diff --git a/src/doc/buffer.h.0.md b/src/doc/buffer.h.0.md
index 7261513..4f58672 100644
--- a/src/doc/buffer.h.0.md
+++ b/src/doc/buffer.h.0.md
@@ -76,7 +76,13 @@ The following macros are defined :
 
 ## Functions
 
-The following functions are defined :
+The following functions/macros are defined :
+
+: [buffer_putbase32](3)
+:: To write given data encoded in base32.
+
+: [buffer_putbase64](3)
+:: To write given data encoded in base64.
 
 : [buffer_putescall](3)
 :: To write given data from a specified offset whilst escaping characters as
@@ -92,4 +98,4 @@ The following functions are defined :
 :: To write given data as hexadecimal dump.
 
 : [buffer_putmsg](3)
-:: To write a message, given as an array of NUL-terminated strings
+:: To write a message, given as an array of NUL-terminated strings.
diff --git a/src/doc/buffer.h/buffer_putbase32.3.md b/src/doc/buffer.h/buffer_putbase32.3.md
new file mode 100644
index 0000000..6164bb0
--- /dev/null
+++ b/src/doc/buffer.h/buffer_putbase32.3.md
@@ -0,0 +1,40 @@
+% limb manual
+% buffer_putbase32(3)
+
+# NAME
+
+buffer\_putbase32, buffer\_putbase64 - write byte array content encoded in
+base32/base64 into buffer
+
+# SYNOPSIS
+
+    #include <limb/buffer.h>
+
+```pre hl
+ssize_t buffer_putbase32(buffer *<em>buf</em>, const char *<em>data</em>, size_t <em>dlen</em>, int <em>pad</em>)
+ssize_t buffer_putbase64(buffer *<em>buf</em>, const char *<em>data</em>, size_t <em>dlen</em>, int <em>pad</em>)
+```
+
+# DESCRIPTION
+
+The `buffer_putbase32`() function writes the content of byte array pointed to by
+`data` of length `dlen` bytes into buffer `buf` encoded in base32. Padding will
+be used in the output unless `pad` is zero.
+
+For more about the encoding, refer to [base32_fmt](3).
+
+The `buffer_putbase64`() function writes the content of byte array pointed to by
+`data` of length `dlen` bytes into buffer `buf` encoded in base64. Padding will
+be used in the output unless `pad` is zero.
+
+For more about the encoding, refer to [base64_fmt](3).
+
+# RETURN VALUE
+
+These functions return the number of bytes written into `buf` on success.
+Otherwise, they return -1 and set `errno` to indicate the error.
+
+# ERRORS
+
+These functions may fail and set `errno` for any of the errors specified for
+[buffer_put](3).
diff --git a/src/liblimb/buffer.h/buffer_putbase.c b/src/liblimb/buffer.h/buffer_putbase.c
new file mode 100644
index 0000000..4ae0233
--- /dev/null
+++ b/src/liblimb/buffer.h/buffer_putbase.c
@@ -0,0 +1,31 @@
+/* This file is part of limb                           https://lila.oss/limb
+ * Copyright (C) 2023 Olivier Brunel                          jjk@jjacky.com */
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <limb/buffer.h>
+
+/* XXX intended for internal use, hence no check is performed on bin/bout and
+ * their validity. Specifically, should bout be too small the output would be
+ * written *outside* of buf leading to, well, problems.
+ */
+
+ssize_t
+buffer_putbase(buffer *b, const char *data, size_t dlen,
+               base_fmt_fn basefmt, size_t bin, size_t bout, int pad)
+{
+    ssize_t w = 0;
+
+    while (dlen) {
+        char buf[bout];
+        size_t l = (dlen > bin) ? bin : dlen;
+        ssize_t n = basefmt(buf, data, l, pad);
+
+        n = buffer_put(b, buf, n);
+        if (n < 0)
+            return -1;
+        w += n;
+        data += l;
+        dlen -= l;
+    }
+
+    return w;
+}
diff --git a/src/liblimb/include/limb/buffer.h b/src/liblimb/include/limb/buffer.h
index 4cf6e2f..1112c77 100644
--- a/src/liblimb/include/limb/buffer.h
+++ b/src/liblimb/include/limb/buffer.h
@@ -30,4 +30,9 @@ extern ssize_t buffer_putesc(buffer *b, const char *s, size_t len);
 extern ssize_t buffer_putescs(buffer *b, const char *s);
 extern ssize_t buffer_puthex(buffer *b, const void *data, size_t dlen);
 
+typedef ssize_t (*base_fmt_fn) (char *dst, const char *data, size_t dlen, int pad);
+extern ssize_t buffer_putbase(buffer *b, const char *data, size_t dlen, base_fmt_fn basefmt, size_t bin, size_t bout, int pad);
+#define buffer_putbase32(b,d,l,p)   buffer_putbase(b, d, l, base32, 40, 64, p)
+#define buffer_putbase64(b,d,l,p)   buffer_putbase(b, d, l, base64, 42, 56, p)
+
 #endif /* LIMB_BUFFER_H */