d3fbdb, 0x5579c0bd, 0x1a60320a,
+	0xd6a100c6, 0x402c7279, 0x679f25fe, 0xfb1fa3cc, 0x8ea5e9f8, 0xdb3222f8,
+	0x3c7516df, 0xfd616b15, 0x2f501ec8, 0xad0552ab, 0x323db5fa, 0xfd238760,
+	0x53317b48, 0x3e00df82, 0x9e5c57bb, 0xca6f8ca0, 0x1a87562e, 0xdf1769db,
+	0xd542a8f6, 0x287effc3, 0xac6732c6, 0x8c4f5573, 0x695b27b0, 0xbbca58c8,
+	0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b,
+	0x9a53e479, 0xb6f84565, 0xd28e49bc, 0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33,
+	0x62fb1341, 0xcee4c6e8, 0xef20cada, 0x36774c01, 0xd07e9efe, 0x2bf11fb4,
+	0x95dbda4d, 0xae909198, 0xeaad8e71, 0x6b93d5a0, 0xd08ed1d0, 0xafc725e0,
+	0x8e3c5b2f, 0x8e7594b7, 0x8ff6e2fb, 0xf2122b64, 0x8888b812, 0x900df01c,
+	0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad, 0x2f2f2218, 0xbe0e1777,
+	0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6, 0xce89e299,
+	0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81, 0xd2ada8d9, 0x165fa266, 0x80957705,
+	0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf,
+	0xebcdaf0c, 0x7b3e89a0, 0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e,
+	0x226800bb, 0x57b8e0af, 0x2464369b, 0xf009b91e, 0x5563911d, 0x59dfa6aa,
+	0x78c14389, 0xd95a537f, 0x207d5ba2, 0x02e5b9c5, 0x83260376, 0x6295cfa9,
+	0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a, 0x1b510052, 0x9a532915,
+	0xd60f573f, 0xbc9bc6e4, 0x2b60a476, 0x81e67400, 0x08ba6fb5, 0x571be91f,
+	0xf296ec6b, 0x2a0dd915, 0xb6636521, 0xe7b9f9b6, 0xff34052e, 0xc5855664,
+	0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a,
+}
+var bfS1 = [256]uint32{
+	0x4b7a70e9, 0xb5b32944, 0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d,
+	0x9cee60b8, 0x8fedb266, 0xecaa8c71, 0x699a17ff, 0x5664526c, 0xc2b19ee1,
+	0x193602a5, 0x75094c29, 0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65,
+	0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07, 0xefe830f5, 0x4d2d38e6, 0xf0255dc1,
+	0x4cdd2086, 0x8470eb26, 0x6382e9c6, 0x021ecc5e, 0x09686b3f, 0x3ebaefc9,
+	0x3c971814, 0x6b6a70a1, 0x687f3584, 0x52a0e286, 0xb79c5305, 0xaa500737,
+	0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d,
+	0xf01c1f04, 0x0200b3ff, 0xae0cf51a, 0x3cb574b2, 0x25837a58, 0xdc0921bd,
+	0xd19113f9, 0x7ca92ff6, 0x94324773, 0x22f54701, 0x3ae5e581, 0x37c2dadc,
+	0xc8b57634, 0x9af3dda7, 0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41,
+	0xe238cd99, 0x3bea0e2f, 0x3280bba1, 0x183eb331, 0x4e548b38, 0x4f6db908,
+	0x6f420d03, 0xf60a04bf, 0x2cb81290, 0x24977c79, 0x5679b072, 0xbcaf89af,
+	0xde9a771f, 0xd9930810, 0xb38bae12, 0xdccf3f2e, 0x5512721f, 0x2e6b7124,
+	0x501adde6, 0x9f84cd87, 0x7a584718, 0x7408da17, 0xbc9f9abc, 0xe94b7d8c,
+	0xec7aec3a, 0xdb851dfa, 0x63094366, 0xc464c3d2, 0xef1c1847, 0x3215d908,
+	0xdd433b37, 0x24c2ba16, 0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd,
+	0x71dff89e, 0x10314e55, 0x81ac77d6, 0x5f11199b, 0x043556f1, 0xd7a3c76b,
+	0x3c11183b, 0x5924a509, 0xf28fe6ed, 0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e,
+	0x86e34570, 0xeae96fb1, 0x860e5e0a, 0x5a3e2ab3, 0x771fe71c, 0x4e3d06fa,
+	0x2965dcb9, 0x99e71d0f, 0x803e89d6, 0x5266c825, 0x2e4cc978, 0x9c10b36a,
+	0xc6150eba, 0x94e2ea78, 0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d,
+	0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66,
+	0xe3bc4595, 0xa67bc883, 0xb17f37d1, 0x018cff28, 0xc332ddef, 0xbe6c5aa5,
+	0x65582185, 0x68ab9802, 0xeecea50f, 0xdb2f953b, 0x2aef7dad, 0x5b6e2f84,
+	0x1521b628, 0x29076170, 0xecdd4775, 0x619f1510, 0x13cca830, 0xeb61bd96,
+	0x0334fe1e, 0xaa0363cf, 0xb5735c90, 0x4c70a239, 0xd59e9e0b, 0xcbaade14,
+	0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf, 0x19bdf0ca,
+	0xa02369b9, 0x655abb50, 0x40685a32, 0x3c2ab4b3, 0x319ee9d5, 0xc021b8f7,
+	0x9b540b19, 0x875fa099, 0x95f7997e, 0x623d7da8, 0xf837889a, 0x97e32d77,
+	0x11ed935f, 0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99,
+	0x57f584a5, 0x1b227263, 0x9b83c3ff, 0x1ac24696, 0xcdb30aeb, 0x532e3054,
+	0x8fd948e4, 0x6dbc3128, 0x58ebf2ef, 0x34c6ffea, 0xfe28ed61, 0xee7c3c73,
+	0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0, 0x45eee2b6, 0xa3aaabea,
+	0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5, 0x654f3b1d, 0x41cd2105,
+	0xd81e799e, 0x86854dc7, 0xe44b476a, 0x3d816250, 0xcf62a1f2, 0x5b8d2646,
+	0xfc8883a0, 0xc1c7b6a3, 0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285,
+	0x095bbf00, 0xad19489d, 0x1462b174, 0x23820e00, 0x58428d2a, 0x0c55f5ea,
+	0x1dadf43e, 0x233f7061, 0x3372f092, 0x8d937e41, 0xd65fecf1, 0x6c223bdb,
+	0x7cde3759, 0xcbee7460, 0x4085f2a7, 0xce77326e, 0xa6078084, 0x19f8509e,
+	0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2, 0x5a04abfc, 0x800bcadc,
+	0x9e447a2e, 0xc3453484, 0xfdd56705, 0x0e1e9ec9, 0xdb73dbd3, 0x105588cd,
+	0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,
+	0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7,
+}
+var bfS2 = [256]uint32{
+	0xe93d5a68, 0x948140f7, 0xf64c261c, 0x94692934, 0x411520f7, 0x7602d4f7,
+	0xbcf46b2e, 0xd4a20068, 0xd4082471, 0x3320f46a, 0x43b7d4b7, 0x500061af,
+	0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840, 0x4d95fc1d, 0x96b591af,
+	0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504,
+	0x96eb27b3, 0x55fd3941, 0xda2547e6, 0xabca0a9a, 0x28507825, 0x530429f4,
+	0x0a2c86da, 0xe9b66dfb, 0x68dc1462, 0xd7486900, 0x680ec0a4, 0x27a18dee,
+	0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6, 0xaace1e7c, 0xd3375fec,
+	0xce78a399, 0x406b2a42, 0x20fe9e35, 0xd9f385b9, 0xee39d7ab, 0x3b124e8b,
+	0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332,
+	0x6841e7f7, 0xca7820fb, 0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527,
+	0x55533a3a, 0x20838d87, 0xfe6ba9b7, 0xd096954b, 0x55a867bc, 0xa1159a58,
+	0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c,
+	0xfdf8e802, 0x04272f70, 0x80bb155c, 0x05282ce3, 0x95c11548, 0xe4c66d22,
+	0x48c1133f, 0xc70f86dc, 0x07f9c9ee, 0x41041f0f, 0x404779a4, 0x5d886e17,
+	0x325f51eb, 0xd59bc0d1, 0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60,
+	0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e, 0xaf664fd1, 0xcad18115,
+	0x6b2395e0, 0x333e92e1, 0x3b240b62, 0xeebeb922, 0x85b2a20e, 0xe6ba0d99,
+	0xde720c8c, 0x2da2f728, 0xd0127845, 0x95b794fd, 0x647d0862, 0xe7ccf5f0,
+	0x5449a36f, 0x877d48fa, 0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74,
+	0x3a6f6eab, 0xf4f8fd37, 0xa812dc60, 0xa1ebddf8, 0x991be14c, 0xdb6e6b0d,
+	0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,
+	0xb5390f92, 0x690fed0b, 0x667b9ffb, 0xcedb7d9c, 0xa091cf0b, 0xd9155ea3,
+	0xbb132f88, 0x515bad24, 0x7b9479bf, 0x763bd6eb, 0x37392eb3, 0xcc115979,
+	0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b, 0x12754ccc, 0x782ef11c,
+	0x6a124237, 0xb79251e7, 0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa,
+	0x3d25bdd8, 0xe2e1c3c9, 0x44421659, 0x0a121386, 0xd90cec6e, 0xd5abea2a,
+	0x64af674e, 0xda86a85f, 0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086,
+	0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0, 0x7745ae04, 0xd736fccc,
+	0x83426b33, 0xf01eab71, 0xb0804187, 0x3c005e5f, 0x77a057be, 0xbde8ae24,
+	0x55464299, 0xbf582e61, 0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2,
+	0x5366f9c3, 0xc8b38e74, 0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84,
+	0x846a0e79, 0x915f95e2, 0x466e598e, 0x20b45770, 0x8cd55591, 0xc902de4c,
+	0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e, 0xb77f19b6, 0xe0a9dc09,
+	0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10,
+	0x1ab93d1d, 0x0ba5a4df, 0xa186f20f, 0x2868f169, 0xdcb7da83, 0x573906fe,
+	0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa, 0xa002b5c4, 0x0de6d027,
+	0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0,
+	0x006058aa, 0x30dc7d62, 0x11e69ed7, 0x2338ea63, 0x53c2dd94, 0xc2c21634,
+	0xbbcbee56, 0x90bcb6de, 0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188,
+	0x39720a3d, 0x7c927c24, 0x86e3725f, 0x724d9db9, 0x1ac15bb4, 0xd39eb8fc,
+	0xed545578, 0x08fca5b5, 0xd83d7cd3, 0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8,
+	0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837,
+	0xd79a3234, 0x92638212, 0x670efa8e, 0x406000e0,
+}
+var bfS3 = [256]uint32{
+	0x3a39ce37, 0xd3faf5cf, 0xabc27737, 0x5ac52d1b, 0x5cb0679e, 0x4fa33742,
+	0xd3822740, 0x99bc9bbe, 0xd5118e9d, 0xbf0f7315, 0xd62d1c7e, 0xc700c47b,
+	0xb78c1b6b, 0x21a19045, 0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79,
+	0xc6a376d2, 0x6549c2c8, 0x530ff8ee, 0x468dde7d, 0xd5730a1d, 0x4cd04dc6,
+	0x2939bbdb, 0xa9ba4650, 0xac9526e8, 0xbe5ee304, 0xa1fad5f0, 0x6a2d519a,
+	0x63ef8ce2, 0x9a86ee22, 0xc089c2b8, 0x43242ef6, 0xa51e03aa, 0x9cf2d0a4,
+	0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6, 0x2826a2f9, 0xa73a3ae1,
+	0x4ba99586, 0xef5562e9, 0xc72fefd3, 0xf752f7da, 0x3f046f69, 0x77fa0a59,
+	0x80e4a915, 0x87b08601, 0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797,
+	0x2cf0b7d9, 0x022b8b51, 0x96d5ac3a, 0x017da67d, 0xd1cf3ed6, 0x7c7d2d28,
+	0x1f9f25cf, 0xadf2b89b, 0x5ad6b472, 0x5a88f54c, 0xe029ac71, 0xe019a5e6,
+	0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc, 0xf8d56629, 0x79132e28,
+	0x785f0191, 0xed756055, 0xf7960e44, 0xe3d35e8c, 0x15056dd4, 0x88f46dba,
+	0x03a16125, 0x0564f0bd, 0xc3eb9e15, 0x3c9057a2, 0x97271aec, 0xa93a072a,
+	0x1b3f6d9b, 0x1e6321f5, 0xf59c66fb, 0x26dcf319, 0x7533d928, 0xb155fdf5,
+	0x03563482, 0x8aba3cbb, 0x28517711, 0xc20ad9f8, 0xabcc5167, 0xccad925f,
+	0x4de81751, 0x3830dc8e, 0x379d5862, 0x9320f991, 0xea7a90c2, 0xfb3e7bce,
+	0x5121ce64, 0x774fbe32, 0xa8b6e37e, 0xc3293d46, 0x48de5369, 0x6413e680,
+	0xa2ae0810, 0xdd6db224, 0x69852dfd, 0x09072166, 0xb39a460a, 0x6445c0dd,
+	0x586cdecf, 0x1c20c8ae, 0x5bbef7dd, 0x1b588d40, 0xccd2017f, 0x6bb4e3bb,
+	0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb,
+	0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e, 0xaec2771b, 0xf64e6370,
+	0x740e0d8d, 0xe75b1357, 0xf8721671, 0xaf537d5d, 0x4040cb08, 0x4eb4e2cc,
+	0x34d2466a, 0x0115af84, 0xe1b00428, 0x95983a1d, 0x06b89fb4, 0xce6ea048,
+	0x6f3f3b82, 0x3520ab82, 0x011a1d4b, 0x277227f8, 0x611560b1, 0xe7933fdc,
+	0xbb3a792b, 0x344525bd, 0xa08839e1, 0x51ce794b, 0x2f32c9b7, 0xa01fbac9,
+	0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7, 0x1a908749, 0xd44fbd9a,
+	0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f,
+	0xf79e59b7, 0x43f5bb3a, 0xf2d519ff, 0x27d9459c, 0xbf97222c, 0x15e6fc2a,
+	0x0f91fc71, 0x9b941525, 0xfae59361, 0xceb69ceb, 0xc2a86459, 0x12baa8d1,
+	0xb6c1075e, 0xe3056a0c, 0x10d25065, 0xcb03a442, 0xe0ec6e0e, 0x1698db3b,
+	0x4c98a0be, 0x3278e964, 0x9f1f9532, 0xe0d392df, 0xd3a0342b, 0x8971f21e,
+	0x1b0a7441, 0x4ba3348c, 0xc5be7120, 0xc37632d8, 0xdf359f8d, 0x9b992f2e,
+	0xe60b6f47, 0x0fe3f11d, 0xe54cda54, 0x1edad891, 0xce6279cf, 0xcd3e7e6f,
+	0x1618b166, 0xfd2c1d05, 0x848fd2c5, 0xf6fb2299, 0xf523f357, 0xa6327623,
+	0x93a83531, 0x56cccd02, 0xacf08162, 0x5a75ebb5, 0x6e163697, 0x88d273cc,
+	0xde966292, 0x81b949d0, 0x4c50901b, 0x71c65614, 0xe6c6c7bd, 0x327a140a,
+	0x45e1d006, 0xc3f27b9a, 0xc9aa53fd, 0x62a80f00, 0xbb25bfe2, 0x35bdd2f6,
+	0x71126905, 0xb2040222, 0xb6cbcf7c, 0xcd769c2b, 0x53113ec0, 0x1640e3d3,
+	0x38abbd60, 0x2547adf0, 0xba38209c, 0xf746ce76, 0x77afa1c5, 0x20756060,
+	0x85cbfe4e, 0x8ae88dd8, 0x7aaaf9b0, 0x4cf9aa7e, 0x1948c25c, 0x02fb8a8c,
+	0x01c36ae4, 0xd6ebe1f9, 0x90d4f869, 0xa65cdea0, 0x3f09252d, 0xc208e69f,
+	0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6,
+}
+
+// Creates a new Blowfish cipher instance with default values.
+func NewBfCipher() *BfCipher {
+	c := new(BfCipher)
+	copy(c.p[0:], bfP[0:])
+	copy(c.s0[0:], bfS0[0:])
+	copy(c.s1[0:], bfS1[0:])
+	copy(c.s2[0:], bfS2[0:])
+	copy(c.s3[0:], bfS3[0:])
+	return c
+}
+
+// Executes the core Feistel network encryption on a 64-bit block represented as two 32-bit words.
+func (c *BfCipher) encryptBlock(l, r uint32) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[0]
+	// Each round XORs the side into the opposite side's F-function result before swapping.
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[1]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[2]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[3]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[4]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[5]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[6]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[7]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[8]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[9]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[10]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[11]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[12]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[13]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[14]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[15]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[16]
+	xr ^= c.p[17]
+	return xr, xl
+}
+
+// Encrypts the 8-byte buffer src using the expanded key state and stores the result in dst.
+func (c *BfCipher) Encrypt(dst, src []byte) {
+	// Reconstruct the 64-bit block from two 32-bit words.
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = c.encryptBlock(l, r)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+// Executes the core Feistel network decryption by reversing the round sequence.
+func (c *BfCipher) decryptBlock(l, r uint32) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[17]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[16]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[15]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[14]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[13]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[12]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[11]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[10]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[9]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[8]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[7]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[6]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[5]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[4]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[3]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[2]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[1]
+	xr ^= c.p[0]
+	return xr, xl
+}
+
+// Decrypts the 8-byte buffer src using the expanded key state and stores the result in dst.
+func (c *BfCipher) Decrypt(dst, src []byte) {
+	// Reconstruct the 64-bit block from two 32-bit words.
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = c.decryptBlock(l, r)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+// Extracts a 32-bit word from the byte slice starting at the given position, automatically wrapping around if the end is reached.
+func (c *BfCipher) getNextWord(b []byte, pos *int) uint32 {
+	var w uint32
+	j := *pos
+	for i := 0; i < 4; i++ {
+		w = w<<8 | uint32(b[j])
+		j++
+		if j >= len(b) {
+			j = 0
+		}
+	}
+	*pos = j
+	return w
+}
+
+// Initialized the P-array by XORing it with the provided key, supporting legacy compatibility behaviors from libxcrypt.
+func (c *BfCipher) SetKey(key []byte, bug bool, safety bool) {
+	// Replicates libxcrypt's flag handling for sign extension bugs.
+	bugFlag := 0
+	if bug {
+		bugFlag = 1
+	}
+
+	safetyFlag := uint32(0)
+	if safety {
+		safetyFlag = 0x10000
+	}
+
+	var sign, diff uint32
+	var tmp [2]uint32
+
+	ptr := 0 // index into key
+	keyLen := len(key)
+
+	// Process the first 72 bytes of data to initialize the 18 P-array pointers.
+	for i := 0; i < 18; i++ {
+		tmp[0] = 0
+		tmp[1] = 0
+		for j := 0; j < 4; j++ {
+			cByte := key[ptr]
+
+			tmp[0] <<= 8
+			tmp[0] |= uint32(cByte)
+
+			tmp[1] <<= 8
+			// Eulate sign extension bug: cast byte to signed char (int8), then up to uint32.
+			stmp := int32(int8(cByte))
+			tmp[1] |= uint32(stmp)
+
+			if j > 0 {
+				sign |= tmp[1] & 0x80
+			}
+
+			ptr++
+			if ptr >= keyLen {
+				ptr = 0
+			}
+		}
+
+		diff |= tmp[0] ^ tmp[1]
+
+		if i < 18 {
+			c.p[i] = c.p[i] ^ tmp[bugFlag]
+		}
+	}
+
+	// Calculate the safety check value used to handle sign extension issues in legacy setups.
+	diff |= diff >> 16
+	diff &= 0xffff
+	diff += 0xffff
+	sign <<= 9
+	sign &= ^diff & safetyFlag
+
+	c.p[0] ^= sign
+}
+
+// Performs the standard Blowfish key expansion by XORing the P-array with the key and modifying state through block encryption.
+func (c *BfCipher) ExpandKey(key []byte) {
+	j := 0
+	for i := 0; i < 18; i++ {
+		c.p[i] ^= c.getNextWord(key, &j)
+	}
+
+	var l, r uint32
+	// Iteratively update the P and S arrays by encrypting all-zero blocks.
+	for i := 0; i < 18; i += 2 {
+		l, r = c.encryptBlock(l, r)
+		c.p[i], c.p[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l, r = c.encryptBlock(l, r)
+		c.s0[i], c.s0[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = c.encryptBlock(l, r)
+		c.s1[i], c.s1[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = c.encryptBlock(l, r)
+		c.s2[i], c.s2[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = c.encryptBlock(l, r)
+		c.s3[i], c.s3[i+1] = l, r
+	}
+}
+
+// Performs key expansion with salt mixing as used in the initial setup of bcrypt.
+func (c *BfCipher) ExpandKeyWithSalt(salt []byte) {
+	// P-array must be XORed with the key via SetKey or ExpandKey before calling this.
+	// Our SetKey already XORed P with Key, so we skip that step here.
+
+	j := 0
+	var l, r uint32
+	// Mix salt into the P-array and S-boxes during the expansion process.
+	for i := 0; i < 18; i += 2 {
+		l ^= c.getNextWord(salt, &j)
+		r ^= c.getNextWord(salt, &j)
+		l, r = c.encryptBlock(l, r)
+		c.p[i], c.p[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l ^= c.getNextWord(salt, &j)
+		r ^= c.getNextWord(salt, &j)
+		l, r = c.encryptBlock(l, r)
+		c.s0[i], c.s0[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l ^= c.getNextWord(salt, &j)
+		r ^= c.getNextWord(salt, &j)
+		l, r = c.encryptBlock(l, r)
+		c.s1[i], c.s1[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l ^= c.getNextWord(salt, &j)
+		r ^= c.getNextWord(salt, &j)
+		l, r = c.encryptBlock(l, r)
+		c.s2[i], c.s2[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l ^= c.getNextWord(salt, &j)
+		r ^= c.getNextWord(salt, &j)
+		l, r = c.encryptBlock(l, r)
+		c.s3[i], c.s3[i+1] = l, r
+	}
+}

go.mod

@@ -9,3 +9,10 @@ require (
 	github.com/pedroalbanese/gogost v0.0.0-20240430171730-f95129c7a5af
 	golang.org/x/crypto v0.31.0
 )
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -1,8 +1,15 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/openwall/yescrypt-go v1.0.0 h1:jsGk48zkFvtUjGVOhYPGh+CS595JmTRcKnpggK2AON4=
 github.com/openwall/yescrypt-go v1.0.0/go.mod h1:e6CWtFizUEOUttaOjeVMiv1lJaJie3mfOtLJ9CCD6sA=
 github.com/pedroalbanese/gogost v0.0.0-20240430171730-f95129c7a5af h1:8jbTN9e84FOzAJtCPdy/NEz8983YdD7nqTBMQlTRP4w=
 github.com/pedroalbanese/gogost v0.0.0-20240430171730-f95129c7a5af/go.mod h1:A4x4C7B6z2POO1x5CZzKXZVCOFPfjzxxVUbWl2Thhp0=
-golang.org/x/crypto v0.25.0 h1:ypSNr+bnYL2YhwoMt2zPxHFmbAN1KZs/njMG3hxUp30=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
 golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

gost_yes_crypt.go

@@ -113,7 +113,7 @@ func SHashGostYesCryptPassword(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with Gost Yes Crypt.
 func SHashGostYesCryptPasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewGostYesCryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

md5_crypt.go

@@ -142,7 +142,7 @@ func SHashMD5Password(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with MD5.
 func SHashMD5PasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewMD5CryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

nt_hash.go

@@ -116,7 +116,7 @@ func SHashNTPassword(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with NT.
 func SHashNTPasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewNTPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

passwd.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"errors"
 	"fmt"
+	"log"
 	"strconv"
 	"strings"
 )
@@ -24,6 +25,8 @@ const (
 	S_CRYPT_MAGIC        = "$7$"
 	YES_CRYPT_MAGIC      = "$y$"
 	GOST_YES_CRYPT_MAGIC = "$gy$"
+	BCRYPT_MAGIC         = "$2"
+	BCRYPT_SALT_LENGTH   = 22
 )
 
 // Standard protocol for working with all hash algorithms.
@@ -245,6 +248,35 @@ func NewPasswd(settings string) (PasswdInterface, error) {
 		return passwd, nil
 	}
 
+	// BCrypt.
+	// $2[abxy]$[cost]$[salt][hash]
+	if strings.HasPrefix(settings, BCRYPT_MAGIC) {
+		passwd := NewBCryptPasswd()
+
+		// Magic prefix is trimmed to handle the rest of the string.
+		s := settings[len(BCRYPT_MAGIC):]
+
+		// The last dollar sign separates the parameters from the salt.
+		lastDollar := strings.LastIndex(s, "$")
+
+		if lastDollar == -1 {
+			return nil, errors.New("Invalid bcrypt hash format: missing separator")
+		}
+
+		// Parameters are everything before the last dollar sign.
+		passwd.SetParams(s[:lastDollar])
+
+		// Salt is the first BCRYPT_SALT_LENGTH bytes after the last dollar sign.
+		saltStart := lastDollar + 1
+		if len(s) < saltStart+BCRYPT_SALT_LENGTH {
+			return nil, errors.New("Invalid bcrypt hash format: salt too short")
+		}
+
+		passwd.SetSalt([]byte(s[saltStart : saltStart+BCRYPT_SALT_LENGTH]))
+
+		return passwd, nil
+	}
+
 	// End of the line.
 	return nil, errors.New("No valid matching algorithm")
 }
@@ -278,6 +310,7 @@ func SCheckPassword(hash string, password string) (bool, error) {
 	if hash == newHash {
 		return true, nil
 	}
+	log.Printf("Hash does not match: %s != %s", hash, newHash)
 	return false, nil
 }
 

passwd_test.go

@@ -1,162 +1,83 @@
 package passwd
 
 import (
-	"fmt"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
-func TestPasswd(t *testing.T) {
+func TestCheckPassword(t *testing.T) {
 	password := []byte("Test")
-	var res bool
-	var err error
 
-	// Confirm password hashes conform to libcrypt standards.
+	tests := []struct {
-	res, err = CheckPassword([]byte("$sha1$245081$NabW/sfk3ZVVQc4BnZ/3$YoV1Iva6GK4tkxwahBmyH0TRCwBO"), password)
+		name string
-	if err != nil {
+		hash string
-		t.Fatalf("sha1 error: %s", err)
+	}{
-	}
+		{"sha1", "$sha1$245081$NabW/sfk3ZVVQc4BnZ/3$YoV1Iva6GK4tkxwahBmyH0TRCwBO"},
-	if !res {
+		{"sun md5", "$md5$lORrojKC$$RD9p64URLn3Wkv4Wa2xOW0"},
-		t.Fatalf("Password check for sha1 failed")
+		{"sun md5 rounds", "$md5,rounds=53125$qrDebYUd$$3pJWS.a6VTC/cGehIfQb30"},
+		{"md5", "$1$wuIXYcHV$1ufSGHoD0EkWPr75i52ST/"},
+		{"nt", "$3$$4a1fab8f6b5441e0493dc7d41304bfb6"},
+		{"sha256", "$5$AsETvlsIoaTP3w6G$OZY9mWRFXR9Pz0Xv1pS2TS/QCpxECLEG/dru/Y.nba/"},
+		{"sha256 rounds", "$5$rounds=243006$oCvhLw/Nn9HuQIm4$VPKzWx9t.NHgmNpVHeSpzQ5y01z4BE14J.bvG8g2yi."},
+		{"sha512", "$6$zt7D9I3Uu.EhrzEv$j50OCJ3oNdO2Ee7RE9XTDF7dhvrgRwc9NmjJUouk7czn4JTc/A6qLJIT1pMk7FUlTCYCLl6uBHm5NoEboAzIo0"},
+		{"sha512 rounds", "$6$rounds=523044$.zMtRwbPP2sDg5a5$YgKUnqEda6wxkvDMbJoNjNBiFNpX7nP/uDFV3jV4ngmrXlFBua3n8oIi5St/Re8H3WOksLaody3eAhaGtAN0c/"},
+		{"scrypt", "$7$CU..../....PpL3ULxY5DvYyvasS/a4a0$jqgg90svZLt5KQqFTwegHSn1pXU.aKDavZ3Eq8t2wx9"},
+		{"yes crypt", "$y$j9T$G/uoZu1orhwOE/lUtohEa.$SMu/wxtyhBLa5xeRLVnznBx5vE0/VxY7rJZlQX27N84"},
+		{"gost yes crypt", "$gy$j9T$etkZHzB483TIuw/58Df.N/$7DjHx/8jx.E/VLdyzMIIOJULHoZJ1PNlFl71KXaf0s7"},
+		{"bcrypt", "$2a$14$QlFncTUDVo7aWRJvDicXzOyd8zipAj1c9vRlOw4no6XiBLHewlPH."},
 	}
 
-	res, err = CheckPassword([]byte("$md5$lORrojKC$$RD9p64URLn3Wkv4Wa2xOW0"), password)
+	for _, tc := range tests {
-	if err != nil {
+		t.Run(tc.name, func(t *testing.T) {
-		t.Fatalf("sun md5 error: %s", err)
+			res, err := CheckPassword([]byte(tc.hash), password)
-	}
+			require.NoError(t, err)
-	if !res {
+			assert.True(t, res, "Password check failed for %s", tc.name)
-		t.Fatalf("Password check for sun md5 failed")
+
+			// Negative test: wrong password
+			res, err = CheckPassword([]byte(tc.hash), []byte("WrongPass"))
+			require.NoError(t, err)
+			assert.False(t, res, "Password check should have failed for wrong password (%s)", tc.name)
+		})
 	}
 
-	res, err = CheckPassword([]byte("$md5,rounds=53125$qrDebYUd$$3pJWS.a6VTC/cGehIfQb30"), password)
+	t.Run("InvalidHash", func(t *testing.T) {
-	if err != nil {
+		res, err := CheckPassword([]byte("$invalid$hash"), password)
-		t.Fatalf("sun md5 with rounds error: %s", err)
+		assert.Error(t, err)
-	}
+		assert.False(t, res)
-	if !res {
+	})
-		t.Fatalf("Password check for sun md5 with rounds failed")
+}
-	}
+
-
+func TestNewPasswordGeneration(t *testing.T) {
-	res, err = CheckPassword([]byte("$1$wuIXYcHV$1ufSGHoD0EkWPr75i52ST/"), password)
+	password := []byte("Test")
-	if err != nil {
+
-		t.Fatalf("md5 error: %s", err)
+	tests := []struct {
-	}
+		name    string
-	if !res {
+		factory func() PasswdInterface
-		t.Fatalf("Password check for md5 failed")
+	}{
-	}
+		{"sha1", NewSHA1Passwd},
-
+		{"sun md5", NewSunMD5Passwd},
-	res, err = CheckPassword([]byte("$3$$4a1fab8f6b5441e0493dc7d41304bfb6"), password)
+		{"sha256", NewSHA256CryptPasswd},
-	if err != nil {
+		{"sha512", NewSHA512CryptPasswd},
-		t.Fatalf("nt error: %s", err)
+		{"scrypt", NewSCryptPasswd},
-	}
+		{"yes crypt", NewYesCryptPasswd},
-	if !res {
+		{"gost yes crypt", NewGostYesCryptPasswd},
-		t.Fatalf("Password check for nt failed")
+		{"bcrypt", NewBCryptPasswd},
-	}
+	}
-
+
-	res, err = CheckPassword([]byte("$5$AsETvlsIoaTP3w6G$OZY9mWRFXR9Pz0Xv1pS2TS/QCpxECLEG/dru/Y.nba/"), password)
+	for _, tc := range tests {
-	if err != nil {
+		t.Run(tc.name, func(t *testing.T) {
-		t.Fatalf("sha256 error: %s", err)
+			passwd := tc.factory()
-	}
+			hash, err := passwd.HashPassword(password)
-	if !res {
+			require.NoError(t, err)
-		t.Fatalf("Password check for sha256 failed")
+			assert.NotEmpty(t, hash)
-	}
+
-
+			res, err := CheckPassword(hash, password)
-	res, err = CheckPassword([]byte("$5$rounds=243006$oCvhLw/Nn9HuQIm4$VPKzWx9t.NHgmNpVHeSpzQ5y01z4BE14J.bvG8g2yi."), password)
+			require.NoError(t, err)
-	if err != nil {
+			assert.True(t, res, "Re-hash check failed for %s", tc.name)
-		t.Fatalf("sha256 with rounds error: %s", err)
+
-	}
+			t.Logf("%s: %s", tc.name, string(hash))
-	if !res {
+		})
-		t.Fatalf("Password check for sha256 with rounds failed")
+	}
-	}
-
-	res, err = CheckPassword([]byte("$6$zt7D9I3Uu.EhrzEv$j50OCJ3oNdO2Ee7RE9XTDF7dhvrgRwc9NmjJUouk7czn4JTc/A6qLJIT1pMk7FUlTCYCLl6uBHm5NoEboAzIo0"), password)
-	if err != nil {
-		t.Fatalf("sha512 error: %s", err)
-	}
-	if !res {
-		t.Fatalf("Password check for sha512 failed")
-	}
-
-	res, err = CheckPassword([]byte("$6$rounds=523044$.zMtRwbPP2sDg5a5$YgKUnqEda6wxkvDMbJoNjNBiFNpX7nP/uDFV3jV4ngmrXlFBua3n8oIi5St/Re8H3WOksLaody3eAhaGtAN0c/"), password)
-	if err != nil {
-		t.Fatalf("sha512 with rounds error: %s", err)
-	}
-	if !res {
-		t.Fatalf("Password check for sha512 with rounds failed")
-	}
-
-	res, err = CheckPassword([]byte("$7$CU..../....PpL3ULxY5DvYyvasS/a4a0$jqgg90svZLt5KQqFTwegHSn1pXU.aKDavZ3Eq8t2wx9"), password)
-	if err != nil {
-		t.Fatalf("scrypt error: %s", err)
-	}
-	if !res {
-		t.Fatalf("Password check for scrypt failed")
-	}
-
-	res, err = CheckPassword([]byte("$y$j9T$G/uoZu1orhwOE/lUtohEa.$SMu/wxtyhBLa5xeRLVnznBx5vE0/VxY7rJZlQX27N84"), password)
-	if err != nil {
-		t.Fatalf("yes crypt error: %s", err)
-	}
-	if !res {
-		t.Fatalf("Password check for yes crypt failed")
-	}
-
-	res, err = CheckPassword([]byte("$gy$j9T$etkZHzB483TIuw/58Df.N/$7DjHx/8jx.E/VLdyzMIIOJULHoZJ1PNlFl71KXaf0s7"), password)
-	if err != nil {
-		t.Fatalf("gost yes crypt error: %s", err)
-	}
-	if !res {
-		t.Fatalf("Password check for gost yes crypt failed")
-	}
-
-	// Confirm new password generation works.
-	var passwd PasswdInterface
-	var hash []byte
-
-	passwd = NewSHA1Passwd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("sha1 error: %s", err)
-	}
-	fmt.Println("sha1:", string(hash))
-
-	passwd = NewSunMD5Passwd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("sun md5 error: %s", err)
-	}
-	fmt.Println("sun md5:", string(hash))
-
-	passwd = NewSHA256CryptPasswd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("sha256 error: %s", err)
-	}
-	fmt.Println("sha256:", string(hash))
-
-	passwd = NewSHA512CryptPasswd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("sha512 error: %s", err)
-	}
-	fmt.Println("sha512:", string(hash))
-
-	passwd = NewSCryptPasswd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("scrypt error: %s", err)
-	}
-	fmt.Println("scrypt:", string(hash))
-
-	passwd = NewYesCryptPasswd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("yes crypt error: %s", err)
-	}
-	fmt.Println("yes crypt:", string(hash))
-
-	passwd = NewGostYesCryptPasswd()
-	hash, err = passwd.HashPassword(password)
-	if err != nil {
-		t.Fatalf("gost yes crypterror: %s", err)
-	}
-	fmt.Println("gost yes crypt:", string(hash))
 }

pbkdf1_sha1_crypt.go

@@ -52,7 +52,7 @@ func (a *SHA1Crypt) Hash(password []byte, salt []byte, iterations uint64) (hash
 	}
 
 	// Create hash with result.
-	b64 := Base64Encode(buf)
+	b64 := SHA1Base64Encode(buf)
 	hash = []byte(fmt.Sprintf("%s%d$%s$", magic, iterations, salt))
 	hash = append(hash, b64...)
 	return
@@ -102,7 +102,7 @@ func SHashSHA1Password(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with SHA1.
 func SHashSHA1PasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewSHA1Passwd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

s_crypt.go

@@ -93,7 +93,7 @@ func SHashSCryptPassword(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with SCrypt.
 func SHashSCryptPasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewSCryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

sha256_crypt.go

@@ -173,7 +173,7 @@ func SHashSHA256Password(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with SHA256.
 func SHashSHA256PasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewSHA256CryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

sha512_crypt.go

@@ -173,7 +173,7 @@ func SHashSHA512Password(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with SHA512.
 func SHashSHA512PasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewSHA512CryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

sun_md5.go

@@ -210,7 +210,7 @@ func SHashSunMD5Password(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with Sun MD5.
 func SHashSunMD5PasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewSunMD5Passwd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}

utils.go

@@ -1,6 +1,7 @@
 package passwd
 
 import (
+	"encoding/base64"
 	"errors"
 	"hash"
 )
@@ -34,8 +35,9 @@ func Base64Append(dst []byte, v uint, n int) []byte {
 	return dst
 }
 
-// Encode to crypt base64.
+// Encode to crypt base64 with flawed logic that misses bytes.
-func Base64Encode(src []byte) []byte {
+// This is used for SHA1 crypt algorithm.
+func SHA1Base64Encode(src []byte) []byte {
 	size := len(src)
 	var b64 []byte
 	var i int
@@ -55,6 +57,79 @@ func Base64Encode(src []byte) []byte {
 	return b64
 }
 
+// Encode to crypt base64.
+func Base64Encode(src []byte) []byte {
+	size := len(src)
+	var b64 []byte
+	var i int
+	for i = 0; i <= size-3; i += 3 {
+		l := uint(src[i])<<16 |
+			uint(src[i+1])<<8 |
+			uint(src[i+2])
+		b64 = Base64Append(b64, l, 4)
+	}
+	remaining := size - i
+	if remaining == 2 {
+		l := uint(src[i])<<8 |
+			uint(src[i+1])
+		b64 = Base64Append(b64, l, 3)
+	} else if remaining == 1 {
+		l := uint(src[i])
+		b64 = Base64Append(b64, l, 2)
+	}
+	return b64
+}
+
+// Decode from crypt base64.
+func Base64Decode(src []byte) ([]byte, error) {
+	size := len(src)
+	if size == 0 {
+		return []byte{}, nil
+	}
+	if size%4 == 1 {
+		return nil, errors.New("invalid base64 length")
+	}
+
+	// Output buffer guessing.
+	// We can't know exact size easily due to the legacy 4->2 behavior vs 4->3,
+	// but (size/4)*3 is a safe lower bound, capacity can be larger.
+	dst := make([]byte, 0, (size/4)*3+3)
+	var i int
+	for i = 0; i < size-4; i += 4 {
+		var v uint
+		for j := 0; j < 4; j++ {
+			c := AToI64(src[i+j])
+			if c > 63 {
+				return nil, errors.New("invalid character in base64")
+			}
+			v |= uint(c) << (uint(j) * 6)
+		}
+		dst = append(dst, byte(v>>16), byte(v>>8), byte(v))
+	}
+	// Handle last block (can be partial)
+	remaining := size - i
+	var v uint
+	for j := 0; j < remaining; j++ {
+		c := AToI64(src[i+j])
+		if c > 63 {
+			return nil, errors.New("invalid character in base64")
+		}
+		v |= uint(c) << (uint(j) * 6)
+	}
+
+	if remaining == 4 {
+		// 4 chars -> 3 bytes
+		dst = append(dst, byte(v>>16), byte(v>>8), byte(v))
+	} else if remaining == 3 {
+		// 3 chars -> 2 bytes
+		dst = append(dst, byte(v>>8), byte(v))
+	} else if remaining == 2 {
+		// 2 chars -> 1 byte
+		dst = append(dst, byte(v))
+	}
+	return dst, nil
+}
+
 // Takes a prior hash, and recycles bytes until the length provided is covered.
 func HashBlockRecycle(h hash.Hash, block []byte, len int) {
 	size := h.BlockSize()
@@ -207,6 +282,70 @@ func MD5Base64Encode(src []byte) []byte {
 	return b64
 }
 
+// Decode MD5 result from MD5 crypt base64.
+func MD5Base64Decode(src []byte) ([]byte, error) {
+	if len(src) != 22 {
+		return nil, errors.New("invalid MD5 base64 length")
+	}
+
+	dst := make([]byte, 16)
+	decode4 := func(b []byte) (uint, error) {
+		var v uint
+		for j := 0; j < 4; j++ {
+			c := AToI64(b[j])
+			if c > 63 {
+				return 0, errors.New("invalid character in base64")
+			}
+			v |= uint(c) << (uint(j) * 6)
+		}
+		return v, nil
+	}
+
+	var v uint
+	var err error
+
+	v, err = decode4(src[0:4])
+	if err != nil {
+		return nil, err
+	}
+	dst[12], dst[6], dst[0] = byte(v), byte(v>>8), byte(v>>16)
+
+	v, err = decode4(src[4:8])
+	if err != nil {
+		return nil, err
+	}
+	dst[13], dst[7], dst[1] = byte(v), byte(v>>8), byte(v>>16)
+
+	v, err = decode4(src[8:12])
+	if err != nil {
+		return nil, err
+	}
+	dst[14], dst[8], dst[2] = byte(v), byte(v>>8), byte(v>>16)
+
+	v, err = decode4(src[12:16])
+	if err != nil {
+		return nil, err
+	}
+	dst[15], dst[9], dst[3] = byte(v), byte(v>>8), byte(v>>16)
+
+	v, err = decode4(src[16:20])
+	if err != nil {
+		return nil, err
+	}
+	dst[5], dst[10], dst[4] = byte(v), byte(v>>8), byte(v>>16)
+
+	// Last 2 characters
+	c0 := AToI64(src[20])
+	c1 := AToI64(src[21])
+	if c0 > 63 || c1 > 63 {
+		return nil, errors.New("invalid character in base64")
+	}
+	v = uint(c0) | uint(c1)<<6
+	dst[11] = byte(v)
+
+	return dst, nil
+}
+
 // The crypt standard likes to rotate bits in base64,
 // although it doesn't really do anything for brute force protection.
 // This performs the rotation algorithm.
@@ -285,3 +424,115 @@ func Base64RotateEncode(src []byte, order bool) []byte {
 	// Return the base64.
 	return b64
 }
+
+// Decode from rotated base64.
+func Base64RotateDecode(src []byte, order bool) ([]byte, error) {
+	b64len := len(src)
+	var l int
+	if b64len%4 == 0 {
+		l = (b64len / 4) * 3
+	} else if b64len%4 == 3 {
+		l = (b64len/4)*3 + 2
+	} else if b64len%4 == 2 {
+		l = (b64len/4)*3 + 1
+	} else {
+		return nil, errors.New("invalid base64 length")
+	}
+
+	dst := make([]byte, l)
+	ia := 0
+	ib := l / 3
+	ic := ib + ib
+	id := 0
+	i := 0      // index in src (base64)
+	outIdx := 0 // index for original bytes loop (mimicking i in Encode)
+
+	// Process blocks of 4 -> 3
+	for ; outIdx < l-3; outIdx += 3 {
+		var v uint
+		for j := 0; j < 4; j++ {
+			c := AToI64(src[i+j])
+			if c > 63 {
+				return nil, errors.New("invalid character in base64")
+			}
+			v |= uint(c) << (uint(j) * 6)
+		}
+		i += 4
+
+		var a, b, c int
+		if order {
+			switch id % 3 {
+			case 0:
+				a, b, c = ia, ib, ic
+			case 1:
+				a, b, c = ib, ic, ia
+			case 2:
+				a, b, c = ic, ia, ib
+			}
+		} else {
+			switch id % 3 {
+			case 0:
+				a, b, c = ia, ib, ic
+			case 1:
+				a, b, c = ic, ia, ib
+			case 2:
+				a, b, c = ib, ic, ia
+			}
+		}
+		dst[a] = byte(v >> 16)
+		dst[b] = byte(v >> 8)
+		dst[c] = byte(v)
+		ia++
+		ib++
+		ic++
+		id++
+	}
+
+	// Process remainder
+	if l-outIdx == 2 {
+		var v uint
+		for j := 0; j < 3; j++ {
+			c := AToI64(src[i+j])
+			if c > 63 {
+				return nil, errors.New("invalid character in base64")
+			}
+			v |= uint(c) << (uint(j) * 6)
+		}
+		dst[l-1] = byte(v >> 8)
+		dst[l-2] = byte(v)
+	} else if l-outIdx == 1 {
+		var v uint
+		for j := 0; j < 2; j++ {
+			c := AToI64(src[i+j])
+			if c > 63 {
+				return nil, errors.New("invalid character in base64")
+			}
+			v |= uint(c) << (uint(j) * 6)
+		}
+		dst[l-1] = byte(v)
+	}
+	return dst, nil
+}
+
+// BCrypt specific alphabet.
+const bcryptAlphabet = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+
+var bcryptEncoding = base64.NewEncoding(bcryptAlphabet).WithPadding(base64.NoPadding)
+
+// Encode to bcrypt base64.
+func BCryptBase64Encode(src []byte) []byte {
+	n := bcryptEncoding.EncodedLen(len(src))
+	dst := make([]byte, n)
+	bcryptEncoding.Encode(dst, src)
+	return dst
+}
+
+// Decode from bcrypt base64.
+func BCryptBase64Decode(src []byte) ([]byte, error) {
+	dst := make([]byte, bcryptEncoding.DecodedLen(len(src)))
+	n, err := bcryptEncoding.Decode(dst, src)
+	if err != nil {
+		return nil, err
+	}
+	return dst[:n], nil
+}

utils_test.go

@@ -0,0 +1,170 @@
+package passwd
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBase64(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+	}{
+		{"Empty", []byte{}},
+		{"1 byte", []byte{'A'}},
+		{"2 bytes", []byte{1, 2}},
+		{"3 bytes", []byte{'A', 'B', 'C'}},
+		{"4 bytes", []byte{'A', 'B', 'C', 'D'}},
+		{"5 bytes", []byte{1, 2, 3, 4, 5}},
+		{"16 bytes", []byte{140, 150, 169, 113, 54, 237, 5, 115, 223, 241, 60, 27, 242, 218, 42, 110}},
+		{"11 bytes", make([]byte, 11)},
+		{"SHA1 style 20 bytes", make([]byte, 20)},
+		{"Hello (5 bytes)", []byte("hello")},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := Base64Encode(tc.input)
+
+			if len(encoded) == 0 && len(tc.input) > 0 {
+				t.Logf("Skipping validation for lossy encode")
+				return
+			}
+
+			decoded, err := Base64Decode(encoded)
+			require.NoError(t, err, "Base64Decode should not return an error for valid input")
+
+			reEncoded := Base64Encode(decoded)
+			assert.Equal(t, string(encoded), string(reEncoded), "Round-trip failed")
+		})
+	}
+
+	t.Run("Invalid", func(t *testing.T) {
+		invalidInputs := []string{
+			"::::",  // Invalid character ':'
+			"abcde", // Invalid length (5 % 4 == 1)
+		}
+		for _, input := range invalidInputs {
+			_, err := Base64Decode([]byte(input))
+			assert.Error(t, err, "Expected error for invalid input: %s", input)
+		}
+	})
+}
+
+func TestMD5Base64(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+	}{
+		{"All Zeros", make([]byte, 16)},
+		{"Sequence", []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}},
+		{"Randomish", []byte{0xde, 0xad, 0xbe, 0xef, 0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef, 0xaa, 0xbb, 0xcc, 0xdd}},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := MD5Base64Encode(tc.input)
+			decoded, err := MD5Base64Decode(encoded)
+			require.NoError(t, err)
+			assert.Equal(t, tc.input, decoded, "Round-trip failed")
+		})
+	}
+
+	t.Run("Invalid", func(t *testing.T) {
+		_, err := MD5Base64Decode([]byte("too short"))
+		assert.Error(t, err)
+	})
+}
+
+func TestBase64Rotate(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+		order bool
+	}{
+		{"SHA256 order false", make([]byte, 32), false},
+		{"SHA512 order false", make([]byte, 64), false},
+		{"Sequence 32 false", []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}, false},
+		{"Sequence 32 true", []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}, true},
+		{"Small 4 false", []byte{1, 2, 3, 4}, false},
+		{"Small 5 false", []byte{1, 2, 3, 4, 5}, false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := Base64RotateEncode(tc.input, tc.order)
+			decoded, err := Base64RotateDecode(encoded, tc.order)
+			require.NoError(t, err)
+			assert.Equal(t, tc.input, decoded, "Round-trip failed")
+		})
+	}
+}
+
+func TestBCryptBase64(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+	}{
+		{"Empty", []byte{}},
+		{"Short", []byte{1, 2, 3}},
+		{"Bcrypt Salt", make([]byte, 16)},
+		{"Randomish", []byte("this is a test for bcrypt base64")},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := BCryptBase64Encode(tc.input)
+			decoded, err := BCryptBase64Decode(encoded)
+			require.NoError(t, err)
+			assert.Equal(t, tc.input, decoded, "Round-trip failed")
+		})
+	}
+
+	t.Run("Invalid", func(t *testing.T) {
+		_, err := BCryptBase64Decode([]byte("invalid!"))
+		assert.Error(t, err)
+	})
+}
+
+func TestSCryptBase64(t *testing.T) {
+	tests := []struct {
+		name  string
+		input []byte
+	}{
+		{"Empty", []byte{}},
+		{"Short", []byte{1, 2, 3}},
+		{"Scrypt Data", make([]byte, 32)},
+		{"Randomish", []byte("scrypt base64 should handle any data")},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := SCryptBase64Encode(tc.input)
+			decoded := SCryptBase64Decode(encoded)
+			assert.Equal(t, tc.input, decoded, "Round-trip failed")
+		})
+	}
+}
+
+func TestBase64Uint32(t *testing.T) {
+	tests := []struct {
+		name  string
+		value uint32
+		bits  uint32
+	}{
+		{"Small 6 bits", 42, 6},
+		{"Medium 12 bits", 1234, 12},
+		{"Large 24 bits", 0xABCDEF, 24},
+		{"Full 32 bits", 0xFFFFFFFF, 32},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			encoded := Base64Uint32Encode(tc.value, tc.bits)
+			decoded := Base64Uint32Decode(encoded, tc.bits)
+			assert.Equal(t, tc.value, decoded, "Round-trip failed")
+		})
+	}
+}

yes_crypt.go

@@ -92,7 +92,7 @@ func SHashYesCryptPassword(password string) (hash string, err error) {
 // Hash an password string with salt using default parameters with YesCrypt.
 func SHashYesCryptPasswordWithSalt(password string, salt string) (hash string, err error) {
 	passwd := NewYesCryptPasswd()
-	hash, err = passwd.SHashPasswordWithSalt(salt, salt)
+	hash, err = passwd.SHashPasswordWithSalt(password, salt)
 	if err != nil {
 		return
 	}