diff --git a/lib/std/crypto.zig b/lib/std/crypto.zig
index 2fb056e60b6f..3807ec7d7981 100644
--- a/lib/std/crypto.zig
+++ b/lib/std/crypto.zig
@@ -46,6 +46,8 @@ pub const aead = struct {
         pub const Aes256Ocb = @import("crypto/aes_ocb.zig").Aes256Ocb;
     };
 
+    pub const aes_ccm = @import("crypto/aes_ccm.zig");
+
     pub const ascon = struct {
         pub const AsconAead128 = @import("crypto/ascon.zig").AsconAead128;
     };
@@ -89,6 +91,7 @@ pub const auth = struct {
         pub const Aegis256Mac_128 = variants.Aegis256Mac_128;
     };
     pub const cmac = @import("crypto/cmac.zig");
+    pub const cbc_mac = @import("crypto/cbc_mac.zig");
 };
 
 /// Core functions, that should rarely be used directly by applications.
diff --git a/lib/std/crypto/aes_ccm.zig b/lib/std/crypto/aes_ccm.zig
new file mode 100644
index 000000000000..f56dc98f4958
--- /dev/null
+++ b/lib/std/crypto/aes_ccm.zig
@@ -0,0 +1,876 @@
+//! AES-CCM (Counter with CBC-MAC) authenticated encryption.
+//! AES-CCM* extends CCM to support encryption-only mode (tag_len=0).
+//!
+//! References:
+//! - NIST SP 800-38C: https://csrc.nist.gov/publications/detail/sp/800-38c/final
+//! - RFC 3610: https://datatracker.ietf.org/doc/html/rfc3610
+
+const std = @import("std");
+const assert = std.debug.assert;
+const crypto = std.crypto;
+const mem = std.mem;
+const modes = crypto.core.modes;
+const AuthenticationError = crypto.errors.AuthenticationError;
+const cbc_mac = @import("cbc_mac.zig");
+
+/// AES-128-CCM* with no authentication (encryption-only, 13-byte nonce).
+pub const Aes128Ccm0 = AesCcm(crypto.core.aes.Aes128, 0, 13);
+/// AES-128-CCM with 8-byte authentication tag and 13-byte nonce.
+pub const Aes128Ccm8 = AesCcm(crypto.core.aes.Aes128, 8, 13);
+/// AES-128-CCM with 16-byte authentication tag and 13-byte nonce.
+pub const Aes128Ccm16 = AesCcm(crypto.core.aes.Aes128, 16, 13);
+/// AES-256-CCM* with no authentication (encryption-only, 13-byte nonce).
+pub const Aes256Ccm0 = AesCcm(crypto.core.aes.Aes256, 0, 13);
+/// AES-256-CCM with 8-byte authentication tag and 13-byte nonce.
+pub const Aes256Ccm8 = AesCcm(crypto.core.aes.Aes256, 8, 13);
+/// AES-256-CCM with 16-byte authentication tag and 13-byte nonce.
+pub const Aes256Ccm16 = AesCcm(crypto.core.aes.Aes256, 16, 13);
+
+/// AES-CCM authenticated encryption (NIST SP 800-38C, RFC 3610).
+/// CCM* mode extends CCM to support encryption-only mode when tag_len=0.
+///
+/// `BlockCipher`: Block cipher type (must have 16-byte blocks).
+/// `tag_len`: Authentication tag length in bytes (0, 4, 6, 8, 10, 12, 14, or 16).
+///            When tag_len=0, CCM* provides encryption-only (no authentication).
+/// `nonce_len`: Nonce length in bytes (7 to 13).
+fn AesCcm(comptime BlockCipher: type, comptime tag_len: usize, comptime nonce_len: usize) type {
+    const block_length = BlockCipher.block.block_length;
+
+    comptime {
+        assert(block_length == 16); // CCM requires 16-byte blocks
+        if (tag_len != 0 and (tag_len < 4 or tag_len > 16 or tag_len % 2 != 0)) {
+            @compileError("CCM tag_length must be 0, 4, 6, 8, 10, 12, 14, or 16 bytes");
+        }
+        if (nonce_len < 7 or nonce_len > 13) {
+            @compileError("CCM nonce_length must be between 7 and 13 bytes");
+        }
+    }
+
+    const L = 15 - nonce_len; // Counter size in bytes (2 to 8)
+
+    return struct {
+        pub const key_length = BlockCipher.key_bits / 8;
+        pub const tag_length = tag_len;
+        pub const nonce_length = nonce_len;
+
+        /// `c`: Ciphertext output buffer (must be same length as m).
+        /// `tag`: Authentication tag output.
+        /// `m`: Plaintext message to encrypt.
+        /// `ad`: Associated data to authenticate.
+        /// `npub`: Public nonce (must be unique for each message with same key).
+        /// `key`: Encryption key.
+        pub fn encrypt(
+            c: []u8,
+            tag: *[tag_length]u8,
+            m: []const u8,
+            ad: []const u8,
+            npub: [nonce_length]u8,
+            key: [key_length]u8,
+        ) void {
+            assert(c.len == m.len);
+
+            // Validate message length fits in L bytes
+            const max_msg_len: u64 = if (L >= 8) std.math.maxInt(u64) else (@as(u64, 1) << @as(u6, @intCast(L * 8))) - 1;
+            assert(m.len <= max_msg_len);
+
+            const cipher_ctx = BlockCipher.initEnc(key);
+
+            // CCM*: Skip authentication if tag_length is 0 (encryption-only mode)
+            if (tag_length > 0) {
+                // Compute CBC-MAC using the reusable CBC-MAC module
+                var mac_result: [block_length]u8 = undefined;
+                computeCbcMac(&mac_result, &key, m, ad, npub);
+
+                // Construct counter block for tag encryption (counter = 0)
+                var ctr_block: [block_length]u8 = undefined;
+                formatCtrBlock(&ctr_block, npub, 0);
+
+                // Encrypt the MAC tag
+                var s0: [block_length]u8 = undefined;
+                cipher_ctx.encrypt(&s0, &ctr_block);
+                for (tag, mac_result[0..tag_length], s0[0..tag_length]) |*t, mac_byte, s_byte| {
+                    t.* = mac_byte ^ s_byte;
+                }
+
+                crypto.secureZero(u8, &mac_result);
+                crypto.secureZero(u8, &s0);
+            }
+
+            // Encrypt the plaintext using CTR mode (starting from counter = 1)
+            var ctr_block: [block_length]u8 = undefined;
+            formatCtrBlock(&ctr_block, npub, 1);
+            // CCM counter is in the last L bytes of the block
+            modes.ctrSlice(@TypeOf(cipher_ctx), cipher_ctx, c, m, ctr_block, .big, 1 + nonce_len, L);
+        }
+
+        /// `m`: Plaintext output buffer (must be same length as c).
+        /// `c`: Ciphertext to decrypt.
+        /// `tag`: Authentication tag to verify.
+        /// `ad`: Associated data (must match encryption).
+        /// `npub`: Public nonce (must match encryption).
+        /// `key`: Private key.
+        ///
+        /// Asserts `c.len == m.len`.
+        /// Contents of `m` are undefined if an error is returned.
+        pub fn decrypt(
+            m: []u8,
+            c: []const u8,
+            tag: [tag_length]u8,
+            ad: []const u8,
+            npub: [nonce_length]u8,
+            key: [key_length]u8,
+        ) AuthenticationError!void {
+            assert(m.len == c.len);
+
+            const cipher_ctx = BlockCipher.initEnc(key);
+
+            // Decrypt the ciphertext using CTR mode (starting from counter = 1)
+            var ctr_block: [block_length]u8 = undefined;
+            formatCtrBlock(&ctr_block, npub, 1);
+            // CCM counter is in the last L bytes of the block
+            modes.ctrSlice(@TypeOf(cipher_ctx), cipher_ctx, m, c, ctr_block, .big, 1 + nonce_len, L);
+
+            // CCM*: Skip authentication if tag_length is 0 (encryption-only mode)
+            if (tag_length > 0) {
+                // Compute CBC-MAC over decrypted plaintext
+                var mac_result: [block_length]u8 = undefined;
+                computeCbcMac(&mac_result, &key, m, ad, npub);
+
+                // Decrypt the received tag
+                formatCtrBlock(&ctr_block, npub, 0);
+                var s0: [block_length]u8 = undefined;
+                cipher_ctx.encrypt(&s0, &ctr_block);
+
+                // Reconstruct the expected MAC
+                var expected_mac: [tag_length]u8 = undefined;
+                for (&expected_mac, mac_result[0..tag_length], s0[0..tag_length]) |*e, mac_byte, s_byte| {
+                    e.* = mac_byte ^ s_byte;
+                }
+
+                // Constant-time tag comparison
+                const valid = crypto.timing_safe.eql([tag_length]u8, expected_mac, tag);
+                if (!valid) {
+                    crypto.secureZero(u8, &expected_mac);
+                    crypto.secureZero(u8, &mac_result);
+                    crypto.secureZero(u8, &s0);
+                    crypto.secureZero(u8, m);
+                    return error.AuthenticationFailed;
+                }
+
+                crypto.secureZero(u8, &expected_mac);
+                crypto.secureZero(u8, &mac_result);
+                crypto.secureZero(u8, &s0);
+            }
+        }
+
+        /// Format the counter block for CTR mode
+        /// Counter block format: [flags | nonce | counter]
+        /// flags = L - 1
+        fn formatCtrBlock(block: *[block_length]u8, npub: [nonce_length]u8, counter: u64) void {
+            @memset(block, 0);
+            block[0] = L - 1; // flags
+            @memcpy(block[1..][0..nonce_length], &npub);
+            // Counter goes in the last L bytes
+            const CounterInt = std.meta.Int(.unsigned, L * 8);
+            mem.writeInt(CounterInt, block[1 + nonce_length ..][0..L], @as(CounterInt, @intCast(counter)), .big);
+        }
+
+        /// Compute CBC-MAC over the message and associated data.
+        /// CCM uses plain CBC-MAC, not CMAC (RFC 3610).
+        fn computeCbcMac(mac: *[block_length]u8, key: *const [key_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8) void {
+            const CbcMac = cbc_mac.CbcMac(BlockCipher);
+            var ctx = CbcMac.init(key);
+
+            // Process B_0 block
+            var b0: [block_length]u8 = undefined;
+            formatB0Block(&b0, m.len, ad.len, npub);
+            ctx.update(&b0);
+
+            // Process associated data if present
+            // RFC 3610: AD is (encoded_length || ad) padded to block boundary
+            if (ad.len > 0) {
+                // Encode and add associated data length
+                var ad_len_encoding: [10]u8 = undefined;
+                const ad_len_size = encodeAdLength(&ad_len_encoding, ad.len);
+
+                // Process AD with padding to block boundary
+                ctx.update(ad_len_encoding[0..ad_len_size]);
+                ctx.update(ad);
+
+                // Add zero padding to reach block boundary
+                const total_ad_size = ad_len_size + ad.len;
+                const remainder = total_ad_size % block_length;
+                if (remainder > 0) {
+                    const padding = [_]u8{0} ** block_length;
+                    ctx.update(padding[0 .. block_length - remainder]);
+                }
+            }
+
+            // Process plaintext message
+            ctx.update(m);
+
+            // Finalize MAC
+            ctx.final(mac);
+        }
+
+        /// Format the B_0 block for CBC-MAC
+        /// B_0 format: [flags | nonce | message_length]
+        /// flags = 64*Adata + 8*M' + L'
+        /// where: Adata = (ad.len > 0), M' = (tag_length - 2)/2 if M>0 else 0, L' = L - 1
+        /// CCM*: When tag_length=0, M' is encoded as 0
+        fn formatB0Block(block: *[block_length]u8, msg_len: usize, ad_len: usize, npub: [nonce_length]u8) void {
+            @memset(block, 0);
+
+            const Adata: u8 = if (ad_len > 0) 1 else 0;
+            const M_prime: u8 = if (tag_length > 0) @intCast((tag_length - 2) / 2) else 0;
+            const L_prime: u8 = L - 1;
+
+            block[0] = (Adata << 6) | (M_prime << 3) | L_prime;
+            @memcpy(block[1..][0..nonce_length], &npub);
+
+            // Encode message length in last L bytes
+            const LengthInt = std.meta.Int(.unsigned, L * 8);
+            mem.writeInt(LengthInt, block[1 + nonce_length ..][0..L], @as(LengthInt, @intCast(msg_len)), .big);
+        }
+
+        /// Encode associated data length according to CCM specification
+        /// Returns the number of bytes written
+        fn encodeAdLength(buf: *[10]u8, ad_len: usize) usize {
+            if (ad_len < 65280) { // 2^16 - 2^8
+                // Encode as 2 bytes
+                mem.writeInt(u16, buf[0..2], @as(u16, @intCast(ad_len)), .big);
+                return 2;
+            } else if (ad_len <= std.math.maxInt(u32)) {
+                // Encode as 0xff || 0xfe || 4 bytes
+                buf[0] = 0xff;
+                buf[1] = 0xfe;
+                mem.writeInt(u32, buf[2..6], @as(u32, @intCast(ad_len)), .big);
+                return 6;
+            } else {
+                // Encode as 0xff || 0xff || 8 bytes
+                buf[0] = 0xff;
+                buf[1] = 0xff;
+                mem.writeInt(u64, buf[2..10], @as(u64, @intCast(ad_len)), .big);
+                return 10;
+            }
+        }
+    };
+}
+
+// Tests
+
+const testing = std.testing;
+const fmt = std.fmt;
+const hexToBytes = fmt.hexToBytes;
+
+test "Aes256Ccm8 - Encrypt decrypt round-trip" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "Hello, World! This is a test message.";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
+
+test "Aes256Ccm8 - Associated data" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "secret message";
+    const ad = "additional authenticated data";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, ad, nonce, key);
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, ad, nonce, key);
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+
+    var m3: [m.len]u8 = undefined;
+    const wrong_adata = "wrong data";
+    const result = Aes256Ccm8.decrypt(&m3, &c, tag, wrong_adata, nonce, key);
+    try testing.expectError(error.AuthenticationFailed, result);
+}
+
+test "Aes256Ccm8 - Wrong key" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const wrong_key: [32]u8 = [_]u8{0x43} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "secret";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    const result = Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, wrong_key);
+    try testing.expectError(error.AuthenticationFailed, result);
+}
+
+test "Aes256Ccm8 - Corrupted ciphertext" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "secret message";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    c[5] ^= 0xFF;
+
+    const result = Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectError(error.AuthenticationFailed, result);
+}
+
+test "Aes256Ccm8 - Empty plaintext" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+
+    try testing.expectEqual(@as(usize, 0), m2.len);
+}
+
+test "Aes128Ccm8 - Basic functionality" {
+    const key: [16]u8 = [_]u8{0x42} ** 16;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "Test AES-128-CCM";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes128Ccm8.tag_length]u8 = undefined;
+
+    Aes128Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    try Aes128Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
+
+test "Aes256Ccm16 - 16-byte tag" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "Test 16-byte tag";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm16.tag_length]u8 = undefined;
+
+    Aes256Ccm16.encrypt(&c, &tag, m, "", nonce, key);
+
+    try testing.expectEqual(@as(usize, 16), tag.len);
+
+    try Aes256Ccm16.decrypt(&m2, &c, tag, "", nonce, key);
+
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
+
+test "Aes256Ccm8 - Edge case short nonce" {
+    const Aes256Ccm8_7 = AesCcm(crypto.core.aes.Aes256, 8, 7);
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "eda32f751456e33195f1f499cf2dc7c97ea127b6d488f211ccc5126fbb24afa6");
+    var nonce: [7]u8 = undefined;
+    _ = try hexToBytes(&nonce, "a544218dadd3c1");
+    var m: [1]u8 = undefined;
+    _ = try hexToBytes(&m, "00");
+
+    var c: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8_7.tag_length]u8 = undefined;
+
+    Aes256Ccm8_7.encrypt(&c, &tag, &m, "", nonce, key);
+
+    var m2: [c.len]u8 = undefined;
+
+    try Aes256Ccm8_7.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectEqualSlices(u8, &m, &m2);
+}
+
+test "Aes256Ccm8 - Edge case long nonce" {
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "e1b8a927a95efe94656677b692662000278b441c79e879dd5c0ddc758bdc9ee8");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "a544218dadd3c10583db49cf39");
+    var m: [1]u8 = undefined;
+    _ = try hexToBytes(&m, "00");
+
+    var c: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, &m, "", nonce, key);
+
+    var m2: [c.len]u8 = undefined;
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectEqualSlices(u8, &m, &m2);
+}
+
+test "Aes256Ccm8 - With AAD and wrong AAD detection" {
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "8c5cf3457ff22228c39c051c4e05ed4093657eb303f859a9d4b0f8be0127d88a");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "a544218dadd3c10583db49cf39");
+    var m: [1]u8 = undefined;
+    _ = try hexToBytes(&m, "00");
+    var ad: [32]u8 = undefined;
+    _ = try hexToBytes(&ad, "3c0e2815d37d844f7ac240ba9d6e3a0b2a86f706e885959e09a1005e024f6907");
+
+    var c: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, &m, &ad, nonce, key);
+
+    var m2: [c.len]u8 = undefined;
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &m, &m2);
+
+    var wrong_ad: [32]u8 = undefined;
+    _ = try hexToBytes(&wrong_ad, "0000000000000000000000000000000000000000000000000000000000000000");
+    var m3: [c.len]u8 = undefined;
+    const result = Aes256Ccm8.decrypt(&m3, &c, tag, &wrong_ad, nonce, key);
+    try testing.expectError(error.AuthenticationFailed, result);
+}
+
+test "Aes256Ccm8 - Multi-block payload" {
+    const Aes256Ccm8_12 = AesCcm(crypto.core.aes.Aes256, 8, 12);
+
+    // Test with 32-byte payload (2 AES blocks)
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "af063639e66c284083c5cf72b70d8bc277f5978e80d9322d99f2fdc718cda569");
+    var nonce: [12]u8 = undefined;
+    _ = try hexToBytes(&nonce, "a544218dadd3c10583db49cf");
+    var m: [32]u8 = undefined;
+    _ = try hexToBytes(&m, "00112233445566778899aabbccddeeff00112233445566778899aabbccddeeff");
+
+    // Encrypt
+    var c: [32]u8 = undefined;
+    var tag: [Aes256Ccm8_12.tag_length]u8 = undefined;
+
+    Aes256Ccm8_12.encrypt(&c, &tag, &m, "", nonce, key);
+
+    // Decrypt and verify
+    var m2: [32]u8 = undefined;
+
+    try Aes256Ccm8_12.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectEqualSlices(u8, &m, &m2);
+}
+
+test "Aes256Ccm8 - Multi-block with AAD" {
+    const Aes256Ccm8_12 = AesCcm(crypto.core.aes.Aes256, 8, 12);
+
+    // Test with multi-block payload (3 AES blocks) and AAD
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "f7079dfa3b5c7b056347d7e437bcded683abd6e2c9e069d333284082cbb5d453");
+    var nonce: [12]u8 = undefined;
+    _ = try hexToBytes(&nonce, "5b8e40746f6b98e00f1d13ff");
+
+    // 48-byte payload (3 AES blocks)
+    var m: [48]u8 = undefined;
+    _ = try hexToBytes(&m, "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f");
+
+    // 16-byte AAD
+    var ad: [16]u8 = undefined;
+    _ = try hexToBytes(&ad, "000102030405060708090a0b0c0d0e0f");
+
+    // Encrypt
+    var c: [48]u8 = undefined;
+    var tag: [Aes256Ccm8_12.tag_length]u8 = undefined;
+
+    Aes256Ccm8_12.encrypt(&c, &tag, &m, &ad, nonce, key);
+
+    // Decrypt and verify
+    var m2: [48]u8 = undefined;
+
+    try Aes256Ccm8_12.decrypt(&m2, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &m, &m2);
+}
+
+test "Aes256Ccm8 - Minimum nonce length" {
+    const Aes256Ccm8_7 = AesCcm(crypto.core.aes.Aes256, 8, 7);
+
+    // Test with 7-byte nonce (minimum allowed by CCM spec)
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f");
+    var nonce: [7]u8 = undefined;
+    _ = try hexToBytes(&nonce, "10111213141516");
+    const m = "Test message with minimum nonce length";
+
+    // Encrypt
+    var c: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8_7.tag_length]u8 = undefined;
+
+    Aes256Ccm8_7.encrypt(&c, &tag, m, "", nonce, key);
+
+    // Decrypt and verify
+    var m2: [m.len]u8 = undefined;
+
+    try Aes256Ccm8_7.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
+
+test "Aes256Ccm8 - Maximum nonce length" {
+    // Test with 13-byte nonce (maximum allowed by CCM spec)
+    var key: [32]u8 = undefined;
+    _ = try hexToBytes(&key, "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "101112131415161718191a1b1c");
+    const m = "Test message with maximum nonce length";
+
+    // Encrypt
+    var c: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm8.tag_length]u8 = undefined;
+
+    Aes256Ccm8.encrypt(&c, &tag, m, "", nonce, key);
+
+    // Decrypt and verify
+    var m2: [m.len]u8 = undefined;
+
+    try Aes256Ccm8.decrypt(&m2, &c, tag, "", nonce, key);
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
+
+// RFC 3610 test vectors
+
+test "Aes128Ccm8 - RFC 3610 Packet Vector #1" {
+    const Aes128Ccm8_13 = AesCcm(crypto.core.aes.Aes128, 8, 13);
+
+    // RFC 3610 Appendix A, Packet Vector #1
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "00000003020100A0A1A2A3A4A5");
+    var ad: [8]u8 = undefined;
+    _ = try hexToBytes(&ad, "0001020304050607");
+    var plaintext: [23]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "08090A0B0C0D0E0F101112131415161718191A1B1C1D1E");
+
+    // Expected ciphertext and tag from RFC
+    var expected_ciphertext: [23]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "588C979A61C663D2F066D0C2C0F989806D5F6B61DAC384");
+    var expected_tag: [8]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "17E8D12CFDF926E0");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm8_13.tag_length]u8 = undefined;
+
+    Aes128Ccm8_13.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm8_13.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm8 - RFC 3610 Packet Vector #2" {
+    const Aes128Ccm8_13 = AesCcm(crypto.core.aes.Aes128, 8, 13);
+
+    // RFC 3610 Appendix A, Packet Vector #2 (8-byte tag, M=8)
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "00000004030201A0A1A2A3A4A5");
+    var ad: [8]u8 = undefined;
+    _ = try hexToBytes(&ad, "0001020304050607");
+    var plaintext: [24]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F");
+
+    // Expected ciphertext and tag from RFC (from total packet: header + ciphertext + tag)
+    var expected_ciphertext: [24]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "72C91A36E135F8CF291CA894085C87E3CC15C439C9E43A3B");
+    var expected_tag: [8]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "A091D56E10400916");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm8_13.tag_length]u8 = undefined;
+
+    Aes128Ccm8_13.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm8_13.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm8 - RFC 3610 Packet Vector #3" {
+    const Aes128Ccm8_13 = AesCcm(crypto.core.aes.Aes128, 8, 13);
+
+    // RFC 3610 Appendix A, Packet Vector #3 (8-byte tag, 25-byte payload)
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "00000005040302A0A1A2A3A4A5");
+    var ad: [8]u8 = undefined;
+    _ = try hexToBytes(&ad, "0001020304050607");
+    var plaintext: [25]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F20");
+
+    // Expected ciphertext and tag from RFC
+    var expected_ciphertext: [25]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "51B1E5F44A197D1DA46B0F8E2D282AE871E838BB64DA859657");
+    var expected_tag: [8]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "4ADAA76FBD9FB0C5");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm8_13.tag_length]u8 = undefined;
+
+    Aes128Ccm8_13.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches RFC expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm8_13.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+// NIST SP 800-38C test vectors
+
+test "Aes128Ccm4 - NIST SP 800-38C Example 1" {
+    const Aes128Ccm4_7 = AesCcm(crypto.core.aes.Aes128, 4, 7);
+
+    // Example 1 (C.1): Klen=128, Tlen=32, Nlen=56, Alen=64, Plen=32
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "404142434445464748494a4b4c4d4e4f");
+    var nonce: [7]u8 = undefined;
+    _ = try hexToBytes(&nonce, "10111213141516");
+    var ad: [8]u8 = undefined;
+    _ = try hexToBytes(&ad, "0001020304050607");
+    var plaintext: [4]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "20212223");
+
+    // Expected ciphertext and tag from NIST
+    var expected_ciphertext: [4]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "7162015b");
+    var expected_tag: [4]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "4dac255d");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm4_7.tag_length]u8 = undefined;
+
+    Aes128Ccm4_7.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm4_7.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm6 - NIST SP 800-38C Example 2" {
+    const Aes128Ccm6_8 = AesCcm(crypto.core.aes.Aes128, 6, 8);
+
+    // Example 2 (C.2): Klen=128, Tlen=48, Nlen=64, Alen=128, Plen=128
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "404142434445464748494a4b4c4d4e4f");
+    var nonce: [8]u8 = undefined;
+    _ = try hexToBytes(&nonce, "1011121314151617");
+    var ad: [16]u8 = undefined;
+    _ = try hexToBytes(&ad, "000102030405060708090a0b0c0d0e0f");
+    var plaintext: [16]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "202122232425262728292a2b2c2d2e2f");
+
+    // Expected ciphertext and tag from NIST
+    var expected_ciphertext: [16]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "d2a1f0e051ea5f62081a7792073d593d");
+    var expected_tag: [6]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "1fc64fbfaccd");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm6_8.tag_length]u8 = undefined;
+
+    Aes128Ccm6_8.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm6_8.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm8 - NIST SP 800-38C Example 3" {
+    const Aes128Ccm8_12 = AesCcm(crypto.core.aes.Aes128, 8, 12);
+
+    // Example 3 (C.3): Klen=128, Tlen=64, Nlen=96, Alen=160, Plen=192
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "404142434445464748494a4b4c4d4e4f");
+    var nonce: [12]u8 = undefined;
+    _ = try hexToBytes(&nonce, "101112131415161718191a1b");
+    var ad: [20]u8 = undefined;
+    _ = try hexToBytes(&ad, "000102030405060708090a0b0c0d0e0f10111213");
+    var plaintext: [24]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "202122232425262728292a2b2c2d2e2f3031323334353637");
+
+    // Expected ciphertext and tag from NIST
+    var expected_ciphertext: [24]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "e3b201a9f5b71a7a9b1ceaeccd97e70b6176aad9a4428aa5");
+    var expected_tag: [8]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "484392fbc1b09951");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm8_12.tag_length]u8 = undefined;
+
+    Aes128Ccm8_12.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm8_12.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm14 - NIST SP 800-38C Example 4" {
+    const Aes128Ccm14_13 = AesCcm(crypto.core.aes.Aes128, 14, 13);
+
+    // Example 4 (C.4): Klen=128, Tlen=112, Nlen=104, Alen=524288, Plen=256
+    // Note: Associated data is 65536 bytes (256-byte pattern repeated 256 times)
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "404142434445464748494a4b4c4d4e4f");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "101112131415161718191a1b1c");
+    var plaintext: [32]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f");
+
+    // Generate 65536-byte associated data (256-byte pattern repeated 256 times)
+    var pattern: [256]u8 = undefined;
+    _ = try hexToBytes(&pattern, "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff");
+
+    var ad: [65536]u8 = undefined;
+    for (0..256) |i| {
+        @memcpy(ad[i * 256 .. (i + 1) * 256], &pattern);
+    }
+
+    // Expected ciphertext and tag from NIST
+    var expected_ciphertext: [32]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "69915dad1e84c6376a68c2967e4dab615ae0fd1faec44cc484828529463ccf72");
+    var expected_tag: [14]u8 = undefined;
+    _ = try hexToBytes(&expected_tag, "b4ac6bec93e8598e7f0dadbcea5b");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm14_13.tag_length]u8 = undefined;
+
+    Aes128Ccm14_13.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Verify tag matches NIST expected output
+    try testing.expectEqualSlices(u8, &expected_tag, &tag);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm14_13.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+// CCM* test vectors (encryption-only mode with M=0)
+
+test "Aes128Ccm0 - IEEE 802.15.4 Data Frame (Encryption-only)" {
+    // IEEE 802.15.4 test vector from section 2.7
+    // Security level 0x04 (ENC, encryption without authentication)
+    var key: [16]u8 = undefined;
+    _ = try hexToBytes(&key, "C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF");
+    var nonce: [13]u8 = undefined;
+    _ = try hexToBytes(&nonce, "ACDE48000000000100000005" ++ "04");
+    var plaintext: [4]u8 = undefined;
+    _ = try hexToBytes(&plaintext, "61626364");
+    var ad: [26]u8 = undefined;
+    _ = try hexToBytes(&ad, "69DC84214302000000004DEAC010000000048DEAC04050000");
+
+    // Expected ciphertext from IEEE spec
+    var expected_ciphertext: [4]u8 = undefined;
+    _ = try hexToBytes(&expected_ciphertext, "D43E022B");
+
+    // Encrypt
+    var c: [plaintext.len]u8 = undefined;
+    var tag: [Aes128Ccm0.tag_length]u8 = undefined;
+
+    Aes128Ccm0.encrypt(&c, &tag, &plaintext, &ad, nonce, key);
+
+    // Verify ciphertext matches IEEE expected output
+    try testing.expectEqualSlices(u8, &expected_ciphertext, &c);
+
+    // Decrypt and verify round-trip
+    var m: [plaintext.len]u8 = undefined;
+    try Aes128Ccm0.decrypt(&m, &c, tag, &ad, nonce, key);
+    try testing.expectEqualSlices(u8, &plaintext, &m);
+}
+
+test "Aes128Ccm0 - Zero-length plaintext with encryption-only" {
+    const key: [16]u8 = [_]u8{0x42} ** 16;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "";
+    const ad = "some associated data";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes128Ccm0.tag_length]u8 = undefined;
+
+    Aes128Ccm0.encrypt(&c, &tag, m, ad, nonce, key);
+
+    try Aes128Ccm0.decrypt(&m2, &c, tag, ad, nonce, key);
+
+    try testing.expectEqual(@as(usize, 0), m2.len);
+}
+
+test "Aes256Ccm0 - Basic encryption-only round-trip" {
+    const key: [32]u8 = [_]u8{0x42} ** 32;
+    const nonce: [13]u8 = [_]u8{0x11} ** 13;
+    const m = "Hello, CCM* encryption-only mode!";
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [Aes256Ccm0.tag_length]u8 = undefined;
+
+    Aes256Ccm0.encrypt(&c, &tag, m, "", nonce, key);
+
+    try Aes256Ccm0.decrypt(&m2, &c, tag, "", nonce, key);
+
+    try testing.expectEqualSlices(u8, m[0..], m2[0..]);
+}
diff --git a/lib/std/crypto/cbc_mac.zig b/lib/std/crypto/cbc_mac.zig
new file mode 100644
index 000000000000..a62f647f9232
--- /dev/null
+++ b/lib/std/crypto/cbc_mac.zig
@@ -0,0 +1,152 @@
+const std = @import("std");
+const crypto = std.crypto;
+const mem = std.mem;
+
+/// CBC-MAC with AES-128 - FIPS 113 https://csrc.nist.gov/publications/detail/fips/113/archive/1985-05-30
+pub const CbcMacAes128 = CbcMac(crypto.core.aes.Aes128);
+
+/// FIPS 113 (1985): Computer Data Authentication
+/// https://csrc.nist.gov/publications/detail/fips/113/archive/1985-05-30
+///
+/// WARNING: CBC-MAC is insecure for variable-length messages without additional
+/// protection. Only use when required by protocols like CCM that mitigate this.
+pub fn CbcMac(comptime BlockCipher: type) type {
+    const BlockCipherCtx = @typeInfo(@TypeOf(BlockCipher.initEnc)).@"fn".return_type.?;
+    const Block = [BlockCipher.block.block_length]u8;
+
+    return struct {
+        const Self = @This();
+        pub const key_length = BlockCipher.key_bits / 8;
+        pub const block_length = BlockCipher.block.block_length;
+        pub const mac_length = block_length;
+
+        cipher_ctx: BlockCipherCtx,
+        buf: Block = [_]u8{0} ** block_length,
+        pos: usize = 0,
+
+        pub fn create(out: *[mac_length]u8, msg: []const u8, key: *const [key_length]u8) void {
+            var ctx = Self.init(key);
+            ctx.update(msg);
+            ctx.final(out);
+        }
+
+        pub fn init(key: *const [key_length]u8) Self {
+            return Self{
+                .cipher_ctx = BlockCipher.initEnc(key.*),
+            };
+        }
+
+        pub fn update(self: *Self, msg: []const u8) void {
+            const left = block_length - self.pos;
+            var m = msg;
+
+            // Partial buffer exists from previous update. Complete the block.
+            if (m.len > left) {
+                for (self.buf[self.pos..], 0..) |*b, i| b.* ^= m[i];
+                m = m[left..];
+                self.cipher_ctx.encrypt(&self.buf, &self.buf);
+                self.pos = 0;
+            }
+
+            // Full blocks.
+            while (m.len > block_length) {
+                for (self.buf[0..block_length], 0..) |*b, i| b.* ^= m[i];
+                m = m[block_length..];
+                self.cipher_ctx.encrypt(&self.buf, &self.buf);
+                self.pos = 0;
+            }
+
+            // Copy any remainder for next pass.
+            if (m.len > 0) {
+                for (self.buf[self.pos..][0..m.len], 0..) |*b, i| b.* ^= m[i];
+                self.pos += m.len;
+            }
+        }
+
+        pub fn final(self: *Self, out: *[mac_length]u8) void {
+            // CBC-MAC: encrypt the current buffer state.
+            // Partial blocks are implicitly zero-padded: buf[pos..] contains zeros from initialization.
+            self.cipher_ctx.encrypt(out, &self.buf);
+        }
+    };
+}
+
+const testing = std.testing;
+
+test "CbcMacAes128 - Empty message" {
+    const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+    var msg: [0]u8 = undefined;
+
+    // CBC-MAC of empty message = Encrypt(0)
+    const expected = [_]u8{ 0x7d, 0xf7, 0x6b, 0x0c, 0x1a, 0xb8, 0x99, 0xb3, 0x3e, 0x42, 0xf0, 0x47, 0xb9, 0x1b, 0x54, 0x6f };
+
+    var out: [CbcMacAes128.mac_length]u8 = undefined;
+    CbcMacAes128.create(&out, &msg, &key);
+    try testing.expectEqualSlices(u8, &out, &expected);
+}
+
+test "CbcMacAes128 - Single block (16 bytes)" {
+    const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+    const msg = [_]u8{ 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a };
+
+    // CBC-MAC = Encrypt(msg XOR 0)
+    const expected = [_]u8{ 0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97 };
+
+    var out: [CbcMacAes128.mac_length]u8 = undefined;
+    CbcMacAes128.create(&out, &msg, &key);
+    try testing.expectEqualSlices(u8, &out, &expected);
+}
+
+test "CbcMacAes128 - Multiple blocks (40 bytes)" {
+    const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+    const msg = [_]u8{
+        0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+        0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+        0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
+    };
+
+    // CBC-MAC processes: block1 | block2 | block3 (last 8 bytes zero-padded)
+    const expected = [_]u8{ 0x07, 0xd1, 0x92, 0xe3, 0xe6, 0xf0, 0x99, 0xed, 0xcc, 0x39, 0xfd, 0xe6, 0xd0, 0x9c, 0x76, 0x2d };
+
+    var out: [CbcMacAes128.mac_length]u8 = undefined;
+    CbcMacAes128.create(&out, &msg, &key);
+    try testing.expectEqualSlices(u8, &out, &expected);
+}
+
+test "CbcMacAes128 - Incremental update" {
+    const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+    const msg = [_]u8{
+        0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+        0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+    };
+
+    // Process in chunks
+    var ctx = CbcMacAes128.init(&key);
+    ctx.update(msg[0..10]);
+    ctx.update(msg[10..20]);
+    ctx.update(msg[20..]);
+
+    var out1: [CbcMacAes128.mac_length]u8 = undefined;
+    ctx.final(&out1);
+
+    // Compare with one-shot processing
+    var out2: [CbcMacAes128.mac_length]u8 = undefined;
+    CbcMacAes128.create(&out2, &msg, &key);
+
+    try testing.expectEqualSlices(u8, &out1, &out2);
+}
+
+test "CbcMacAes128 - Different from CMAC" {
+    // Verify that CBC-MAC and CMAC produce different outputs
+    const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
+    const msg = [_]u8{ 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a };
+
+    var cbc_mac_out: [CbcMacAes128.mac_length]u8 = undefined;
+    CbcMacAes128.create(&cbc_mac_out, &msg, &key);
+
+    // CMAC output for same input (from RFC 4493)
+    const cmac_out = [_]u8{ 0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44, 0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a, 0x28, 0x7c };
+
+    // They should be different
+    try testing.expect(!mem.eql(u8, &cbc_mac_out, &cmac_out));
+}